Chapter 16: Monitors and Displays^373
the display by applying current to the pixels at a fixed refresh rate. Active matrix displays
control each LCD element (diode) individually with one or more transistors that continually
refresh each element of the display.Resolution
The number of pixels on a monitor, whether CRT or LCD, determine the amount of detail
thatcanbeusedtocreateandimage.Asthenumberofpixelsincreases,thebettertheimage
resolution a monitor can produce. The number of pixels on a monitor is its resolution,
which is expressed in the number of pixels on each row of the display and the number of
rows of pixels on the display. For example, the VGA standard resolution is 640 × 480,
which is read as 640 by 480. This means that the monitor has 640 pixels arranged horizon-
tally on each row of pixels and 480 vertical rows of pixels. A monitor with 640 × 480
resolution uses 307,200 (640 times 480) pixels to create displayed images. Table 16-2
shows the resolutions most commonly supported by today’s monitors.
Larger size monitors, such as 19- or 21-inch, have trouble displaying smaller resolu-
tions and on most smaller monitors, such as a 14- or 15-inch monitor, higher resolutions
don’t have the image quality you desire. It is always best to match the monitor and its
resolution to your needs.
Resolution is mostly a real estate issue. Most of the larger monitors that natively
support higher resolutions can also support lower resolutions, though not well, by using
fewer pixels to produce the display. LCD displays have fixed resolutions for the most
part and if you use another resolution higher or lower, the image quality will suffer.
Where the CRT can enlarge or reduce an image, based on the resolution in use, LCD panels
have some trouble doing so.
Because of their construction, LCD displays have natural resolutions that are set by
the number of pixels on each line of the display. This is why an LCD display must often
reduce the size of the display area to reproduce images in resolutions lower than its
naturalone. For example, a 12.1-inch LCD monitor (800 × 600 resolution) has 800 pixelsResolution Total Pixels Used
640 × 480 307,200
800 × 600 480,000
1024 × 768 786,432
1280 × 1024 1,310,720
1600 × 1200 1,920,000Table 16-2. Monitor Resolutions