This presentation contain all content about display screens

2. LUQMAN YUNAS
UW-13-CPS-BS-080
BS 5th “B”

3. Display Screens
Bitmap,CRT, LCD,Random Scan,
Direct View Storage Tube,
Situated Displays, Digital Paper

4. Bitmap Displays
Pixels

5.  A representation, consisting of rows and columns of dots,
of a graphics image in computer memory.
 The value of each dot (whether it is filled in or not)
is stored in one or more bits of data. For
simple monochrome images, one bit is sufficient to
represent each dot, but for colors and shades of gray, each
dot requires more than one bit of data.
 Most modern personal computers & working stations have
bitmap displays, allowing the efficient use of Graphical
User Interfaces & interactive graphics.
Bitmap screens

6.  To display a bit-mapped image on a monitor or
to print it on a printer, the computer translates
the bit map into pixels (for display screens) or
ink dots (for printers). Optical scanners and fax
machines work by transforming text or pictures
on paper into bit maps.
 JPEG, TIFF, and PNG graphics files are examples
of bitmap images.
Bitmap Images

7.  In computers, resolution is the number of pixels
(individual points of color) contained on a
display monitor, expressed in terms of the
number of pixels on the horizontal axis and the
number on the vertical axis. The sharpness of
the image on a display depends on the resolution
and the size of the monitor.
Resolution

8. Aliasing:-
Aliasing is an effect that causes different signals to
become indistinguishable when sampled.
Anti-aliasing:-
Antialiasing is the smoothing of the image or sound
roughness caused by aliasing.
Aliasing & Anti-Aliasing

9.  The cathode ray tube (CRT) is a vacuum tube containing one or more
electron guns, and a phosphorescent screen used to view images.
 Within the CRT are three electron guns, red, green, and blue. Each of these
guns streams a steady flow of electrons, left to right, for each line of your
monitor.
 Bulky, heavy, use vacuum tube technology.
 Using technology that was developed in the 19th century
Cathode Ray Tube
electron gun
focussing and
deflection
electron beam
phosphor-
coated screen

10.  Do not sit too close to the screen
 Do not use very small fonts
 Do not look at the screen for long periods without a break
 Do not place the screen directly in front of a bright window
 Work in well-lit surroundings
Take extra care if pregnant.
but also posture, ergonomics, stress
Health Care Hints

11. • Most are capable of displaying unlimited colors.
 Multiple video Resolutions
 Faster response time
• Look a very wide angle
Advantages of CRT

12.  Liquid-crystal-display televisions (LCD TV) are television
sets that use LCD display technology to produce
images. LCD televisions are thinner and lighter than
cathode ray tube (CRTs) of similar display size, and are
available in much larger sizes
 LCD a type of display used in digital watches and
many portable computers.
Liquid Crystal Display

13.  Top plate transparent and polarised,
 Bottom plate reflecting.
 Light passes through top plate and crystal, and reflects
back to eye.
 Voltage applied to crystal changes polarisation and hence
colour
 Less eye strain
How LCD Works

14.  Compact & Lightweight
 Space saving
 Can be mounted on wall or panel
 Consume less energy & more durable
 Does not emit radiation
 Lower Prices in the Long-Term
Advantages of LCD

15.  Random-scan monitors draw a picture one line at a time and
for this reason are also referred to as vector displays.
 lines need to be constantly redrawn
 On zooming in ,it remains Smooth
 rarely used except in special instruments
 Cannot display realistic shaded scenes.
 Random scan displays are designed
to draw all the component lines of a
Picture 30 to 60 times each second.
No jaggies
Random Scan

16. Conceptually the Direct View Storage Tube (DVST)
behaves like a CRT with highly persistent phosphor.
 Pictures drawn on there will be seen for several minutes
before fading.
 It is similar to CRT as far as the electronic gun and
phosphor-coated mechanisms are concerned.
 But instead of the electron beam directly writing the
pictures on the phosphor coated CRT screen, the writing
is done with the help of a fine-mesh wire grid.
Direct View Storage Tube

17.  Can be incrementally updated but not selectively erased
 Used in analogue storage oscilloscopes
 No flicker
Direct View Storage Tube

18.  Used for meetings, lectures, conferences, etc.
 Usually wide screen
 Lots of small screens together
Large Displays

19.  displays in ‘public’ places
 Framed photographs, blackboards in classrooms,
posters, billboards, road-signs are all visual forms of
communication that play a vital role in the way we
understand, navigate and behave in our
environment.
 They inform us about places, and events of interest
and reflect the activities of others.
 Although location matters
Situated Displays

21. Digital Paper
Digital paper, also known as interactive paper, is patterned paper
used in conjunction with a digital pen to create handwritten digital
documents.
The printed dot pattern uniquely identifies the position coordinates
on the paper.
The digital pen uses this pattern to store the handwriting and upload
it to a computer

22. The dot pattern is a kind of two dimensional barcode.
The complete pattern space is divided into
various domains.
These domains can be used to define paper types, or to
indicate the paper's purpose (for example, memo
formatting, personal planners, notebook paper, et cetera).
Digital Paper