Light extraction from LEDs with light pipes
First Claim
1. A non-imaging optical coupler that is a figure of revolution comprising, in combination:
- a) a light-transmitting body defining a recessed input cavity, a transparent-droplet shaped encapsulant of a light emitting diode, or array of diodes in the cavity, b) there being a body curved side wall shaped to totally internally reflect all the light emitted from the LED and encapsulant, traveling toward said side wall, within a predetermined distance from the diode or center of said array, c) there also being a body cylindrical transition section extending from said curved side wall and forwardly, d) a planar exit face at the forward end of the body, transverse to an axis of said figure of revolution.
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Accused Products
Abstract
A non-imaging optical coupler that is a figure of revolution combining a light-transmitting body defining a recessed input cavity, a transparent droplet-shaped encapsulant of a light-emitting diode, or array of diodes in the cavity, the body having a curved side wall shaped to totally internally reflect all the light emitted from the LED and encapsulant, traveling toward the side wall, within a predetermined distance from the diode or center of array, the body having a cylindrical transition section extending from a curved side wall and forwardly, and a planar exit face at the forward end of the body, transverse to the central axis of the figure of revolution.
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Citations
13 Claims
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1. A non-imaging optical coupler that is a figure of revolution comprising, in combination:
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a) a light-transmitting body defining a recessed input cavity, a transparent-droplet shaped encapsulant of a light emitting diode, or array of diodes in the cavity, b) there being a body curved side wall shaped to totally internally reflect all the light emitted from the LED and encapsulant, traveling toward said side wall, within a predetermined distance from the diode or center of said array, c) there also being a body cylindrical transition section extending from said curved side wall and forwardly, d) a planar exit face at the forward end of the body, transverse to an axis of said figure of revolution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
i) blue light, used for curing of dental materials, photodynamic therapy ii) red light used for dental whitening, photodynamic therapy iii) UV light for UV curing epoxies or for stimulation of fluorescent emission.
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6. The combination of claim 1 wherein the body has two external wall sections, one of which is parabolic, and the other of which joins said one section, and has increasing curvature toward the rim of said cavity.
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7. The combination of claim 6 wherein said one section is configured to reflect light rays from the cavity toward the body exit face and to have angles θ
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m of incidence with said body exit face, where θ
m is slightly less than sin−
1(1/n) for refractive index n of said light-transmitting body.
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m of incidence with said body exit face, where θ
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8. The combination of claim 1 wherein the encapsulant in the cavity excludes any air gap between the encapsulant and the cavity interior wall.
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9. The combination of claim 1 wherein the encapsulant consists of epoxy or silicone.
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10. The method of efficiently transmitting light from an LED, or array of LEDs, that includes:
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a) providing a light transmitting body defining a recessed input cavity, a transparent-droplet shaped encapsulant of a light emitting diode, or array of diodes in the cavity, b) the body provided to have a curved side wall shaped to totally internally reflect substantially all the light emitted from the LED and encapsulant, traveling toward said side wall, within a predetermined distance from the diode or center of said array, c) the body provided to have a cylindrical transition section extending from said curved side wall and forwardly, d) and the body provided to have a planar exit face at the forward end of the body, transverse to an axis of said figure of revolution. - View Dependent Claims (11, 12, 13)
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Specification