# Sharp introduces a new LCD TV that uses a 4th color



## tonyvdb (Sep 5, 2007)

Sharp has (in my opinion) always been a little behind in sales and positive consumer reviews. They have released a new lineup of LCD displays, the Quattron not only have the usual red/blue/green LCD colors but is now adding a 4th color yellow. 
Reports are saying that this display looks and is much more natural in color reproduction. I wonder if this is where we will see more companies going?


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## mechman (Feb 8, 2007)

I cannot recall where but I'm pretty sure that I read some bad things about these 4 pixel color tvs. It may have had to do with calibration. :scratch: I know that when I seen the announcement I asked myself "When did yellow become a primary color?" :huh: I realize that it is a primary color in printing and artwork for some. But it's never been considered a primary in video. 

We've got a lot of calibration folks hanging around lately. :T Hopefully they'll comment on this. And maybe I should run to the local store and take a look at one of them.


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## lcaillo (May 2, 2006)

There is a discussion of the sets here:
http://www.hometheatershack.com/for...processors/29306-sharp-aquos-lc52le810un.html

As techs and calibration professionals, we have been all over trying to understand the reasons for this technology. It seems purely a marketing matter, with little real benefit from a color accuracy point of view.


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## tonyvdb (Sep 5, 2007)

Thanks, Thats kind of what I thought. Printers have been using the added yellow for years but I was wondering if it made any difference in a video image. I'll have to go have a look at one sometime.


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## lcaillo (May 2, 2006)

It can certainly make a difference. The question is what kind of difference is it and does it improve on what we have already. If you want to make a case for expanded gamut, it just seems peculiar to me to not build a set capable of the extended gamut systems that have already been defined (even though they are not used for television) and extend your gamut only in the direction of yellow, where there is little to be gained.

The effect seems to be simply saturating yellow a bit more and reducing the yellow luminance. The Sharp people that I talked to in service could not really make a case for it, nor did they have a clear idea of what the set actually does with color.

That said, it will likely be a very successful product and there will be lots of demand for it. The marketing that they are doing is really pretty good.


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## eugovector (Sep 4, 2006)

The tech takes a beating in this article: http://www.maximumpc.com/article/features/display_myths_shattered?page=0,4


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## robbo266317 (Sep 22, 2008)

Many, many years ago at Uni I was told that CRT's using Phosphor could not truly recreate Brown as it did not "map into" the range of their colours and you would need a yellow phosphor to get there. 
This argument shouldn't be applicable to LCD's or Led's though.

Just my 2c.


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## lcaillo (May 2, 2006)

Brown is really a highly saturated red-orange, with really low luminance. Just adding the ability to saturate yellow without extending the red gamut would not get you there. 

The point here is that there is simply not that much to gain in the area of yellow alone. Many displays can already display the saturation in yellow that the Sharp can, along with wxpanded gamut for R,G,& B. Remember that if you extend the gamut of red and green, you by definition extend yellow as well, along with browns and oranges.


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## Guest (Jun 1, 2010)

I've been trying to find more information about this for awhile. A family member has one (only it replaced a older TV under warranty) and it didn't cost anything. I helped picked it out and one of the main reasons was power consumption. We had to pick something out at sears and they didn't have a whole lot to choose from. Overall it has a great picture once things are turned down a tad. Colors are over saturated out of the box. When I was picking it out, I was scratching my head as to how yellow could be used with a R,G,B signal, but again, power consumption was a large reason for picking this out.

What I've been reading, but not finding detailed information on (detailed enough for me) is that the yellow sub pixel can create yellow using less power. So while Sharp might be over playing the TVs capability, it does seem Sharp has been very serious about making TVs that use less power. So if your interested in that, I would still look at this TV.

I've not been too impressed with some of the reviews as they don't talk about this at all. They all talk about what yellow can't do, not what it can do. Every color can be calibrated on the TV (the US model) so it should be able to be fully compatible with video standards. If it can do that using less power, then Sharp is on to something. Granted, they are promoting it in the wrong way, perhaps they felt that people wanted to hear about more colors, not less power.


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## mechman (Feb 8, 2007)

eugovector said:


> The tech takes a beating in this article: http://www.maximumpc.com/article/features/display_myths_shattered?page=0,4


That's where I saw it! Thanks Marshall. :T


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## lcaillo (May 2, 2006)

If you read the review linked above, Generic, they tried to adjust the set using the CMS provided and were unable to get even close to the right luminance on green, yellow, and cyan.

Just because a set claims to have color management controlos does not mean that it can be adjusted to standards.

Once again, many people will likely be very happy with the product.


