Technology Showcase: Large HD Projectors
May 1, 2008 12:00 PM, By Jay Ankeney
New technologies expand market.
The term “future proofing” even pops up often to justify high-definition resolutions being shown to corporate boardrooms, training centers, and employee gatherings in which viewers are sitting too far from the screen to appreciate HD's enhanced detail. This remains pleasantly oblivious to the reality that resolutions far higher than HD are already being used in many business applications, but that hasn't stopped lots of people from investing in HD projectors. Pacific Media Associates, a high-tech market-research and publishing firm that specializes in providing information on large-screen display products, predicts sales for HD projectors in general to grow to $150 million next year.
Much of this has been made possible by the fact that what was already pretty good has recently become even better. Of the three technologies behind the light engines in large projectors — Digital Light Processing (DLP), Liquid Crystal Display (LCD), and its derivative Liquid Crystal on Silicon (LCoS) — it is LCD that powers most projectors overall. LCD panels transmit a light source through color-twisted nematic liquid crystals mounted on a glass substrate with transparent indium tin oxide (ITO) electrodes directing their alignment. Therefore, it is a transmissive technology, depending on the ability of those crystals to either block or pass the light shined through them.
The single-chip LCD approach has developed into 3-chip designs largely with the support of a consortium of chip manufacturers called 3LCD for front-projection systems. The largest manufacturers of the chips themselves are Sony and Epson, and these are incorporated into many projector brands. In February 2008, Pacific Media Associates said that 3LCD finished 2007 as the clear technology choice of the pro AV market with more than 75-percent market share for the period of January 2007 through December 2007.
Due in part to their vulnerability to heat even when using the more recently developed inorganic liquid crystals, 3-chip LCD projectors currently top out at 15,000 lumens with XGA resolution. HD projectors using LCD chips in the 5000-lumen to 10,000-lumen range are becoming increasingly popular.
This brings up the question of what those brightness measurements actually mean. An ANSI lumen is a measurement of light that has been standardized by American National Standards Institute (ANSI). For a techno-geeky description: If a light source emits one candela of luminous intensity into a solid angle of one steradian, the total luminous flux emitted into that solid angle is one lumen. But you probably already knew that.
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