I follow display technologies some, but not especially closely, so I was happy to get the opportunity to catch up on some recent developments during CES this past week. Everyone is waiting for OLEDs to sweep in and overwhelm the market, but in the meantime, some of today's more mainstream display technologies are getting significant refinements, in part thanks to LED lighting.
One of the most promising developments I saw on the CES show floor was at the Dolby booth, where I learned that Dolby had acquired BrightSide technologies this past February. I first met one of the guys from BrightSide at the Radeon X1000-series launch, and I've been watching since then to see when their technology would go mainstream.
BrightSide's basic innovation is to use intelligent LED backlighting to enhance the dynamic range and contrast of LCD panels. What they do is control the brightness of the individual LEDs behind the display, creating a sort of low-resolution grayscale image that's then filtered through the LCD panel. You may get a better sense of how it works by looking at this picture I snapped after the Dolby rep turned off the LCD, exposing only the backlight behind it.
You can make out the image of a person's face there. By modulating the brightness of the small regions of the display illuminated by each LED, this technology is able to enhance an LCD panel's capabilities, providing truer blacks, brighter peaks, and more steps in between. I've seen it in person more than once, and believe me: it works and works well.
The first applications of BrightSide's technology involved ultra-expensive displays, incredibly bright LEDs, eye-popping color contrast, and power draw too exorbitant for your average living room. Dolby has rebranded BrightSide tech under the name Dolby HDR, though, and has adapted it for use in consumer displays. The firm claims it still can achieve high dynamic range results, up to 16 bits per color channel, and here's the best news: Dolby being Dolby, it will license the technology and the code to make it work to display manufacturers. Dolby HDR could potentially see widespread adoption among LCD makers, once it becomes affordable.
The first step to affordability will be an FPGA implementation of the Dolby HDR image processing algorithms, followed inevitably by a custom ASIC to make it cheap and simple to adopt. Dolby is working with an FPGA maker on that first step now.
At present, very little content exists that can truly take advantage of an HDR display, since even HD content standards use eight bits per color channel. As a result, Dolby does some post-processing on existing content, stretching out the color contrast and interpolating where possible. This technique works, but in the demo on the show floor, it tended to look overdone at some points, washing out the finer gradients in dark areas of the screen. Some additional tuning is probably still needed here. Longer term, Dolby says it will work with providers to encourage the production of HDR content. So, now that Blu-ray vs. HD-DVD seems to have reached a tipping point, we can all hurry up and wait for HDR movies.
Of course, computer games are an obvious candidate for HDR displays, as well. Today's GPUs are already capable of producing HDR images in real time, and LCDs are the display technology of choice for PCs. Dolby seems to be focusing first on TVs rather than computer displays, unfortunately.
LCDs aren't the only display type to benefit from LED lighting, though. Texas Instruments has also made the switch to LED lighting for its DLP projection display technology. Earlier DLPs used a conventional bulb, which had a pretty limited lifespan and was expensive to replace, and they used a color wheel spinning in front of the bulb in order to produce red, green, and blue images. The earliest, slowest DLP color wheels tended to produce a sometimes-visible "rainbow effect" on high-contrast images. Faster rotational speeds helped mitigate the problem, but didn't eliminate it entirely. By using LEDs, newer DLPs eliminate both the bulb and the color wheel, replacing them with a longer-lasting, cooler, and lower-power light source. These display use a trio of LEDs in red, green, and blue hues. Here's a look at a green LED module from a DLP display.
Samsung has been selling DLPs with LED lighting for a while now, but the newest innovation TI had on hand at CES was its next-generation DLP chip. DLP chips consist of three basic layers: a substrate, a hinge, and a mirror. TI's latest chip has a less reflective substrate and, if I have my facts straight, smaller gaps between the mirrors thanks to a smaller fab process. These changes allow for an improved contrast ratio and better color fidelity—up to 10 bits per color channel, according to a TI representative. The company even had wafers on display below the TVs, and the newer chips were visibly darker than the prior generation.
The refined DLP definitely had more total contrast between dark and light, but much like the Dolby HDR display, the new DLP engine produced exaggerated highs and lows that tended to overwhelm subtle color differences, particularly in darker areas. I pointed this out, and that's when the TI rep at the booth revealed that he was a DLP firmware engineer. He said the light engine in the demo display was brand new, and that he didn't yet have a working front end for it, so he couldn't tune it. He seemed very confident this weakness could be corrected with proper tuning.
Between the move to LED lighting and the chip-level refinements, DLP looks like it could remain a formidable player in the market for larger, projection displays. At the very least, it certainly has fewer downsides and a much better contrast ratio in this latest incarnation.
Speaking of DLPs, here's a look at a crazy implementation of them: Alienware's ultra-wide wraparound monitor.
This beast is just a prototype at present, but Alienware seem intent on bringing it to market eventually. This thing's resolution is 2880x900 and its response time is a crazy-low 0.02ms. The prototype Alienware was showing had visible seams between the different DLP projectors, although Alienware claimed this problem will be resolved by the time these displays go to production. Other downsides include what looked to be a relatively poor contrast ratio (at least in the bright room where we saw it), and a relatively deep cabinet.
Also, I'm just guessing here, but I wouldn't expect this baby to come cheap. The trouble is, I'd take a 30" 16:9 LCD over this thing in a heartbeat for general use and perhaps even for gaming. Cool concept, but it's too wide and not tall enough for my tastes.
This display, on the other hand, is plenty tall enough for me. In fact, it's taller than me. Panasonic's massive plasma measures 150" from corner to corner, bringing near-actual-size pandas onto the CES show floor, striking fear in the hearts of the nearsighted. Since it's a plasma, this display had great color contrast and pristine performance at odd viewing angles. Panasonic needed to install a drool-moat around the stage. I have to wonder what shipping would cost on one of these puppies, though.