2/25 - A display technology that merits consideration when purchasing a HDTV is LCoS, or Liquid Crystal on Silicon, a competing display technology to Plasma, LCD, DLP, and CRT TVs. LCoS got off to a slow start. Intel was going to manufacture LCoS panels but abandoned the project. Some companies have gone bankrupt working on the technology. Others have dropped the technology or not prioritized with it. Nevertheless it appears that the day for LCoS has come and that it has unseated CRT technology as the standard by which other displays are judged.

LCoS offers certain advantages over LCD, plasma, and DLP displays, such as higher resolutions, fewer artifacts, and higher refresh rates.

LCoS produces the highest resolutions of all of the principle display technologies. Some of the units tested for one article came with a native resolution of 1920 x 1080. LCoS easily handles this HDTV resolution, "and the technology is scalable up to even higher resolutions".

As a side-note, a resolution of 1080 does make a difference over a resolution of 720. Both are high definition resolutions. Some of the units tested had a native resolution of 1280 x 720. Others 1920 x 1080. In the evaluations of the panels, the 1080 displays tended to score higher than the 720s. The explanation is that the 720 units "have roughly half the number of pixels and therefore the images should appear a bit fuzzier, and they did".

Contrast ratio is a measure of the range between brightness and darkness that a display is able to produce. Contrast is important for being able to render details in dark scenes and details in very bright scenes. The greater the contrast ratio, the better. The contrast ratio for the LCoS sets were the highest that the tester had "ever measured for a non-CRT display".

One of the units tested was a lower end, consumer model LCoS unit. Even this unit scored a 936 for contrast ratio, "which is very good for its price class".

All of the intensities between a display's black level and its peak white is known as the display's gray-scale and is represented by a gamma curve chart.. All of the LCoS HDTVs tested had a gamma curve very close to the ideal. This is an improvement over other display technologies and "another reason why these LCoS HDTVs are delivering excellent picture quality".

Irregularities in the gray-scale can produce artifacts. Some of the LCoS units had gray-scale irregularities, "but they were nonetheless much better than most displays using other technologies".

DLP and Plasma displays tend to produce dithering artifacts thanks to the gray-scale being produced by a digital signal. These artifacts were absent from the LCoS displays, because LCoS produces its gray-scale through an analog liquid crystal response. "This is very impressive and imparts a very smooth CRT-like gray-scale to the LCoS HDTVs".

There is convergence happening between the world of the PC and the world of consumer electronics. One of the LCoS sets in particular demonstrated that the "Holy Grail of convergence is finally a reality".

Nevertheless, there remains much work to be done. One of the problems with purchasing TV sets in general is that the brightest sets tend to sell the best, but these very bright settings are not the best for most viewing environments. This problem can become more pronounced in using a HDTV as a PC monitor. Excessive brightness "was even more disturbing than with video".

Graphics cards makers (ATI and NVIDIA) need to implement an overscan control in their drivers. Most importantly, "Microsoft needs to implement a very simple and cleanly layered video driver interface if it wants the PC welcomed into every living room".

HDTV could be useful in scientific applications in exposing greater levels of detail. The level of detail revealed could prove unflattering for some actors. In the viewing tests, certain features were apparent, not all of which were desirable: "irregular cuticles, hang nails and cracks and breaks in his fingernails".

CRTs have dominated display technologies for over 75 years. Even though they are big and bulky and have lost market share to sleeker flat panels recently, they nevertheless continued to do some things better than anything else and provided a standard by which to judge other, competing display technologies. Now with the advent of LCoS, all of that seems to have changed. "An impressive achievement for a technology that has only recently started shipping in quantity".

One reason why LCoS succeeded in dethroning CRT technology was because it was such a difficult technology to master, that now "its drive electronics are the most sophisticated of all of the display technologies".

Competing display technologies—Plasma, LCD, DLP—ought not to go away. Rather they should raise themselves to the new standards. "Plasma and LCD have the most to gain from improving their electronics up to LCoS standards. The payoff there is a very big return for a modest investment".