Specifications
874
Chapter 15 Video Hardware
Hitachi’s Super-IPS technology also rearranges the liquid crystal molecules into a zig-zag pattern,
rather than the typical row-column arrangement, to reduce color shift and improve color uniformity.
The similar multidomain vertical alignment (MVA) technology developed by Fujitsu divides the screen
into different regions and changes the angle of the regions.
Both Super-IPS and MVA provide a wider viewing angle than traditional TFT displays. Other compa-
nies have different names for the same technology—for example, Sharp calls it Ultra High Aperture
(UHA). Manufacturers often like to think up their own buzzwords for the same technology because it
makes their products seem different. Because larger LCDs (17'' and wider) are large enough to cause
shifts in viewing angle even for an individual user, these advanced technologies are being used pri-
marily on larger and more expensive panels and have been licensed to other display vendors.
Flat-Panel LCD Monitors
LCD desktop monitors, once seen mainly on the office sets of futuristic TV shows, are now becoming
a common choice for use in today’s office computing environment. Many users with dual-display-
capable video cards have added an LCD panel as a second monitor or use one as their only monitor.
LCD monitors offer a number of benefits when compared to conventional CRT “glass tube” monitors.
LCD panels feature a larger effective viewable area than CRTs; a 17'' LCD is essentially equal in usabil-
ity to a 19'' CRT. Because LCDs use direct addressing of the display (each pixel in the picture corre-
sponds with a transistor), they produce a high-precision image. LCDs can’t have the common CRT
display problems of pin-cushion, barrel distortion, or convergence errors (halos around the edges of
onscreen objects).
LCD panels are less expensive to operate because they feature lower power consumption and much
less heat buildup than CRTs. Because LCD units lack a CRT, no concerns exist about electromagnetic
VLF or ELF emissions. Although LCDs offer a comparable mean time between failures (MTBF) to CRT
displays, the major reason for LCD failures is the backlight, which is relatively inexpensive to replace.
CRT failures usually involve the picture tube, which is the most expensive portion of the display and
is often—especially on displays 17'' and smaller—not cost-effective to replace.
LCD panels offer a smaller footprint (front-to-back dimensions), and some offer optional wall or stand
mounting. Several LCD panels offer a pivoting feature, enabling the unit to swivel 90° and providing
a choice between the traditional landscape horizontal mode for Web surfing and the portrait vertical
mode for word processing and page-layout programs. LCD panels weigh substantially less than com-
parably sized CRTs. For example, the ViewSonic VE175, a 17'' LCD, weighs only 13.6 lbs., compared to
the 50 lbs. weight of typical 19'' CRTs.
There have been two major digital LCD panel standards and specifications:
■ The Digital Flat Panel (DFP) standard approved by the Video Electronic Standards Association (VESA)
in February 1999. DFP was previously known as PanelLink; DFP has now been replaced by DVI.
■ The Digital Visual Interface (DVI) standard proposed by the Digital Display Working Group (DDWG)
in April 1999. DVI has become a de facto standard supported by most recent mid-range and
high-end VGA display cards, including models with dual-display capabilities.
Figure 15.4 shows how DFP and DVI connectors found on some video cards and digital LCDs com-
pare to the standard VGA connector used on conventional video cards, CRTs, and analog-compatible
LCDs.
16 1738 ch15 7/30/04 10:31 AM Page 874