Instructables

How to Diffuse LED??

Hello. I'm new to LEDs. Does anyone have advice on how to diffuse the light from an LED (or group of LEDs) so that it might illuminate a clear sheet of plexiglass. Backlighting the glass is not a possibility with this particular project. Thank you.

Minion713 years ago
well what i do is flatten the led so the focused lens is flat made 10degree led to approximately 120 degree
20104 years ago
Try using sand paper 600 to 1000 grit the higher the beter.
Just rub it against the led be carefull not too bend the terminals too much or they will snap off.
Fill the box with hot glue.
trialex7 years ago
It's all about the edge lighting... try drilling 5mm diameter, 5mm deep holes in the SIDES of the plexi, then stick the LEDs in. Use a slow drill speed to keep the holes clean
Yogurt Ogre (author)  trialex7 years ago
Thanks trialex. I don't think, however, that my plexi is thick enough to drill into.
Use a thicker sheet then :-)
Yogurt Ogre (author)  trialex7 years ago
haha!
HAHAHAA that is one FUNNY suggestion! (By the way, this conversation was a year ago, let's continue it! It's fun to continue 1-year-old coversations!)
It was NOT a year ago. It was TWO years ago
Oops... My mistake. So, anyways, 2 years ago I still remember my friend putting a piece of plasticene in our professor's cup. Man was that a big mistake! Time flies like an arrow! Fruit flies like an orange! ( Get it? Flies? )
eyebot1175 years ago
...but neither of those would let you see the painting. If there's a will, there's a way.
eyebot1175 years ago
a white backdrop or piece of paper behind the glass will help, or you could try a more opaque (cloudy) piece of lexan to help diffuce the light....
royalestel7 years ago
You gotta give more info. A sketch or something. Anyhow, want to make a screen to cath light? Sand the surface of the plexiglass. But more info needed to answer your Q better.
Yogurt Ogre (author)  royalestel7 years ago
The plexiglass is going to be situated vertically in front of a painting. The painting behind needs to be visible from behind. Als, the plexiglass has clear stickers of individual objects that need to be made visibly apart from the painting. Thanks!
So a shadowbox, diarama type thing? You could place LEDS in the frame. Sand the point of the LED. LEDs are made with different... focus(?) spread of light. Get some wide angle lights. It might take a number of attempts to get the right amount of light. Perhaps mock up a cardboard box for testing. Then you'll have to make a frame to hide the inner frame. This could make a good instructable.
Yogurt Ogre (author)  SacTownSue7 years ago
Thanks for your input, SacTownSue. The painting, however, is less of a shadow box. I forgot to specify in my description that I intend the plexiglass to be connected like a hinge to the top and bottom of the canvas.
kadris37 years ago
the drilling advise above was good. do all 4 corners. run the LEDs in at a 45 degree angle. they could also be added 90 degrees in the center of the glass. you can rough up the LEDs for more dissapation. use corse sandpaper or a sharpening stone, or heck a rock. it may be enough to have the journals that hold the leds almost white from roughing and leave the leds in tact. u probably want 3mm LEDs for the sake of narrow journals and narrow plexiglass. lite the world. good luck.
Yogurt Ogre (author)  kadris37 years ago
Thank you very much, kadris3, for your advice on sanding the LEDs. I'll take it into consideration. : )
LasVegas7 years ago
Defuse the edges of the plexiglas rather than the LEDs themselves.
Yogurt Ogre (author)  LasVegas7 years ago
How might I diffuse the edges? Thank you LasVegas.
Course sandpaper on a block with circular strokes, or a small sand blaster. Don't remove the protective film until you're done.
Yogurt Ogre (author)  LasVegas7 years ago
Thanks LasVegas!!!
acer737 years ago
If you wanna be getto just cover the plexiglass with tissuepaper