Lighting fixture

• US 20050063185A1
• Filed: 02/10/2003
• Published: 03/24/2005
• Est. Priority Date: 02/12/2002
• Status: Active Grant

• Current Assignee: Daisho Denki Inc., Nichia Corporation
• Original Assignee: Daisho Denki Inc., Nichia Corporation
• Inventors: Inuzuka, Tomoaki, Monjo, Yoshio
• Granted Patent: US 7,073,922 B2
• Time in Patent Office: Days
• US Class Current: 362/269
• CPC Class Codes: F21V 14/02 by movement of light sources in vehicle head lamps F21S41/657
• CPC Class Codes: F21V 14/04 by movement of reflectors in vehicle head lamps F21S41/675
• CPC Class Codes: F21V 23/04 the elements being switches safety devices F21V25/00
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 23/0457 the sensor sensing the operating status of the lighting device, e.g. to detect failure of a light source or to provide feedback to the device
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios
• CPC Class Codes: F21Y 2107/10 on concave supports or substrates, e.g. on the inner side of bowl-shaped supports
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A lighting apparatus comprises a plurality of light-emitting diodes emitting red, blue, and green light, the plurality of light-emitting diodes emitting light beams and being arranged so as to emit the light beams toward a focusing point; a control circuit for controlling the intensity of light emission of each of the light-emitting diodes emitting red, blue, and green light; a concave reflector reflecting and radiating the light focused from the light-emitting diodes to the focusing point so that the light is further focused or scattered; and a position-changing mechanism for changing a relative position of the concave reflector relative to the focusing point of the light-emitting diodes.

Claims

1. A lighting apparatus comprising:

a plurality of light-emitting diodes emitting red, blue, and green light, the plurality of light-emitting diodes emitting light beams and being arranged so as to emit the light beams toward a focusing point;

a control circuit for controlling the intensity of light emission of each of the light-emitting diodes emitting red, blue, and green light;

a concave reflector reflecting and radiating the light focused from the light-emitting diodes to the focusing point so that the light is further focused or scattered; and

a position-changing mechanism for changing a relative position of the concave reflector relative to the focusing point of the light-emitting diodes,

wherein the position-changing mechanism changes a relative position of the focusing point of the plurality of the light-emitting diodes relative to a focal point of the concave reflector so that the light beams from the light-emitting diodes are focused or scattered by the concave reflector.

2. The lighting apparatus according to claim 1, wherein a convex reflector is disposed between the concave reflector and the light-emitting diodes, and the convex reflector reflects the light focused from the light-emitting diodes to the focusing point, and the concave reflector reflects and radiates the light from the light-emitting diodes reflected by the convex reflector, so that the light is focused or scattered.

3. The lighting apparatus according to claim 2, wherein the position-changing mechanism changes a relative position of the concave reflector relative to the convex reflector or a relative position of the light-emitting diodes relative to the convex reflector, so that the light beams from the light-emitting diodes are focused or scattered by changing the relative position of the convex reflector relative to the concave reflector or the relative position of the light-emitting diodes relative to the convex reflector by the position-changing mechanism.

4. The lighting apparatus according to claim 3, wherein a reflection surface of the convex reflector is a spherical shape or a parabolic shape.

5. The lighting apparatus according to claim 1, wherein when the focusing point of the light-emitting diodes is positioned at the focal point of the concave reflector, the concave reflector reflects the light beams from the light-emitting diodes so as to focus the light beams.

6. The lighting apparatus according to claim 1, wherein the plurality of light-emitting diodes are arranged on a spherical base so that the light beams are focused to the focusing point.

7. The lighting apparatus according to claim 1, wherein the concave reflector is disposed so that its lower surface serves as a reflection surface, and the light-emitting diodes are arranged so as to upwardly emit the light beams from the lower side of the concave reflector.

8. The lighting apparatus according to claim 1, wherein a conical reflector horn, an inner surface of which reflects the light emitted from the light-emitting diodes so as to focus the light to its tip portion, is disposed between the light-emitting diodes and the concave reflector, and the conical reflector horn focuses the light emitted from the plurality of light-emitting diodes to the focusing point.

9. The lighting apparatus according to claim 8, wherein the conical reflector horn is a conical reflector with its inner surface serving as a reflection surface.

10. The lighting apparatus according to claim 8, wherein the conical reflector horn is molded in a conical shape from a transparent material, through which the light can pass.

11. The lighting apparatus according to claim 2, wherein the convex reflector is disposed adjacent to the focal point of the concave reflector, and the convex reflector reflects the light beams from the light-emitting diodes so that the concave reflector reflects the light beams.

12. The lighting apparatus according to claim 2, wherein the convex reflector is disposed adjacent to the focal point of the concave reflector, and the concave reflector has a center hole opening therein, and the light beams from the light-emitting diodes pass through the center hole in the concave reflector, and the convex reflector reflects light beams so that the concave reflector reflects the light beams.

13. The lighting apparatus according to claim 12, wherein a center portion of the convex reflector is sharpened so that the light beams striking the center portion are scattered around the periphery thereof.

14. The lighting apparatus according to claim 11, wherein a conical reflector horn, an inner surface of which reflects the light emitted from the light-emitting diodes so as to focus the light to its tip portion, is disposed between the light-emitting diodes and the convex reflector, and the conical reflector horn focuses the light emitted from the plurality of light-emitting diodes so that the convex reflector reflects the light.

15. The lighting apparatus according to claim 1, wherein the control circuit controls the intensities of light emissions of the light-emitting diodes emitting red, blue, and green light so that color of the whole light emissions is varied.

16. The lighting apparatus according to claim 1, wherein the control circuit controls the intensities of light emissions of the light-emitting diodes emitting red, blue, and green light so that color temperature of light emission is varied.

17. The lighting apparatus according to claim 1, wherein a temperature sensor for directly or indirectly detecting temperature of the light-emitting diodes is connected to the control circuit, and the control circuit controls the intensities of light emissions of the light-emitting diodes emitting red, blue, and green light based on the temperature detected by the temperature sensor so as to achieve a specified chromaticity coordinates.

18. The lighting apparatus according to claim 1, wherein a photo sensor for directly or indirectly detecting light of wavelengths corresponding to red, blue, and green emitted from the light-emitting diodes is connected to the control circuit, and the control circuit controls the intensities of light emissions of the light-emitting diodes emitting red, blue, and green light based on a signal detected by the photo sensor so as to achieve a specified chromaticity coordinates.