Picking the right flat panel
- By Dan Carney
- Jun 12, 2000
Government buyers are accustomed to looking at three main specifications
when shopping for monitors: size, dot pitch and resolution. However, those
traditional specifications are treated differently when looking at flat-panel
Size: This is straightforward when comparing monitors that are of like
design. But it's a bit trickier when comparing CRT with LCD because CRT
display size refers to the size of the CRT's glass, not the viewable area
displayed on that glass. So 19-inch CRTs tend to have a viewable size of
less than 18 inches. LCD size is an accurate representation of the display.
So the correct comparison with a 19-inch CRT is to a 17-inch LCD.
Dot pitch: This refers to how far apart, in millimeters, the color pixels
are in a CRT. The closer together and the smaller the number, the better.
However, dot-pitch specifications do not apply to flat-panel displays.
Resolution: Resolution is important when looking at flat panels because
they cannot adapt well to alternate resolutions the way CRTs do. The native
resolution of an LCD is the actual number of LCD pixels in the display.
Such monitors are sharp when running at their intended resolution, but look
terrible at other resolutions. So if the buyer has an application that is
designed to run at a specific resolution, then the LCD must be in that same
resolution. Logic might suggest that an LCD should be able to display lower
resolutions satisfactorily, but that isn't the case.
Resolution must not be considered apart from screen refresh rate. The
refresh rate is how many times per second the picture flickers. Refresh
too slowly, and the flicker becomes visible. Even when it isn't consciously
visible, it can be a problem by causing users to experience headaches and
fatigue. The minimum refresh rate is about 75 Hz, below which the screen
flicker will start to cause problems.