5166 5170.output

* GB785573 (A)
Description: GB785573 (A)
No title available
Description of GB785573 (A)
PATENT SPECIFICATION
7859573 Date of Application and filing Complete Specification: Nov 14,
1955.
No 32462/55.
5/ D Application made in Germany on Feb 8, 1955.
'> 9 </> Complete Specification Published: Oct 30, 1957.
Index at acceptance:-Class 97 ( 1), B 7 C.
International Classification:-GO 2 b.
COMPLETE SPECIFICATION
Improvements in or relating to Rapid Taking Lenses with Variable Focal
Length for Photography or Cinematography I, MARGARETE CAMILLA
SCHNEIDER, of German nationality, sole proprietress of the firm Jos
Schneider & Co, Optis'che Werke, of Kreuznach (Rhineland), Germany, do
hereby declare the invention, for which I pray that a patent may be
granted to me, and the method by which it is to be performed, to be
particularly described in and by the following statement:Taking lenses
of variable focal length are known They consist normally of a
multicomponent main objective facing the image plane and a system of
lenses preceding the multi-component main objective and composed of
three members, of which the one with the longer focal length and the
one facing the multi-component main objectivedhave a positive
refractive power, and these two components enclose a negative member
preferably consisting of two lenses of opposite refractive powers
cemented together, which can be displaced in the direction of the
optical axis, in order to change the focal length.
Such systems which have become known hitherto with a relative aperture
of 1: 2 8 have a range of focal lengths of the ratio of about 1: 3 One
of the factors determining the focal length is the displaceable
negative member In order to maintain the back lens/image distance
constant the front positive member of the supplementary system must

also be displaced The greatest length of the total system is obtained
for a medium focal length over the entire setting range, while for a
smaller and larger focal lengths the front member of the supplementary
system must move towards the rear members under the control of a cam.
It is the aim of the invention to increase the range of focal lengths
of such systems, while the comparatively high relative aperture of 1:
2 8 is retained, in order to achieve a range of focal lengths of the
ratio of about 1:4 This is achieved by making the main objective of
four air-spaced lenses, which may be described as a modified
Taylor-triplet while the positive member of the supplementary system,
displaceable and facing the longer conjugate, consists of two members
separated by an air space and the fixed member facing the
multi-component main objective must consist of a single lens, and also
the negative member between the said positive members, which is
axially displaceable and consists of two lenses of opposite refractive
powers cemented together, is curved in such a way that its shape is
substantially plano-concave, or that of a negative meniscus.
In order to increase the range of focal lengths, or to improve the
quality of the image within the setting range which has been achieved
so far, it has been found to be advantageous to constitute the
displaceable positive member of the supplementary system of two
individual components, each of which has preferably the shape of a
positive meniscus with external surfaces convex towards the longer
conjugate of which the forward member is a single lens, and the
following member consists of two lenses of opposite refractive powers
cemented together so that the negative lens faces with its concave
surface the following displaceable negative member.
By means of this design scheme the aberrations could be substantially
reduced in a system designed according to the invention Due to the
arrangement of the intermediate displaceable negative member of the
supplementary
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* GB785574 (A)

Description: GB785574 (A) ? 1957-10-30
Pharmaceutical compositions containing tetracycline antibiotics
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
785,574 Date of Application and filing Complete Specification Dec 13,
1955
No 35723/55.
Application made in United States of America on March 29, 1955.
Complete Specification Published Oct 30, 1957.
Index at Acceptance: -Class 81 ( 1), B 2 (G: L: N: R: S: T).
International Classification:A Ak.
Pharmaceutical Co Lunpositions co ntain Tetracycline Antibiotics We,
CHAS PFIZER & Co, INC, a Corporation organized and existing under) the
Laws of the State of Delaware, United States of America, located at
11, Bartlett Street, Brooklyn 6, State of New York, United States of
America, do hereby declare the invention, for which we pray that a
patent may be granted to us, and the method by which it is to be
performed, to be particularly described in and by the following
statement:-
This invention is concerned with certain pharmaceutical compositions
In particular, it is concerned with compositions containing one of a
group of antibiotics together with certain vitamins The antibiotics
useful in the present compositions are oxytetracycline,
chlortetracycline, and tetracycline The vitamins which are of
particular value in the present compositions are the water soluble
vitamins, that is, the B vitamins, ascorbic acid, vitamin K, and are
hereinafter specified.
The broad-spectrum antibiotics, chlortetracycline, oxytetracycline,
and tetracycline have very great value in the treatment of a variety

of infectious diseases These compounds are, however, occasionally
accompanied during their administration, by certain undesirable side
effects Some of these side effects may be due to changes brought about
in the intestinal flora This may lead to difficulty in recuperating
fully and most rapidly from the effects of various infectious
diseases, despite the fact that the infecting microorganism is
eradicated by the antibiotic.
It has now been found that compositions containing one of the
antibiotics indicated above, that is oxytetracycline,
chlortetracycline, or tetracycline together with the water soluble
vitamins, particularly the B vitamins, are very effective in the
treatment of infectious diseases Use of these compositions leads to
the greatest rapidity in complete recovery from the effects of the
disease This is true despite the fact that the side effects to which
reference is made above, are often not encountered for several days or
more after the administration of the broad-spectrum antibiotics listed
above It has been found that lPrice 3 MQ 45 Ad the compositions of the
present invention are particularly effective in bringing about com 50
plete and uncomplicated recovery from debilitating infectious diseases
The effect upon these diseases of the present compositions is an
effect which could not normally be anticipated from the known
antibacterial 55 activity of the antibiotics and the known nutritional
value of the vitamins.
The compositions of the present invention may be prepared in a variety
of forms including capsules, tablets, suspenions and other 60
pharmaceutical forms A variety of pharmaceutically-acceptable carriers
may be utilized in the preparation of these compositions These
carriers serve to present the compositions in easily administered, con
65 venient form for therapy of the various infectious diseases with
which the broad-spectrum antibiotics may be treated In general, from
about 50 to about 500 milligrams of the antibiotic is used per unit
dosage form 70 The antibiotic in the present compositions may be
utilized in the form of the amphoteric compound or in the form of its
hydrochloride or other acceptable (i e non-toxic) salt The a-6 anhydro
and 4-desdimethyl amino 75 derivatives of the antibiotics which are
microbiologically active may also be utilized in the preparation of
the present compositions However, the amphoteric antibiotic compounds
are particularly suited for the preparation of these 80 materials,
especially when a suspension of the antibiotic is to be prepared Since
certain of the vitamins utilized in the present compositions have a
low order of solubility, it is advisable that these compounds be
finely divided, 85 as must also the antibiotic, if a suspension of
these materials is to be prepared If a suspension form of the
compositions is to be utilized, it is desirable to include suspending

and wetting agents in the composition to facilitate the 90 formation
of a uniform composition so that administration of the material will
be accompanied by a uniform dosage of the material when a given volume
is measured out.
At last the two water-soluble vitamins not 95 all in the same group or
class are employed in 785,574 the present compositions, which are
selected from the groups or classes consisting of ascorbic acid, or a
salt of ascorbic acid, for instance, the sodium or calcium salt, or a
mixture of these; thiamin, generally utilized in the form of the
hydrochloride, although the mono nitrate may also be used; riboflavin;
niacin or niacinamide; pyridoxine, generally utilized as the
hydrochloride; pantothenic acid, normally utilized as the calcium
salt; folic acid; vitamin K, which may be in the form of the natural
material or various synthetic analogs; and vitamin Bl,, which is
available as the crystalline material or in the form of various
partially purified concentrates If an orally administratable,
suspension form of the compositions is to be prepared, various
fiavoring materials may be included, as well as coloring materials
Monosodium glutamate is useful in imparting a desirable flavor to the
composition, and sweetening agents such as sucrose, sucaryl, and other
similar materials may be added to the preparations As suspending
agents one may utilize esters or ethers of cellulose, for instance,
carboxymethyl cellulose A wetting agent is often desirable in order to
obtain a uniform suspension which is readily wetted upon the addition
of the liquid diluent, preferably water Wetting agents which are
useful are fatty acid esters of poelyoxyrnethylene derivatives of
anhydro sugars such as Tweens (Registered Trade Mark).
If tablets are to be prepared from the present compositions, various
agents which are useful as binders, such as polyvinylpyrrolidone and
various natural or synthetic gums, together with starches and such
lubricants as magnesium stearate, may be prepared in a suitable
composition before the formation of the tablets by conventional
manufacturing procedures.
Ascorbic acid may be utilized in the present compositions to the
extent of from about 30 to about 100 milligrams per unit dosage form.
This material may be in the form of the acid or partly or wholly as a
salt such as the sodium salt In the aqueous suspensions, mixtures of
ascorbic acid and sodium ascorbate are particularly useful Thiamin is
utilized to the extent of about 1 to about 3 milligrams per unit
dosage of the present compositions Riboflavin is utilized to the
extent of from about I to about 3 milligrams per unit dosage form.
Niacin, or preferably niacinamide, is utilized to the extent of from
about 2 to about 20 milligrams per unit dosage form Pyridoxine is
utilized to the extent of from about 0 1 to 0 5 milligrams per unit

