Page 67 - Computer

devices include monitors, projectors,
plotters, and printers.

Monitors Computer Science
FOR ONLINE READING ONLY
A monitor, also known as the Visual
Display Unit (VDU) or the screen,
is used to display information in the
form of text, pictures, or video. The
monitor forms images using tiny dots,
called pixels, which are arranged in a Figure 3.32: CRT monitor
rectangular form. The sharpness of the
image depends on the number of pixels Liquid Crystal Display
per inch in the monitor and the size of LCD is a widely used electronic display
the pixels. The smaller the pixels, the device that operates by applying a
better the image clarity or resolution. It varying electric voltage to a layer of
takes more than one million illuminated liquid crystal, thereby inducing changes
pixels to form the whole character, such in its optical properties. LCD screens
as the letters in the word “help”. A finite have replaced CRT displays in most
number of characters can be displayed applications due to several advantages:
on the screen at once. The screen can be (i) LCDs are lighter and more
divided into a series of character boxes, compact, making them suitable
a fixed location on the screen where for portable devices like
a standard character can be placed. smartphones, digital cameras,
Monitors are classified into two types and laptops.
based on display technology: Cathode (ii) LCDs consume less power,
Ray Tube (CRT) and Liquid Crystal making them more energy-
Display (LCD). efficient than CRT displays.

Cathode Ray Tube monitors (iii) LCDs do not suffer from image

CRT monitors produce an image using an burn-in, a common issue with
electron beam produced by the cathode CRT displays, where a static
ray tube. They are characterised by their image displayed for a long time
small size, weight, and high, power can cause permanent damage.
consumption. These monitors use the
same technology as old TVs and have LCD displays are the most common type
become rare these days. Figure 3.32 of display you will find today. The main
shows an example of a CRT monitor. drawback of these monitors is that they

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