The Resurrection of LCoS

20/20 Hindsight

If we travel back to the fall of 2004, the news came like a one-two punch: First, Phillips announced that it was exiting the LCoS TV business, then, in short order, Intel followed suit. It came as a blow to many consumers and industry watchers, who had come to the conclusion that LCoS was akin to the Great White Hope – an embodiment of a promising new display technology that combined the best of both worlds: In this case, it blended the finest attributes of liquid crystal displays (LCD) and DLP (originally an acronym for Digital Light Processing, though it is now a trademarked brand name owned by Texas Instruments).

Like direct view and projection LCD TVs, LCoS uses tiny liquid crystals to create the colored pixels that make up the TV’s onscreen display. By applying an electrical charge to a cell filled with the liquid crystals, the state of the crystal is changed to permit or block light – turning the pixel on or off. The LCoS architecture also borrows from DLP technology, which uses microscopic mirrors to direct light. In an LCoS imaging system, the liquid crystal layer sits on top of a reflective mirror substrate. Instead of shining a backlight directly through the LCD layer, light is bounced off the mirror behind the liquid crystal.

There are several inherent advantages of LCoS technology:

1. Unlike conventional DLPs, there are no moving parts – no pivoting micro-mirrors or spinning color wheels. The latter is the culprit behind the “rainbow effect” artifacts that bother some DLP viewers.

2. Unlike conventional LCD display panels, the matrix lines that separate individual pixels are thinner, eliminating the “screen door” effect of black lines appearing between pixels.

So, what’s not to like? Well, along with other drawbacks that became evident in the manufacturing process, high cost was a major culprit. LCoS favors the production of larger, higher-definition displays. By and large, they proved to cost more than the majority of consumers were prepared to pay in 2004 and early 2005 – particularly when a variety of other excellent and more affordable display technologies were readily available. Plasma technology, in particular, became considerably less expensive, and its mixture of large screen sizes with highly coveted thinness made most buyers think twice before purchasing a comparatively bulky rear-projection TV (RPTV).