Light-emitting module and image projection apparatus using same

Abstract

A light-emitting module has: a single reflector having a plurality of concave reflection surfaces; and light emitters in a same number as a number of the concave reflection surfaces. Each of the concave reflection surface has an outer shape partially notched at a boundary thereof with the adjacent concave reflection surface. Each of the light emitters emits light toward the concave reflection surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are elevation views for explaining effect provided by structure of adjacent concave reflection surfaces in one detailed example of a reflector according to the present invention;

FIGS. 2A and 2B are diagrams for explaining effect of thinning the concave reflection surfaces in one detailed example of the reflector;

FIGS. 3A, 3B, and 3C are elevation views showing detailed examples of the reflector having a plurality of concave reflection surfaces;

FIG. 4 is a perspective view showing outer appearance of a light-emitting module according to one embodiment of the invention;

FIG. 5 is an elevation view showing outer appearance of the light-emitting module according to one embodiment of the invention;

FIG. 6 is a perspective view showing outer appearance of a light source unit (type 1) according to the invention;

FIGS. 7A and 7B are diagrams showing front side outer appearance and sectional structure of the light source unit (type 1);

FIG. 8 is a perspective view showing outer appearance of a light source unit (type 2) according to the invention;

FIGS. 9A and 9B are diagrams showing front side outer appearance and sectional structure of the light source unit (type 2);

FIGS. 10A to 10D are diagrams showing concrete examples of turn-on timing of the light-emitting module;

FIG. 11 is an elevation view showing arrangement condition of the light source units (type 1) of RGB;

FIG. 12 is a plan view showing schematic optical configuration of a projector provided with the light source unit (type 1) of FIG. 11;

FIG. 13 is an optical configuration diagram schematically showing one embodiment of an image projection apparatus according to the invention;

FIGS. 14A and 14B are diagrams for explaining telecentricity of a projection optical system according to the invention;

FIG. 15 is a diagram schematically showing one embodiment of an image projection apparatus having a cooling structure according to the invention;

FIG. 16 is an optical configuration diagram for explaining the NA relationship in the image projection apparatus provided with a light-emitting module;

FIG. 17 is an optical configuration diagram showing a first configuration example using a reflection type polarizing plate according to the invention; and

FIG. 18 is an optical configuration diagram showing a second configuration example using the reflection type polarizing plate.

Claims

1. A light-emitting module comprising: a single reflector having a plurality of concave reflection surfaces each having an outer shape partially notched at a boundary thereof with the adjacent concave reflection surface; andlight emitters in a same number as a number of the concave reflection surfaces, each of the light emitters emitting light toward the concave reflection surface.

2. The light-emitting module according to claim 1, wherein the light emitter is a light-emitting diode including: a light-emitting diode chip which is arranged at or near a focal position of each of the concave reflection surfaces and which radiates light toward the concave reflection surface; and an electrode lead, for fixing the light-emitting diode chip, which electrode lead is arranged opposite to the concave reflection surface with respect to the light-emitting diode chip.

3. The light-emitting module according to claim 1, wherein the concave reflection surface is a rotation-symmetrical surface having one focal point, andwherein a thickness of the concave reflection surface in an optical axis direction is substantially equal to a distance from a surface vertex of the concave reflection surface to the focal point thereof.

4. The light-emitting module according to claim 1, wherein the concave reflection surface is a rotation-symmetrical surface having two focal points, andwherein a thickness of the concave reflection surface in an optical axis direction is substantially equal to a distance from a surface vertex of the concave reflection surface to the focal point thereof located closer to the surface vertex.

5. The light-emitting module according to claim 1, wherein the light-emitting module has, as the concave reflection surface, four concave reflection surfaces.

6. The light-emitting module according to claim 2, wherein a number of colors of light emitted by the light-emitting diode is at least three including red, blue, and green.

7. The light-emitting module according to claim 2, wherein a size of the electrode lead in a direction parallel to an optical axis of the concave reflection surface is larger than a smallest size thereof on a plane perpendicular to the optical axis of the concave reflection surface.

8. The light-emitting module according to claim 7, wherein the electrode lead is formed into a plate-like shape, andwherein a ratio y/x is 2 to 6 where y is a width of the electrode lead as the size in the direction parallel to the optical axis of the concave reflection surface and x is a thickness as the smaller size on the plane perpendicular to the optical axis of the concave reflection surface.

9. The light-emitting module according to claim 2, wherein the electrode leads in contact with the light-emitting diode chips all face a same direction.

10. A light-emitting module comprising: a single reflector having a plurality of concave reflection surfaces arranged in rotational symmetry to a center axis of the reflector, wherein, when the reflector is viewed along the center axis thereof from front, a boundary between the adjacent concave reflection surfaces forms a straight line directed toward the center axis of the reflector; andlight emitters in a same number as a number of the concave reflection surfaces, each of the light emitters emitting light toward the concave reflection surface.