dosage form Pantothenic acid, preferably as the calcium salt, is
utilized to the extent of from about 1 to about 10 milligrams per unit
dosage form Folic acid is utilized to the extent of from about 0 1 to
2 milligrams per unit dosage form Vitamin K is utilized to the extent
of from about 0 1 to about 1 milligram per unit dosage form.
Vitamin B 12 is utilized to the extent of from about 0 1 microgram to
about 20 micrograms per unit dosage form.
It should be noted that not only are the compositions of the present
invention quite compatible, that is, the components of the
compositions do not exert an adverse effect on one another, but, in
addition, the compositions exert certain effects that could not be
predicted from the known properties of their components Thus, side
effects which sometimes occur are often averted and recurrence of the
infection is frequently avoided The patients resistance and ability to
ward off the damaging effects of the infection are generally
increased.
Toleration of tie medication is also often enhanced and convalescence
may be decreased in time.
The following examples are given by way of illustration and are not to
be considered as the sole embodiments of this invention.
EXAMPLE I
A blendor commonly used for the preparation of pharmaceutical
compositions was charged with 1700 grams of sucrose The material was
blended and to this was added 90 the flavoring agent, such as
synthetic raspberry flavor Three hundred grams of sucrose was placed
in a mixer To this was added 0 6 grams of Tween (Registered Trade
Mark) 80.
The material was thoroughly mixed for a 95 period of 20 minutes To
this blended mixture was added 5 grams of sodium sucaryl, 60 grams of
carboxymethyl cellulose No 70 medium viscosity, and 2 grams of
monosodium glutamate The material was mixed for an 100 additional 20
minutes and then it was passed through a mill to form a very finely
divided powder This mixture was then thoroughly mixed with the source
containing the flavoring agents prepared above The combined 105
mixture was passed through a mill so that it was thoroughly blended
and pulverized.
To 100 grams of sucrose in a mixer was added 1 7 grams of riboflavin
The mixture was thoroughly agitated to obtain a uniform 110 product To
this was added 160 grams of anhydrous amphoteric tetracycline, 2 7
grams of ascorbic acid, 55 6 grams of sodium ascorbate, 2 0 grams of
thiamin hydrochloride, 15.0 grams of niacinamide, 0 3 grams of 115
pyridoxine hydrochloride, 4 5 grams of calcium pantothenate, 0 27
grams of folic acid, 0.3 grams of vitamin K, 0 9 grams of a triturate
of vitamin B 12 in mannitol containing an activity equivalent to 0 1 %

by weight The 120 composition was thoroughly mixed until homogeneous
throughout It was then passed through a micropulverizer to obtain an
extremely finely divided powder This was then blended with the
sucrose, sucaryl, car 125 boxymethyl cellulose, monosodium glutamate
mixture prepared as described above 23 3 gram portions of this
material were placed in 2 ounce bottles.
vitamin D (one million USP units in the form of irradiated yeast
powder as supplied by Standard Brands Corporation), 5 56 grams of
niacinamide, 860 grams of dibasic calcium phosphate, 10 grams of
ferric phosphate and 4785 grams of a chocolate powder (containing a
mixture of sugar and chocolate together with certain gums which forms
a relatively stable suspension-Banker's " Four-in-One " chocolate
powder) The mixture was thoroughly blended and packaged in small
wide-mouth bottles One teaspoon of this preparation contained
approximately 100 milligrams of amphoteric oxytetracycline The powder
was readily suspended in water, milk or any other beverages and
constituted an easily administered therapeutic agent for treatment df
various infections diseases.
It was found that upon filling the bottle with water a suspension was
readily prepared which was highly palatable, uniform throughout, and
easily resuspended on standing The S mixture proved highly effectitve
in obtaining rapid remission of a variety of infectious diseases due
to organisms susceptible to tetracycline It was found that, in
addition, the material brought about a rapid rehabilitation of the
patient, to a degree not commonly encountered when tetracycline alone
was utilized for treatment of these individuals.
EXAMPLE II
A tetracycline-vitamin composition was prepared by thoroughly blending
with the antibiotic a mixture of vitamins, corn oil, and an inert,
edible microcrystalline wax The detailed method follows: 41 g of
edible wax was melted at 600 C This material was added to 273 g of USP
corn oil which was agitated strongly during the addition of the melted
wax The mixture was thoroughly mixed and cooled to 300 C While it was
being agitated, the following materials were added in the indicated
order: 278 g of amphoteric tetracycline 93 g of sodium ascorbate 4 g
of a mixture of essential oil flavoring agents 0 5 g of vitamin K USP
0.4 g of folic acid USP 3.4 g of thiamin mononitrate 2.9 g of
riboflavin 0.5 g of pyridoxine hydrochloride 0 5 g of vitamin B 1,
concentrate having a potency of 3000 micrograms per gram 7.5 g of
calcium pantothenate USP g of lecithin 25 g of nicotinamide The
mixture was thoroughly agitated until a complete uniform suspension
was obtained.
The mixture was then packed in gelatin capsules utilizing sufficient
material for each capsule so that each contained 250 milligrams of the

antibiotic.
EXAMPLE III
The preparation of the above example was repeated utilizing in place
of tetracycline, oxytetracycline amphoteric This material also was
prepared in capsules of two different sizes, one containing 100
milligrams of oxytetracycline and the second containing 250 milligrams
of oxytetracycline.
EXAMPLE IV
A mixture was prepared containing 227 8 grams of amphoteric
oxytetracycline, 6 09 grams of dry vitamin A acetate in gelatin (in
the forms of fine beadlets having a total activity of two million
units), 3 0 grams of thiamin mononitrate, 1 15 grams of riboflavin,
99.75 grams of ascorbic acid, 1 38 grams of EXAMPLE V
A hard candy base was prepared by combining a concentrated solution of
sucrose in water and corn sugar The mixture was melted in a jacketed
kettle and heated to about 85 2400 F It was then passed through a coil
at about 2900 to 3000 F to thoroughly cook the mixture The mixture was
then concentrated under vacuum to dehydrate the material At this
stage, a mixture wars 90 obtained containing approximately 60 %
sucrose and 40 % corn syrup solids and a very limited percentage of
water (less than 1 %).
Ten pounds of this candy base mix was placed in a mixing kettle and to
this was added 18 95 milliliters of oil and orange and 3 grams of
orange paste color The mixture was stirred thoroughly and cooled to
1180 C and 25 14 grams of Terramycin (Registered Trade Mark)
amphoteric (amphoteric oxytetracycline) was 100 added with thorough
mixing This was followed by 0 6 grams of a vitamin A dry product
assaying about one million units of vitamin A activity per gram There
was then added thet following materials: 1 5 grams of 105 thiamin
hydrochloride, 2 64 grams of riboflavin, 1512 grams of niacinamide, 43
2 grams of ascorbic acid, 2 7 grams of pantothenyl alcohol, 1 26 grams
of pyridoxine, 1 584 grams of vitamin E and 0 00378 grams of vitamin
110 B 12 The mixture was thoroughly blended, cooled and cast in the
form of lozenges of such a size that approximately 120 were formed
from each pound of the mixture Each tablet contained approximately 18
milligrams of 115 amphoteric Terramycin (Registered Trade Mark), 6000
units of vitamin A, 500 units of vitamin D, 1 25 milligrams of
thiamin, 2 milligrams of riboflavin, 12 milligrams of niacinamide, 36
milligrams of ascorbic acid, 2 milli 120 grams of pantothenyl alcohol,
1 milligram of pyridoxine, 1 2 milligrams of vitamin E, and 3
micrograms of vitamin B 12 These candy tablets proved highly effective
for administering a composition of the antibiotic and vita 125 mins to
young patients.
785,574 EXAMPLE VI

The preparation described in the example directly above was repeated
utilizing in place of the amphoteric oxytetracycline an equivalent
weight of amphoteric tetracycline This product was also found to be
highly effective in the treatment in children of infectious diseases
such a throat infections.
EXAMPLE VII
The preparation described in Example I above was repeated utilizing in
place of oxytetracycline an equivalent weight of chlortetracycline The
composition thus obtained was proven to be highly effective in
combatting infectious diseases, resulting in rapid and thorough
rehabilitation of the infected patient.
In view of Section 9 Subsection ( 1) of the Patents Act, 1949,
attention is directed to
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* 5.8.23.4; 93p
* GB785575 (A)
Description: GB785575 (A) ? 1957-10-30
Compatible image-reproducing system
A high quality text as facsimile in your desired language may be available
amongst the following family members:
CH337875 (A) DE1024561 (B) FR1141121 (A) US2759993 (A)
CH337875 (A) DE1024561 (B) FR1141121 (A) US2759993 (A) less

Date of Application and filing Complete Specification: Dec 13, 1955.
No 35782155.
Application made in United States of America on Jan 17, 1955.
Complete Specification Published: Oct 30, 1957.
Index at acceptance:-Class 40 ( 3), F( 3 B: 5 F).
International Classification:-H 04 n.
Compatible Image-Reproducing System We, HAZELTINE CORPORATION, a
corporation organized and existing under the laws of the State of
Delaware, United States of America, of 59-25 Little Neck Parkway,
Little Neck 162, New York, United States of America, do hereby declare
the invention, for which we pray that a patent may be granted to us,
and the method by which it is to be performed, to be particularly
described in and by the following statement: -
GENERAL The present invention is directed to compatible
image-reproducing systems for colortelevision receivers and, more
specifically, to such image-reproducing systems in a compatible-color
television receiver of the NTSSC type,utilizing a single-gun type of
picture tube employing a switching signal for directing the electron
beam onto different 'color phosphors.
By compatible image-reproducing system is meant an image-reproducing
system capable of reproducing color and monochrome images in response
to color and monochrome signals, respectively.
In la form of color-television system more completely discussed in
many articles in the January, 1954 issue of the PROCEEDINGS OF THE I R
E information representative of a scene in color being televised is
utilized to develop at the transmitter two substantially simultaneous
signals, one of which is primarily representative of the brightness or
luminance and the other of which is representative of the chrominance
of the televised image The latter signal is a subcarrier wave signal
having a mean frequency within the video-frequency pass band and
having each of successive cycles thereof modulated in amplitude at
different phases by signall components representative of specific
'hues of the televised image The 'composite video-frequency signal
comprising the luminance signal and the modulated subcarrier wave or
chrominance signal is then employed in a conventional manner to
modulate a radio frequency wave signal The signals just described are
utilized in an NTSC type of system and, therefore, T Price 3 s -L -,,

