DIY and/or repair LED picture frame lightbox?

Out of curiosity, I recently acquired a 16x20" LED lightbox that has a front opening frame whereby I can insert a picture. I placed a picture within it, plugged it in, and I now have it on the wall and I impressed with the illumination it provides. Since I got this lightbox from a friend, it didn't cost anything but there's another area on the wall that could use a 16x20" lightbox too. However, when I see the prices online, I am taken aback.

Being a somewhat DIYer in the past, I decided to carefully disassemble this lightbox to see how it worked. To me, it just looks like there are LED strings that were stuffed all along the insides of the aluminum frame with a diffuser behind the picture. I don't see anything behind the diffuser. I see that aluminum or steel "snap frames" are available non-lighted and significantly cheaper than the lightbox. I'm wondering if it just wouldn't be possible to simply acquire a non-lighted 16x20" metal snap frame that opens in the front and then line the inside perimeter of the frame with the LED's and then use a diffuser behind the image. I have three concerns that I'm hoping someone here might address:

1) I'm assuming that the non-lighted metal snap frames, that open from the front to insert pictures, are the same frames used for their LED lighted counterparts. Does anyone know for sure, or are the metal snap frames that have the LEDs made differently?

2) The LED strips I see lining the inside edges seem to almost be like LED chips. Any idea what LED type I should look for? I'm guessing for starters that they have 6500K color temp, and they are definitely using

12 VDC since that it the size of the power supply feeding the frame. Beyond that, I'm not sure of the wattage or output.

3) The diffuser is the last question, not sure what to use for that.

I see DIY plans around the web for lightboxes, but most are much thicker than these 1" thin ones, and I have yet to come across anyone reverse engineering one of the types I have, so if anyone knows please share. Just trying to keep things simple and cheap.

Thanks in advance for any help, Bill

Reply to
Bill Stormer
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The design of the picture holder shouldn't matter provided you can swap the opaque back plate for a transulcent white perspex diffuser.

Probably sets of three in series to run off 12v with a current regulator or series resistor. Your problem will be arranging to get an even illumination in a thin frame. It is easier if you make it deeper. LCD displays now manage it in an incredibly thin chassis. Canibalising a scrap one of them would be the obvious way to proceed.

Acrylic sheet is the usual choice.

You will find it hard to get the illumination even over a large area without some devious design tricks. Painting the inside with aluminium paint might be good enough but I suspect unless you are very careful the edges will be noticeably brighter than the middle.

Regards, Martin Brown

Reply to
Martin Brown

r

Laptops etc use sheets especially tailored to the light source and geometry to get even lighting, followed by several sheets of diffusers and partial reflectors. If you find a dead screen large enough I'd borrow its diffusers & partial reflectors to really help, but it's hard to get even illuminatio n really. You could get fairly near by laying small LEDs out in a matrix on the back, and painting the edges white. LEDs round the edges won't work fo r you, unless you do that with an LCD's thick plastic sheet with the gradie nt of diffusing dots on.

If you don't have those various sheets to play with, space blanket should g ive partial reflection and ground glass, lightly finely sanded acrylic or s ome clear plastic booklet covers should get you varying degrees of diffusio n.

Wattage isn't too important, it's trivial to reduce power later.

NT

Reply to
tabbypurr

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