2.0 Laptop and Portable Devices
2.1 Identify the fundamental principles of using laptops and
LCD technologies (e.g. active and passive matrix,
resolution such as XGA, SXGA+, UXGA, WUXGA, contrast ratio, native
LCD (short for Liquid Crystal Display) is the technology used for displays in
notebook and other smaller computers. LCDs consume much less power than
conventional CRT (Cathode Ray Tube) displays, and at the same time much thinner,
making it ideal for use in portable devices.
There are two types commonly used in LCD displays. These are
Passive Matrix Displays, and
Active Matrix Displays.
The active matrix LCD is also known as a Thin Film Transistor
The passive matrix LCD consists of a grid of conductors with pixels located
evenly at each intersection in the grid. Current is sent across two conductors
on the grid to control the light emitted through a given pixel element.
An active matrix has a transistor located at each pixel intersection, and the
switching times are very fast. For this reason, the active matrix display
provides better interactivity, and smooth scrolling of text/images. Active
matrix technology is superior to passive matrix, and TFT is used widely for
notebook computers for this reason.
Different display resolutions widely used in notebook or portable computers
is as given below:
Standard 4:3 Aspect Ratio
SVGA (Super Video Graphics Array): 800 x 600
XGA (Extended Graphics Array): 1024 x 768
SXGA (Super Extended Graphics Array): 1280 x 1024
SXGA+ (Super Extended Graphics Array+): 1400 x 1050
UXGA (Ultra Extended Graphics Array): 1600 x 1200
WUXGA (Wide Ultra Extended Graphics Array) 1920 x 1200
Resolutions higher than 1024 x 768 are used for display sizes of 14 inches or
WUXGA 1920X1200 is best suited for HDTV. This is a wide screen display
with aspect ratio of 16:9.