In the electronic display world, success will only come to any display technology that can quickly realize the economies of scale from mass manufacturing, no matter how spectacular that technology may work.
Every year around InfoComm, one or another publication asks me to look into the future and see what’s coming down the pike in the way of new display technologies. And each year, after digging myself out of the annual blizzard of press releases about “me too!” projectors, rearprojection displays, and flat-panel monitors, I wonder if I’ll ever again see any truly “ground breaking” display products.
An old friend used to tell me “When you least expect it – expect it.” And that has certainly held true for the display market, where there are thousands of research projects operating just under our radar, surfacing for a brief instant at such conferences as the annual Consumer Electronics Show to tease the press, or at technical conferences like the Society for Information Display’s annual get together each May.
Consider that this year alone, public demonstrations have already been made of slim profile CRTs for monitors and TVs, plasma “in a tube’, a solid-state CRT-like flat display, projectors powered by LEDs, LCD monitors backlit by LEDs, and super- flat color displays with inkjet-printed emissive polymers.
Some of these products will definitely find their niche in the coming years, while others will quietly fade into oblivion – and not always for reasons of technical and manufacturing complexity. A good example is one particularly intriguing technology – the Grating Light Valve, or GLV. GLV has taken on ‘urban legend’ status the past five years as Sony struggles to harness its unique pixel-less imaging system to the power of a focused, coherent light source (the laser), creating the ultimate in a high-resolution RGB front projection system.
However, to date, there have been no GLV projector prototypes shown publicly at major trade shows. In fact, Sony may have already obsoleted the GLV with their new 10,000 lumens SRX-R110 high brightness 4K cinema-grade LCOS projector (shown at NAB and ShoWest). Unlike the GLV, this projector is a deliverable product with a reasonable price point. In fact, it is available in two brightness levels (the SRX-R105 version is 5,000 lumens).
Let’s take a look at some of the ‘better mousetraps’ that have surfaced in 2005.
A Little Undersized, but Plenty Bright
The versatile light-emitting diode (LED) has been around for nearly four decades, lighting up everything from control panels to super-large digital stadium signs. Now, there are some attempts to harness its power as an illumination source for both projectors and flat panels.
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At CES, several manufacturers including BenQ (see Figure 1), InFocus, and Mitsubishi all showed ‘pocket’ projectors with LED illuminators made by LumiLEDs. These SVGA (800x600) projectors fit comfortably in the palm of your hand and ran off internal batteries. No specifics were available on just how much light these mighty mites could crank out, but estimates were in the 20 – 40 lumens range.
LEDs also figured prominently in the Samsung and Sony booths as light sources for 40-inch and 46-inch TFT LCD monitors. Why? Better color! The theory behind LED lighting is that the combined array of red, green, and blue LEDs has no inherent color bias, unlike fl uorescent lamps.
By controlling the mixture and on-off cycles of LEDs, it should be possible to achieve a high degree of accuracy when referencing standard red, green, and blue color coordinates. In fact, LumiLEDs claims their LED backlight system can achieve 105% of the NTSC (SMPTE-C) color space (see Figure 2).
The construction of the LED stripes takes into account the sensitivity (or insensitivity) of the human eye to the color blue, with seven rows of LEDs each configured with 26 red LEDs, 26 green, and 13 blue for a total of 455 individual LEDs. Peak brightness is rated at 500 nits and LED life is predicted between 50,000 and 100,000 hours.
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The only immediate drawback to using LEDs is the power they consume. LEDs are by nature low-voltage, high-current semiconductors, and it’s expected that same size LCD monitors and TVs with LED backlights will use as much as if not more power than a plasma monitor or TV – unless, of course, they employ a switched-power duty cycle system, such as pulse width modulation (PWM).
Jammin’ Those Pixels
The latest ‘buzz’ in the display industry is ‘1080p’, or native 1920x1080 pixel resolution with progressive scan. Both the consumer and professional world are jumping on ‘1080p’ as ‘true’ HD, never mind that 1280x720p is a perfectly good HD format on its own, thank you.
