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LAS VEGAS — Marrying expertise in what some might consider a humdrum side of their sprawling business -- fluorescent light bulbs -- with cutting-edge large-panel LCD manufacturing, Philips introduced a 32-inch display with improved motion sharpness and contrast at CES in Las Vegas earlier this month.
Normally, fast-moving objects appearing on LCD screens look blurry, as a result of LCD's inherent "sample and hold" technology, which holds each frame (or field) of video for one-thirtieth or one-sixtieth of a second (for U.S. TV). In real life, the moving object would travel some distance over the duration of each frame.
Philips' Aptura backlight technology sharpens fast moving images by reducing the "hold" time. Instead of illuminating each frame for its full duration, the screen is darkened for a portion of each frame. The "on" portion of the fluorescent lamps' on/off duty cycle is thus reduced.
The result, as demonstrated in Philips' booth at CES and at their press conference, is a noticeably sharper-looking LCD image for fast-moving objects. Philips calls this ClearLCD.
Motion on ClearLCD appears more movie-like. Theatrical film projectors darken the movie screen for roughly 50% of the time -- the fraction of a second (1/48th, typically) the projector requires to mechanically advance to the next frame. (A shutter, behind the lens, switches the projection on and off.)
But reducing the LCD backlight's duty cycle also darkens the image. To compensate, new HCFL (Hot Cathode Fluorescent Lamp) high-output lamps provide 300 percent more light. (At 25% of normal duty cycle, this creates roughly the same overall perceived brightness as a regular LCD screen.)
The duty cycle varies dynamically, based on video content, to improve contrast. For darker scenes the backlight dims. Philips calls this Deep Dynamic Dimming (D-3) technology -- it darkens poor black levels, and also improves gray details in dark scenes (by "stretching" the video signal).
The new Aptura backlight module also reduces the number of fluorescent lamps and drivers in the 32-inch display from 16 to 8, and widens the viewing angle.
The Aptura backlight and ClearLCD feature are the main improvements in Philips' new 32-inch LCD-TV, the 32PF9630A, shipping in September 2005, with a $2,199 suggested retail price.
"We expect that this breakthrough technology will be applied rapidly in several model sizes of Philips' LCD-TV portfolio, said Theo van Deursen, CEO of Philips Lighting. "We solved the typical LCD-TV issues, and created razor sharp moving images."
Philips' 37, 42, and 60-inch LCD screens will most likely be the next recipients of Aptura backlight technology.
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