EEVblog #916 - Work Bench Lighting From A Dumpster LCD TV

How to scrap a dumpster LCD TV to get work bench or architrave lighting.
A look at the LED's used and the lens system for direct backlit panels.
Also looking at the diffusion and prism layers of typical LCD TV's.

LED LCD Panel Teardown Video:

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[PeterCCamilleri]

I dunno. Seems to me that the real value here was to keep it as a panel. The base leds and even the strips are just bulky versions of readily available parts. The real gem is the unique blend of optics that made the panel so hard to duplicate with off the shelf parts.

[antmallett]

One of the most interesting EEVblogs. Amazing how much tech goes into creating a back light. To say nothing of how much tech goes into a LCD panel.

[electronicsNmore]

LCD and CCFL backlight panels come in very handy.

[Graham_Langley]

It's more a reflector than a lens - it spreads most of the light out sideways by total internal reflection from the conical top surface.

[fromfin]

DAmn thats a lot of science in a everyday item like that, hats off for the engineers!

[Chalky.]

This is making me think back to all the massive gadgets I was using on my old Gameboy just to get one little spot of light on the screen.

[materialsguy]

Good video Dave. Lots of tech and materials engineering in these panels.

[ForViewingOnly]

Light engineering is fascinating! It's a real challenge to distribute the light evenly in LED backlit and sidelit TVs without bright or dark spots. It gets even more interesting when the TV has a number of independently controlled backlight zones (the 2016 Panasonic flagship has 512 such zones!). You've gotta wonder how far they can go with LED LCD TVs... just when you think they've had their day they keep improving the design.

[jmsoccer]

I had the flux screen temp program running on my computer and the light looked purple to me, thought I was color blind for a second when you said the light was blue!

[dawnberlitz]

this was certainly enlightening Dave and you given me some wonderful ideas

[stationplaza]

@14:08 LOL.!
 i Had no idea Dave has such talent with the wobbly board :-)

[Alexanification]

Thank you for your video. Why not using the whole panel with the filters on as a light?

[WaltonPete]

The dot pattern on the led backing reflector works in a similar way to the dots around the windows on a modern car. On a car, however, the dots serve to visually blend the edges of the windows into the seals and body work as the dot size increases towards the far edges. They're also used to help obscure fixings and other functional items which would otherwise detract from the visual appeal of the design.

[kristiandawe]

that is so cool, leds from a tv used as under cabinet light, even if they are blue in color tone, i really like them, great stuff dave, time for me to hit the dumpster in my apartment building. :)

[JerryWalker]

I think that the backlight spectrum is specifically chosen as the image panel passes some wavelengths better than others and the backlight is chosen to give a reasonably flat picture colour. I used to work for a company that manufactured spectrophotometers. Optics is a very interesting subject and the intersection from optics to electronics can provide some very interesting projects.

[voltlog]

I would not enjoy working under that bluish colored light. I don't think it's healthy for the eye either. But I've thought about reusing these led backlights as well. Maybe waiting for another TV with better leds is a good idea.

[SuperHemulen]

Hey Dave! Try freeze-spray on the double backed adhesive next time. Works like a charm.

[THEtechknight]

Looks purple to me. but the LCD panel requires this particular color temperature to get a nice paper white on the display, likely because of the impurities of the color filters in the panel. Notice projection sets that use HID lamps have the same color lamp!

[avshomerx]

Those Prism films could make a fun window cover in the office.

[szabolcs__]

Yes The dot on the end is light absorbant because holes are like perfect black bodis absorbant