7/30/2019 Intro Ch 04Ar

1/20

Copyright 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education

McGraw-Hill Technology Education Copyright 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

7/30/2019 Intro Ch 04Ar

2/20

Copyright 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education

Chapter 4A

Video and Sound

7/30/2019 Intro Ch 04Ar

3/20

4A-3

Monitors

Most common output device Connects to the video card

Categorized by color output

Monochrome One color with black background

Grayscale

Varying degrees of gray Color

Display 4 to 16 million colors

7/30/2019 Intro Ch 04Ar

4/20

Monitors

Cathode Ray Tube (CRT) Most common type of monitor

Electrons fired from the back

Magnetic yoke guides streams of electronsdown and across the screen

Electrons excite phosphor to glow

Phosphor is arranged in dots called pixels

Dot mask ensures proper pixel is lit

7/30/2019 Intro Ch 04Ar

5/20

CRT Monitor

1. Electron guns

2. Electron beams

3. Focusing coils

4. Deflection coils

5. Anode connection

6. Mask for separating beams

for red, green, and blue part

of displayed image

7. Phosphor layer with red,

green, and blue zones

8. Close-up of the phosphor-

coated inner side of the

screen

7/30/2019 Intro Ch 04Ar

6/20

Monitors

CRT color Phosphor dots arranged in triads

Red, green, and blue dots

Three colors blend to make colors

Varying the intensity creates new colors

7/30/2019 Intro Ch 04Ar

7/20

Monitors

CRT drawbacks Very large

Very heavy

Use a lot of electricity

7/30/2019 Intro Ch 04Ar

8/20

Monitors

Liquid Crystal Display (LCD) Commonly found on laptops

Desktop versions exist

Solve the problems of CRT

Fluorescent lights provide illumination

7/30/2019 Intro Ch 04Ar

9/20

Monitors

Passive matrix LCD Pixels arranged in a grid

Pixels are activated indirectly

Row and column are activatedAnimation can be blurry

7/30/2019 Intro Ch 04Ar

10/20

Monitors

Active matrix LCD Each pixel is activated directly

Pixels have 4 transistors

One each for red, green, blue One for opaqueness

Transistors arranged in a thin film

Animation is crisp and clean

7/30/2019 Intro Ch 04Ar

11/20

Monitors

Drawbacks to LCD More expensive than CRT

Must sit directly in front of screen

Can be more fragile than CRT

Laptop LCD screen viewed at an

extreme angle.

http://upload.wikimedia.org/wikipedia/en/0/05/LCD-angle.png

7/30/2019 Intro Ch 04Ar

12/20

Monitors and Video Cards

Resolution Number of pixels on the screen

Higher number creates sharper images

Higher number creates smaller images

One pixel

7/30/2019 Intro Ch 04Ar

13/20

Monitors and Video Cards

Refresh rate Number of time the screen is redrawn

Modern equipment sets this automatically

Improper settings can cause eyestrain

The electron gun scans from left to right

and from top to bottom refreshing every

phosphor dot in a zig-zag pattern

7/30/2019 Intro Ch 04Ar

14/20

Monitors and Video Cards

Dot pitch Distance between the same color dots

Ranges between .15 mm and .40 mm

Smaller creates a finer picture

Should be less than .22

7/30/2019 Intro Ch 04Ar

15/20

Video Cards

Device between the CPU and monitor Better cards result in better output

Removes burden of drawing from CPU

Have their own processor and RAM

Modern cards have up to 512 MB RAM

Capable of rendering 3D images

At 256 color, each pixel requires 1 byte

of data

7/30/2019 Intro Ch 04Ar

16/20

Video Card

Image of Graphics Card, Model: PNY, nVidia 6600GT

7/30/2019 Intro Ch 04Ar

17/20

Sound Systems

Integral part of the computer experience Capable of recording and playback

7/30/2019 Intro Ch 04Ar

18/20

Sound Systems

Sound card Device between the CPU and speakers

Converts digital sounds to analog

Can be connected to several devices Modern cards support Dolby Surround

Sound

7/30/2019 Intro Ch 04Ar

19/20

Sound Card

Creative Labs Sound

Blaster Live! Value.

CT4830

7/30/2019 Intro Ch 04Ar

20/20

Copyright 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education

Chapter 4A

End of Chapter