Light source device and projection-type image display device

Patent metadata

Field	Value
Publication number	US-9547226-B2
Application number	US-201214439931-A
Country	US
Kind code	B2
Filing date	Nov 1, 2012
Priority date	Nov 1, 2012
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

To provide a light source device and a projection-type image display device which can improve light emitting efficiency and service life of a fluorescent material. The light source device includes: an excitation light source for emitting excitation light; a fluorescent material for emitting fluorescent light when excited by the excitation light; and an optical member for directing the excitation light to the fluorescent material. The optical member has a curvature that is set such that a light-condensing position of the excitation light is positioned on a light-emitting side of the excitation light relative to the fluorescent material. An optical fiber is disposed between the excitation light source and the light source, so that the excitation light from the excitation light source may be made incident on the optical fiber.

First claim

The invention claimed is:

1. A light source device comprising:
an excitation light source for emitting excitation light;
a fluorescent material for emitting fluorescent light when excited by the excitation light; and
an optical member for directing the excitation light to the fluorescent material,
wherein the optical member has a curvature that is set so as to allow the excitation light that has passed through the optical member to be made incident on the fluorescent material at a front side of the fluorescent material as a light-condensing position, and
wherein supposing that an area of the luminance distribution of the excitation light irradiated onto the fluorescent material is B and that an area of the image display element is A, the following formula is satisfied: 0.0136×A≦B≦0.0513×A.

2. The light source device according to claim 1 , further comprising:
a dichroic mirror disposed between the excitation light source and the fluorescent material,
wherein the optical member is a condenser lens disposed between the fluorescent material and the dichroic mirror.

3. The light source device according to claim 1 ,
wherein the excitation light irradiated onto the fluorescent material has a luminance distribution that is substantially analogous to the image display element.

4. The light source device according to claim 1 , further comprising an optical fiber for directing the excitation light to the fluorescent material.

5. The light source device according to claim 1 , further comprising:
a dichroic mirror disposed between the excitation light source and the fluorescent material; and
a condenser lens for condensing the excitation light disposed between the fluorescent material and the dichroic mirror,
wherein the optical member is disposed between the excitation light source and the dichroic mirror.

6. The light source device according to claim 5 ,
wherein the optical member is a convex lens and a concave lens, with the convex lens and the concave lens being disposed in this order from the excitation light source toward the dichroic mirror.

7. The light source device according to claim 6 ,
wherein at least either one of the convex lens and the concave lens has a curvature that is set so as to allow the excitation light to be made incident on the fluorescent material at a front side of the fluorescent material as a light-condensing position.

8. A projection-type image display device comprising:
a light source device;
an image display element;
an illumination optical system having a plurality of optical elements for irradiating the image display element with light from the light source device; and
a projection lens for enlarging an optical image formed by the image display element to project the resulting image,
wherein the light source device includes:
an excitation light source for emitting excitation light;
a fluorescent material for emitting fluorescent light when excited by the excitation light; and
an optical member for directing the excitation light to the fluorescent material, and
the optical member has a curvature that is set such that a light-condensing position of the excitation light is positioned on an emission side of the excitation light relative to the fluorescent material,
a dichroic mirror disposed between the excitation light source and the fluorescent material; and
a condenser lens for condensing the excitation light disposed between the fluorescent material and the dichroic mirror,
wherein the optical member is disposed between the excitation light source and the dichroic mirror, and
wherein the optical member is a convex lens and a concave lens, with the convex lens and the concave lens being disposed in this order from the excitation light source toward the dichroic mirror.

9. The projection-type image display device according to claim 8 , further comprising an optical fiber for directing the excitation light to the fluorescent material.

10. The projection-type image display device according to claim 8 ,
wherein at least either one of the convex lens and the concave lens has a curvature that is set so as to allow the excitation light to be made incident on the fluorescent material at a front side of the fluorescent material as a light-condensing position.

11. The projection-type image display device according to claim 8 , further comprising:
a dichroic mirror disposed between the excitation light source and the fluorescent material,
wherein the optical member is a condenser lens disposed between the fluorescent material and the dichroic mirror.

12. The projection-type image display device according to claim 8 ,
wherein the excitation light irradiated onto the fluorescent material has a luminance distribution that is substantially analogous to the image display element.

Assignees

• Hitachi Maxell

Inventors

• Kimura Nobuyuki
• Miyoshi Kohei

Classifications

• G03B21/204 Primary

  using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197) · CPC title

• G03B21/208 Primary

  Homogenising, shaping of the illumination light · CPC title

• G02B6/4298

  coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers · CPC title

• G02B6/0008

  the light being emitted at the end of the fibre · CPC title

• G03B21/2066

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title