- cross-posted to:
- videos@lemmy.world
- cross-posted to:
- videos@lemmy.world
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The safety warning about CRTs is no joke. My dad used to work appliance repair in the 80s. These guys were all well trained in that shop. They had a shelf of tvs with dates on them. No tv was to even be looked at until at least 3 days from dropoff, then they discharged the capacitors. They hated the tvs most, because they ran test after test before plugging them back in. I miss the free crap Dad would drag in due to missed payments or abandoned electronics. We had a 24 in industrial microwave that I miss to this day. I could be lazy and microwave anything in that damn thing, regardless of metal content, and could defrost a small turkey.
Does anyone remember older 747 jets having these types of projectors to show movies on international flights? Always thought it was so cool.
We had one in an auditorium where I work. Only problem is it was underneath an MRI scanner. Every time they’d open the door to the MRI, the magnetic field would knock the projector tubes out of alignment.
The technician who came out to work on it said it was hopeless. He told us he had a customer whose projector would get out of alignment if he moved a speaker in the room.
I was so happy when we finally replaced it with an LCD projector.
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!
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.
still used for a type of advanced microscopy.
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
So they used to be ridiculously cool, but they’re still ridiculously cool too.
