Light emitting diode with integral parabolic reflector
First Claim
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1. A light emitting diode (LED) assembly comprising:
- a dielectric casing of optically transparent material;
first and second electrical leads extending within said dielectric casing;
at least one semiconductor die embedded in said dielectric casing and coupled to said first and second leads in a manner allowing for transfer of electrical energy to and illumination of said at least one semiconductor die; and
wherein said dielectric casing has a surface, at least a portion of which is parabolic, said parabolic surface portion located and dimensioned for reflecting light emitted by said at least one semiconductor die.
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Abstract
The dielectric casing of a light emitting diode (LED) incorporates an integral parabolic reflector system which redirects light in a collimated pattern deflected at significant angles relative to the axis of symmetry of the LED.
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Citations
12 Claims
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1. A light emitting diode (LED) assembly comprising:
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a dielectric casing of optically transparent material;
first and second electrical leads extending within said dielectric casing;
at least one semiconductor die embedded in said dielectric casing and coupled to said first and second leads in a manner allowing for transfer of electrical energy to and illumination of said at least one semiconductor die; and
wherein said dielectric casing has a surface, at least a portion of which is parabolic, said parabolic surface portion located and dimensioned for reflecting light emitted by said at least one semiconductor die. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of directing light in a light emitting diode (LED) assembly, said method comprising:
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emitting light from a semiconductor die embedded in a dielectric casing; and
reflecting said emitted light from a parabolic surface portion of said dielectric casing. - View Dependent Claims (9, 10)
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11. A light emitting diode (LED) assembly having an integral reflector comprising:
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a dielectric casing of optically transparent material;
first and second electrical leads extending within said dielectric casing; and
at least one semiconductor die embedded in said dielectric casing and coupled to said first and second leads in a manner allowing for transfer of electrical energy to and illumination of said at least one semiconductor die;
wherein said dielectric casing includes an integral concavity substantially opposite said at least one semiconductor die, the concavity being shaped and dimensioned for reflecting light emitted by said at least one semiconductor die;
wherein said concavity forms a truncated cone whose surface is described by revolving around the symmetric axis of said LED a parabolic segment defined by the equation y2=2Px, P representing a constant scale factor, the parabolic segment having its focus coincident with the centroid of said at least one semiconductor die and its vertex coincident with a line representing the x-axis passing through said centroid, the angle between said x-axis and said LED axis of symmetry determining the deflection angle of the reflector and being greater than 0° and
less than 180°
; and
wherein reflection at said parabolic surface occurs by means of total internal reflection according to Snell'"'"'s Law as expressed by the equation sin θ
c=n1/n2, θ
c representing the critical minimum angle of incidence beyond which a ray striking the parabolic surface will be totally reflected, n1, representing the refractive index of air, and n2 representing the refractive index of said dielectric casing.
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12. A light emitting diode (LED) assembly having multiple integral reflectors, said assembly comprising:
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a dielectric casing of optically transparent material;
first and second electrical leads extending within said dielectric casing; and
at least one semiconductor die embedded in said dielectric casing and coupled to said first and second leads in a manner allowing for transfer of electrical energy to and illumination of said at least one semiconductor die;
wherein said dielectric casing includes a multiplicity of convex surfaces substantially opposite said at least one semiconductor die, the convex surfaces shaped and dimensioned for reflecting light emitted by said at least one semiconductor die;
wherein each said convex surface has an associated x-axis which passes through the centroid of said at least one semiconductor die; and
each said convex surface forms a truncated cone as described by revolving around said associated x-axis a parabolic segment defined by the equation y2=2Px, P representing a constant scale factor, said parabolic segment having its focus coincident with the centroid of said at least one semiconductor die and its vertex coincident with said associated x-axis, the angle between said associated x-axis and the LED axis of symmetry determining the deflection angle of the reflector and being greater than 0° and
less than 180°
; and
wherein reflection at said parabolic surface occurs by means of total internal reflection according to Snell'"'"'s Law as expressed bythe equation sin θ
c=n1/n2, θ
c representing the critical minimum angle of incidence beyond which a ray striking the parabolic surface will be totally reflected, n1, representing the refractive index of air, and n2 representing the refractive index of said dielectric casing.
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Specification