Collimator comprising a prismatic layer stack, and lighting unit comprising such a collimator

Patent metadata

Field	Value
Publication number	US-9383075-B2
Application number	US-201213985056-A
Country	US
Kind code	B2
Filing date	Feb 21, 2012
Priority date	Feb 22, 2011
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

The invention provides a collimator comprising a first collimator face, a second collimator face, and a stack region. The stack region comprises a first layer having a first prismatically shaped top face with a plurality of 1D arranged first prisms having first prism axes, and a second layer having a second prismatically shaped top face with a plurality of 1D arranged second prisms having second prism axes. The first and second prism axes are in a crossed configuration. In a direction from the first collimator face to the second collimator face, the index of refraction of material upstream of the first prismatically shaped top face is larger than that of material downstream of the first prismatically shaped top face, and the index of refraction of material upstream of the second prismatically shaped top face is larger than that of material downstream of the second prismatically shaped top face.

First claim

The invention claimed is:

1. A collimator comprising:
a first collimator face;
an opposite second collimator face;
a stack region comprising:
a first layer having a first prismatically shaped top face with a plurality of one dimensionally (1D) arranged first prisms having first prism axes;
a second layer having a second prismatically shaped top face with a plurality of 1D arranged second prisms having second prism axes;
an intermediate layer; and
a top layer, wherein the first layer, the intermediate layer, the second layer, and the top layer are adjacently arranged;
wherein the first prism axes and the second prism axes are in a crossed configuration, wherein in a direction from the first collimator face to the second collimator face the index of refraction of material upstream of the first prismatically shaped top face is larger than that of material downstream of the first prismatically shaped top face, and wherein the index of refraction of material upstream of the second prismatically shaped top face is larger than that of material downstream of the second prismatically shaped top face,
wherein the first prismatically shaped top face is the interface between the first layer and the intermediate layer, and wherein the second prismatically shaped top face is the interface between the second layer and the top layer, wherein the index of refraction of the first layer is larger than that of the intermediate layer, and wherein the index of refraction of the second layer is larger than that of the top layer.

2. The collimator according to claim 1 , wherein the first prisms and second prisms have prism apex angels (α) and groove angles (β) selected from the range of 70-150°.

3. The collimator according to claim 2 , wherein the first prisms and second prisms have prism apex angels (α) and groove angles (β) selected from the range of 80-100°.

4. The collimator according to claim 3 , wherein the first prism axes and the second prism axes have mutual angles (θ) in the range of 80-100°.

5. The collimator according to claim 4 , wherein the first layer and the second layer have a prismatic layer pitch (p) selected from the range of 5-5000 μm.

6. The collimator according to claim 5 , wherein the prismatic layer pitch (p) is selected from the range of 5-200 μm.

7. A collimator comprising:
a first collimator face;
an opposite second collimator face;
a stack region comprising:
a first layer having a first prismatically shaped top face with a plurality of one dimensionally (1D) arranged first prisms having first prism axes; and
a second layer having a second prismatically shaped top face with a plurality of 1D arranged second prisms having second prism axes;
wherein the first prism axes and the second prism axes are in a crossed configuration, wherein in a direction from the first collimator face to the second collimator face the index of refraction of material upstream of the first prismatically shaped top face is larger than that of material downstream of the first prismatically shaped top face, and wherein the index of refraction of material upstream of the second prismatically shaped top face is larger than that of material downstream of the second prismatically shaped top face;
wherein the first prisms and second prisms have prism apex angels (α) and groove angles (β) selected from the range of 80-100°;
wherein the first prism axes and the second prism axes have mutual angles (θ) in the range of 80-100°;
wherein the first layer and the second layer have a prismatic layer pitch (p) selected from the range of 5-200 μm;
wherein the stack region comprises a bottom layer, the first layer, an intermediate layer, the second layer, and a top layer, wherein the bottom layer, the first layer, the intermediate layer, the second layer and the top layer are adjacently arranged, wherein the first prismatically shaped top face is the interface between the first layer and the intermediate layer, and wherein the second prismatically shaped top face is the interface between the second layer and the top layer, wherein the index of refraction of the first layer is larger than that of the intermediate layer, and wherein the index of refraction of the second layer is larger than that of the top layer.

8. The collimator according to claim 7 , wherein the first prism axes as well as the second prism axes are parallel arranged axes.

9. The collimator according to claim 7 , wherein the first prism axes and the second prism axes are radially and concentrically-arranged, respectively.

10. The collimator according to claim 9 , comprising a plurality of adjacently arranged prismatic layer stack regions.

11. A lighting unit comprising a light source, configured to provide light source light, and the collimator according to claim 10 , configured to collimate the light source light.

12. The lighting unit according to claim 11 , further comprising a light box, wherein the light box encloses the light source and wherein the light box comprises a light transmissive window, wherein the light transmissive window comprises the collimator.

13. A collimator comprising:
a first collimator face;
an opposite second collimator face;
a stack region comprising:
a first layer having a first prismatically shaped top face with a plurality of one dimensionally arranged first prisms having first prism axes;
a second layer having a second prismatically shaped top face with a plurality of arranged second prisms having second prism axes; and
an intermediate layer, wherein the first layer, the intermediate layer, and the second layer are adjacently arranged;
wherein the first prism axes and the second prism axes are in a crossed configuration, wherein in a direction from the first collimator face to the second collimator face the index of refraction of material upstream of the first prismatically shaped top face is larger than that of material downstream of the first prismatically shaped top face, and wherein the index of refraction of material upstream of the second prismatically shaped top face is larger than that of material downstream of the second prismatically shaped top face;
wherein the first prisms and second prisms have prism apex angels (α) and groove angles (β) selected from the range of 80-100°;
wherein the first prism axes and the second prism axes have mutual angles (θ) in the range of 80-100°;
wherein the first layer and the second layer have a prismatic layer pitch (p) selected from the range of 5-200 μm; and
wherein the first prismatically shaped top face is the interface between the first layer and the intermediate layer, and wherein the second prismatically shaped top face is the interface between the intermediate layer and the second layer, wherein the index of refraction of the first is larger than that of the intermediate layer, and wherein the index of refraction of the intermediate layer is larger than that of the second layer.

Assignees

• Pijlman Fetze
• Vissenberg Michel Cornelis Josephus Marie
• De Zwart Siebe Tjerk
• Van Gheluwe Jochen Renaat
• Koninkl Philips Nv

Inventors

• Pijlman Fetze
• Vissenberg Michel Cornelis Josephus Marie
• De Zwart Siebe Tjerk
• Van Gheluwe Jochen Renaat

Classifications

• G02B5/045

  Prism arrays · CPC title

• F21V5/005 Primary

  using microprisms · CPC title

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G02B27/30

  Collimators · CPC title