11. The light-emitting module according to claim 10, wherein the light emitter is a light-emitting diode including: a light-emitting diode chip which is arranged at or near a focal position of each of the concave reflection surfaces and which radiates light toward the concave reflection surface; and an electrode lead, for fixing the light-emitting diode chip, which electrode lead is arranged opposite to the concave reflection surface with respect to the light-emitting diode chip.

12. The light-emitting module according to claim 10, wherein the concave reflection surface is a rotation-symmetrical surface having one focal point, andwherein a thickness of the concave reflection surface in an optical axis direction is substantially equal to a distance from a surface vertex of the concave reflection surface to the focal point thereof.

13. The light-emitting module according to claim 10, wherein the concave reflection surface is a rotation-symmetrical surface having two focal points, andwherein a thickness of the concave reflection surface in an optical axis direction is substantially equal to a distance from a surface vertex of the concave reflection surface to the focal point thereof located closer to the surface vertex.

14. The light-emitting module according to claim 10, wherein the light-emitting module has, as the concave reflection surface, four concave reflection surfaces.

15. The light-emitting module according to claim 11, wherein a number of colors of light emitted by the light-emitting diode is at least three including red, blue, and green.

16. The light-emitting module according to claim 11, wherein a size of the electrode lead in a direction parallel to an optical axis of the concave reflection surface is larger than a smallest size thereof on a plane perpendicular to the optical axis of the concave reflection surface.

17. The light-emitting module according to claim 16, wherein the electrode lead is formed into a plate-like shape, andwherein a ratio y/x is 2 to 6 where y is a width of the electrode lead as the size in the direction parallel to the optical axis of the concave reflection surface and x is a thickness as the smaller size on the plane perpendicular to the optical axis of the concave reflection surface.

18. The light-emitting module according to claim 11, wherein the electrode leads in contact with the light-emitting diode chips all face a same direction.

19. An image projection apparatus comprising: a light-emitting module which generates illumination light;a spatial modulation element of a transmission type which forms an image by spatially modulating illumination light; anda projection optical system which projects an image formed by the spatial modulation element,wherein the light-emitting module includes: a single reflector having a plurality of concave reflection surfaces each arranged in rotational symmetry to a center axis of the reflector, wherein, when the reflector is viewed along the center axis thereof from front, a boundary between the adjacent concave reflection surfaces forms a straight line directed toward the center axis of the reflector; and light-emitting diodes in a same number as a number of the concave reflection surfaces, each light-emitting diode including: a light-emitting diode chip which is arranged at or near a focal position of each of the concave reflection surfaces and which radiates light toward the concave reflection surface; and an electrode lead, for fixing the light-emitting diode chip, which electrode lead is arranged opposite to the concave reflection surface with respect to the light-emitting diode chip.

20. The image projection apparatus according to claim 19, wherein a size of the electrode lead in a direction parallel to an optical axis of the concave reflection surface is larger than a smallest size thereof on a plane perpendicular to the optical axis of the concave reflection surface.

21. The image projection apparatus according to claim 19, wherein at least one of the plurality of light-emitting diode chips emits light in a wavelength range different from those of light emitted by the remaining light-emitting diode chips.

22. The image projection apparatus according to claim 19, wherein the spatial modulation element is driven in a timed shared manner.

23. The image projection apparatus according to claim 19, wherein the projection optical system is telecentric to the spatial modulation element side.

24. The image projection apparatus according to claim 19, wherein a screen center of the spatial modulation element and an optical axis of the projection optical system agree with each other.

25. The image projection apparatus according to claim 19, further comprising a cooling device which cools down the spatial modulation element and the light-emitting module.

26. The image projection apparatus according to claim 25, further comprising a duct for leading wind from the cooling device to the spatial modulation element via the light-emitting module.

27. An image projection apparatus comprising: a spatial modulation element of a transmission type which forms an image by spatially modulating illumination light; anda light-emitting module for illuminating the spatial modulation element; and a projection optical system which projects an image formed by the spatial modulation element,wherein the light-emitting module includes: a light-emitting diode; and

28. The image projection apparatus according to claim 27, wherein a size of the electrode lead in a direction parallel to an optical axis of the concave reflection surface is larger than a smallest size thereof on a plane perpendicular to the optical axis of the concave reflection surface.

29. The image projection apparatus according to claim 28, wherein the reflector is a single reflector having a plurality of concave reflection surfaces each having an outer shape partially notched at a boundary thereof with the adjacent concave reflection surface.

30. The image projection apparatus according to claim 28, wherein the reflector is a single reflector having a plurality of concave reflection surfaces each arranged in rotational symmetry to a center axis of the reflector, andwherein, when the reflector is viewed along the center axis thereof from front, a boundary between the adjacent concave surfaces forms a straight line directed toward the center axis of the reflector.