US 2010/0165637 A1 · ILLUMINATION LENSES INCLUDING LIGHT REDISTRIBUTING SURFACES

Abstract

Illumination lenses (1806, 1902, 2002, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 3006, 3100) having surfaces shaped according to given differential equations in order to distribute light in a highly controlled manner with minimum reflection losses are provided. Both primary lenses and secondary lenses are provided. The secondary lenses include outer surfaces that are defined as loci of constant optical distance from an origin at which a light source is located. Versions are provided of both the primary and secondary lenses having Total Internal Reflection (TIR) wings. These are useful in the case that narrower distributions of light are required. A method of refining the shape of the lenses to obtain more obtain lenses that produce better fidelity ideal light distributions is also provided.

Claims20

Dependent claims

A lens comprising:

first surface and a second surface wherein at least a portion of the first surface has a shape described by a differential equation DE1 defined in a polar coordinate system:
DE

1
∂
∂
φ1

r


1

(
φ1
)
=
-
r


1

n


2

sin

(
φ2
-
φ1
)
n


2

cos

(
φ2
-
φ1
)
-
n


1
where:
n2 is an index of refraction of the lens;
n1 is an index of refraction of a medium surrounding the lens;
phi1 is a polar angular coordinate of the first surface;
phi2 is a polar angle of an ideal ray emitted at an origin of a coordinate system in which the differential equation DE1 is defined that was initially emitted at angle phi1 after the ideal ray been refracted by the first lens surface;
with an initial condition r1_ini.

55 more elements

An illumination lens comprising a refracting surface having a generatrix described by a differential equation:

DE

1
∂
∂
φ1

r


1
=
r


1

n


2

sin

(
φ2
-
φ1
)
-
n


2

cos

(
φ2
-
φ1
)
+
n


1
where,
r1 is a radial coordinate of the refracting surface;
phi1 is a polar (zenith) angle coordinate of the refracting surface, and is also a domain variable over which the equation is defined
n1 is an index of refraction of the lens;
n2 is the index of refraction of a surrounding;
and
phi2 is given by:
∫
φ1_

MIN
φ1

rad_in

(
φ1
)
·
2

π
·
sin

(
φ1
)



φ1
∫
φ1_

MIN
φ1_

MAX

rad_in

(
φ1
)
·
2

π
·
sin

(
φ1
)



φ1
=
∫
φ2_

MIN
φ2

(
rad_out

(
φ2
)
-
∑
i
=
1
N
-
1


Error
i

(
φ2
)
)
·
2


π


·
sin

(
φ2
)



φ2
∫
φ2_

MIN
φ2_

MAX

(
rad_out

(
φ2
)
-
∑
i
=
1
N
-
1


Error
i

(
φ2
)
)
·
2

π
·
sin

(
φ2
)



φ2
where,
phi1_MIN is a lower polar angle limit of light collected by the lens;
phi1_MAX is an upper polar angle limit of light collected by the lens;
phi2_MIN is a lower polar angle limit of a predetermined specified output light intensity distribution;
phi2_MAX is an upper polar angle limit of the predetermined specified output light intensity distribution;
rad_in(phi1) is a light intensity distribution of a light source for which the lens is designed;
and
rad_out(phi2) is the predetermined specified output light intensity distribution;
with initial condition r1_ini for r1;
Errori(phi2) is a measured difference between rad_out(phi2) and an intensity distribution produced by an iTH prototype;
and
N is a cardinal number identifying the lens in a sequence of prototype lenses.

207 more elements

Dependencies are inferred from the claim text.

Illumination lenses including light redistributing surfaces

Life of this patent

Illumination lenses including light redistributing surfaces

Life of this patent

Abstract

Claims20