Projection type display device and light source device

• US 7,988,305 B2
• Filed: 03/22/2007
• Issued: 08/02/2011
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kasazumi, Kenichi, Itoh, Tatsuo, Mizushima, Tetsuro, Yamamoto, Kazuhisa
• Primary Examiner(s): Dowling; William C
• Assistant Examiner(s): HOWARD, RYAN D
• Application Number:
  US12/293,668
• Publication Number:
  US 20100231862A1
• Time in Patent Office: 1,594 Days
• Field of Search: 353/94, 353/30, 353/31, 353/102, 353/38, 353/101, 359/207.6, 359/210.1, 359/210.2, 359/209.1, 359/619, 359/623, 359/624, 372 4301- 5023, 362/311.01, 36231106-3111, 362/326, 362/330, 362/331, 362/336, 362/553, 362/259, 362/277, 385/133, 385/901
• US Class Current: 353/94
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G03B 21/2013 Plural light sources
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 3/2383 Parallel arrangements
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

Miniaturization is realized and high-output lights are obtained by optimizing the arrangement of a laser light source unit and a homogenizer.

A laser light source unit 1 has a light emission region for emitting an elliptical laser light. A focusing lens unit 2 focuses the laser light emitted from the laser light source unit 1. A rod integrator 4 has a rectangular incident surface on luminous flux focused by the focusing lens unit 2. A spatial light modulation element 7 modulates the laser light emitted from the rod integrator 4. A projection lens 8 projects the laser light modulated by the spatial light modulation element 7. The incident surface of the rod integrator 4 has a rectangular shape, and the laser light source unit 1 is arranged such that a longer axis direction of the light emission region and a longer side direction of the incident surface of the rod integrator are parallel.

Claims

1. A projection type display device, comprising:

a laser light source unit having a light emission region for emitting an elliptical laser light;

a focusing lens unit for focusing the laser light emitted from the laser light source unit;

a lenticular lens for refracting the laser light focused by the focusing lens unit;

a homogenizer having a rectangular incident surface on luminous flux focused by the focusing lens unit;

a spatial light modulation element for modulating the laser light emitted from the homogenizer; and

a projection lens for projecting the laser light modulated by the spatial light modulation element,

wherein;

the lenticular lens is rotatable about an axis parallel to an optical axis,

the incident surface of the homogenizer has a rectangular shape, and

the laser light source unit is arranged such that a longer axis direction of the light emission region and a longer side direction of the incident surface of the homogenizer are substantially parallel.

2. A projection type display device according to claim 1, wherein:

the laser light source unit includes a plurality of semiconductor laser light sources;

the focusing lens unit includes a plurality of focusing lenses provided in a one-to-one correspondence with the plurality of semiconductor laser light sources for focusing laser lights emitted from the plurality of semiconductor laser light sources on one point; and

the homogenizer has the rectangular incident surface on a focal point of a plurality of laser lights.

3. A projection type display device according to claim 2, wherein the plurality of semiconductor laser light sources are arranged symmetrically with respect to an optical axis of the homogenizer.

4. A projection type display device according to claim 3, wherein:

the laser light source unit includes a plurality of semiconductor laser light sources;

the focusing lens unit includes a plurality of collimator lenses provided in a one-to-one correspondence with the plurality of semiconductor laser light sources for collimating laser lights emitted from the plurality of semiconductor laser light sources, a convex lens for focusing the laser lights collimated by the condenser lenses and a concave lens disposed between the convex lens and a focal point of the convex lens; and

the homogenizer has the rectangular incident surface on a focal point of a combined lens comprised of the convex lens and the concave lens.

5. A projection type display device according to claim 4, wherein:

the laser light source unit includes a red laser light source for emitting a red laser light, a blue laser light source for emitting a blue laser light and a green laser light source for emitting a green laser light;

the red and blue laser light sources are arranged symmetrically with respect to the optical axis of the homogenizer; and

the green laser light source is arranged on the optical axis of the homogenizer.

