Multi-chip LED color mixing by diffraction
First Claim
1. A light emitting device comprising:
- a diffractive optical element;
a first light emitting diode emitting first light having a first range of wavelengths, said first light directed onto said diffractive optical element at a first range of angles of incidence; and
a second light emitting diode emitting second light having a second range of wavelengths, said second light directed onto said diffractive optical element at a second range of angles of incidence;
wherein said first light and said second light substantially overlap on said diffractive optical element and said diffractive optical element diffracts at least a portion of said first light and at least a portion of said second light into a same range of angles of diffraction to obtain light having a desired range of wavelengths.
4 Assignments
0 Petitions
Accused Products
Abstract
A light emitting device in accordance with an embodiment of the present invention includes a diffractive optical element, a first light emitting diode emitting first light having a first range of wavelengths, and a second light emitting diode emitting second light having a second range of wavelengths. The first light is directed onto the diffractive optical element at a first range of angles of incidence, and the second light is directed onto the diffractive optical element at a second range of angles of incidence. The diffractive optical element diffracts at least a portion of the first light and at least a portion of the second light into the same range of angles of diffraction to obtain light having a desired range of wavelengths. A light emitting device in accordance with an embodiment of the present invention can efficiently mix the outputs of two or more light emitting diodes to form a substantially uniform output of, for example, white light.
-
Citations
24 Claims
-
1. A light emitting device comprising:
-
a diffractive optical element;
a first light emitting diode emitting first light having a first range of wavelengths, said first light directed onto said diffractive optical element at a first range of angles of incidence; and
a second light emitting diode emitting second light having a second range of wavelengths, said second light directed onto said diffractive optical element at a second range of angles of incidence;
wherein said first light and said second light substantially overlap on said diffractive optical element and said diffractive optical element diffracts at least a portion of said first light and at least a portion of said second light into a same range of angles of diffraction to obtain light having a desired range of wavelengths. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A light emitting device comprising:
-
a diffraction grating;
a first light emitting diode emitting blue light, said blue light directed onto said diffraction grating at a first range of angles of incidence;
a second light emitting diode emitting green light, said green light directed onto said diffraction grating at a second range of angles of incidence; and
a third light emitting diode emitting red light, said red light directed onto said diffraction grating at a third range of angles of incidence;
wherein said blue light, said green light, and said red light substantially overlap on said diffraction grating and said diffraction grating diffracts at least a portion of said blue light, at least a portion of said green light, and at least a portion of said red light into a same range of angles of diffraction to thereby form a white light output.
-
-
16. A method of mixing light emitted by a plurality of light emitting diodes, the method comprising:
-
directing first light emitted by a first light emitting diode and having a first range of wavelengths onto a diffractive optical element at a first range of angles of incidence; and
directing second light emitted by a second light emitting diode and having a second range of wavelengths onto said diffractive optical element at a second range of angles of incidence such that said first light and said second light substantially overlap on said diffractive optical element, and such that at least a portion of said first light and at least a portion of said second light are diffracted into a same range of angles of diffraction to obtain light having a desired range of wavelengths. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
-
Specification