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Glossary
LCD:
Shorthand for color “
Liquid Crystal Display
”, the LCD uses the liquid crystals and
polarizers to manipulate light. Some LCD panels use two polarizers with the same
alignment so that a charge applied to a liquid crystal cell results in light that’s blocked
because it’s twisted. There are two methods used to apply charges to liquid crystal cells.
The
Passive
matrix
use only a relatively few electrodes arranged as strips along the liquid
crystal layer and rely on timing to make sure the correct cells are charged. The charges
in passive matrix cells fade quickly, causing the colors to look faded. The
Active matrix
displays
, such have individual transistors for each of the cells. The individual transistors
provide a more precise and stronger charge, creating more-vivid colors. But active matrix
is more expensive to produce because about 80 percent of the displays are currently
rejected due to malfunctioning transistors.
Pixel:
Shorthand for “picture elements”, pixels are small dots of colored light that a monitor
uses to compose an image. Each pixel actually is a group of three illuminated phosphors:
red, green, and blue. For most part, your eye interprets each pixel as a bright dot. Most
monitors can display in several pixels-per-inch (ppi) modes: 640x480, 800x600,1024x768,
1280x1024, and more.
Dot Pitch:
The gray space between the phosphor pixels that create a monitor’s image is
call the dot pitch. A higher dot pitch means there’s more gray space between dots,
yielding a fuzzier image that’s harder on the eyes.
Color Depth:
Also known as bit depth, simply means the number of colors that the video
card can generate and display on-screen (most can display at more than one bit depth).
n
4-bit (16 colors)
: Most video can handle more than 16 colors today, and in fact,
Windows 95 doesn’t look too great with only 16 colors. Only a couple of years ago,
most laptop systems only offered a 16-color display.
n
8-bit (256 colors)
: Even though most systems are capable of displaying more colors
now, 256 is enough for most computing tasks.
n
16-bit (65,536 or 64K colors)
: If you’re planning to use newer edutainment
CD-ROMs or dabble in graphics,16-bit color looks great. The 16-bit color is also
called
high color
(some adapter also offer 15-bit depth – 32,768 or 32K colors).
n
24-bit (16,777,216 or 16.8M colors)
: For professionals and other color connoisseurs,
this is the best display possible. It’s so good, it’s also referred to as
true color
.
VGA and SVGA:
Video cards some times are labeled according to industry standard
names. VGA (Video Graphics Array) cards handle up to 640x480 resolution and 256
colors. SVGA (Super VGA) displays handle resolutions of at least 800x600 and up to 256
colors
Appendix
A