Method and apparatus for light redistribution by internal reflection
First Claim
1. A method for redistributing light by internal reflection within a lens comprising the steps of:
- receiving divergent light from a light source into a lens, said light source having an optical axis and a generally symmetrical light radiation pattern;
converting the divergent light into generally collimated light within the lens by internal reflection, said generally collimated light symmetrically distributed about said optical axis and having a first direction generally parallel to said optical axis;
diverting a first portion of said generally collimated light from said first direction to a second direction by internal reflection within the lens, while permitting a second portion of said generally collimated light to continue in said first direction;
redirecting said first portion from said second direction to a third direction by internal reflection within the lens, said third direction being generally parallel to said first direction, whereby said first portion is emitted from the lens at a position radially displaced from said second portion and the optical axis of the light source.
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Accused Products
Abstract
A method and apparatus are disclosed for redistributing light to shift the apparent position of light generation and provide a more uniform area of light emission from a light assembly incorporating a plurality of spaced-apart light sources. Divergent light from each light source is collimated into a beam. Portions of each beam are diverted from the direction of the beam, transmitted laterally and redirected to emerge from the light assembly radially spaced from the position of the light source producing the beam. An internal reflecting lens member molded from optical plastic is disclosed as one apparatus for carrying out the method. The disclosed method and apparatus are particularly applicable to light assemblies incorporating an array of LEDs.
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Citations
19 Claims
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1. A method for redistributing light by internal reflection within a lens comprising the steps of:
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receiving divergent light from a light source into a lens, said light source having an optical axis and a generally symmetrical light radiation pattern;
converting the divergent light into generally collimated light within the lens by internal reflection, said generally collimated light symmetrically distributed about said optical axis and having a first direction generally parallel to said optical axis;
diverting a first portion of said generally collimated light from said first direction to a second direction by internal reflection within the lens, while permitting a second portion of said generally collimated light to continue in said first direction;
redirecting said first portion from said second direction to a third direction by internal reflection within the lens, said third direction being generally parallel to said first direction, whereby said first portion is emitted from the lens at a position radially displaced from said second portion and the optical axis of the light source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
arranging a first internal lens surface to reflect said first portion, said first internal lens surface having an angular orientation relative to said first direction such that said first portion is reflected generally perpendicular to said first direction.
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3. The method of claim 2, wherein said first internal lens surface is planar.
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4. The method of claim 2, wherein said first internal lens surface is curved.
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5. The method of claim 4, wherein said curved first internal lens surface has a curvature defined by a portion of a parabola.
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6. The method of claim 1, wherein said step of diverting comprises:
arranging a plurality of first internal lens surfaces to reflect said first portion, each of said plurality of first internal lens surfaces separated from an adjacent of said plurality of first internal lens surfaces by a lens portion which permits some of said second portion of said generally collimated light to continue in said first direction, each of said plurality of first internal lens surfaces having an angular orientation relative to said first direction such that said first portion is reflected generally perpendicular to said first direction.
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7. The method of claim 1, wherein said step of redirecting comprises:
arranging a second internal lens surface to reflect said first portion from said second direction to said third direction, said second internal lens surface having an angular orientation relative to said second direction such that said first portion is reflected generally perpendicular to said second direction.
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8. The method of claim 7, wherein said second internal lens surface is planar.
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9. The method of claim 7, wherein said second internal lens surface is curved.
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10. The method of claim 9, wherein said curved second internal lens surface has a curvature defined by a portion of a parabola.
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11. The method of claim 1, wherein said step of redirecting comprises:
arranging a plurality of second internal lens surfaces to reflect said first portion, each of said plurality of second internal lens surfaces radially separated from an adjacent of said plurality of second internal lens surfaces, each of said plurality of second internal lens surfaces having an angular orientation relative to said second direction such that said first portion is reflected generally perpendicular to said second direction and generally parallel to said first direction.
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12. A warning light assembly comprising:
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an array of LED light sources, each LED generating diverging light;
an integrally formed lens member defining;
a plurality of collimators positioned to receive the diverging light generated by a corresponding one of the LEDs and convert said diverging light into a substantially collimated beam having a first direction;
a first internal lens surface arranged to divert part of at least one of said collimated beams in a second direction by reflection within the lens, said second direction being substantially perpendicular to said first direction;
a second internal lens surface arranged to receive and redirect light from said first internal lens surface in a third direction by reflection within the lens, said third direction being substantially perpendicular to said second direction and substantially parallel to said first direction;
wherein light redirected by said second internal lens surface is emitted from said lens member radially spaced from said at least one of said collimated beams. - View Dependent Claims (13, 14, 15, 16)
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17. A lens member for a light assembly comprising a plurality of light sources generating divergent light, said lens member comprising:
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a collimator arranged to receive the divergent light from a light source and convert said divergent light into a substantially collimated beam by internal reflection, said substantially collimated beam having a first direction and a first position relative to the light source; and
a light pipe comprising;
a first internal lens surface arranged to divert a portion of the substantially collimated beam from said first direction into a second direction;
a second internal lens surface arranged to redirect light from said first internal lens surface into a third direction; and
a lens portion for transmission of light from said first internal lens surface to said second internal lens surface, wherein said light redirected by said second internal lens surface is emitted from said lens member at a second position radially spaced from said first position. - View Dependent Claims (18)
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19. A method for shifting the apparent position of light generation in a light assembly, said light assembly comprising a light source generating divergent light and having an optical axis, said method comprising:
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collimating the diverging light from said light source into a substantially collimated beam substantially symmetrically arranged about said optical axis and having a first direction substantially parallel to said optical axis;
arranging a first lens surface to divert a portion of said substantially collimated beam from said first direction into a second direction;
transmitting said portion radially relative to said optical axis; and
arranging a second lens surface to redirect said portion into a third direction, wherein said portion is emitted from said light assembly at a position radially displaced from said optical axis.
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Specification