PLANAR LIGHT SOURCE AND PLANAR LIGHTING APPARATUS

• US 20060198144A1
• Filed: 03/06/2006
• Published: 09/07/2006
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Miyairi, Hiroshi, Watanabe, Kazunori
• Granted Patent: US 7,422,347 B2
• Time in Patent Office: Days
• US Class Current: 362/257
• CPC Class Codes: A47F 3/001 Devices for lighting, humidifying, heating, ventilation
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 3/06 with cylindrical or toric faces
• CPC Class Codes: G09F 13/22 electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A planar light source comprises at least one point light source disposed on a supporting substrate, and a cylindrical lens that covers the light emitting observation side of the point light source, wherein the cylindrical lens has a concave lens function in the direction (y direction) perpendicular to the supporting substrate, and has a convex lens function in at least part of the horizontal direction (x direction).

Claims

1. A planar light source comprising at least one point light source disposed on a supporting substrate, and a cylindrical lens that covers the light emitting observation side of the point light source,

wherein the cylindrical lens has a concave lens function in the direction (y direction) perpendicular to the supporting substrate, and has a convex lens function in at least part of the horizontal direction (x direction).

2. The planar light source according to claim 1, wherein the point light source is disposed between the cylindrical lens having a convex lens function and the focal point of the cylindrical lens having the convex lens function.

3. The planar light source according to claim 1, wherein the point light source has orientation characteristics with a cosine curve relative to the x and y directions, and light that has passed through the cylindrical lens has orientation characteristics that have two peaks and are in right and left symmetry relative to the x and y directions.

4. The planar light source according to claim 1, wherein the cylindrical lens is a hollow structure having a space between itself and the point light source.

5. The planar light source according to claim 1, wherein the cylindrical lens is formed from one or more materials selected from the group consisting of acrylic resin, polycarbonate resin, amorphous polyolefin resin, polystyrene resin, norbornene-based resin, cycloolefin-based polymer (COP), epoxy resin, silicone resin, acrylonitrile-butadiene-styrene resin (ABS resin), sapphire, quartz, soda glass, borosilicate glass, silica glass, oxynitride glass, and rear earth glass.

6. The planar light source according to claim 1, wherein the cylindrical lens is composed of a material having different refractive indices in the portion having the concave lens function and in the portion having the convex lens function, and the material forming the portion having the concave lens function has a lower refractive index than the material forming the portion having the convex lens function.

7. The planar light source according to claim 1, wherein a diffusing agent is admixed in only the portion of the cylindrical lens having the concave lens function.

8. The planar light source according to claim 1, wherein the point light source is a light emitting diode.

9. The planar light source according to claim 1, wherein the light emitting diode is a surface mount type.

10. The planar light source according to claim 1, wherein the light emitting diode emits white light.

11. The planar light source according to claim 10, wherein the point light source is constituted by a light emitting diode comprising light emitting diode chip and a fluorescent substance that converts the wavelength of light emitted by the light emitting diode chip, and the emitted light is mixed-color light comprising light from the light emitting diode chip and light from the fluorescent substance.

12. The planar light source according to claim 10, wherein the point light source is constituted by a single light emitting diode including a plurality of light emitting diode chips, and the emitted light is white light produced by color-mixing the light from the plurality of light emitting diode chips.

13. The planar light source according to claim 10, wherein the emitted light is white light produced by color-mixing the light from a plurality of light emitting diodes.

14. A planar lighting apparatus comprising planar light sources of claim 1 installed in the x direction at regular intervals.