Originally Posted by lsorensen
I suspect they changed the control electronics in the panel to allow VRR and the better BFI. So the OLED part of the panel itself may not be changing, but that doesn't mean the electronics driving it weren't improved. I did expect LG would have to be first with VRR since they make the panels and would have to make any required changes to it first.
The wording is vague enough that we're going to need to wait for first owners to report on what actual options are supported to have any real insight into how the 'OLED Motion Pro' has been implemented, but it almost-certainly represents a significant upgrade to the backpkane.
I can concieve of three obvious options:
1/ Double native backplane refresh speed from 120Hz to 240Hz. A backplane that is fast-enough to refresh [email protected]
will also be able to refresh [email protected]
, so if the 8K WOLED supports 120Hz refresh, this might be the 'easiest' option.
A backplane with 240Hz native refresh rate would support 50% BFI @ 120Hz and would also support 25% BFI @ 60Hz, but cannot support 25% BFI @ 120Hz, so we'll need to wait to see what LG's reference to BFI at '120Hz and with shorter black frame cycle (25% vs. 50% of last year)' translates to to understand whether this 'simple' solution could be involved or not.
2/ Addition of a seperate 'blanking' control to the backplane. This involves the addition of another transistor within each subpixel, so it is a more significant (and more expemsive, in terms of additional yield loss) solution, but this option would support 25% BFI @ 120Hz and does not require 'speeding up' the backplane to a native refresh rate of 240Hz, so if 25% BFI @ 120Hz is supprted but the 8K WOLED only support 60fps (and not a full [email protected]
refresh), this may be how it's been done.
3/ A backplane that supports [email protected]
native refresh rate is capable of writing one row of pixels every 1/259,200th of a second (259.1kHz row write speed), and if the backplane has been modified to support row-write speeds that are twice as fast (518.4kHz), this write speed would be needed to support [email protected]
refresh but can also be used to support 25% BFI @ 120Hz with 4K content if it is designed to support a refresh architecture more sophisticated than the simple 'full-frame-refresh described in option 1.
By alternating between the write of one line of the new frame and writing to black (blanking) another line of the old frame, 120Hz BFI of 25%, 50%, 75%, or theoretically almost any % could be supported.
This would also be the easiest way to support VRR, since a framerate of any integer divisor of 518.4kHz could be supported.
I'm keeping my fingers crossed that this is what LG has implemented: increase line write speed to 518.4KHz and use it in a way that is not possible for scanning-backlight LED/LCD (line-granurality blanking rather than backlight segment-granularity blanking).
In terms of the earlier posts on 25% BFI, it is correct that 25% BFI is less effective than 50% BFI (50% more persistance and persistance-based motion blur) but the hope and expectation is that any BFI solution supporting 25% BFI also supports 75% BFI, and 75% BFI has half the perisitance of 50% BFI.
The light loss associated with 75% BFI will be twice that of 50% BFI (so 1/4 brighess instead of 1/2 brightness) but I'm also hoping that LG will eventually figure out that BFI means they can use the full HDR peak brightness levels for SDR content without any impact on aging/lifetime.
1ms @ 600 cd/m2 ages (and generates heat) exactly the same as 4ms @ 150cd/m2, so there is absolutely no reason for engagement of BFI when viewing SDR content to result in and noticable decrease in brightness.
If LG has implemented 'OLED Motion Pro' in a manner that supports 75% BFI without sacrificing brighness, the result will be a decrease in persistance from 8.3ms to 2.1ms at brightness levels of at least 150cd/m2 peak and possibly as high as 250cd/m2 peak (1/4 of 1000cd/m2). 2.1ms is getting close to plasma-like persistance levels of 1.7ms...
We'll need to wait for all the specs to be fully announced and tested, but it's looking to me as though 2019 may prove to be the year LG finally had the confidence to step to the front and start leading the industry...