Texas Instruments is already shipping two kinds of 1080p DMDs; one that has less than the full 2,073,600 pixels and uses a scanning trick to achieve higher perceived resolution, and a more expensive model with true 1920x1080 mirrors that is winding up for now in very expensive large venue and DLP cinema projectors.
Sony and JVC have countered with their own 1920x1080 liquid crystal on silicon (LCOS) panels in home theater and professional projectors that are better suited to smaller rooms and have lower price tags. Now, Epson is joining the fray by manufacturing .9-inch 1920x1080 high-temperature polysilicon (HTPS) LCD panels for both front projectors and rearprojection TV sets.
This move to native 1920x1080 imaging is far down the road for many potential customers who are still pondering the purchase of their first widescreen (16:9) front projector of any kind. Nevertheless, you will see more and more 1080p projection systems coming to the large venue and installation market as manufacturers try to siphon off additional market share.
1080p is also catching on in the flat panel market, where LCD monitors and TVs at 45 inches and above offer it, along with super-sized plasma displays at 71 inches and up. Samsung, Clarity, and NEC all have 46-inch LCD professional monitors for sale now, with other brands (such as BenQ and Sharp) expected to join the crowd shortly. LG stands alone in the plasma world with a 71-inch 1080p display for now.
Faster than a Speeding Photon
Apparently LCD projector manufacturers have heard enough about the ‘superior imaging quality’ of DLP technology and are doing something about it. In the fall of 2004, both Sony and Panasonic launched front LCD projectors for home theater that incorporate a super-fast variable iris. The effect of this super-fast iris mechanism is to enhance black levels when showing images or video with medium to low luminance levels.
In addition, Panasonic has also made changes to their optical systems that reduce the so-called ‘screen door effect’. If you’ve ever stood close to an image from an LCD projector, you know what the ‘screen door effect’ is. Thousands of tiny LC pixels are easy to spot as they are superimposed over the projected image. However, with the Panasonic system, they’re as difficult to see as the pixels on a DMD.
Panasonic has also made tremendous improvements to color accuracy, using the talents of one of Hollywood’s top colorists. Sanyo, the world’s largest LCD projector manufacturer, has started including the variable iris and improved color correction in several of their new LCD projectors, and Mitsubishi just announced a rear-projection TV engine incorporating a dynamic iris, at their 2005 consumer TV line show.
Dynamic irising works so well that it’s even being adapted to flat-panel LCD displays as a way to cut down on motion blur. The backlight is actually switched on and off at a super-fast rate to insert ‘black’ frames and eliminate blur, much the same way a shutter in a motion picture projector works. Look for more LCD and DLP projectors and flat-panel LCD displays to incorporate this trick in 2005.
It Looks Exactly Like – No, it Doesn’t…
Canon and Toshiba have been working for some time now on replacing the CRT with something a lot slimmer, lighter, and brighter, but retaining the CRT’s excellent grayscale reproduction, saturated colors, wide viewing angles, and deep black levels. The result is something called the surface-conduction electron-emitter display, or SED, for short.
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The concept behind the flat-panel SED is similar to that of a CRT (Figure 3). Electrodes along the backplane of the display emit electrons when they are switched into a conductive state. These electrons are attracted to the front of the SED (which you could consider to be the functional equivalent of an anode) by a high voltage potential, somewhere around 10 kV.
The front glass is coated with tiny red, green, and blue phosphors just like a CRT. The electrons are accelerated to very high speeds and strike each individual phosphor, causing it to glow brightly. Since the emitters (or cathodes, for you old-timers) are aligned precisely with the phosphors, there’s no need for any defl ection yokes.
That makes for a much more compact, brighter, and lighter display. Toshiba claims 10,000:1 contrast in a darkened room for the SED. There’s no question that the 36-inch SED demonstration I saw at CES 2005 left the adjacent plasma and LCD monitors in the dust across all picture quality parameters.
But SED will have to swim upstream against a torrent of lowpriced plasma and LCD monitors in similar screen sizes over the next few years. And with only Toshiba and Canon behind it, SED won’t have the marketing clout that companies like Samsung, Panasonic, Hitachi, LG, and Pioneer bring to the flat panel business. If you get a chance to see it demonstrated, grab the opportunity – you may never see it again.
