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Led light

I arranged 4 LED strips to a old laptop display but still the light is not diffusing. I am looking for a cheap setup of LED which will illuminate the entire screen with white light like a LCD backlight will do.

Is there any way to do so?

I am looking for something like this.

backlight

chicks
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Browniepoints
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  • Increase the distance between the screen and the LEDs. If the LEDs have lenses on their ends they will de difficult to diffuse without a translucent plexiglass screen. Good luck. – Stan Sep 16 '21 at 19:03
  • By lenses, do you mean the outer covering of each led? – Browniepoints Sep 17 '21 at 00:49
  • Ideally you would get or make a diffuser film. Note that in the usual installation, the lights aren't distributed under the panel like a layer of a sandwich, but pointed along the long axis of the diffuser. – Luke Sawczak Sep 17 '21 at 10:27
  • LEDs have polished or matte, round or flat surfaces. Flat matte lenses (ends) will disperse better than the other case configurations. Sorry for the delay answering. – Stan Sep 17 '21 at 13:22
  • @Luke Sawczak Yes, the display’s original backlight only has a strip of 10 or 12 small leds but the display was too bright. I could try that method, guiding light through the plastic glass. I think its plexiglass. – Browniepoints Sep 17 '21 at 16:10
  • @Stan Yes I googled Flat surface. This is round leds. Maybe, a cello tape on each individual LED like a dome would work. Do ypu have any suggestions. But first, I will try to guide the light to the Plexiglass glass like you and Luke suggested. – Browniepoints Sep 17 '21 at 16:14
  • what we used to do was file the round end off the led – Polypipe Wrangler Sep 27 '21 at 12:59
  • Have you seen this video? https://m.youtube.com/watch?v=6bqBsHSwPgw – dzh Oct 10 '21 at 02:37

1 Answers1

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Talking Dirty (Optical Engineers do this in small groups at OSA1 conventions in foreign cities): Evenly diffuse irradiance patterns made from discrete (separate) points of illumination such as LEDs must be placed in a pattern that fulfils the requirements prescribed by "Sparrows Criterion."

That is fulfilled when they are close enough so their irradiance patterns (light beams) overlap enough to appear diffuse rather than discrete. This typically happens when the centres of the LED light pattern are a tiny bit closer than the point where the intensity drops to 47% of the light cone. The intensity diagram looks like this: LED illuminance profile diagram

Here's (finally) the hack: You must either increase the distance between the LEDs and the diffusion screen or push the LEDs closer together until the beams intersect to form a continuous source. (or both)

And/Or

Find a piece of translucent plexiglass to better diffuse the LEDs light cones.

Good luck.

1. Optical Society of America

Stan
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