281
this post was submitted on 08 Oct 2025
281 points (98.0% liked)
Technology
76275 readers
3179 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related news or articles.
- Be excellent to each other!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
- Check for duplicates before posting, duplicates may be removed
- Accounts 7 days and younger will have their posts automatically removed.
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
And then they invented the colour wheel. And the DMD with lots of tiny mirrors. And afterwards they used LEDs and laser diodes...
The micromirror arrays are the wildest of the bunch to me. That is just such a prima facie batshit insane idea and it's astonishing that it actually works.
"Yeah, we need to be able to individually display and shut off these pixels, so we're going to go ahead and design a chip with 6,220,800 tiny mirrors that physically tilt when you poke them with electricity. Rather than, I don't know, literally any other solution that presents itself."
It sounds insane, but the array that drives it is functionally not that different from the array that individually causes LCD crystals to shift.
I have DLP parts sitting around because they're cool.
Edit pics:
Edit2 explanation: A white light is focused onto the DLP mirror chip through a kind of kaleidoscopic lens, I'll spare you the details on that. The individual microscopic mirrors are aligned with charges to bounce light. The mirror array pulses synced frames through the spinning color wheel to create a composite image. It's a fucking insane idea that barely works... and people like me, with low persistence of vision, are not fooled very well and we see color banding and all kinds of weird artifacting lol
Woah that color wheel... You can see the cyan, magenta, yellow light reflecting but red, green, blue light passing through to the table, respectively. Such a great example of complementary primaries
I'm so happy you noticed, the colors cannot be reproduced in a digital photo, when it shines in the sun it's so beautiful!
What's the 4th color on the wheel used for? White minus white... black, yes. But why?
Straight answer, I don't know lol
Backlit through window
Toplit by LED lamp
There is no way that the pictures I've snapped can produce the colors accurately. When I look at that small section, it reflects forest green light back to my eye. The light that passes through seems to be muddy yellowish
:)
I tried to find something on the internets. It says something about additional color spaces - in that regard the yellowish color makes sense. and reducing color flickering. 🤷♀️
My assumption was it had something to do with luminosity, but I'm at the end of my technical expertise for this implementation of insane technology lol
There was an idea I read about, sorta along the same crazy track, (might have been Popular Science or something like 25 years ago) where they came up with an idea for a jet that didn't use traditional control surfaces like ailerons, but rather line the wings and fuselage in thousands of tiny flaps that would all be precisely computer controlled. It would be able to basically mold and shape the airstream around itself to make precise movements.
You are totally remembering correctly! I recall this as well, but the hype died out quickly.
still used for a type of advanced microscopy.
I could also see DLP being applied in new QM research... lasers are being increasingly used to trap and manipulate atomic nuclei
There was a micromirror e-paper too. Though i don't think they got a reader on market. Got bought up by E Ink corp, like everythiing else e-paper.
RGB flashing sequentially is the wooooooorst. Most people can't see it but holy shit i can and it's like random colored strobes flashing everywhere. Bleh
I believe the crt projector doesnt have that issue
I was referring to the spinning color wheel that op was taking about, but yeah the simultaneous three color projector likely doesn't have that problem
I'm going to actually you lol
The reason it works better with CRT is because of the phosphors. They continue to glow, long after the signal has passed over. Check out a CRT slow motion.
Everything to do with display technology involves tricking the eye and relying on persistence of vision which is innate.
Yes, I could tell if dlp, whenever my eyes moved.
They fixed the issue by increasing the color changing frequency in led beamers.:)
I still see it in even the most modern projectors, but I'm also able to see the flicker in phones that use pwm dimming which only a very small percent of people can see, so sucks to be me. My eyes seem to work at a much higher image capture rate than most people, which has no apparent benefits, only problems
Useless superpowers... :) CRTs must have been fun.
Interestingly enough crts didn't seem to cause a problem, my guess is because the pixel phosphors don't actually flash off, they fade out. But that's just a guess
Interesting.
It was hard for me to tolerate the 50hz flickering. Especially in peripheral vision. Same with fluorescent tubes. Good times (not).
Oh yeah fluorescent tubes are a awful. They're not white, they're sequentially yellow blue yellow blue yellow blue
So they used to be ridiculously cool, but they’re still ridiculously cool too.