l will be referred to hereinafter as NT Sz C type of signals.
A receiver in NTSC type of system intercepts the radiated signal and
derives the composite video-frequency signal, including the luminance
and chrominance signals, therefrom One type of such receiver includes
a pair of principal channels for individually translating the
luminance and chrominance information for application m an
image-reproducing device in such receiver The channel for translating
the luminance signal is substantially the ssame as the video-frequency
amplifier stage of a conventional monochrome receiver In one type of
receiver the channel for translating the chrominance signal includes
means for deriving signals representative of the primary colors red,
green, and blue and for combining such derived signals with the
luminance signal to provide signals which may be utilized in an
imiage-reproducing device to effect color reproduction of the
televised image.
More recently, a one- gun type of image" reproducing device, referred
t'o as a focusmask type of device, and circuits for modifying the NTSC
type of composite video-frequency signal for use in such device have
been described in an article entitled " Processing of the NTSIC Color
Signal for One-,Gun Seqential Color Displays " in the January 195 '4
issue of the PROCEEDINGS OF THE I R E at pages 299-3018, inclusive As
described in such article, the focus-mask type of picture tube
includes repeating groups of parallel strips of different phosphors
individually for emitting green, red and blue colors, each group
having the sequence green, red, green, blue A grid structure
comprising a plurality of conductors which are parallel to each other
and to the phosphor strips on the screen has one of such conductors
positioned behind each of the phosphor strips for emitting red and
blue colors and none behind the strip for emitting green Such grid is
energized by a signal synchronized with the modulated subcarrier wave
signal so Has to direct the cathoderay beam, intensity-modulated by
the brightness and sub'carxier wave signals, onto the proper phosphor
strips As described in the I R E.
article, an NTSC type of signal may not be applied directly to a
picture tube of the type just described if fidelity of color
reproduction is to be obtained Prior to application to such picture
tube, the luminance signal should be modified ito include a
lurninance-correction component and the modulated subcarrier wave
signal should be converted into one wave signal of the same mean
frequency as the detected chrominance signal, and including only color
information representative of red and blue, and into a second harmonic
wave signal including information representative of green.
The modified luminance signal and fundamental and second harmonic
subcarrier wave signals are combined for application to such picture

tube to effect reproduction of the color image.
Such modified NTSC type of composite videe-frequency signal is
adequate to reproduce a color image in such picture tube when color
information is being transmitted and received However, when only
monochrome information is being received, or it is desired to
reproduce a monochrome image from color signals, the black-and-white
image reproduced in this type of picture tube tends to have spurious
color patterns having red and blue elements These spurious patterns
apparently arise from a heterodyning 'of the high-frequency monochrome
signals, particularly those signals in, the range of 3-4 megacycles,
with the color-switching operation occurring at approximately 3 6
megacycles Such heterodyning results in low-frequency beat signals of
approximately 0- 6 megacycle which appear with high visibility as red
and blue patterns These spurious effects have been reduced by
including in the luminance channel a filter network having an upper
cutoff frequency of approximately 3 megacycles so that effectively no
luminance information above 3 megacycles is utilized However, the use
of such filter network is detrimental in preventing the reproduction
of high-definition monochrome images Though it is desirable to
eliminate or minimize such spurious color patterns reproduced in a
monochrome image, it is equally important to utilize all of the
luminance information 'available in order to obtain the highest
quality of reproduction and the maximum degree of compatibility The
compatible anage-reproducing system in accordance with the present
invention is designed to effect such result.
It is, therefore, an object of the present invention to provide a new
and improved comnpatible image-reproducing system in which the
deficiencies of prior such systems when utilizing an NTSC signal are
diminished.
It is another object of tthe present invention to provide a new and
improved imagereproducing system for a color'television receiver
including a single-gun type of picture tube in which the monochrome
images reproduced by such system have increased definition 70 It is a
still further object of the present invention to provide a new and
improved compatible image-reproducing system for a colortelevision
receiver including a single-gun type of picture tube, and in which an
NTSC type 75 of signal is employed, in which reproduced monochrome
images have higher definition than in prior such systems with a
minimum of spurious color patterns.
In accordance with the present invention, 80 a compatible
image-reproducing system comprises a circuit for supplying monochrome
or color signals representative, respectively, of televised monochrome
or color images and comprises image-reproducing apparatus The 85
image-reproducing apparatus includes a plurality of parallel

color-reprcducing strips, means for developing an electron beam,
deflection means for causing the beam to scan a raster on the strips,
and color-switching 90 means for cyclically moving the beam across the
strips to reproduce a monochrome or color image Spurious color
patterns tend to appear in the reproduced monochrome images from
signals applied to the apparatus having 95 frequencies in the vicinity
of the color-switching frequency The image-reproducing system also
comprises a first signal-translating channel coupled between the
supply circuit and the beam-developing means for translating a 100
band of the supplied monochrome signals having frequencies below the
color-switching frequency for intensity-modulating the beam when
monochrome images are being reproduced Finally, the image-reproducing
sys 105 tem comprises a second signal-translating channel, including
an auxiliary deflection means for developing a field in the path of
the electron beam, and coupled to the supply circuit for translating a
band of the supplied 110 monochrome signals having frequencies in: the
vicinity of the color-switching frequency fox effecting deflection
modulation of the beam lengthwise of the strips to provide the
highdefinition monochrome information when 115 monochrome images are
being reproduced, thereby to minimize the spurious patterns in the
reproduced monochrome images.
For a better understanding of the present invention, together with
other and further ob 120 jects thereof, reference is had to the
following description taken in connection with the accompanying
drawings, and its scope will be pointed out in the appended claims.
Referring to the drawings: 125 Fig 1 is a schematic diagram of a
colortelevision receiver including a compatible image-reproducing
system in accordance with the present invention; Fig la is a vector
diagram useful in ex 130 7 t 85,5175 and the amplifier 22 will be
considered hereinafter with respect to Fig 2 An output circuit of the
selector 20 is also coupled through an R-B amplifier 35, having a pass
band of 3.0-4 2 megacycles, and the adder circuit 13 70 to the cathode
of the image-reproducing apparatus 14.
For effecting control of the signal-detecting and color-switching
signals iin a manner to be considered more fully hereinafter, the 75
system 12 includes, in cascade in the order named and coupled to an
output circuit of the amplifier 19, an automatic-phase-control system
27 and a reference-signal generator 218 The generator 28 can be a
conventional 80 sine-wave generator and the system 27 maintains the
operation of tlhe generator 2,8 in synchronism and at a specific phase
with respect to a reference signal developed at the transmitter, A
more detailed description of the sys 85 tem 2,7 will be presented
hereinafter when considering the system 12 in detail The output
circuit of the generator 28 is coupled through a push-pull amplifier

29 to a colorswitching control grid 14 b in the image-re 90 producing
apparatus 14.
There are also coupled in cascade in the order named between an output
circuit of the axis selector 20 'and an input circuit of the adder
circuit 13, la modulator 23 and a 16 6 95 7.8 megacycle filter network
24 The output circuit of the generator 28 is coupled through a second
harmonic amplifier 34 and:a phasedelay circuit 32 to an additional
input circuit of the axis selector 20 A control circuit in the 100
axis selector 20 for controlling the state of operation thereof is
coupled to an output circulit of a colior-killer circuit 36, a
component in the system 12 and to be considered more fully hereinafter
The output circuit of the 105 generator 28 is 'also coupled through a
phasedelay circuit 30 and a third harmonic amplifier 31 to an input
'circuit of the modulator 23 The modulator 23, the filter network 24,
and the third harmonic amplifier 31 can be of 110 conventional
construction, units of these types being so well known as to require
no further description The phase-delay circuits 30 and
32 'are networks for delaying the phase of the signal generated in the
generator 28 by appro 115 priate amounts so that the signals applied
to the axis selector 20 and the modulator 23, after such phase delays,
are in phase with the desired modulation axis of the subcarrier wave
signal, 'as will be discussed more fully herein 120 after.
There are also coupled in cascade in the order named between an output
circuit of the amplifier 19 and an input circuit of the adder circuit
13, an M-Y synchronous detector 25 125 and a 0-0 6 megacycle filter
network 2 '6 An input circuit of the synchronous detector 2 '5 is
coupled to the oolor-killer circuit 316 to control the state of
operation of the detector 25, in a manner to be considered more fully
130 plaining the operation of the image-reproducing system of Fig 1;
Fig lb comprises a group of curves useful in explaining the operation
of the compatible image-reproducing system of Fig 1; Fig 2 is la more
detailed diagram of a portion of the image-reproducing system of Fig.
1, and Fig 3 is a diagram of la modified portion of the
image-reproducing system of Fig 1.
GENERAL DESCRIPTION OF RECEIVER OF
FIG 1 Referring now to Fig 1 of the drawings, there is represented a
color-television receiver of the super-heterodyne type suitable for
utilizing an NTSC type of color-television signal and, more
specifically, a receiver of the type described in the aforementioned I
R E article entitled " Processing of the NTSC Color Signal for One-1
Gun Sequential Color Displays " The receiver includes a
video-frequency signial source 10 The source 10 can ibe conventional
equipment for supplying an NTSIC type of composite video-frequency
signal, for example it may include a radio-frequency amplifier having

an input circuit coupled to an antenna 11 an oscillator-modulator, an
intermediatefrequency iamplifier, -and a detection system for deriving
the video-frequency signal An inage-reproducing system 12, in
accordance with the present invention, is coupled to;an output circuit
of the unit 10 Though the system 12 will be described fully
hereinafter, it will be helpful to described at this time, at least
generally, some of the components in the system 12 and their
combination The system 12 includes a luminance channel coupled to the
aforesaid output circuit of the unit 10 and including, in cascade in
the order named, a delay line 15, a luminance-signal amplifier 16, 0-3
megacycle filter network 17 and an adder circuit 13, the output
circuit of the latter unit being coupled to the cathode of a
single-gun image-reproducing apparatus '14 The delay line 15 is
conventional 'and serves to equalize the time of translation of the
luminance signal through the units 15, 116, and 17 with that for
translation of the chrominance signal through other channels to be
considered hereinafter The amplifier 116 is a conventional wide band
amplifier The image-reproducing apparatus 14 is 'a single-gun,
focusmask type 'of apparatus fully considered in the aforesaid I R E
article and will be considered more fully hereinafter.
The image-reproducing system 12 also includes, coupled in cascade in
the order named between the aforesaid output circuit of the source 10
iand an auxiliary deflection winding 14 d in the apparatus 14, 'an
amplifier 19 having a pass band of approximately 3 0-4 2 megacycles,
an R-B and G-M axis selector 20 a 3 '0-4 2 megacycle filter network
21, and a deflection-signal amplifier 22 Deetails of the taxis
selector 20, the network 21, 785,5175 hereinafter An additional input
circuit of the synchronous detector 25 is coupled through a
phase-delay circuit 33 to the output circuit of the generator 28 for
the purpose of applyilg, from the unit 28 to the detector 25, a
locally generated signal which is in phase with the AMI-Y modulation
component of the subcarrier wave signal as more fully described in the
aforesaid I R E article.
A synchronizing-signal separator 37 is also coupled to an output
circuit of the video-frequency signal source 10 and has output
circuits coupled through a line-scanning generator 38 and a
field-scanning generator 39 to horizontal and vertical deflection
windings 14 c, respectively, in the image-reproducing apparatus 14 An
output circuit of the generator 38, for example, a tap on the
horizontal deflection transformer therein is coupled to input circuits
of the APC system 27 and the colorkiller circuit 36, both components
of the system 12 and to be considered more fully hereinafter, for
applying horizontal flyback pulses as gating signals to such units.
An output circuit of the video-frequency signal source 10 is also

