Dolby and SIM2 Demonstrate LED LCD
By Scott Wilkinson April 3, 2008 — Following an initial showing at CES in January, Dolby Laboratories and SIM2 demonstrated their latest prototype LCD flat-screen display in New York on Monday. The panel utilizes Dolby's LED backlighting with local dimming, which the company calls HDR (high dynamic range). This moniker is highly appropriate, since the LEDs behind dark portions of the image can be dimmed or even turned off completely for black areas, resulting in a literally infinite contrast ratio!

Instead of fluorescent lights behind the panel of LCD pixels, HDR uses LEDs (light-emitting diodes), which are divided into small groups or zones that can be dimmed or brightened independently. In essence, the LEDs form a low-resolution version of the video image, dimming behind darker parts and brightening behind lighter parts. The result is far deeper blacks than conventional LCD TVs can hope to achieve.

The prototype being demonstrated this week has a 46-inch screen with 1920x1080 resolution and 1838 LEDs behind it. Peak brightness is specified to be 4000 cd/m² (1168fL) with 95% uniformity across the panel. Brightness is controlled with 16-bit precision, resulting in over 65,000 luminance steps.

This isn't the first LED-backlit LCD TV with local dimming; last year, Samsung introduced its 81-series, including the LN-T5281F. But the Dolby/SIM2 announcement bodes well for the future of LCD technology, which has traditionally suffered from poor black performance. There is no indication when a SIM2 product might be available, but we eagerly await one for review.