Apparatus for controlling the re-distribution of light emitted from a light-emitting diode
AssigneeKorry Electronics Co.
InventorsJohn R. Green, Stephen H. Humphrey, Timothy R. Robinson
Life of this patent
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Abstract
A system for re-distributing light emitted from a light source using an optical element is described. The optical element is manufactured using a bulk matrix material, and diffusing particles and/or scattering particles are embedded within the bulk material. The optical element is coupled to the light source to capture emitted light and redistribute the light in a desired angular distribution pattern depending on the ratio of total weight of diffusing particles to total weight of scattering particles.
Claims19
An illumination system comprising:
- an illumination source configured to emit light in forward directions away from the illumination source;
- and
- an optical element coupled to the illumination source and configured to receive the emitted light, the optical element comprising a material embedded with forward-scattering particles with negligible light absorption that redirects a first portion of the light forwardly away from the illumination source, and backward-scattering particles with negligible light absorption and that redirect a second portion of the light rearwardly toward and past the illumination source, wherein the redirected first and second portions of the light are angularly distributed in a substantially quasi-isotropic light distribution relative to the illumination source, wherein at least a portion of the quasi-isotropic light distribution is rearward of the illumination source.
A light-redirecting optical element, comprising:
- a bulk material configured to receive light emitted from a source in forward directions having a first angular distribution pattern and to redistribute the received light in a second angular distribution pattern;
- a plurality of forward-scattering particles with negligible light absorption embedded in the bulk material and configured to redirect a first portion of the light forwardly away from the illumination source;
- and
- a plurality of backward-scattering particles with negligible light absorption embedded in the bulk material and configured to redirect a second portion of the light rearwardly toward and past the illumination source;
- wherein the redirected first and second portions of the light are angularly distributed in a substantially quasi-isotropic light distribution relative to the illumination source;
- wherein at least a portion of the quasi-isotropic light distribution is rearward of the illumination source.
A method of changing a distribution of emitted light from a source, comprising:
- emitting light from a light-emitting diode (LED) in forward directions away from the LED;
- receiving the emitted light with an optical element, wherein the optical element comprises a bulk material embedded with a plurality of forward-scattering particles and a plurality of backward-scattering particles;
- re-emitting at least some of the received light in a distribution pattern, wherein at least a first portion of light incident on the plurality of forward scattering particles is re-emitted with negligible light absorption in the forward direction away from the LED and wherein at least a second portion of light incident on the plurality of backward-scattering particles is re-emitted with negligible light absorption in a backward direction toward and past the illumination source;
- wherein the re-emitted first and second portions of the light are angularly distributed in a substantially quasi-isotropic light distribution relative to the illumination source;
- wherein at least a portion of the quasi-isotropic light distribution is rearward of the illumination source.
Dependencies are inferred from the claim text.