Hello,
I'm a university student who is currently doing a plant incubator project, which requires LED grow light system. One of the project objectives is to provide a wavelength-tunable light source, so I plan to combine 4 LEDs (with different wavelengths) into a single source. One of the example I saw from papers is they design a freeform TIR lens for color uniformity via commercial software. But I was wondering if there is any other way to combine and collimate the LED beam via lens/optics?
Thank you.
Dear Jie,
This problem has been solved for LCDs to obtain uniform white emitting screens on the basis of RGB LED arrays. You have to use a scattering screen, e.g. based on a SiO2 nanoparticle (200 - 400 nm) coated light guide. Moreover, the array of LEDs have to placed at a sufficient large distance to obtain colour uniformity. The attached image from a presentation at a SID Meeting in 2004 might help you.
All the best,
Thomas
Ideed, the simplest technique is distance, assuming all your LEDs have a similar far field. If you need the light more concentrated, you may look for integrators or Köhler illumination.
May I raise an objection ? You don't need a good CRI for horticulture. And luminous flux is not an adequate measure here.
Dear all,
I agree on Henning! In other words for horticulture lighting you do not need to regard the CRI, but a good overlap with action curves (photosynthesis rate, chlorophyll formation and so on) of the specific plant. You can find some relevant action curves in the DIN regulation 5031-10.
All the best,
Thomas
- Badges
- Science topic