I feel like they probably have something to do with light level detection or infrared signal receiving but I genuinely have no idea. They could just as likely be part of the sound system for all I know.
The TV is a Sony KP-43T85T or similar. The service manual is here with on page 55 the exact part: https://www.manualslib.com/manual/772761/Sony-Kp-43t85t.html?page=55#manual
It states "3D COMB FILTER" and is part of the picture in picture mode. It's probably an optional upgrade, which is why it's on a separate board if I were to guess.
Looking up 3D comb filters, I found this:
https://www.edn.com/revisiting-the-analogue-video-decoder-brushing-up-on-your-comb-filters/
My guess is this is a CRT TV, and these sensors precisely measure the timing of the scan line in the overscan regions (off the sides of the display), and allow the TV to make adjustments.
Wow. Thank you so much. Now I need to find out if I can use it in some weird home brew project!
Awesome!
I found manuals of a similar product, but it did not have the correct labels, may have been a different brand or older models.
I give you props on finding the part!
IR receivers for the remote
I just wonder why they are covered and face inward. The shiny part is pointed towards the inside of the unit.
I guess I should find out what voltage they operate on and see if I can use them in some tiny project.
Edit: thanks!
Why would you need more than one IR receiver for a remote control?
optical line of site
Those are sensors for the auto-registration. It flashes a pattern for each color tube and aligns them.
Other thoughts: S3001 implies that it’s some kind of switch (also present is D3001 and CN3001 for diode and connector).
One thought is reed switch? Maybe it’s not optical at all. Were there any magnets near this sensor inside the TV? Maybe it’s a way to determine that the screen is fully mounted/aligned correctly?
What kind of projection? DLP? LCD?
What’s confusing to me is the diode. It almost looks like a freewheeling diode for an inductive load, but I can’t imagine what that would be.
Could also be ESD protection, but I wouldn’t expect a large IR photodiode to need much ESD protection.
Also if it’s truly a passive component like a receiver, I’m surprised there isn’t any local components for filtering or amplification.
The diode is a zener- it basically clamps the voltage.
Yeah, but trying to figure out what it’s for in this circuit. I suppose it could just be ESD.
Could the screen have had IR touch?
IMO It would be helpful if you provide more information on the product number/model of projection TV you took apart, if you have such information.
It may help people find repair/service manuals or schematics of parts...
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.