OLED TVs: Technology Advancements Thread - Page 399 - AVS | Home Theater Discussions And Reviews
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post #11941 of 11953 Old Yesterday, 10:22 PM
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Originally Posted by Rich Peterson View Post
I'm reminded of comments made by LG's Ken Hong at IFA last summer. He said True RGB OLED TV cannot compete with WRGB and the white OLED patents LG bought from Kodak were the key to getting high enough manufacturing yields for success.


http://news.oled-display.net/lg-sams...mpete-wrgb-tv/
That's true of both yield and efficiency. A straight up RGB OLED panel is very inefficient when displaying white, which is the primary color used on computer displays. WRGB is going to be key to expanding out of the TV / smartphone market. Instead of an OLED screen causing a laptop to use more energy in many use-cases than an LED backlit LCD, it would do the opposite and barring costs/reliability, would be the technology of choice.

It's also more practical to implement low-persistence scanning on a WRGB panel. You want pixels that get very bright if you're going to pulse them for a short period of time and then turn them off for the rest of a refresh cycle, but if to produce a white color you have to simultaneously light 3 separate colored sub-pixels that's never going to get particularly bright with any sort of ABL scheme working against you.
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post #11942 of 11953 Old Yesterday, 10:45 PM
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Originally Posted by Kaldaien View Post
That's true of both yield and efficiency. A straight up RGB OLED panel is very inefficient when displaying white, which is the primary color used on computer displays. WRGB is going to be key to expanding out of the TV / smartphone market. Instead of an OLED screen causing a laptop to use more energy in many use-cases than an LED backlit LCD, it would do the opposite and barring costs/reliability, would be the technology of choice.

It's also more practical to implement low-persistence scanning on a WRGB panel. You want pixels that get very bright if you're going to pulse them for a short period of time and then turn them off for the rest of a refresh cycle, but if to produce a white color you have to simultaneously light 3 separate colored sub-pixels that's never going to get particularly bright with any sort of ABL scheme working against you.
It may not be obvious, but WRGB is actually the less efficient tech. It is composed of all white sub-pixels that require filters to generate red, green, and blue. A lot of light output is lost in those filters. The single unfiltered white sub-pixels was only added to help compensate but it's not enough.

This is why the discontinued Samsung 55" RGB OLED was much brighter and offered a low-persistence mode with full motion resolution. I hope Samsung finds a way to make RGB work again.
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post #11943 of 11953 Old Yesterday, 11:45 PM
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Originally Posted by Wizziwig View Post
It may not be obvious, but WRGB is actually the less efficient tech. It is composed of all white sub-pixels that require filters to generate red, green, and blue. A lot of light output is lost in those filters. The single unfiltered white sub-pixels was only added to help compensate but it's not enough.

This is why the discontinued Samsung 55" RGB OLED was much brighter and offered a low-persistence mode with full motion resolution. I hope Samsung finds a way to make RGB work again.
Really? At fullscreen displaying a white image, I've measured power consumption of 180w on my 55EG9600. A solid red image draws the most power, at roughly 250w. The other two colors are slightly more efficient (< ~10w difference). But since most of the screen on a PC is typically white, that bodes very well for using WRGB pixels as a laptop display. It's usually the other way around, where white draws a crazy amount of power on OLED.
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post #11944 of 11953 Old Today, 05:26 AM
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Originally Posted by Kaldaien View Post
Really? At fullscreen displaying a white image, I've measured power consumption of 180w on my 55EG9600. A solid red image draws the most power, at roughly 250w. The other two colors are slightly more efficient (< ~10w difference). But since most of the screen on a PC is typically white, that bodes very well for using WRGB pixels as a laptop display. It's usually the other way around, where white draws a crazy amount of power on OLED.
I don't think you understand how LG OLED's are designed. And part of the problem stems from the industry which has conflated "WRGB" with this different design, instead of simply signifying an ordering of subs and the addition of white.

The LG OLED colors come from filtering a dichromatic white (or trichromatic white----jury's still out on this one----it depends upon which Kodak patent you read) formed from a stack of OLED materials underneath. For any one of the subs to be active requires that the entire stack be emitting that composite white and a filter remove all but the needed color. In the case of the white sub, it's unclear if there's no filter at all or a carefully tuned one.

If you believe you can win an argument by stating that scientists "often" get things wrong, all you're doing is selectively ignoring the overwhelming legion of things they have gotten right. Viewed as an aggregate, scientists very very rarely get things wrong.

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post #11945 of 11953 Old Today, 05:30 AM
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Originally Posted by Wizziwig View Post
The single unfiltered white sub-pixels was only added to help compensate but it's not enough.
Yeah, that's what we've been speculating for quite some time. I too believe that the reason to use white was entirely driven by the inherent losses involved in a filtered design. Filters exist solely to throw light (and effectively power) away.

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This is why the discontinued Samsung 55" RGB OLED was much brighter and offered a low-persistence mode with full motion resolution. I hope Samsung finds a way to make RGB work again.
ABSOLUTELY. Besides, their approach to having ever enlarging subs (from red to green to blue) was absolutely the correct approach, and you don't lose the subpixel density you do when you move to 4 subs.

