Light source unit, illuminator, and display

Patent metadata

Field	Value
Publication number	US-9735550-B2
Application number	US-201113511697-A
Country	US
Kind code	B2
Filing date	Jul 22, 2011
Priority date	Jul 30, 2010
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An illuminator and a display capable of achieving miniaturization are provided with use of a plurality of light sources emitting light with two or more kinds of wavelengths. In the light source unit 11 , a red-color laser 11 R, a green-color laser 11 G, a blue-color laser 11 B, a microlens section 116 , and a microprism 117 are integrated on a base material. Each laser beam emitted from each of the laser light sources is transmitted through the microlens section 116 , and then, comes into the microprism 117 . In the microprism 117 , optical path conversion is performed to shorten the distance between the optical paths of the incident light beams (to allow the optical axes of the incident light beams to be closer to each other). Due to the above-described integration, the optical paths of the laser beams are allowed to be synthesized using the microscopic-scaled microlens section and microprisms.

First claim

The invention claimed is:

1. A light source unit comprising:
a supporting plate;
a stem supported on the supporting plate;
a sealing member supported on the supporting plate and enclosing the stem, the sealing member having an opening;
a holder in the opening;
a plurality of semiconductor laser chip light sources supported on the stem, each laser light chip to emit a respective laser light beam with polarized light, the laser chip light sources positioned in parallel and at a pitch such that major-axis directions of far field patterns (FFPs) of their outgoing light match;
a microlens section including a plurality of microlenses each of which is associated with a respective one of the light sources, the microlens supported on the holder;
a microprism with a plurality of dichroic structures each of which is associated with a respective one of the light sources, the microprism supported on the holder; and
a retardation plate that brings first and second polarization directions of light beams to be closer to each other, the first and second polarization directions being different from each other,
wherein,
the retardation plate is attached to the microprism,
except for a last dichroic structure each dichroic structure reflects light emitted by its associated light source, and
the last dichroic structure is transmissive with respect to light emitted by its associated light source but reflective with respect to light emitted by other light sources.

2. The light source unit according to claim 1 , wherein the microprism performs optical path conversion on the light beams from the light sources to approximately match the optical paths of the light beams.

3. The light source unit according to claim 1 , wherein the dichroic structures are arranged in series from a first dichroic structure to the last dichroic structure, the first dichroic structure reflecting light of a first color, the last dichroic structure transmitting light of last color but reflecting light of other than the last color, the light of other than the last color being light from light sources not associated with the last dichroic structure.

4. The light source unit of claim 3 , wherein:
the light beams are emitted from the light sources in a first direction,
except for the last dichroic structure, the light beams are reflected by the dichroic structures along a second direction orthogonal to the first direction, and
the last dichroic structure transmits the light beam from its associated light source in the first direction and redirects light reflected by the other dichroic structures from the second direction to the first direction.

5. The light source unit according to claim 1 , wherein the plurality of light sources include two or more lasers selected from the group consisting of a red-color laser, a green-color laser, and a blue-color laser.

6. The light source unit according to claim 5 , wherein the plurality of light sources are a red-color laser, a green-color laser, and a blue-color laser.

7. The light source unit according to claim 5 wherein the retardation plate allows the first and second polarization directions to approximately match each other.

8. The light source unit according to claim 1 , wherein the microlens section is supported on a side of the holder facing the laser chips and the microprism is supported on a side of the holder facing away from the laser chips.

9. The light source unit according to claim 1 , wherein:
the first polarization direction is the same as the major-axis direction of the FFPs, while the second polarization direction is the same as a minor-axis direction of the FFPs; and
the retardation plate is a half-wavelength plate allowing the first and second polarization directions to approximately match each other by selectively rotating the first polarization direction by 90 degrees.

10. The light source unit of claim 1 , wherein each dichroic structure includes a dichroic film.

11. The light source unit of claim 1 , wherein the microprism comprises a plurality of prisms joined together in series with joints between them, each dichroic structure comprising a joint and a dichroic film, each joint comprising a surface angled with respect to the light source associated with the dichroic structure, the dichroic film being on the joint surface.

12. The light source unit of claim 1 , wherein the retardation plate is on an light incident side of the microprism.

13. The light source unit of claim 1 , wherein the retardation plate is on a light emitting side of the microprism.

14. The light source unit of claim 1 , wherein the plurality of light sources, the microlens section, the microprism and retardation plate are positioned on a single supporting plate.

15. The light source unit of claim 1 , wherein the retardation plate is attached to a light outgoing side of the microprism.

16. The light source unit of claim 1 , wherein the retardation plate is attached to a light incoming side of the microprism.

17. A light source unit comprising:
a supporting plate;
a stem supported on the supporting plate;
a plurality of semiconductor laser chip light sources supported on the stem, each laser light chip to emit a respective laser light beam with polarized light, the laser chip light sources positioned in parallel and at a pitch such that major-axis directions of the far field patterns (FFPs) of their outgoing light match;
a microlens section including a plurality of microlenses each of which is associated with a respective one of the light sources, the microlens supported on the supporting plate;
a microprism with a plurality of dichroic structures each of which is associated with a respective one of the light sources, the microprism supported on the supporting plate; and
a retardation plate that brings first and second polarization directions of light beams to be closer to each other, the first and second polarization directions being different from each other,
wherein,
the stem with the plurality of laser chip light sources, the microlens section, and the microprism are laminated on a same planar surface of the supporting plate,
the retardation plate is attached to the microprism,
except for a last dichroic structure each dichroic structure reflects light emitted by its associated light source, and
the last dichroic structure is transmissive with respect to light emitted by its associated light source but reflective with respect to light emitted by other light sources.

18. An illuminator including the light source unit of claim 1 or claim 17 .

19. The illuminator of claim 18 , wherein the retardation plate is attached to a light outgoing side of the microprism.

20. The illuminator of claim 18 , wherein the retardation plate is attached to a light incoming side of the microprism.

21. A display comprising:
the light source unit of claim 1 or claim 17 ; and
a light modulation device modulating light emitted from the light source unit based on an image signal.

22. The display according to claim 21 , further comprising a projection optical system projecting light modulated by the optical modulation device onto a surface.

23. The display of claim 21 , wherein the retardation plate is attached to a light outgoing side of the microprism.

24. The display of claim 21 , wherein the retardation plate is attached to a light incoming side of the microprism.

Assignees

• Takahashi Kazuyuki
• Miura Koji
• Oiwa Tatsuya
• Sony Corp

Inventors

• Takahashi Kazuyuki
• Miura Koji
• Oiwa Tatsuya

Classifications

• H04N9/3161

  using laser light sources (using laser beams scanning the display screen H04N9/3129) · CPC title

• H04N9/3152

  for shaping the light beam (beam shaping per se G02B27/09) · CPC title

• H01S5/02212

  Can-type, e.g. TO-CAN housings with emission along or parallel to symmetry axis · CPC title

• H01S5/4093 Primary

  Red, green and blue [RGB] generated directly by laser action or by a combination of laser action with nonlinear frequency conversion · CPC title

• H04N9/3173

  wherein the projection device is specially adapted for enhanced portability · CPC title