The document provides an overview of CRT and flat panel displays, outlining their structures, functioning, and differences. CRT monitors use a cathode ray tube to display images and are less space-efficient, while flat panel displays, including LCD, ELD, and gas plasma technologies, are lightweight and energy-efficient. Notable advantages of flat panels include reduced size, lower energy consumption, and lack of harmful radiation.

1. Different Types of
Display Screens
Overview of CRT and Flat Panel Displays

2. 1. CRT Monitor
 CRT monitor is the most common form of display screen. It looks like
a television. It can display text and graphics.
Working of CRT Monitor:
 It uses a Cathode Ray Tube (CRT) to display an image on the screen.
 CRT consists of one or more guns that fire a beam of electrons
inside the screen.
 The screen is coated with tiny phosphor dots from inside. The beam
of electrons repeatedly falls on the surface of screen. Every beam-
fall takes only a fraction of a second.
 CRT in color monitors consists of three guns. These guns generate
red, green and blue (RGB) colors. The other colors are generated
with the combination of these three colors.

3. Working of CRT Monitor:

5. 2. Flat Panel
Display
 Flat-panel monitors take
less space and are
lightweight. These
monitors use much less
power than CRTs.
Notebook computers use
flat panel monitors.
 Flat panel display is made
of two plates of glass.
These plates contain a
substance between them
the substance is activated
in different ways

6. types of Flat Panel Display
 There are three types of technologies used in flat
panel display screens:
 1. Liquid Crystal Display (LCD)
 2. Electro Luminescent Display (ELD)
 3. Gas Plasma Display

7. Liquid Crystal Display (LCD)
 This type of display screen contains a substance
called liquid crystal.
 The molecules of this substance line up in such a
way that the light behind the screens blocked or
allowed to create an image.

8. Electro Luminescent
Display (ELD)
 This type of display screen contains a substance
that glows when it is charged by electric current.

9. Gas Plasma Display
 This type of display screen is similar to neon bulb.
The display uses a gas that emits light in the
presence of an electric current.
 It is more expensive technology.
 It is not commonly used.

10. Advantages of Flat Panel
Display over CRT
 The advantages of flat panel display over CRT are as
follows:
 - It takes less desk space.
 - It uses less energy than CRT monitor.
 - It uses liquid crystal technology.
 - Its weight is less than CRT.
 - It is used for notebook computers, PDAs, cellular
phones and personal computers.
 - It does not emit harmful radiation.

11. Difference b/w CRT and
LCD