If you believe you can win an argument by stating that scientists "often" get things wrong, all you're doing is selectively ignoring the overwhelming legion of things they have gotten right. Viewed as an aggregate, scientists very very rarely get things wrong.
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post #11946 of 11953 Old Today, 07:02 AM
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Originally Posted by tgm1024 View Post
I don't think you understand how LG OLED's are designed. And part of the problem stems from the industry which has conflated "WRGB" with this different design, instead of simply signifying an ordering of subs and the addition of white.

The LG OLED colors come from filtering a dichromatic white (or trichromatic white----jury's still out on this one----it depends upon which Kodak patent you read) formed from a stack of OLED materials underneath. For any one of the subs to be active requires that the entire stack be emitting that composite white and a filter remove all but the needed color. In the case of the white sub, it's unclear if there's no filter at all or a carefully tuned one.
No, I understand that there's a filter used for the non-white colors. However, energy efficiency when displaying pure white is phenomenal, which is what you do most of the time on a PC. It sort of turns everything on its head - Samsung has to illuminate the R, G and B sub-pixels in order to produce white.
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post #11947 of 11953 Old Today, 09:51 AM
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Originally Posted by Kaldaien View Post
No, I understand that there's a filter used for the non-white colors. However, energy efficiency when displaying pure white is phenomenal, which is what you do most of the time on a PC. It sort of turns everything on its head - Samsung has to illuminate the R, G and B sub-pixels in order to produce white.
Again, you're missing something. IF the subs themselves were spectral emitters (instead of filtering the broad white), then you'd have significant savings (such as if the samsung S9 were to have RGBW configurations). However, with LG OLED, even though they're saving with the white, it's coupled with a significant loss.

By the way, the savings of white isn't quite what most expect anyway, even with spectral emitters. There are two primary ways of producing white, trichromatically with 3 emitters or dichromatically with two emitters or a single blue emitter with a yellow phosphor. It's not as though there's a single OLED capable of blasting out white by itself. White doesn't have any one specific frequency to center on.

If you believe you can win an argument by stating that scientists "often" get things wrong, all you're doing is selectively ignoring the overwhelming legion of things they have gotten right. Viewed as an aggregate, scientists very very rarely get things wrong.
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post #11948 of 11953 Old Today, 10:20 AM
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Quote:
Originally Posted by Kaldaien View Post
Really? At fullscreen displaying a white image, I've measured power consumption of 180w on my 55EG9600. A solid red image draws the most power, at roughly 250w. The other two colors are slightly more efficient (< ~10w difference). But since most of the screen on a PC is typically white, that bodes very well for using WRGB pixels as a laptop display. It's usually the other way around, where white draws a crazy amount of power on OLED.
I think the ABL may complicate that calculation a bit. Possibly red draws the most power because it is least throttled?
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post #11949 of 11953 Old Today, 10:53 AM
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I think the ABL may complicate that calculation a bit. Possibly red draws the most power because it is least throttled?
Absolutely, further the CMS will complicate that as well. Look carefully at the sub arrangements to make sure that white has only white showing, etc.

But I agree, the non-configurable ABL is right in the way of figuring out precisely what's going on. And of course, even though the panel itself is the largest draw, there are other factors that must be subtracted first before calculating out display usage as any kind of useful percentage. Depending upon where you're measuring, the AC->DC converter by itself will consume a lot. As will the other more ancillary electronics.

If you believe you can win an argument by stating that scientists "often" get things wrong, all you're doing is selectively ignoring the overwhelming legion of things they have gotten right. Viewed as an aggregate, scientists very very rarely get things wrong.
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post #11950 of 11953 Old Today, 01:30 PM
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Originally Posted by barth2k View Post
I think the ABL may complicate that calculation a bit. Possibly red draws the most power because it is least throttled?
I fooled around with it a little more and the difference in power consumption on white shifts around as you play with color temperature. It swings as much between Cool and Warm2 as the difference between full red and blue, which makes sense in the end. If you're not asking the TV to display white that matches the W sub-pixel's natural white point, it's going to have to mix in some filtered color to do that.

What seems odd to me is that Warm2 is the most efficient for white, yet red is the least efficient color to display. I'd sort of intuitively expect a warmer color temperature to do really well with red?

Either way, I can definitely see why producing R, G and B by filtering W is not as practical as I thought. It's not nice and additive like RGB would be.

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post #11951 of 11953 Old Today, 02:06 PM
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Display Week 2015 is in San Jose from May 31st to June 5th for those that have the means and are interested. Interesting short courses on OLED and other display technologies.

Link to the Sunday short course on Fundamentals of OLED Displays.

http://displayweek.org/2015/Program/...a2eafbddfd3c47

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post #11952 of 11953 Old Today, 02:13 PM
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Did not see this posted anywhere...sorry if it had been prior to this.

http://www.hdtvtest.co.uk/news/super...1503064026.htm
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post #11953 of 11953 Unread Today, 09:58 PM
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The funny thing is though that I have always kind of assumed that with the stacked OLEDs (the kind I hear LGD uses), you'd only have to drive each element of the stack to one-third ,what with the light coming from the single "source" and hitting the same rod cells (and these little whit buggers don't see color, they see "brightness") and stuff, you know , (blue to 30W, red to 30W and green to 30W) to get 90W "white" whereas in a standard RGB arrangement you'd have to drive every sub-pixel to the max to get white (90W for blue, 90W for red and 90W for green)... but what do I know, right...

....
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