hi this is sohail in this slide we focus on crt and how is works..

1. Cathode Ray Tubes (CRT)
Display
By Sohail

2. CRT Display
Outline
• Picture
• Video
• Display
• CRT

3. CRT Display
Picture
• A picture is a visual capture of an object
• Pictures can be created using devices such as
a digital camera, scanner, smartphone, or are
works of art created on the computer

4. CRT Display
Video
• displaying moving images
• Number of moving picture in particular time
• Refers to displaying images and text on
a computer monitor
• Example
– Movies
– Flipbook

5. CRT Display
Video
flipbook

6. CRT Display
Display
• A display is a computer output surface and
projecting mechanism that shows text and
often graphic images to the computer user

7. CRT Display
• Cathode Ray Tubes
• A cathode ray tube (CRT) is a specialized
vacuum tube
• Images are produced when an electron beam
strikes a phosphorescent surface
CRT Tube

8. CRT Display
PRINCIPLE
Electron emission
• Electrons are emitted from the Cathode tube.
Phosphorescence
• It is the emission of visible light, when
electron beam strikes Phosphor material

9. CRT Display

10. CRT Display
MAIN PARTS OF CRT
• E GUN
Produces constant stream of electrons
• Contorl Grid
Sets intensity of spot on screen
• Focusing System
Forces e-beam into narrow stream
• Deflection Coils
Indicates target phosphor spot

11. CRT Display
MAIN PARTS OF CRT
• High positive V coating
15-20,000 V Accelerates e-beam to screen

12. CRT Display
• But ONLY ONE SPOT or ONLY ONE ELECTRONS
STREAM?
• Then how CRT makes full picture?

13. CRT Display
• Eyes and brains are not good at processing
Fast visual information
Its easy to trick our eyes into seeing something
that’s not real there

14. CRT Display

15. CRT Display

16. CRT Display
• Brains cant process the light’s fast motion
• It blurs together into a solid line.
• This phenomenon is called persistence of
vision

17. ANY QUESTION