After wandering through the desert of bigger screens, increased pixel counts, and 3D, this year’s CES was the consumer industry’s opportunity to show off image quality. Not able to bring down the cost of OLED technology quickly enough, manufacturers were eager to show a new generation of relatively low cost 4K LCD displays, backlit with color-enhancing quantum dot technology. While colorful display technology was everywhere, the surprise was that Dolby was not. Dolby Vision was not on the trade show floor, although manufacturers were keen to show off high dynamic range (HDR) displays. Dolby itself was tucked in a (fancy) hotel suite on the Las Vegas strip, away from the crowds. While this shouldn’t be taken to be dire, it does indicate a change in position.
Quantum dots, the star of the show, are a form of nanocrystal, which, when excited by a light source, emit a specific color. LCD screens require a white backlight (light behind the LCD which the LCD then limits). In practice, a backlight panel consisting of blue LEDs is situated behind a film coated with quantum dots designed to emit specific spectrums of green and red light. The combination of colors produces a white backlight, and each of the RGB colors are efficiently tuned to the primaries of the display. The colors are stable: the spectrum of a quantum dot is a quantum mechanical property of the material (thus the name), and not a chemical reaction that changes with age and/or temperature. The result is a massive improvement in color and light efficiency that can readily be manufactured on existing LCD display production lines. Consumers are about to learn that color matters.
Expanded color spaces will be emerging, too. Quantum dot technology will allow display manufacturers to accurately set primaries in a manner not before achievable in low cost displays. The language of color space is also entering the consumer market. Manufacturers now talk about Rec. 2020, as it defines the color space of UHDTV, but one also sees reference to DCI P3. Color is no longer the sacred cow of cinema.
While quantum dots make for better displays, the one characteristic that quantum dots cannot yet improve is better blacks. Good detail in blacks is important for HDR. A trick to achieve HDR in LCD displays is to modulate sections of the backlight, darkening or brightening small areas of the display depending on the overall light required of the image in the area. In current products, the florescence of quantum dot material is driven by optical stimulation, not electrically. The speed of response to optical modulation is said to not be quick, which may not make these displays useful for both expanded color and higher frame rates. But this could be a temporary matter, as even companies such as Apple have gotten into the game with a patent or two. (When mentioning Apple and Dolby in the same report, it’s important to keep perspective: Apple could buy Dolby for a rounding error in its cash horde.)
This reviewer did not expect Dolby Vision to be absent from the trade show floor. Dolby introduced the technology at last year’s CES, albeit not in its “brightest” manner. Dolby, probably more than anyone, has solved an array of problems associated with the production, distribution, and display of high dynamic range content. But not only was Dolby Vision absent from the floor, it was also apparent that major display manufacturers were flexing their own muscle in this area. Samsung, eager to sell HDR displays, organized its own meeting with key players at the show in an attempt to jump start distribution of HDR content.
Almost simultaneously with CES, Dolby opened its first Dolby Cinema, the cinema version of Dolby Vision’s high dynamic range display, in Belgium. Dolby Cinema utilizes Christie laser projectors modified for additional luminance modulation, giving the projector the ability to produce stunning blacks as well as bright highlights. Dozens of these are expected to be installed elsewhere this year. It’s not inconceivable that Dolby put the brakes on its consumer rollout to let cinema get out the gate. But it’s hard to believe.