coupled to a soundsignal reproducing unit 40 which may comprise a
conventional intermediate-frequency amplifier, an audio frequency
detector, an audio-frequency amplifier, and a sound reproducer.
Except for the details of combination of circuits in the
image-reproducing system 12, all of the circuit components thus far
described are conventional and well known, most of such components
being fully considered in the aforesaid January 1954, I R E article
entitled "Processing of the NTSC Color Signal for One-Gun Sequential
Color Displays " Therefore, no detailed description of such circuit
components is provided herein.
GENERAL OPERATION OF RECEIVER OF FIG 1 Considering briefly now the
operation of the receiver of Fig 1 as a whole and assuming the
components of the inmage-reproducing system 12 and their combination
to be conventional and as described in the aforesaid I R E.
article, a desired composite color-television signal of the NTSC type
is intercepted by the antenna system 11, selected, amplified,
converted to an intermediate-frequency signal, further amplified, and
the composite videofrequency signal component thereof detected in the
unit 10 If color information is being transmitted, the composite
video-frequency signal comprises conventional line and
fieldsynchronizing components, a color burst synchronizing component,
and the aforementioned luminance and chrominance signals.
The luminance signal is translated through the luminance-signal
channel, including the units 15, 16, 17, and 13 in the
image-reproducing system 12, and applied to the cathode of the
image-reproducing apparatus 14.
The chrominance signal is translated through the amplifier 19 and
converted by means of the axis selector 20 to g pair of chrominance
signals One of these chrominance signals has only information re 70
presentative of red and blue, that is, is a subcarrier wave signal
modulated only by an RBl component The other chrominance signal has
information representative of green, that is, is a subcarrier wave
signal modulated only 75 by a G-M component The converted signal
having red land blue information is translated through ithe amplifier
35, the adder circuit 13, and applied to the cathode of the picture
tube in the image-reproducing apparatus 14 80 In the modulator 23, the
converted signal having green information is heterodyned with a signal
having the third harmonic frequency of the initially applied
subcarrier wave signal for developing a second harmonic chromin 85
ance signal including information representative of green The latter
signal is translated through the filter network 24, the adder circuit
13, and applied to the cathode of the image-reproducing apparatus 14
The phasing 90 of the third harmonic signal is such that the developed
signal, iafter translation through the network 24 and the adder

circuit 13, will apply the G-M information to the cathode of the
picture tube in coincidence with the 95 impinging of the electron beam
on the green phosphors.
The chrominance signal in the output circuit of the amplifier 19 is
also utilized in the synchronous detector 25 to derive a luminance 100
correction signal M-Y, the low-frequency components of which are
translated through the filter network 26 and the adder circuit 13 for
utilization in the image-reproducing apparatus 14 to correct for
luminance errors in 105 herently caused by the chrominance signals in
a single-gun tube such as utilized in the apparatus 14.
To effect proper operation of the axis selector 20, the modulator 23,
and the synchron 110 ous detector 25, that is, to control these units
te operate in correct relationship with respect to the appropriate
phases of the modulated subcarrier wave signal applied thereto, a
sinewave reference signal of the same frequency 115 as the subcarrier
wave signal is developed in the generator 28 and controlled in phase
with respect to the subcarrier wave signal by means of the AP C system
27 The system 27 is responsive to the reference signal and the 120
color burst signal translated through the amplifier 19 and maintains
the reference signal at a specific phase with respect to the color
burst synchronizing signal and thus maintains the reference signal at
specific phases with re 125 spect to the different modulation phases
of the applied subcarrier wave signal These phase relationships are
represented by the vector diagram of Fig la, the R-B modulation axis
of the subcarrier wave signal is 29 clock 130 7 + 85,575 modulated by
G-M information and Curve C represents the composite of the
fundamental (F) and second harmonic (S) suboarrier wave signals Line M
represents the corrected luminance-signal level, that is, the level
for 70 the signal M.
In the synchronizing-signal separator 317, the line and
field-synchronizing signals are separated from the composite
video-frequency signal and from each other land are utilized, 75
respectively, in the generators 38 and 3 > 9 to develop horizontal
deflection land field deflection signals employed in the deflection
windings 14 c to effect deflection of the cathoderay beam to scan a
raster on the image screen 80 14 a The scanning of such raster, the
intensity-modulation of the cathode-ray beam by means of the corrected
lumlaance, fundamental, 'and second harmonic sub carrier signals
applied thereto, and the differential vertical 85 deflection of the
beam by means of the colorswitching signal applied to the grid 14 b
combine to cause the intensity-Amodulated beam to impinge upon the
phosphors for developing the different colors in correspondence with
90 intensity-modulation on such beam for these colors, thereby to
reproduce a 'color image.

In addition to the picture signal, a sound signal is also intercepted
land an intermediatefrequency sound signal developed in the 95 source
10 Such intermediate-frequency sound signal is then further amplified
in the unit 40 and the audio-frequency components thereof are
detected, additionally amplified, and utilized to reproduce sound in
the unit 40 100 When a monochrome television signal is intercepted by
the antenna 11, all of the units in the receiver of Fig 1 function in
the manner just described except for some of the units used for
developing color images Since no 105 color-synchronizing signal is
received with a monochrome signal, the APC system 2 i 7 is unable to
function and the 'color-switching signal developed by the generator
218, though it h'as a frequency of approximately 3 6 mega 110 cycles,
is no longer locked in specific phase relation with line frequency The
failure of the APC system 27 to function causes the color-killer
circuit 36, in a manner to be explained more fully hereinafter, to
develop a 115 negative bias potential which causes the modulator 23
and the detector 25 to become nonconductive and which changes the mode
of operation of the selector 20 in a manner to be considered in detail
hereinafter As a result, 120 only monochrome information is applied to
the picture tube to cause the reproduction of a monochrome image To
reproduce such monochrome image the intensity of the 'beam in the
picture tube, during each cycle of ver 125 tical deflection caused by
the color-switching signal, is such las to excite the different color
phosphors to develop a composite neutral shade having a brightness
range between black and white for every elemental area of the 13 Q
wise, the G-M axis 40 counterclockwise, and the M-Y signal axis 161 '
clockwise or 1990 counterclockwise with respect to the phase of the
color burst signal.
The reference signal developed in the generator 28 is doubled to a
second harmonic signal in the amplifier 34 and the phase of such
second harmonic signal is delayed by means of the phase-delay circuit
32 so as to render the axis selector 20 cyclically and sequentially
conductive in phase with the R-B and the G-M axes of the modulated
subcarrier wave signal to develop a pair of subcarrier wave signals,
one of which is, modulated solely by R-B information and the other of
which is modulated solely by G-M information The manner in which the
developing of these wave signals is effected will be described more
fully hereinafter when considering the system 12 The signal developed
in the generator 28 is controlled in phase by the phase-delay circuit
30 so as to have la specific phase with respect to the time of
impingement of the beam in the picture tube on the green phosphors and
such phase-controlled signal is then multiplied to a third harmonic
signal in the amplifier 31, the latter signal being employed in the
modulator 23 to develop' a second harmonic subcarrier wave signal

modulated by G-M information at a phase such that, when such developed
signal is applied to the picture tube, the G-M information is applied
to the green phosphors.
The signal developed in the generator 28 is also controlled in phase
by the circuit 33 to be in phase with the M-Y axis of the applied sub
carrier wave signal, thereby to derive the M-Y component in the
detector 25.
The signal developed in the generator 28 is also applied through the
push-pull amplifier 29 to the color-switching grid 14 b in the
image-reproducing apparatus 14, the applied or color-switching signall
having a specific phase with respect to the fundamental subcarrier
wave signal translated through the amplifier 35 and which includes
KR-B information at a specific phase The colorswitching signal also:
has a specific phase with respect to the second harmonic subcarrier
wave signal developed in the modulator 23 and which includes G-M color
information at a specific phase The phase relations of the
color-switching, fundamental and second harmonic wave signals are as
represented by the curves of Fig lb The vertical lines G, R', R, 'G,
B, and B represent the times of impingement of the cathode-ray beam on
the green (G), red (R), and blue (B) phosphors.
Curve F represents the phase of the fundamental subcarrier wave signal
modulated by R-B information and it is apparent that the fundamental
signal is in phase with the colorswitching operation Curve 'S
represents the second harmonic subcarrier wave signal 78 '55175 6
785,575 image In practice, when the frequency of the
intensity-modulation of the electron beam is in the vicinity of 3 6
megacycles, that is, of Pthe frequency of the color-switching signal,
an excess of beam energy may be applied to gither the red or blue
phosphors at the expense of less energy applied to the other thereof
This results in red and blue areas in the reproduced image forming the
spurious red and blue patterns Such excess does not occur in the green
phosphors since they are excited by the ibeam at tvice the rate of
excitation of the red and blue phosphors.
DESCRIPTION OF IMAGE-REPRODUCING
SYSTEM OF FIGS 1 AND 2.
In describing the image-reproducing system 12 of Fig 1, reference will
be made to Fig 1 to describe generally the combination of spedific
units in accordance with the prevent invention and te Fig 2 to
describe details of at least some of these units.
The compatible inage-reproducing system 12 of Fig 1 comprises a
circuit for supplying monochrome or color signals representative,
respectively, of televised monochrome or color images More
specifically, such circuit includes the output circuit of the
video-frequency signal source 10 coupled to the input circuits of the

