Quantum Dots Enable High Dynamic Range TV

A year ago, high dynamic range (HDR) was not part of anybody's stated technical envelope for advanced generation television. Now, all major TV makers are at least mentioning it. In his SID keynote address, Kazumasa Nomoto, Senior GM of Sony's Display Device Development Division, specifically mentioned HDR as part of the envelope of future TVs, and at this year's CES, Sharp showed an HDR technology demonstrator using Dolby technology.

On the show floor at SID 2014, Nanosys' 10-foot-by-10-foot booth won a Best in Show award in the small exhibit category.  Nanosys, which makes the quantum dots used in 3M's quantum-dot enhancement film (QDEF), was showing two TV sets side-by-side: one was a conventional LCD TV; the second incorporated both QDEF and Dolby's HDR technology, and the image was compelling. But what does QDEF have to do with HDR?

Nanosys' Jeff Yurek told me that QDEF turns out to be a critical tool in reducing the cost and power consumption of HDR, which up to now have limited the technology to very expensive professional monitors. Dolby's current technology uses 2300 red, green, and blue light-emitting diodes in a full-matrix backlight array.  Controlling the LEDs in clusters, known as local-area-dimming, is the key to HDR, and Dolby is currently controlling the LEDs individually.  Some of the LEDs are very inefficient, with the result that lots of heat is generated and the power consumption is very high.

However, if only efficient blue LEDs are used and the QDEF is used to convert the blue light to red and green, power consumption would be reduced.  For consumer television, it is likely that the number of LEDs would be sharply reduced. This side-by-side comparison drew a lot of attention, creating heavier traffic around the Nanosys booth. – Ken Werner