[Masterbrew2]

What's stopping manufacturers from making a display with one LED for every subpixel?

 

[GregLee]

Cost.


The 1080p monitor Dolby had built for them to test out ideas about "Dolby Vision" did have an individual led backlight for each lcd pixel (as I understand). The acronym for this system is "imled", I think, standing for "individually modulated led", and now some such monitors are available commercially.


Correction: IMLED displays have lots of leds, but not one for each pixel. This one has 2202.

 

[tgm1024]



Quote:
Originally Posted by Masterbrew2  /t/1522106/a-led-display/0_60#post_24469854


What's stopping manufacturers from making a display with one LED for every subpixel?

 

It's been a dream for many of us, one that some of us actually thought stood a chance when Sony announced their "Crystal LED" TV a couple years ago .  It was an unbelievably beautiful TV, and using LED.  But our hopes were dashed when Rogo pointed out that there was no way to build them in any quantity.  LOL.....  Ah well.

 

I still hold out hope for the thing though.

 

 

[GregLee]

It's interesting that the Crystal LED display has 400 nits of brightness.

 

[tgm1024]



Quote:
Originally Posted by GregLee  /t/1522106/a-led-display/0_60#post_24493512


It's interesting that the Crystal LED display has 400 nits of brightness.

 

I suppose sure, but again, it wasn't even an alpha release; it's barely a show prototype.  A one time only show-only demo.  If they found a way to produce it, who knows how bright it might have been.

 

[fafrd]



Quote:
Originally Posted by GregLee  /t/1522106/a-led-display#post_24470858


Cost.


The 1080p monitor Dolby had built for them to test out ideas about "Dolby Vision" did have an individual led backlight for each lcd pixel (as I understand). The acronym for this system is "imled", I think, standing for "individually modulated led", and now some such monitors are available commercially.


Correction: IMLED displays have lots of leds, but not one for each pixel. This one has 2202.

I think that is right. Essentially each individual LED on the backlight can be individually controlled as it's own dimming zone. So the IMLED display you provided the link to effectively had 2202 dimming zones. For a 1080p display with 2,073,600 pixels, that is about one LED (& dimming zone) for every 942 pixels...


By way of comparison, the Vizio Reference Series, with 384 dimming zones, has one dimming zone for each 5400 pixels (at 1080p equivalent - 4X that numbers based on actual 4K pixel count), about 5.7 times larger than the IMLED display.


More importantly, the IMLED display you found had a brightness of 4000 Nits over 47" 16:9 surface, versus the 65" Reference Series with 800 Nits. So if we assume roughly equal light output per LED, that would mean that the IMLED display had a total brightness of about 4000 Nit x 944 cmsq = 3,775,620 Candella. And in terms of brightness/LED, that would be 3,775,620 / 2202 = 1,714.6 Candella / LED.


And so the 65" Vizio Reference Series probably has approximately 800 Nit X 1,805 cmsq = 1,444,273 Candella, or a total of 842 LEDs based on a similar light output of 1,714.6 Candella/LED.


And for 384 dimming zones, that would correspond to between 2 and 3 LEDs per dimming zone.


So if all of these estimates have anything to do with reality, the backlight of the Vizio Reference Series should have 768 LEDs is LED brightness output has increased since the days of the SIM2 IMLED display, or should have 1152 LEDs if the SIM2 IMLED display was based on expensive high-brightness LEDs and lower cost LEDS with slightly reduced light output were used by Vizio for the Reference Series...