Blur Busters Forums

Hello guys,
I am trying to develop an autostereoscopic/holographic display and I think I have a novel approach. Now truth is, some guy probably thought about this before and wrote a paper about it but then again - I don't see many GOOD holographic displays around so I guess no one cared to try to build it. (I know the Looking Glass exists, but they have only 45 horizontal viewing directions, I want to beat that!)
Anyways, a holographic display has the fundamental problem that for each frame it has to display not just 1 frame lot of pixels, i.e. 1920x1080 or whatever resolution you desire, but it has to do this *for each viewing direction*, so if you want perhaps 20x20 viewing directions then you actually need 400x1920x1080 pixels, or maybe I should say "point source colored light emission events".
So, either I find a display with a ridiculous ppi - or I spread these necessary pixels over time.
In other words I would need to display 400 subframes for each actual frame, and this at high luminosity since my brightness gets reduced by 400 due to flickering. This means I need a ridiculous refresh rate. Someone redirected me to you guys.
Now, I know that 1000Hz displays just don't exist yet. HOWEVER maybe it is more accurate to say "normal" 1000Hz displays don't exist.
Say I am willing to give up a bunch of resolution and pixel pitch for refresh rate and luminosity - what can I do here?
One more detail: The display should be in strobe mode, so every subframe gets shown for a short time and then the display goes black until it is time for the next subframe. The lights light up only maybe 1/10 to 1/5 of the time from one subframe to the next.
Can you give me some advice regarding this?
Thanks a lot!

You submitted your post 3 times, I approved one of the posts (new users first posts need approval).

If you can live with DLP, there are many specialized DLP projectors that can do the refresh rates you need. From the Christie Digital Projector that can do 480Hz, to the Viewpixx 1440Hz DLP projector (the lower the Hz, the better the gresycale/color depth).

You can also stack multiple DLP projectors onto the same screen to do different temporals on different DLP projectors, if you need more color depth. Consumer projectors are a hassle, you probably want barebones DLP or buying an high-Hz-workflow-capable DLP.

For example, one Viewpixx might only do 8-bit monochrome, but you can use three Viewpixx (R,G,B) for full color. Some universities have already been doing for more than 10 years, using three InFocus 120Hz+colorwheel projectors to generate 360Hz without a colorwheel (modifying projector to remove colorwheel).

DLP mirrors is really high refresh rate at 1-bit because it requires 1440Hz to generate 60 refresh cycles of 24-bit color, but reducing color depth at higher refresh rates (creates nasty motion artifacts worse than 240 Hz LCD) so I prefer increasing refresh rates on non-DLP technologies. You simply bypass the DLP chip's normal workflow ("simply" is a misnomer as it's very hard to do it very fast -- often requires a FPGA) and do whatever you want with the DLP mirrors 1440 times per second, like half-colordepth at twice-refresh-rate. Or temporally spread color over multiple refresh cycles (I hate this, though). However, for your special application, I think DLP may be superior.

I have a fondness of non-DLP engineering (it's totally my domain), but your application sounds like DLP becomes the cheapest path to achieve what you need. For example, a 1440Hz DLP chip, you could project 24 DLP chips simultaneously onto the same screen to do true 24-bit 1440Hz (8 each color filtered to R, G, B). Quite a hacky workflow, but is one of the paths to doing full-pixel-control zero-temporal-color (I hate DLP temporal artifacts).

You can add as much blackness you need to DLP, in pretty fine increments (1/1440sec) as long as you're willing to rob temporal color depth. Just pretend it's a 1440Hz 2-bit (fullblack + fullwhite) display, and go nuts with how you design the display output workflow of DLP with your favourite FPGA/ASIC, or pony up for the high-priced vision science projectors (approx $30K each) if you just want something boxed.

Now, there's the 512Hz Windows limitation you must bear with (and may need to do Linux), but I have an Inside Build (that I successfully convinced Microsoft about) capable of doing 1000 Hz. There are ways to bypass this with special apps (e.g. an app that framepacks 24 different 1-bit refresh cycles in one actual 60Hz DLP refresh cycle, and have the app send those odd refresh cycles for the specialized DLP to playback through) -- This is the algorithm that Viewpixx has been doing this for more than a decade.

Anyway, the point being, there are some (super-expensive) off-the-shelf DLP solutions that can be driven by a custom app to do what you want (you'll have to write your own control of all those 1-bit refresh cycles) if you don't mind the projection route. No new algorithms. It's just incredibly expensive to purchase projectors that gives you full control over the 1-bit refresh cycles. If you need a prototype really fast at cost-no-object, buying multiple $30K+ projectors and programming your own custom 1440Hz 1-bit refresh cycles to do what you need (including your own custom black frame insertion in 1/1440sec increments) to generate color, it's doable with the Viewpixx, and you can certainly stack multiple color-filtered Viewpixx projectors onto the same screen ($$$) to generate ultra-high-Hz color that you need.

On the other hand, if you are considering cheaper routes, I've got many alternate cheaper solutions, in the non-DLP domain. If you require paid Blur Busters consulting services, please contact me via services.blurbusters.com or mark[at]blurbusters[dot]com if you require display consulting services help. I've received multiple quotes of "Best use of consulting money." for my services. There are multiple various methods of improving motion clarity and/or increasing refresh rates on LCD / OLED / MiniLED / MicroLED displays that I have done over the last ten years. And I have worked with display algorithms and video processors (deinterlacing) for twenty years. Thanks!