Color Displays
LCDs that display colors have three subpixels at each pixel location that have red, green,
and blue filters over them to produce a color on the screen. By controlling the voltage
applied to each subpixel, each of which has its own transistor, it can display 256 shades of
its color. Combining all of the possible shades for all three of the subpixels yields over 16
million colors that can be displayed.Viewing Angles
The viewing angle of a display measures how far above, below, or to the side of the
display the user can be and still be able to accurately view its image. Table 16-7 compares
the viewing angles of the two LCD displays to a CRT. Figure 16-15 illustrates the relative
differences of the viewing angles of these displays.
What impacts the viewing angle as much as the shape of the screen is the amount of
image contrast the display produces. An active matrix (TFT) display has deeper color,
clarity, and contrast than a passive matrix display. LCD displays begin to lose their
picture quality as the angle of view increases because less of the display’s light (image) is
able to reach the viewer.Integrated PC and Monitors
New systems are being introduced almost on a weekly basis that integrate the PC into a
flat-panel monitor. These PCs are the ultimate in desktop space efficiency, making the
keyboard the largest single piece of the PC. The PC’s footprint is literally the space taken
by the foot on the monitor’s stand. PCs integrated with flat-panel monitors have been a
mainstayinmanyindustrialapplicationsforafewyears,butnowthetechnologyistrans-
ferring to the desktop.
These systems vary in features and pricing and generally offer a fair to good configu-
ration in terms of RAM and disk space. However, because of their tight packaging, there
isn’t much room for expansion cards, disk drives, or other internal devices. Any addi-
tional peripheral devices that the user wishes to add must be done through either a USB
or an IEEE 1394 (FireWire) connector.(^394) PC Hardware: A Beginner’s Guide
Display Type Viewing Angle
Passive Matrix LCD 49–100 degrees
Active Matrix LCD 90–120 degrees
CRT 120–180 degrees
Table 16-7. Display Viewing Angles