LED Lens Design with More Uniform Color-Over-Angle Emission
First Claim
1. An apparatus, comprising:
- a substrate with a upper surface;
light emitting diode (LED) dies disposed on the upper surface of the substrate, wherein a surface emitter length is a maximum distance between farthest apart edges of the LED dies;
a lens material disposed on the upper surface of the substrate over the LED dies, wherein the lens material is shaped as a portion of a sphere having a dome and a radius, and wherein a dome height extends from a top of the dome to the upper surface of the substrate; and
phosphor particles disbursed throughout the lens material, wherein a bottom chord length is a maximum length that the lens material extends over the upper surface of the substrate, wherein the bottom chord length is less than twice the surface emitter length, and wherein the dome height is between 57% and 73% of the radius.
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Accused Products
Abstract
An LED device with improved angular color performance has a silicone lens shaped as a portion of a sphere. The lens is molded over an array of LED dies disposed on the upper surface of a substrate. Phosphor particles are disbursed throughout the material used to mold the lens. The distance between farthest apart edges of the LED dies is more than half of the length that the lens extends over the surface of the substrate. The distance from the top of the lens dome to the surface of the substrate is between 57% and 73% of the radius of the sphere. Shaping the lens as the top two thirds of a hemisphere reduces the non-uniformity in the emitted color such that neither of the CIE color coordinates x or y of the color changes more than 0.004 over all emission angles relative to the surface of the substrate.
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Citations
20 Claims
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1. An apparatus, comprising:
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a substrate with a upper surface; light emitting diode (LED) dies disposed on the upper surface of the substrate, wherein a surface emitter length is a maximum distance between farthest apart edges of the LED dies; a lens material disposed on the upper surface of the substrate over the LED dies, wherein the lens material is shaped as a portion of a sphere having a dome and a radius, and wherein a dome height extends from a top of the dome to the upper surface of the substrate; and phosphor particles disbursed throughout the lens material, wherein a bottom chord length is a maximum length that the lens material extends over the upper surface of the substrate, wherein the bottom chord length is less than twice the surface emitter length, and wherein the dome height is between 57% and 73% of the radius. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method, comprising:
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attaching light emitting diode (LED) dies on an upper surface of a substrate, wherein a surface emitter length is a maximum distance between farthest apart edges of the LED dies; disbursing phosphor particles in a lens material; and forming a lens over the LED dies using the lens material containing the disbursed phosphor particles, wherein the lens is shaped as a portion of a sphere, wherein the sphere has a radius and the lens has a dome, wherein a dome height extends from a top of the dome to the upper surface of the substrate, wherein a bottom chord length is a maximum length that the lens material extends over the upper surface of the substrate, wherein the bottom chord length is less than twice the surface emitter length, and wherein the dome height is between 57% and 73% of the radius. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. An apparatus, comprising:
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light emitting diode (LED) dies disposed on an upper surface of a substrate, wherein a surface emitter length is a maximum distance between farthest apart edges of the LED dies; phosphor particles disbursed throughout a material molded over the LED dies on the upper surface of the substrate, wherein the LED dies emit bluish light, wherein the phosphor particles convert some of the bluish light to light with a longer wavelength, wherein the emitted bluish light combined with the emitted light with the longer wavelength exhibit a color at each angle relative to the upper surface, and wherein each color has a CIE-1931 color coordinate x; and means for reducing a non-uniformity in the color exhibited over all angles relative to the upper surface such that the CIE-1931 color coordinate x of the color does not change more than 0.004 over all angles relative to the upper surface, wherein the surface emitter length is more than half a maximum length that the means extends over the upper surface of the substrate. - View Dependent Claims (18, 19, 20)
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Specification