The document discusses Cathode Ray Tube (CRT) technology, detailing its definition, features, and color display methods. Key components include the electron gun, deflection system, fluorescent screen, and glass tube, while color displays are achieved through beam-penetration and shadow mask methods. Despite its advantages like fast response time and high pixel resolution, CRTs are less favored today due to their bulkiness, high energy consumption, and harmful electromagnetic fields.

1. Presentation
Course Title : Computer Graphics
Course Code : CSE421
Our Presentation Topic : Cathode ray tube technology
Submitted By
ID: 201-15-3770
ID: 201-15-5771
ID: 201-15-6044
ID: 191-15-12275
Submitted To
Name: Md. Deawan Rakin Ahamed Remal
( Lecturer )
Daffodil International University
1

2. 2

3. Definition: A cathode ray tube (CRT) is a device that displays
images by shooting electrons at a screen that lights up when the
electrons hit it. It was commonly used in old TVs and computer
monitors before newer technologies came along.
3

4. Features
The features of a CRT can be split into 4 main sections:
• Electron gun.
• Deflection system.
• Fluorescent screen.
• Glass Tube & Base.
4

5. Heatissuppliedtothecathodebycurrentthroughthefilament,whichproduces
electrons.Theintensityoftheelectronbeamiscontrolledbysettingvoltagelevels
onthecontrolgrid.Ahighnegativevoltageshutsoffthebeam,andasmaller
negativevoltagesimplydecreasesthenumberofelectronsinthebeam.The
focusingsystemisneededtoforcetheelectronbeamtoconvergeintoasmallspot
asitstrikesthephosphor.
5

6. There are two techniques for producing color displays with a
CRT:
1. Beam-penetration method
2.Shadow mask method
3. Shadow mask method Shadow mask method

7. The beam penetration method for displaying color pictures has been used
with random scan monitors. Two phosphor layers, usually red and green
are coated onto the screen and the displayed color depends on how far the
electron beam penetrates the phosphor layers.
Beam Penetration Technique

8. Shadow mask method
The shadow-mask CRT can produce a much wider range of colors
compare to the beam-penetration method. Each pixel on the phosphor
screen consists of three color dots—red, green, and blue. This type of
CRT uses three electron guns, one for each color.

9. �
�
�
�
In Televisions
In Computer Monitors
As a display device in radar
In cathode ray oscilloscope
9

10. ⚫Less expensive than other display technology
⚫Fast response time
⚫Highest pixel resolutions generally available
⚫They produce more colors
⚫CRT also suitable for use even in dim or dark light
⚫Easily increases the monitor's brightness by reflecting
the light
⚫Fast response times and no motion artifacts
1
0

11. ⚫Big back and take up space on a desk
⚫Not suitable for very bright environments because less
bright than LCD
⚫They are large, heavy and bulky
⚫Consume a lot of electricity and also produce a lot of
heat
⚫Harmful DC and AC electric and magnetic fields
1
1

12. 1
2