6. A projection type display device according to claim 5, wherein:

the plurality of focusing lenses include a focusing lens for red for focusing a red laser light emitted from the red laser light source on one point, a focusing lens for blue for focusing a blue laser light emitted from the blue laser light source on one point and a focusing lens for green for focusing a green laser light emitted from the green laser light before being incident on the homogenizer; and

an angle between the optical axis of the homogenizer and the outermost edge of the green laser light at the focal point of the focusing lens for green is equal to an angle between the optical axis of the homogenizer and the red or blue laser light at the focal point of the focusing lens for red or the focusing lens for blue.

7. A projection type display device according to claim 6, wherein:

the red and blue laser light sources include semiconductor laser light sources; and

the green laser light source includes a semiconductor laser light source for excitation for emitting an excitation laser light, a laser medium to be excited by a laser light emitted from the semiconductor laser light source for excitation and a wavelength conversion element for emitting the green laser light by converting the wavelength of the laser light emitted from the laser medium.

8. A projection type display device according to claim 7, wherein the plurality of semiconductor laser light sources include a red semiconductor laser light source for emitting a red laser light and a blue semiconductor laser light source for emitting a blue laser light.

9. A projection type display device according to claim 8, wherein:

the red semiconductor laser light source and the blue semiconductor laser light source are arranged such that the polarizing surfaces differ, and

the projection type display device further comprises a half-wave plate arranged on either one of an optical path of the laser light emitted from the red semiconductor laser light source until reaching the homogenizer and an optical path of the laser light emitted from the blue semiconductor laser light source until reaching the homogenizer to align the polarizing surfaces of the respective semiconductor laser light sources.

10. A projection type display device according to claim 9, wherein:

the laser light source unit includes a semiconductor laser light source having a plurality of light emission regions respectively arranged on a straight line; and

the semiconductor laser light source is arranged such that an arrangement direction of the plurality of light emission regions and a longer side direction of the incident surface of the homogenizer are parallel.

11. A projection type display device according to claim 10, wherein the laser light source unit is arranged such that the longer axis direction of the light emission regions and the longer side direction of the incident surface of the homogenizer are parallel if the length of the laser light in the longer axis on the incident surface of the homogenizer is longer than that of the shorter sides of the homogenizer.

12. A projection type display device according to claim 1, wherein:

the laser light source unit includes a semiconductor laser light source having a plurality of light emission regions respectively arranged on a straight line; and

the semiconductor laser light source is arranged such that an arrangement direction of the plurality of light emission regions and a longer side direction of the incident surface of the homogenizer are parallel.

13. A projection type display device according to claim 1, wherein:

the laser light source unit includes a plurality of semiconductor laser light sources;

the focusing lens unit includes a plurality of collimator lenses provided in a one-to-one correspondence with the plurality of semiconductor laser light sources for collimating laser lights emitted from the plurality of semiconductor laser light sources, a convex lens for focusing the laser lights collimated by the collimator lenses and a concave lens disposed between the convex lens and a focal point of the convex lens; and

the homogenizer has a rectangular incident surface at a focal point of a combined lens comprised of the convex lens and the concave lens.

14. A projection type display device according to claim 1, wherein

the laser light source unit includes a plurality of semiconductor laser light sources;

the focusing lens unit includes a plurality of collimator lenses provided in a one-to-one correspondence with the plurality of semiconductor laser light sources for collimating laser lights emitted from the plurality of semiconductor laser light sources, a first convex lens for focusing the laser lights collimated by the collimator lenses and a second convex lens disposed at a side of a focal point of the first convex lens opposite to the first convex lens for relaying the focused laser lights; and

the homogenizer has a rectangular incident surface at a focal point of the second convex lens.

15. A projection type display device according to claim 14, wherein the plurality of semiconductor laser light sources include a red semiconductor laser light source for emitting a red laser light and a blue semiconductor laser light source for emitting a blue laser light.

16. A projection type display device according to claim 15, wherein:

the red semiconductor laser light source and the blue semiconductor laser light source are arranged such that the polarizing surfaces differ, and

the projection type display device further comprises a half-wave plate arranged on either one of an optical path of the laser light emitted from the red semiconductor laser light source until reaching the homogenizer and an optical path of the laser light emitted from the blue semiconductor laser light source until reaching the homogenizer to align the polarizing surfaces of the respective semiconductor laser light sources.