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## Guest (Jun 1, 2010)

Ya, I read that, and I'm starting to suspect that these sets have software issues. That link said that changing the settings didn't seem to change anything. I installed the latest version, but the power button on the TV doesn't work. I did change the settings around a little, but I could see a change, so I think its possible that they got a bad set, because so did we (different problem) and if it isn't fixed soon, its going back for a different TV.

Another thing that is different on our TV is the screen aspect settings. While they do the same thing, it doesn't have a dot by dot option. Its called something else.

So, the hardware on the TV seems fine, but the software seems like its all over the place.

In the end, I would like to know the extra yellow color can create yellow using less power compared to a RBG set, because that is one of the things its suppose to be able to do. I doubt that any of the independent reviews will cover that, they all talk about how yellow isn't needed to create the standard RGB format.

Color wheels on DLP projectors have extra colors too. Are all those a gimmick too?


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## lcaillo (May 2, 2006)

Whether something is a gimmick or not has to be answered specifically to each set. In general, the answer is yes, it is a marketing gimmick. Having the discrete colors in the color wheel may increase the effciency of the system some, just as having a yellow pixel may provide the same improvement. There are so many variables in the execution of these systems that it may or may not end up being done well. The Mitsubishi sets with the six color system and the six colors on the wheel work well now, but the early versions did not have as much control to get the colorimetry and luma correct. The consumer PerfectColor and PerfectTint is pretty much a gimmick as it is impossible to adjust it properly without a meter. Even then, we usually do adjustments with the more advanced menu options.

It is really the exception rather than the rule that color management systems allow sets to be adjusted accurately to the standards. This is why most professionals and consumers who want that accuracy use either a Lumagen processor or the new VideoEq from Spectracal. If you have SDI you can use the BlackMagic unit which also has LUTs.


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## bambino (Feb 21, 2010)

tonyvdb said:


> Sharp has (in my opinion) always been a little behind in sales and positive consumer reviews. They have released a new lineup of LCD displays, the Quattron not only have the usual red/blue/green LCD colors but is now adding a 4th color yellow.
> Reports are saying that this display looks and is much more natural in color reproduction. I wonder if this is where we will see more companies going?


My brother just picked up a 47'' model and he nor i were to keen on the picture. Nice looking set overall though. I just didn't care for the pic.addle:


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## randtek (Jun 3, 2010)

> In the end, I would like to know the extra yellow color can create yellow using less power compared to a RBG set, because that is one of the things its suppose to be able to do. I doubt that any of the independent reviews will cover that, they all talk about how yellow isn't needed to create the standard RGB format.


Since the color systems in TVs are controlled using the Red, Green, and Blue signals, it seems to me that they would need a process to extrapolate the yellow information from the red and green signals, which, in order to keep gamma and tracking correct, would require that the corresponding info would have to then be subtracted from the red and green channels to prevent over-saturating the yellow, or affecting the quality of reds and greens. It will be interesting to see how well (or poorly) this works. I have just seen the first one come through the service center where I work. The unit does not turn on, but as soon as I get it working, I plan to really check out the picture quality. I have been very curious about these sets since Sharp first announced them.

From a technical standpoint, I don't see how this could really provide any serious improvement in picture quality. The power savings may be something to consider, but I just don't forsee the power savings to be a very significant amount, as these sets are still LCD technology, and activating an LCD pixel is not a very large percentage of the power used in these sets. Besides, in currently used LCD displays, current is used to turn a given pixel off, not on. In other words, brighter pixels = less current than darker pixels. So in RGB based LCD display configurations, a yellow pixel would actually use less current than a red or green pixel of comparable level.

When OLED technology becomes more prominent, using a yellow pixel might result in greater power saving potential.


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## lcaillo (May 2, 2006)

When questioned about the power savings issue, the service trainer that I spoke to said that it was not a significant factor in the decision to add the yellow pixels. But then, he did not have much real information about the sets nor how they work.

The conversion to a four color system from RGB itself could be done rather easily, as the math could be simple matrix manipulation. The problem is that it would have to be done in the display, and at that point in the signal chain the signal is not linear, since gamma correction has been applied at the camera level. This makes the transform more complex, then the real problem comes in. That is getting non-linear RGB to the display level, and dealing with the peculiarities of the panel itself. Combine that with the myriad of priorities that might be affected by marketing decisions, and you have a rather complex mess. Considering that Sharp tends to be an outlier in panel production and does not share technology with others to the degree that the other manufacturers do, it is no surprise that they might come up with some rather unusual colorimetry and luminance results like we are seeing in these sets.

There is no evidence yet that the sets are anything to be excited about if you want accurate video reproduction, but lots of people seem to like the way they look. Differences do sell, no matter what the product type.


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