amplifier 19 and the delay line 15 Thie signal supplied by such
circuit is, when color information is being transmitted, an NTSC type
of composite video-frequency signal including a luminance signal
having a band width of approximately 0-4 2 megacycles and a modulated
subcarrier wave signal, conventionally designated as a chrominance
sig-nal, having a mean frequency of approximately 3 6 megacycles and
side bands extending over the frequency range of approximately 3 0-4 2
megacycles Such subcarrier wave signal includes modulation components
at specific phases as represented by the vector diagram of Fig la When
monochrome information is being transmitted, such supplied signal is a
conventional monochrome signal having a band width of approximately
0-4 megacycles.
The image-reproducing system 12 of Fig.
1 also includes image-reproducing apparatus, specifically the
apparatus 14, including a plurality of parallel color-reproducing
strips, means for developing an electron beam, deflection means for
causing the beam to scan a raster on the strips, and color-swvitching
means for cyclically moving the electron beam across the strips to
reproduce a monochrome or color image Specifically, the
image-reproducing apparatus i 14 is a single-gun focusmask type of
picture tube fully considered in the aforementioned January, 1954 I R
E.
article The apparatus 14 includes a picture tube having an image
screen 14 a on which color-reproducing strips, specifically, groups of
phosphors for emitting green, red, and blue lights are deposited in an
interleaved manner in the order, for each group, of green, red, green,
and blue As conventionally employed, these strips extend horizontally
Such tube also includes color-switching means, such as the control
grid 14 b, coupled to the output 70 circuit of the push-pull amplifier
29 The grid 14 b is arranged to have a wire of one group of grid wires
positioned behind each red phosphor and wire of another group of grid
wires positioned behind each blue phos 75 phor The 3 6 megacycle
signal developed in the amplifier 29 by means of the generator 2 'S is
applied to the two groups of grid wires to effect a 3 6 megacycle
vertical deflection to cause the electron beam, emitted from the 80
cathode of the picture tube and deflected to scan a raster on the
phosphor strips by means of the deflection windings 14 c, to move
vertically across each group of phosphor strips for each elemental
area of the reproduced 85 image as each horizontal line is being
scanned.
Spurious color patterns tend to appear in reproduced monochrome images
in such apparatus when signals applied to the cathode thereof have
frequencies in the vicinity of the color 90 switching frequency, that
is, frequencies of approximately 3 6 megacycles or, more specifically,

in the range of 3 0-4 2 megacycles.
The compatible image-reproducing system also includes a
signal-translating channel 95 coupled between the supply circuit and
the beam-developing means for translating a band of the supplied
signals having frequencies below the color-switching frequency for
intensity-modulating the electron beam More 100 specifically, such
channel includes the luminance channel comprising the delay line 15,
the amplifier 16, the filter network 17, and the adder circuit 13
coupled in that order between the output circuit of the source 10 and
105 the cathode of the picture tube The filter network 17 has an upper
cutoff frequencv of 3 megacycles and thus only signals in the range of
1-3 megacycles are translated through the luminance channel to inten
110 sity-modulate the cathode of the picture tube.
-Finally, the compatible image-reproducing system of Fig 1 includes
another signal-translating channel including auxiliary deflection
means for developing a field in the path of 115 the electron beam Such
other channel comprises the amplifier 19, the R-B and G-M axis
selector 20, the filter network 21, the amplifier 22, and the
auxiliary deflection winding 14 d This channel is coupled to the 120
supply circuit, specifically to the source 10, for translating a;band
of the supplied monochrome signals having frequencies in the vicinity
of the color-switching frequency for effecting deflection modulation
of the electron 125 beam lengthwise of the phosphor strips on the
image screen 14 a, thereby to provide highdefinition monochrome
information when monochrome images are being reproduced and
consequently to minimize the spurious red and 130 785,575 wor 23, 'and
in the M-Y synchronous detector 25.
Referring now to Fig 2 of the drawings, the color-killer circuit 36 is
a control circuit coupled to the axis selector 20 for controlling 70
such selector to translate high-frequency lcomponents applied thereto
cyclically to different output circuits when a color image is being
reproduced land to one output circuit when monochrome images are being
reproduced 75 The color-killer circuit 3,6 comprises a triode 50
having the cathode thereof grounded and the control electrode thereof
coupled to the in-phase detector in, the APC system 27.
The anode of the triode 50 is coupled through 80 the secondary winding
of a transformer 51 and a load resistor '52 to the cathode of the
triode Additionally, the junction of the secondary winding of the
transformer 51 and the load resistor 52 is coupled through a low 85
pass 'filter network 53 and a switch 54 to an input circuit of the
axis selector 20 The pass band of the filter '53 is such as to
translate substantially only direct-current or very low frequency
signals 90 The second harmonic amplifier 34 in Fig.
2 includes a triode '55 having the control electrode thereof coupled

through a biasing netporlk 56 to the output circuit of the
referencesignal generator 28 Sand having the cathode 95 thereof
grounded The anode of the tube 55 is coupled to a tapped terminal on
'a parallel-resonant circuit 57 having one of the terminals thereof
connected through a load resistor 58 to a source of +B potential and
the 10 ( other terminal thereof connected through 'a condenser 59 to a
prarallel-resonant circuit in the phase-delay circuit 32 The resonant
circuit '57 is tuned to approximately 7 2 megacycles, that is, to the
second harmonic of the 105 mean frequency of the subcarrier wave
signal.
The resonant circuit 60 is tuned to approximately 7 2 megacycles and
coupled to the tuned circuit 517 with such degree of inductive
coupling or other reactive coupling, such as 110 capacitive, as
represented by the condenser 59, or resistive, as to obtain the phase
delay of the 7 2 megacycle reference signal required for use in the
axis selector 20, now to be described in detail The reference
generator 2 '8, second 115 harmonic amplifier 34, and phase-delay
circuit 32 comprise means coupled to the selector 20 ' for controlling
such selector cyclically to translate different segments of the
highfrequency 'components supplied by the ampli 120 fier 19 through
different ones of a pair of output circuits of the selector 20 when
color images are being reproduced.
The axis selector 20 is a signal-translating device including a pair
of output circuits and, 125 specifically, includes a special type of
electron tube 61 commercially known as a beamswitching tube, for
example,' a type 6 AR-8 tube In addition to conventional cathode and
control electrodes, the tube 61 includes 130 blue patterns in the
reproduced monochrome i images More specifically, the band of supplied
monochrome signals has frequencies in the range of 3 0-4 2 megacycles,
as determined by the pass band of the amplifier 19, i and the
auxiliary deflection winding 14 d is so positioned physically on the
neck of the picture tube that the field developed by such winding is
effective to cause minute horizontal deflection of the electron beam
in magnitude and sense determined by the intensity and polarity of the
high-frequency monochrome signal More specifically, such differential
horizontal deflection is such as to vary the horizontal velocity of
the beam in inverse relation to the magnitude of the high-frequency
component.
The additional signal-translating channel also includes the
reference-signal generator 2 '8 the second harmonic amplifier 34, the
phasedelay circuit 32, and the color-killer circuit 36 The generator
28 is a sine-wave generator for developing a signal which is
substantially equal in frequency to the mean frequency of the
modulated subcarrier wave signal translated through the amplifier 19,

that is, for developing a signal of approxinately 3 16 megacycles The
phase and frequency 'of the signal developed in the generator 2,8 are
controlled by the automatic-phase-control system 217 which may be of a
type described in an article entitled " The DC Quadricorrelator: A
TwoMode,Synchronization System," published in the January, 1954 issue
of the PROCEEDINGS OF THE I R E at pages 288-299, inclusive The
details of such an automaticphase-control system are particularly
considered at page 293 of this 'article with reference to Fig 5
thereof As described in such article, the system 27 includes the
conventional quadrature-phase detector for controlling the phase of
the signal developed 'in the generator 28 so that the reference signal
has a specific phase relation with respect to the modulated suboarrier
wave signal and also includes an in-phase detector The in-phase
detector is utilized to improve the automatic phase control of the
system 27 and additionally develops a unidirectional potential which
has a maximum magnitude when the signal developed in the generator 28
is in proper phase relation with respect to the modulated subcarrier
wave signal In the circuit described in such article, such potential
is negative when the generator 218 'is properly synchronized and is
utilized by the color-killer circuit 36 to control the state of
operation of circuits in the chrominance and luminance channels of the
receiver The color-killer circuit 36 has input circuits coupled to the
inphase detector in the APC system 27 and to a tap on the horizontal
transformer in the line-scanning generator 38 The output circuit of
the color-killer circuit 36 is coupled to control circuits in the
selector 20, in the modula7 + 85,57 + 5 a pair of deflection
electrodes 62 a, 62 b and a pair of anodes The cathode of the tube 61
is coupled through a biasing resistor 63 to ground while an electron
intensity control electrode of the tube 61 is coupled to the output
circuit of the amplifier 19 Another grid electrode of the tube 61 is
grounded, this electrode being conventionally known as the fucusing
electrode, and the third grid electrode, known as the accelerating
electrode, is coupled directly to a source of potential + B. The
deflection electrodes 62 a, 62 b are coupled to opposite terminals of
a tuned secondary circuit 64 of a transformer 65, the resonant
frequency of the tuned circuit being approximately 7 2 megacycles The
primary winding of the transformer 65 is coupled to the output circuit
of the phase-delay circuit 32 and the secondary winding of such
transformer has a center tap connected to ground The deflection
electrode 62 b is coupled to the tuned circuit 64 through a condenser
65 a and is also coupled through an isolating resistor 66 to the
output circuit of the color-killing circuit 36 The anodes of the tube
61 are components of a pair of anode output circuits, specifically
being individually coupled through different ones of resistors 67 and

