The document outlines the principles of operation for common display types in modern aircraft, including cathode ray tubes, light emitting diodes, and liquid crystal displays. It explains the methods for deflection control in CRTs and describes the differences between color and black-and-white screens. Additionally, it covers raster and stroke scanning, as well as the characteristics and operating principles of LED and LCD displays.

1. 5.11 ELECTRONIC DISPLAYS
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2. SYLLABUS
• 5.11 Electronic Displays - L2
• Principles of operation of common types of
displays used in modern aircraft, including
– Cathode Ray Tubes
– Light Emitting Diodes
– Liquid Crystal Display.

3. CRT – CATHODE RAY TUBE

4. CONTROLLING THE DEFLECTION
• There are two separate ways to control the
deflection:
– Electromagnetic deflection- magnetic principle
– Electrostatic deflection – depend on charges.
• Electromagnetic Deflection (Remember i=current)

6. ELECTROSTATIC DEFLECTION

8. • A color TV screen differs
Color TV Screen from a black-and-white
screen in three ways:
• Three electron beams (Red,
Green, Blue)that move
simultaneously across the screen.
• The screen is coated with red,
green and blue phosphors
arranged in dots or stripes.
• On the inside of the tube, very
close to the phosphor coating,
there is a thin metal screen called
a shadow mask. This mask is
perforated with very small holes
that are aligned with the
phosphor dots (or stripes) on the
screen.
• .

9. RASTER/STROKE SCANNING
Honeywell GREEN
YELLOW
STROKE
ATT 2 GS
SCANNING IS RASTER
USED FOR SCANNING RANGE
ALL OTHER AOA DATA
20 20
DISPLAYED (BLUE)
F
DATA
10 10
G 40
MODE
10 10 30
(BLUE)
S
CMD 20 20 I
M .99 20
200 DH DH 140 RA WX
RED
10
• Raster Scanning for Attitude • Raster Scanning - weather
Sphere return
• Stroke Scan for reminder • Stroke for texts, range,

10. LED DISPLAY
• PN diode
• Doping modify the color,
oxygen, nitrogen are used
• 7 bar display for numbers.
• Segment type display with
diffuser plate or plastic
deflector to increase the
size
P134

11. LED DISPLAY
Tapes and Pointers Dot Matrix Display
• LED's are also used to • LED's are normally arranged
replace the pointers or in a 9 X 5 matrix or a 4 X 7
tapes on circular scale or matrix.
vertical scale displays. • requires special driver
• individual diodes are circuits.
arranged in groups to form • more common in fields
the illuminated bars. outside aviation, with
• example is the TCAS displays being produced
Electronic Vertical Speed using light bulbs, metal
Indicator ‘Fly-From’ and discs and electromagnetic
‘Fly-To’ indications. devices.

12. LCD – LIQUID CRYSTAL DISPLAY
• Operating Principle
– The liquid crystal is enclosed between two set of
polarizes glass (p137) .
– In normal situation, the light can pass, but when
current is passed, the molecules of the crystal
changes its alignment and control the light.
– Color is obtained by color filter on top of the LCD.

13. PASSIVE AND ACTIVE MATRIX
• Passive Matrix
– Relies on grids of vertical / horizontal conductors
– Scanning current through the horizontal
conductors.
– pixel is off controlled by vertical conductors.
• Active matrix – TFT (Thin Film Transistors)
– Pixels are controlled by individual transistors.
– Expensive – 800x 600 resolution – 1.4 millions
transistors.