Lasers. Few words more effortlessly conjure thoughts of sci-fi and the future. When Mitsubishi first announced they were working on using lasers as a light source for their TVs, many of us were understandably intrigued.

Laser Beams
A regular DLP based rear-projection TV has a lamp (think light bulb) that creates the light. This light is focused down and shown through a rotating color filter wheel. Single chip DLP systems, like what is found in RPTVs, create sequential color. That is to say, at any given moment, only one color is on the screen. Because these colors change rapidly, your eye and brain blur them together so you see a full color image. Some people can see a "rainbow" like effect with this technique, but because modern DLP color wheels move at high speeds, the number of people truly bothered by this artifact are fairly few (or at least fewer than early DLP). After the color filter, the light is focused down again to shine on the DMD (Digital Micromirror Device) chip, which creates the individual pixels and grayscale that makes the image.

Using lasers as the light source simplifies this process. Three lasers, red, green, and blue, are expanded to fill the DMD chip. The color is still sequential, but the lasers can turn on and off faster than any color wheel, so the "rainbow" effect should be unnoticeable. Removing many of the lenses in the light path makes the light engine less expensive to produce, as well as more efficient. A less powerful light source can be used to create the same amount of brightness.

This is not, however, what Mitsubishi is talking about when they're discussing their LaserVue display, at least not primarily. Their big push is color. They claim that by using a pure light source (laser) they can create richer colors, "twice the color" according to the press release. For the average consumer, this seems cool. After all, it's lasers. For the enthusiast, it's perhaps a bit more troublesome.

Too Much Color
Most modern displays are capable of reproducing all the colors available in the HDTV signal. Many are designed to reproduce more than that, creating "oversaturated" colors. In a store, these displays seem to have lots of color, and often get purchased over displays with more accurate colors. What happens is green grass is really green. Red apples are almost candy red. Again, perhaps not a big deal for the average consumer, but for those looking for a display that just shows what is in the original material ("as the director intended") this oversaturation of color is an artifact.

The problem, in effect, is in the signal. As good as HDTV is, it doesn't have the ability to encode all the colors that the human eye can see. New technologies, such as xvYCC aim to expand this limited color palette, but these are a long way away (if ever). This is because every step in the chain, from the transfer, to the encoding, to the decoding, to the transmission, to the display, all need to be xvYCC in order for it to work. Right now the only steps that are xvYCC are the display and the blu-ray player (if you're lucky). So it's a useless feature at the moment.

So every time a manufacturer starts talking about how much more color their TVs can create, I cringe. There are several displays on the market now that create perfectly accurate colors, or can be set up that way (Most Samsung RPTVs for one, and if you can find one, the last generation of Sony RPTVs had the ability as well).

Speculation
My concern is that in their push for this "twice the color" gamut for their laser TVs, Mitsubishi won't let an end user, or calibrator, adjust these colors back down to be accurate. It took Sony years of journalistic complaining from myself and others before they put in a mode that created accurate (as in not oversaturated) color points. If we can dial the colors back down, then we'll all be happy.

With the colors dialed back down, then the benefit comes in the form of efficiency. According to Mits, their LaserVue TVs will consume half the power of an LCD TV, and a third of the power of a plasma TV. This isn't trivial, as many modern TVs consumer more power than the family refrigerator.

Then there is the question of contrast ratio. At its core, the LaserVue TVs are DLP RPTVs. The lasers are just a fancy (and undeniably cool) light source. So the contrast ratio is going to be limited to the native contrast of the DMD. In theory the lasers can be turned up and down to increase or decrease the brightness (even turning them off to create an absolute black), but this is functionally the same as the auto-iris in other RPTVs. So the full-on/full-off contrast ratio will most likely be impressive. But the ANSI contrast (a checkerboard pattern of 8 white and 8 black boxes), which is a more accurate representation of what's on the screen, will no doubt be poor. This is because the laser is only able to ramp up and down the brightness of the whole image, not parts of the image (like say a local dimming LED LCD or what plasma and CRTs do inherently). In addition, all RPTVs have internal reflections that further lower the ANSI rating. Mitsubishi RPTVs typically measure very well compared to other companies as far as ANSI contrast goes, but we're still talking numbers in the hundreds, not the thousands of say a Pioneer KURO.

And lastly, it is still a RPTV. In the past year we've seen several big players in the RPTV market leave to concentrate on flat panels. Mitsubishi will no doubt get a larger portion of this RPTV market pie, but the overall pie is continually getting smaller as more and more consumers choose flat panels over RPTVs. For the next few years, though, Mitsubishi does stand to make some money as one of the only manufacturers of large screen RPTVs. After all, there is something to be said about a $3,200 73-inch DLP RPTV (the current WD-73735) over a $3,200 50-inch plasma.

First Look
At their Dealer Line Show they had several LaserVue displays set up. In the back, they had one next to a Sharp LCD and a Pioneer KURO plasma. The color was impressive, but it was definitely oversaturated. Without more familiarity of the demo material, I can't be more specific than that. I will say that it has the best purple of any TV I've ever seen. Also the "speckle" that we saw in the prototype is gone. There was some mild "silk-screen effect" that is typical of RPTVs, and at a normal viewing distance, it wasn't noticeable. The contrast and black level seemed good, though there were lights on so it's hard to say definitively. All in all it looked good, but I'll reserve judgment till I see a production model in a controlled environment.

They wouldn't talk about screen sizes or prices other than to say it will be comparable in price to a similarly sized flat panel. They did have three of the LaserVue sets hanging on walls, and admittedly they weren't much further stuck out than a flat panel with a big wall mount. I wonder if the consumer will feel the same way. We'll find out in the third quarter, which is the time frame Mitsubishi swears LaserVue will hit the streets.

The rest: LCDs and DLP RPTVS…

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