17. A projection type display device according to claim 15, wherein the red semiconductor laser light source and the blue semiconductor laser light source are arranged such that polarizing surfaces thereof are parallel.

18. A projection type display device according to claim 1, wherein:

the laser light source unit includes a red laser light source for emitting a red laser light, a blue laser light source for emitting a blue laser light and a green laser light source for emitting a green laser light;

the red and blue laser light sources are arranged symmetrically with respect to the optical axis of the homogenizer; and

the green laser light source is arranged on the optical axis of the homogenizer.

19. A projection type display device according to claim 18, wherein:

the red and blue laser light sources include semiconductor laser light sources; and

the green laser light source includes a semiconductor laser light source for excitation for emitting an excitation laser light, a laser medium to be excited by a laser light emitted from the semiconductor laser light source for excitation and a wavelength conversion element for emitting the green laser light by converting the wavelength of the laser light emitted from the laser medium.

20. A projection type display device according to claim 18, wherein:

the plurality of focusing lenses include a focusing lens for red for focusing a red laser light emitted from the red laser light source on one point, a focusing lens for blue for focusing a blue laser light emitted from the blue laser light source on one point and a focusing lens for green for focusing a green laser light emitted from the green laser light before being incident on the homogenizer; and

an angle between the optical axis of the homogenizer and the outermost edge of the green laser light at the focal point of the focusing lens for green is equal to an angle between the optical axis of the homogenizer and the red or blue laser light at the focal point of the focusing lens for red or the focusing lens for blue.

21. A projection type display device according to claim 1, wherein the laser light source unit is arranged such that the longer axis direction of the light emission region and the longer side direction of the incident surface of the homogenizer are parallel if the length of the laser light in the longer axis on the incident surface of the homogenizer is longer than that of the shorter sides of the homogenizer.

22. A light source device, comprising:

a laser light source unit having a light emission region for emitting an elliptical laser light;

a focusing lens unit for focusing the laser light emitted from the laser light source unit;

a lenticular lens for refracting the laser light focused by the focusing lens unit; and

a homogenizer having a rectangular incident surface on luminous flux focused by the focusing lens unit,

wherein;

the lenticular lens is rotatable about an axis parallel to an optical axis,

the incident surface of the homogenizer has a rectangular shape, and

the laser light source unit is arranged such that a longer axis direction of the light emission region and a longer side direction of the incident surface of the homogenizer are substantially parallel.

23. A projection type display device, comprising:

a plurality of laser light sources;

a plurality of focusing lenses provided in a one-to-one correspondence with the plurality of laser light sources for focusing the laser lights emitted from the plurality of laser light sources;

a lenticular lens for refracting the laser light focused by the focusing lens;

a homogenizer having a rectangular incident surface on luminous fluxes focused by the plurality of focusing lenses;

a spatial light modulation element for modulating the laser lights emitted from the homogenizer; and

a projection lens for projecting the laser lights modulated by the spatial light modulation element,

wherein;

the lenticular lens is rotatable about an axis parallel to an optical axis,

the plurality of laser light sources include a red laser light source for emitting a red laser light, a blue laser light source for emitting a blue laser light and a green laser light source for emitting a green laser light;

the red and blue laser light sources are arranged symmetrically with respect to the optical axis of the homogenizer;

the green laser light source is arranged on the optical axis of the homogenizer;

the plurality of focusing lenses include a focusing lens for red for focusing a red laser light emitted from the red laser light source on the incident surface of the homogenizer, a focusing lens for blue for focusing a blue laser light emitted from the blue laser light source on the incident surface of the homogenizer and a focusing lens for green for focusing a green laser light emitted from the green laser light before being incident on the homogenizer; and

an angle between the optical axis of the homogenizer and the outermost edge of the green laser light at a focal point of the focusing lens for green is equal to an angle between the optical axis of the homogenizer and the red or blue laser light at a focal point of the focusing lens for red or the focusing lens for blue.