68 to the source of +B potential One output circuit is coupled to the
R-o B amplifier 35 and the other output circuit is coupled to the
modulator 23 and through ia condenser 73, the filter network 21, and
the amplifier 22 to the auxiliary deflection winding 14 d The filter
network 21 comprises a, pair of coupled damped tuned circuits,70 and
71 each tuned approximately to a mean frequency of 3 6 megacycles and
being sufficiently broadly tuned to have a pass band of approximately
3 0-4 2 megacycles The amplifier 22 is a conventional cathode-follower
type of power amplifier for developing signals for application to the
deflection winding 14 d.
OPERATION OF IMAGE-REPRODUCING SYSTEM OF D'IG 1 The general operation
of the image-reproducing system 12 of Fig 1 has been prevriously
described herein and, therefore, the specific operation of only that
portion of the system -which is modified in accordance with the
present invention will be considered in detail.
The luminance channel including the units 15, 16, 17, and 13, the
channel for developing the second harmonic subcarrier wave signal
modulated by information representative of green and including the
units 30, 31 23, and 24, and the channel for developing the M-Y
correction signal including the units 33, 25, and 26 operate in a
conventional manner such as described in the January, 1954 I R E.
article previously referred to herein and entitled " Processing of the
NTS'C Color Signal for One-Gun Sequential Color Displays " The
operation of the axis selector 20 and the units 21, 22, and 14 d
coupled to the output circuit thereof as well as of the color-killer
circuit 36 will be considered in some detail.
Before considering the operation of the last-mentioned units, as more
fully represen 70 ted in Fig 2, it will be helpful to consider in
-some detail the problem which applicants' image-reproducing system is
designed to solve.
As previously mentioned, when an image-reproducing apparatus of the
focus-mask type, 75 such as represented by the apparatus 14 of Fig.
1, is reproducing a monochrome image, spurious red and blue patterns
tend to appear in such image These patterns result from the combined
effect of a high-frequency intensity 80 modulation of the electron
beam in the picture tube, a frequency in the vicinity of 3.6
megacycles, and of a 3 6 megacycle colorswitching signal If the
intensity-modulation and the color switching happens to be in 85
phase, the positive peak of the beam intensity wvill occur as one
phosphor is being excited, for example, as the red phosphor is excited
and the negative peak will occur as the blue phosphor is excited,
since these phos 90 phors are excited at a 3 6 magacycle rate.
This will result in an excess of red over blue where no such excess
should exist As the phase relations of the color-switching operation

and the intensity-modulation of the beam 95 vary from such in-phase
relation caused, for example, by a small difference in the frequency
of the two, there will tend to be periods when the blue is in excess
and other periods when the red is in excess As a result, 100 spurious
red and blue patterns appear in the monochrome image If the operation
of the picture tube were linear, then none of these effects would
appear for green because the beam impinges on the green phosphors at a
105 rate twice that of impingement on the red and blue phosphors
However, the operation is not linear and rectification of the signal
occurring in coincidence with the impingement of the beam on the green
phosphors 110 does occur resulting in spurious green patterns These
patterns are not,as evident or present to the same degree when a color
image is being reproduced because the inter-laced relationship of the
color information with line 115 frequency causes any such patterns to
have low visibility Since there is no such interlacing when a
monochrome image is being reproduced, due to the lack of
synchronization of the color-switching operation, with line fre 120
quency, these patterns tend to be highly visible, to destroy all
high-definition information in the monochrome image,land otherwise
deleteriously affect the reproduced monochrome image 125 The beatin,
of the high-frequency components and the color-switching operation
causes the proportions of red, green, and blue lights emitted from an
elemental area to become unbalanced toward red or blue If the 130 78
'5,5175 wave signal to the control electrode In this manner, the
output signal developed in the circuit including the upper 'anode
includes 'a subcarrier wave signal at fundamental frequency modulated
substantially only along the 70 G-M axis 'and the output signal in the
circuit including the lower anode includes a fundamental subcarrier
wave signal modulated substantially only along the R-B axis Since the
G-M 'and R-B axes are separated by 75 approximately 70 and the
operation of the selector 20 is based on a quadrature relationship,
for these axes, the output signals are not pure R-B and G-M signals
but are sufficiently pure for utilization If desired, 'a cor 80
rection network for cross coupling the outputs may be employed to
improve the degree of purity The R-B and G-M wave signals are utilized
in the manner previously described herein to reproduce a color image
85 When a color signal is being received, the in-phase detector in the
system 27 develops a negative potential which is applied to the grid
of the triode 50 in the color-killer circuit 36 to render such trio de
nonconductive 90 Therefore, during such period of time no po/tential
is developed in the output circuit of the unit 3 ( 6 and no bias
potential is applied from the unit 36 to the deflection electrode 162
b in the axis selector 20 Consequently, the 95 tube 61 in the unit 20
can function in its normal manner However, when a monochrome signal is

being received, the system 27 does not develop a negative bias
potential and the tube 50 is rendered conductive periodically 100 when
positive-going flybiack pulses are applied to the anode thereof
through the transformer 51 This results in 'a net negative potential
being developed across the load resistor 52.
This negative potential is applied through the 105 resistor 616 to the
deflection electrode 162 b resulting in 'a continuous deflection of
the beam in the tube 161 away from the electrode 62 b toward the
electrode 62 a Alternatively, the same effect can be accomplished when
color 110 signals are being received by connecting the blade of the
switch 54 to the negative bias potential source 'C, if the viewer
wishes to view a monochrome Image instead of a color image When such
negative potential is 115 applied to' the deflection electrode 62 b,
the electron beam impinges solely on the upper anode since the
intensity of the 7 2 megacycle signal applied to the deflection
electrodes 62 a and 62 b is insufficient to overcome the 120 high
negative bias on the deflection electrode 62 b Consequently, the 3 0-4
2 megacycle components:appliedl to the control electrode of the
tube:61 are translated only to the output circuit including the upper
anode and 125 translated through the filter network 21 and the
deflection amplifier 22 for application to the auxiliary deflection
winding 14 d This results in the high-frequency monochrome
information, being applied to the electron beam 130 high-frequency
information is applied 'as differential horizontal deflection of the
electron beam to sharpen edges in the reproduced monochrome image,
then, though the position of the beam on the red, green, and blue
phosphors is changed on each phosphor in accordance with the magnitude
and sense of the highfrequency information, the relative intensities
of the red, green, and blue lights for each elemental area 'are not
disturbed Consequently, no excess of one or another color occurs and
the spurious color patterns are minimized.
The deflection modulation also eliminates the spurious green patterns
because high-frequency information in coincidence with the impingement
on 'the green phosphors is no longer introduced by means of the
nonlinear intensity effect of the beam Therefore, all monochrome
high-frequency information is applied to the picture tube as
horizontal deflection modulation of the be'am The selector is
conditioned to operate to apply highfrequency information as
intensity-modulation when a color image is being reproduced and
conditioned to operate ito apply the high-frequency information as
deflection modulation when a monochrome image is being reproduced
Referring to Fig 2 of the drawings, the reference signal developed in
the output circult of the generator 28 is applied to the harffonic
amplifier; 34 wherein it is doubled to become a second harmonic or 7 2

megacycle signal The second harmonic signal is controlled in, phase by
the phase-delay circuit 32 and coupled through the transformer '65 for
application with opposite phases to the pair of deflection electrodes
'62 a land 62 b The 3 04.2 megacycle signal translated through the
amplifier 19, regardless of whether it is a monochrome or color
signal, is applied to the control electrode of the tube '61 In
operation the deflection electrodes 62 a and 16,2 b in the tube 61, if
a color image is being reproduced, cause deflection of the electron
beam emitted.
from the cathode therein to cause such beam to impinge on the anodes
therein at a 7 2 megacycle rate If the deflection operation is
properly phased by controlling the phasing of the 7 2 megacycle
reference signal with respect to the modulated sub carrier wave signal
applied to the control electrode in the tube 61, then the electron
beam is directed on the upper anode of the tube 161 in coincidence
with the application of the phase of the modulated suboarrier wave
signal which includes information representative of green, that is, in
coincidence with the application of the G-M axis of the wave signal to
the control electrode of the tube Similarly, the electron beam is
caused to impinge on the lower anode in coincidence with the
application of that phase of the subcarrier wave signal including red
and blue information, that is, in coincidence with the application of
the R-B axis of the 1785 C 57 '5 as differential horizontal
deflection, thereby effecting reproduction of such high-frequency
information in the reproduced image without causing the reproduction
of spurious color patterns.
If the brightness in the image is changing from one level to a higher
level, the differential horizontal deflection has the effect of
accelerating the horizontal sweep of the beam as the intensity of the
beam starts to change from the one level and decelerating the
horizontal sweep as the intensity of the higher level is approached Of
course, the acceleration and deceleration occur in -coincidence with
changes in beam intensity only if such changes represent
high-definition information such as the edge of a vertical bar or any
object having sharp, distinct, vertical edges.
Otherwise, there would 'be no high-frequency information received and,
consequently, the auxiliary deflection winding would not develop an
accelerating or retarig field.
D Esc RIPT Io N AND OPERATION OF PORTION OF IMAGE-REPRODUCING SYSTEM
OF -FIG 3 ' ahe image-reproducing system described with reference to
Figs 1 and 2 utilizes some of the fircts of the chrominance channel in
a dual capacity These circuits function in one manner when, a color
image is being reproduced and function in a different manner, to
effect deflection modulation of the electron beam in the picture tube

in response to highfrequency monochrome components, when, a monochrome
image is being reproduced However, it is not essential that circuits
in the chrominance channel be so used, and, in fact, under some
conditions it may not ibe desirable ito employ such circuits
Alternatively, the high-frequency components of the composite
video-frequency signal may be translated through an auxiliary
luminance channels as represented in Fig 3, for application of such
high-frequency components to the auxiliary deflection winding Since
many of the units of Fig 3 are identical with units in Figs 1 and 2
such are identified by means of the same reference numerals.
In, Fig 3, the luminance channel including the units 1 t 5, 16, 70,
and 13 is modified to translate directly, for intensity-modulation of
the electron beam developed in the picture tube, only those
video-frequency components in the range of, for example 0-1 L 8
megacycles by proportioning the pass band of a filter network 70 to
effect such result An auxiliary luminance channel coupled to the
output circuit of -the delay line 15, has, in cascade in the order
named, a filter network 71, the amplifier 22, and the auxiliary
deflection winding 14 d The filter network 71 is proportioned 'to have
a pass band of, for example, 18-42 megacycles for translating the
high-frequency video-frequency components through such auxiliary
channel The RB and G-M axis selector in the chrominance channel is
modified in that, as represented in Fig 3, it has output circuits
coupled only to the R-B amplifier 35 and to the modulator 23 and is
further modified in having the color 7 C killer circuit 36 coupled to
an intensity control electrode therein rather than to one of the
deflection electrodes as in Figs 1 and 2.
Considering now the operation of the portion of the image-reproducing
system repre 75 sented by Fig 3, when a monochrome image is being
reproduced, that portion of the composite video-frequency signal
supplied from dhe source 10, having components in the frequency range
of 0-1 8 megacycles, is trans 80 lated through the units 15, 16, 70,
and 13 and applied to the cathode of the picture tube in the
image-reproducing apparatus 14 That portion of the same composite
video-frequency signal having components in the fre 85 quency range of
1 18-4 2 megacycles is translated through the delay line 15, the
filter network,71, amplified in the unit 22, and utilized to effect
differential horizontal deflection modulation by means of the
auxiliary deflec 90 tion winding 14 d When a mono-chrome image -is
being reproduced, the chrominance channel is effectively rendered
inoperative by means of the color-killer circuit 36 and, specifically,
the axis selector 72 is made noncon 95 ductive during this period.
Although the operation just explained results in some duplication of
the high-frequency components applied to the picture tube when a color

