Question about OLED displays

[bigbluefe]

I'd appreciate it if an expert could clear something up for me.

Why can't OLED monitors just flicker at like 500hz so that they don't have any motion blur? It would be fast enough to not notice the flicker, but enough flicker to eliminate the motion blur. OLED panels are incredibly fast, right, so flickering at that speed should be possible?

I don't get it. Why do monitors BLOW?

 

[Vega]

Strobing the back-light four times per frame doesn't accomplish anything. You only want to pulse the back-light once per real frame to eliminate eye tracking motion blur.

For a 120 Hz display like the new Dell 4K OLED monitor, you would want to strobe the back light exactly 120 times.

 

[Sancus]

So in order to strobe you need a duty cycle of significantly less than 100%, ie the screen needs to be producing light much less than 100% of the time.

1ms of persistence is a common target, it translates to 1 pixel of motion blur at 1000pixels/second movement. 120hz is 8.33ms of persistence normally, with no strobing. To get that down to 1ms, your OLED screen has to be on for only 1/8.33 = 12% of the time!

That means you need 8.3x normal brightness to achieve a given brightness without strobing. OLEDs can't get that bright. This is also why ULMB modes in LCDs are so dark, they have to max out the backlight just to achieve that much brightness, and maxed out white LED backlights are much brighter than the current maximum possible for OLED screens.

The alternative to this is to have incredibly high refresh rates and high framerates, but as Vega stated above, this doesn't do anything if you don't have the framerates, and we don't even have 120fps in most use cases, nevermind 300, 500, or 1000fps.

 

[bigbluefe]

1000fps is definitely achievable for emulators running older games, though. A modern PC runs Pacman at like 10,000% speed.

I can run the Neo Geo driver in MAME at around 800fps, too.

Give it to me now.

 

[zone74]

1000fps is definitely achievable for emulators running older games, though. A modern PC runs Pacman at like 10,000% speed.
I can run the Neo Geo driver in MAME at around 800fps, too.
Give it to me now.

The systems that are being emulated typically link game speed to framerate. So at 800 FPS a game designed for 60Hz will be running at 13.3x speed.

 

[XoR_]

they could make option to turn down brightness using PWM at refresh rate (for those who want it)
even going down to like 50% at 4ms would be better than going 50% at 500Hz which itself improve nothing (well, it flickers less )

 

[Sancus]

1000fps is definitely achievable for emulators running older games, though. A modern PC runs Pacman at like 10,000% speed.

Maybe but there's no connector standard that has this sort of bandwidth and even if there were there's no tcons that will run the panel at those refresh rates and even if there were I have no idea if oled panels can even do refresh rates as high as their theoretical response times imply that they can.

Basically no part of the chain is anywhere near this and there's little incentive to develop all these very expensive pieces to play pacman.

 

[bigbluefe]

Maybe but there's no connector standard that has this sort of bandwidth and even if there were there's no tcons that will run the panel at those refresh rates and even if there were I have no idea if oled panels can even do refresh rates as high as their theoretical response times imply that they can.

Basically no part of the chain is anywhere near this and there's little incentive to develop all these very expensive pieces to play pacman.

Your point is well taken, but I still wants it. I can run Street Fighter 2 at 600% speed, too, so it's not like only really primitive games can run that fast.

I bet Quake 3 level games run at 1000fps today.

 

[KG-Prime90]

Oleds don't have a backlight. Each individual oled "pixel" would have to have it's current strobed, which would obviously affect their brightness. Then there's lifespan to take into account. Unless i'm too high to understand them, i've read very little on it but, it seems black frame insertion would be more compatible. Though until they actually become mainstream for a while, and going by how things always get "rushed" to market, none of these things will be addressed right away. Their primary goal is always to make them available to whoever will pay, and worry about everything else later.