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.


  • 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, 2021 at 19:03
  • By lenses, do you mean the outer covering of each led? Sep 17, 2021 at 0:49
  • 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. Sep 17, 2021 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, 2021 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. Sep 17, 2021 at 16:10

1 Answer 1


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)


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

Good luck.

1. Optical Society of America


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