image is being reproduced, for 100 example, the duplication caused by
the translation of components in the frequency range of 3 0-42
megacycles through both the network 71 and the amplifier 22 to effect
horizontal deflection modulation -and through the 105 amplifier 35 to
effect some intensityodulation of' the beam' in the picture tube, such
duplication is usually beneficial since there tends to be a lack of
sharpness in' reproduced color images and such excess of high-fre 110
quency information tends to make such images more crisp and sharp.
The visibility of red and blue spurious patterns in a monochrome image
reproduced by an irmage-reproducing system, including the 115 circuits
of Fig 3, is so diminished as to be substantially nonexistent This
substantial reduction -is caused by utilizing no frequency components
having frequencies higher than one-half the frequency of the
color-switching 120 signal, that is, having frequencies higher than
1.8 megacycles for intensity-modulation of the electron beam in the
picture tube All components having frequencies higher than 1 8
megacycles are utilized to effect differential 125 horizontal
deflection modulation Consequently, any tendency of the 3 6 megacycle
color-switching signal to heterodyne with the intensity-modulation
signals of the electron beam does not result in developing
low-fre-'130 785,57,5 785,575 11 quency beat signals in the frequency
range of 0 ( 1 8 megacycles and therefore, any such beat signals are
practically invisible.
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* 5.8.23.4; 93p
* GB785576 (A)
Description: GB785576 (A) ? 1957-10-30
Improvements in or relating to the catalytic conversion of gasoline
hydrocarbons

A high quality text as facsimile in your desired language may be available
amongst the following family members:
DE1028728 (B) NL101545 (C)
DE1028728 (B) NL101545 (C) less
78, Date of Application and filing Complete Specification Dec 30, 1955
ao.37385/55.
Application mode in United States of America on Dec 31, 1954.
Index a; ' -c ass 2 ( 3), B 2.
International Cassificaton:
COAMIPLET 1 E SPECIFICATION
Improvetnents in er relat,-tg to the Catalytic Conversion of C'e Li R
Le H v T xbo Ts We UNIVERSAL Ott PP Thn TT,-1 r 5,576 EPRATA
SECIFICATION NO O 785,5 Th Page 3, line 109, for Iscapen read "scope'.
page 4, line i 5, for ncycle' read 'cyclic 5, Page 6, line 83, after
nfurther 1 ' insert othe, Pa Ge 7, line 53, for frefilnaten read
nraffinatem.
Page 7, line 54, after "fractlon"t insert "comprising lsohexanes froi
a hligher boiling rafflinate fraction".
Page 8, line 4, for icomapentsn read "components".
THE PATENT OFFICE, 3 gist December, 1957 t Uy XLt:conainons that must
be mintained in order to saisfactorily unarade the hieher boiling
Daraffinic constituents of the feed ar too Qevere for come of the
cther constituents The result is that an appreciable part of the feed
stock is unnecessarily lIrico Pri S 145 6 d v uic present invention a
mixture of hydrogen, a fresh gasoline fraction and a high boiling
paraffinic recycle stock prepared as hereinafter described is
subjected in the reforming zone to reforming at an elevzated
temperature and pressure in the presence of a catalyst comprising D 13
oi 82 oi 2 (i)13624 150 12/57 R 9 a O : ' 1 1 1 1 -,114 % j,t '
lPATENT SPECIFICATION

785,576 Date of Application and filing Complete Specification Dec 30,
1955 " I g +dffi No 37385/55.
Application made in United States of America on Dec 31, 1954.
Index at Acceptanc:-Class 2 ( 3), B 2.
International Classification: o 6 07 c.
Improvenients in or relating to the Catalytic Conversion of GacAtin Le
1-ydrocarlbbons We, UNIVERSAL OIL PRODUCTS COMPANY, a Corporation
organised under the Laws of the State of Delaware, United States of
America, of No 30, Algonquin Road, Des Plaines, Illinois, United
States of America, do hereby declare the invention, for which we pray
that a patent may be granted to us, and the method by which it is to
be performed, to be particularly described in and by the following
statement:This invention relates to the catalytic conversion of
hydrocarbons boiling within the gasoline range It is more specifically
concerned with a novel combination of reforming and solvent
extraction.
The recent developm ents in the automotive industry have increased the
demand for high octane numbered gasolines and the petroleum industry
has been striving to keep up with these demands One nrocess that has
achieved great commercial acceptance is the catalytic reforming
process The term " reforming " is well known in the petroleum industry
and refers to the treatment of gasoline fractions to immrove the
anti-knock characteristic thereof.
A highly successful and economical reforming process is described in
the United Kingdom Patent No 657,565 filed November 23, 1948.
However, the present reforming processes are all limited by decreasing
yields at increasing octane numbers There are also other limitations
For example, when a full boiling range strainht-run gasoline or a
relatively wide boiling range naphtha is reformed in the presence of a
catalyst that promotes dehydro)zenation of naphthenes,
dehydrocvclization of paraffins and bvdrocracking of parafins,
relatively poor yields and considerable fouling of the catalyst are
obtained when the operation conditions are selected to obtain large
octane number appreciation This apparentlv is due to the fact that the
relatively severe operating conditions that must be maintained in
order to satisfactorily upgrade the higher boiling paraffinic
constituents of the feed are too Severe for some of the other
constituents The result is that an appreciable part of the feed stock
is unnecessarily lPrice ?ribg l 4 s 6 d converted to gases and to
catalyst carbon.
Thus; under the usual conditions of operation, the yield of liquid
product and the catalyst life are limited, to a considerable extent,

by and primarily dependent upon the decomposition and carbon forming
tendencies of the higher boiling constituents The reforming process of
the present invention largely overcomes these objectionable features
of the prior art reforming processes.
It is an object of the present invention to reform a full boiling
range straight-run gasoline, or a relatively wide boiling fraction
thereof, in such a manner that increased yields of reformate and
longer catalyst life are obtained while producing a liquid product of
the desired quality.
According to the present invention gasoline hydrocarbons are reformed
by a process which comprises supplying a fresh gasoline charge which
contains paraffins and naphthenes to a reforming zone and therein
subjecting it in the presence of hydrogen to a catalyzed reforming
which includes the essential reactions of dehydrogenation of
naphthenes and dehydrocyclization and hydrocracking of paraffins,
separating the normally gaseous reaction products from the normally
liquid reformed product, subjecting the latter to an extraction
treatment and therein separating the same into a rafflinate poor in
aromatic hydrocarbons and into an extract rich in aromatic
hydrocarbons, subjecting the raffinate to fractional distillation and
therein separating a low boiling fraction comprising isohexanes from a
higher boiling raffinate fraction containing normal hexane, and
returning this higher boiling raffinate fraction to the reforming zone
and subjecting it therein to the catalyzed reforming reaction in
admixture with the fresh gasoline charge.
In a more specific embodiment of the present invention a mixture of
hydrogen, a fresh gasoline fraction and a high boiling paraffinic
recycle stock, prepared as hereinafter described, is subjected in the
reforming zone to reforming at an elevated temperature and pressure in
the presence of a catalyst comprising so 785,576 platinum, alumina and
combined halogen, the reformed product is fractionated to remove
normally gaseous components, the remaining product fraction, namely
the normally liquid reformed product is introduced into an extraction
zone wherein it is treated with a selective solvent having a
relatively higher solvent power for aromatic hydrocarbons, a raffinate
rich in paraffinic hydrocarbons and an extract phase containing the
solvent and a substantial amount of the aromatic hydrocarbons of the
reformed product are separately removed from the extraction zone, the
extract phase is treated to separate the solvent from the aromatic
hydrocarbons, the raffinate is fractionated separating a low boiling
paraffinic fraction comprising isohexanes and lower boiling paraffins
from a higher boiling raffinate fraction containing normal hexane, at
least a portion of the low boiling fraction is returned to the
extraction zone and at least a portion of the high boiling paraffinic

fraction is recirculated to the reforming reaction.
In the present process a fresh gasoline fraction is reformed in
admixture with a paraIfinic recycle stock in the presence of hydrogen
Hydrogen is separated from the reforming step effluent and is recycled
to this reforming step Net product hydrogen may be withdrawn The
remaining products are fractionated to reject the gaseous hydrocarbons
produced in the process and the resultant liquid product is extracted
in an extraction zone to separate the aromatics therefrom The
raffinate from the extraction zone is preferably fractionated to
remove a fraction boiling lower than normal hexane since these lighter
components are usually high in octane number and their further
reforming does not result in substantial octane number appreciation;
therefore it is usually not economical to reform this lighter
paraffinic fraction The higher boiling fraction of the raffinate is
then recycled to the reforming zone In some cases the raffinate may
contain constituents which are so heavy that they tend to deposit
carbon on the catalyst in the reforming zone; it is preferred to also
remove these heavy constituents from the raffinate The raffinate
fraction that is recycled to the reforming zone in the preferred mode
of operation, therefore, is a middle cut of the raffinate that is
removed from the extraction unit The separated aromatics may be
recovered as such and may be used, for example, in solvents However,
they preferably are blended with the lower boiling fraction of the
raffinate to produce a reformed gasoline of high quality.
A feature of the present process is that mild processing conditions
may be employed in the reforming step minimizing undesirable side
reactions which otherwise keduce yields of useful gasoline products
Recycling of the low octane number, high boiling paraffins results in
their being dehydrocyclized to aromatics and/ or their being converted
to lower boiling, high octane number paraffins without the excessive
production of gaseous hydrocarbons that would result, if these higher
boiling paraffins were substantialy completely reacted in one pass in
a reforming operation at conditions of high severity High severity
single pass operation is also not desirable from considerations of the
chemical equilibria involved; as in such single pass operations the
aromatics present in the product limit the extent to which such
aromatics can be formed from naphthenes and paraffins In contrast,
however, the use of the present process involves the removal of a
substantial portion of the product aromatics from the recycle to the
reaction zone which thus permits the formation of additional aromatics
unrestricted by the limitations of chemical equilibria Similarly, the
isomerization of low octane rating straight chain paraffins to higher
octane quality branched structure paraffins is an equilibrium chemical
reaction As the isomerization of normal hexane is important to achieve

