Chapter 4: Display Devices

Question 1

VDU

Answer 1

Video Display Unit

Monitor

Question 2

CRT stands for

Answer 2

Cathode Ray Tube

Question 3

LCD stands for

Answer 3

Liquid Crystal Display

Question 4

TTL

Answer 4

Transistor-Transistor Logic

A legacy technology that VGA replaced.

Question 5

VGA stands for

Answer 5

Video Graphics Array

Question 6

This is an example of what type of VDU:

Answer 6

CRT

Question 7

Two ways to measure CRT monitor’s quality

Answer 7

Dot Pitch

Resolution

Question 8

What is dot pitch

Answer 8

A way of measuring CRT monitor’s image quality.

Measurement expressed in dots per inch (DPI) or in millimeters.

Example: 0.28mm

The higher the dots per inch (or the lower the millimeters, if expressed in mm), the better the image.

Question 9

Resolution

Answer 9

A way of measuring picture quality.

How many software picture elements (pixels) are used to draw the screen.

Expressed in terms of rows and columns of pixels.

Example: 1024x768

Question 10

Two types of LCD displays

Answer 10

Active-Matrix

Passive-Matrix

Question 11

Active Matrix LCD Display

Answer 11

Uses several independent LCD pixels. Allows display to be seen easily from all angles, including from the side. Does not require constant refreshing to maintain an image.

Uses more power than passive-matrix LCDs

Majority of LCDs are active matrix.

Question 12

Passive Matrix LCD

Answer 12

Display does not have a dedicated transistor for each pixel or subpixel, unlike active matrix LCDs.

Turns a pixel “on” by sending a signal across the x and y coordinate traces that intersect the pixel. See image.

It’s difficult to see the screen unless you’re right in front of it. No easy viewing from the sides.

Question 13

Dual Scan LCDs

Answer 13

A variation on Passive Matrix LCDs.

The passive matrix is split into two and each half of the is updated seperately

Question 14

Passive-matrix LCDs have a lower response rate than active-matrix LCDs, which can lead to an effect known as Submarining, which is _____

Answer 14

The temporary visual loss of the cursor because you moved it faster than the screen could keep up.

One of the reasons Mouse Trails were introduced.

Question 15

Privacy Filter

Answer 15

Panel that fits over the front of a display and uses a polarization effect to limit the viewing angle of the onitors.

Not needed for passive-matrix LCDs, but since most LCDs are active-matrix, they’re applicable.

Can also be used as antiglare filters

Question 16

LED displays are just ____ panels with light emitting diods as light sources instead of fluorescent bulbs.

Answer 16

LCD

Question 17

PDP

Answer 17

Plasma Display Panel

Question 18

Plasma Displays create a cloud of plasma, or _____, to create an image

Answer 18

cloud of ionized particles (atoms and molecules with electrons in an unstable state)

Question 19

Both PDPs and CRTs can ____ over time

Answer 19

burn out / become “used up”

Question 20

Refresh Rate

Answer 20

The vertical scan frequency of a monitor. Specifies how many times in one second the scanning beam of electrons redraws a screen in a CRT monitor or are refreshed in an LCD monitor.

Measured in Hertz

Question 21

Steps to change the refresh rate in Windows 7.

Answer 21

I can’t list the answer here. It’s in the book on page 210. Be sure you can reproduce it.

Question 22

Screen Resolution

Answer 22

The number of vertical and horizontal pixels that make up the display

Question 23

Degaussing

Answer 23

Reduction of the magnetic field of an object.

Strictly for CRT monitors, which use magnetic fields (while LCDs do not).

Reduces changes made to the display from magnetic fields NOT caused by the CRT monitor (Like a magent or eletromagnetic interference)

Look like this:

Question 24

Five primary groups of display adapters in history

Answer 24

Monochrome

CGA

EGA

VGA

DVI/HDMI and other modern digital video

Question 25

Monochrome Video

Answer 25

First video technology for PCs.

Black and white (well - more like green and amber)

Could display just text at first. Eventually Hercules Computer Technology introduced the Hercules Graphics Card (HGC) that could switch between text mode and graphics mode.

Resolution was 720x350

Question 26

CGA

Answer 26

Color Graphics Adapter

Allowed for color. Up to 16 colors for text.

Graphics could be displayed with limited color.

Question 27

VGA

Answer 27

Video Graphics Array

Used for Windows Safe Mode, until recently.

VGA is analog, while MDA, CGA, EGA and later technologies (HDMI and DVI-D) are all digital.

Buil from 256 colors, chosen from various shades of 262,114 colors.