in upgrading gasolines, due to the very limited extent that it
undergoes dehydrocyclization at reasoable operating conditions, a
feature of the present process is the continuous removal of isohexanes
and the continuous recirculation of normal hexane to the reaction zone
thus obtaining complete conversion of low octane normal hexane to much
higher quality isohexanes without any restriction in yield due to
chemical equlibrium considerations.
The aromatics are separated from the paraflins and naphthenes of the
reformate (that is the normaly liquid reformed product) for several
reasons One reason is that recycling the aromatics results in lower
over-all yields of reformate Dresumably due to conversion of the
aromatics to gaseous hydrocarbons and to hydrocarbons boiling above
the gasoline range nmother reason is that high concentrations of
aromatics in the reaction zone tend to result in a greater carbon
decomposition and consequently a shorter process Deriod Still another
reason is that high concentrations of aromatics in the reaction zone
tend to suppress the dehydrogenation of naphthenes to aromatics and to
suppress the dehydrocyclization of paraffins to aromatics, said
dehydrogenation and said dehydrocyclization being equilibrium
reactions By eliminating low octane number, high boiling paraffins
from the final product and recycling them to the reaction zone the end
product is a reformate of high quality even though the lower boiling
portions of the charging stock have never been subjected to the
relatively severe operating conditions that previously have been
thought to be necessary to produce high quality reformate.
The charge stocks that may be reformed in accordance with the present
process comprise hydrocarbon fractions that boil within the gasoline
range and that contain naphthenes 1)S 785,576 and paraffins The
preferred stocks are those i:
consisting essentially of naphthenes and para r ffins, although minor
amounts of aromatics and r even of olefins also may be present This
pre g ferred class includes straight-run gasoline, natural gasoline
and the like The gasoline r fraction may be a full boiling range
gasoline 1 having an initial boiling point substantially from 100 C to
380 C, and an end boiling I point substantially from 1770 C to about
218 c C., or it may be a higher boiling fraction corm monly referred
to as naphtha and having an I initial boiling point substantially from
660 C f to 1210 C, and an end boiling point substanti l ally from 1770
C to 2180 C Mixtures of the various gasolines and/or gasoline
fractions may also be used and thermally cracked and/or catalytically
cracked gasolines may also be used as charging stock, however, when
these unsaturated gasoline fractions are used, it is preferred that
they be used in admixture with a straight-run or natural gasoline
fraction, or else hydrogenated prior to use as charging stock for the

present process.
The catalysts that may be used in the reforming step of this invention
comprise those reforming catalysts that promote dehydrogenation of
naphthenic hydrocarbons and hydrocracking of paraffinic hydrocarbons.
Starting with a paraffinic hydrocarbon, from a yield-octane standpoint
it is preferable to upgrade the paraffinic hydrocarbon by
dehydrocyclizing the same to an aromatic rather than by cracking the
paraffinic hydrocarbon Since the recycle raffinate to the reforming
zone consists predominantly of paraffinic constituents it is best to
upgrade this recycle stream by dehydrocyclisation Therefore, it is
preferred that the catalyst in the reforming zone be such that it has
a substantial amount of dehydrocyclization activity A satisfactory
catalyst comprises a platinum-alumina-silica catalyst of the type
described in the United States of America Patent No 2,478,916 issued
August 16, 1949, the platinum being present in an amount of from 0 2
gram to 2 0 grams per 100 cubic centimeteres of final catalyst A
preferred catalyst comprises a platinumn-alumina-combined halogen
catalyst of the type described in the United Kingdom Patent No 657,565
filed November 23, 1948 Other catalysts such as molybdena-alumina,
chromia-alumina, and platinum on a cracking catalyst base may be used
It has been found that catalysts of the platinum-alumina-combined
halogen type, wherein the halogen content lies within the range of
from about 0 1 % to about 3 % by weight of the final catalyst,
especially those that contain about 0 01 % to about 1 % by weight of
platinum and from about 0 1 % to about 1 % combined fluorine or those
that contain about 0 1 % to about 3 0 % combined chlorine are
especially effective and economical in the present process because of
the long life they exihibit, and also because they promote
somerization reactions of both paraffins and iaphthenes and paraffin
dehydrocyclization eactions as well as the naphthene dehydroenation
and paraffin hydrocracking reactions.
The operating conditions maintained in the 70 reforming step of this
process should be such hat substantial conversion of naphthenes to
aromatics and relatively mild hydrocracking of paraffins are induced
Further the operating conditions should be such that there is substan
75 Jal conversion of paraffinic compounds to aromatics by
dehydrocyclization It is also preferred that process conditions be
used which result in only minor amounts of olefins being present in
the product When employing plati 80 num-alumina-combined halogen
catalyst the reforming process will be effected at a temperature
within the range of from about 316 C to 5380 C, pressure within the
range of from about 3 4 to about 68 atmospheres, and a 85 weight
hourly space velocity of from about 0.5 to about 20 The weight hourly
space velocity is defined as the weight of oil per hour per weight of

catalyst in the reaction zone The reforming reaction is conducted in
the pre 90 sence of hydrogen In one embodiment of the process
sufficient hydrogen will be produced in the reforming reaction to
furnish the hydrogen required in the process; and therefore, it may be
unnecessary to introduce hydrogen 95 from an extraneous source or to
recycle hydrogen within the process However, it will be preferred to
introduce hydrogen from an extraneous source, generally in the
beginning of the operation, and to recycle hydrogen 100 within the
process in order to be assured of a sufficient hydrogen atmosphere in
the reaction zone The hydrogen present in the reaction zone will be
within the range of from about 0 5 to about 20 mols of hydrogen pepl
mol of 10 > hydrocarbon In some cases the gas to be recycled will
contain hydrogen sulfide introduced with the charge or liberated by
the catalyst, and it is within the scape of the present invention to
treat the hydrogen containing gas 110 to remove hydrogen sulfide or
other impurities before recycling the hydrogen to the reforming zone.
The effluent from the reforming zone is usually passed to a stabilizer
which effects 115 separation of the normally gaseous material which
comprises hydrogen, hydrogen sulfide, ammonia, and hydrocarbons
containing from one to four carbon atoms per molecule, from the
normally liquid hydrocarbons A more con 120 centrated aromatic
fraction is then obtained in accordance with the present invention by
subjecting the reformate, containing aromatic hydrocarbons, to a
solvent extraction process subsequent to being suitably treated to 125
improve its characteristics as a charge stock for the solvent
extraction processes.
Solvent extraction processes are used to separate certain components
in a mixture from other components thereof by a separation pro 130
785,576 cess based upon a difference in solubility of the components
in a particular solvent It is frequently desirable to separate various
substances by solvent extraction when the substances to be separated
have similar boiling points, are unstable at temperatures at which
fractionation is effected, or form constant boiling mixtures It is
particularly desirable to separate aromatic hydrocarbons from a
petroleum fraction containing these aromatic hydrocarbons by solvent
extraction because a petroleum fraction is normally a continuous
mixture of hydrocarbons whose boiling points are extremely close
together and because the -15 petroleum fraction contains numerous
cycle compounds which tend to form constant boiling or azeotropic
mixtures Since the basis of a solvent extraction separation is the
difference in solubility in a given solvent of one of the substances
to be separated from the others, it is apparent that the more extreme
this difference, the easier will be the separation, and an easier
separation reflects itself process-wise, in less expensive equipment

and greater yields per pass as well as in higher purity of product.
A particularly preferred solvent for separating aromatic hydrocarbons
from non-aromatic hydrocarbons is a mixture of water and a hydrophiliq
organic solvent Such a solvent may have its solubility regulated by
adding more or less water Thus by adding more water to the solvent,
the solubility of all components in the hydrocarbon mixture are
reduced, but the solubilitv difference between the components is
increased This effect is reflected process-wise in fewer contacting
stages required to obtain a given purity of Droduct, however, a
greater throughput of solvent must be used in order to obtain the same
amount of material dissolved Suitable hvdrophilic organic solvents
include alcohol, glycols, aldehydes, glycerine and phenol Particularly
preferred solvents are diethylene glycol, triethylene glycol,
dipropylene glycol, tripropylene glycol, and mixtures of two or more
of these, in admixture with from about 2 ' to about 30 % by weight of
water Other hydrophilic solvents such as, for example, sulfur dioxide,
may be used.
In classifying hydrocarbon and hydrocarbon type compounds according to
increasing solubility in such a solvent, it is found that the
solubility of the various classes increases in the following manner:
the least soluble are the paraffins followed in increasing order of
solubility by naphthenes olefins, diolefins, acetylenes, sulfur,
nitrogen, and oxygen-contaming compounds and aromatic hydrocarbons It
may thus be seen that a charge stock which is rich 60) in unsaturated
compounds will present a greater problem in solvent extraction than a
saturated charge stock since the unsaturated compounds fall between
the paraffins and arm matics in solubility Further difficulty in
having unsaturated compounds in the feed is that they tend to
polymerize at higher temperatures to form sludges and other
undesirable materials which causes great difficulty in processing
equipment It may be seen that an ideal charge to solvent extraction is
one containing para 70 ffinic and aromatic hydrocarbons exclusively.
The paraffinic compounds also differ in their relative solubility in
the solvent The solubility appears to be a function of the boiling
point of the paraffins, with the lower boiling or 75 tighter paraffins
being more soluble than the higher boiling or heavier paraffins
Therefore, when heavy paraffins are dissolved in the solvent, they may
be displaced from the solvent by adding lighter paraffins thereto In
an 80 embodiment of this invention it is preferred to recycle the
heavier paraffins to the reforming zone and therefore a light paraffin
is preferably charged to the extraction zone to displace these heavier
paraffins from the solvent 85 by putting the heavier paraffins into
the raffinate phase.
Additional features and advantages of this invention will be apparent

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