LIGHT SOURCE DEVICE, AND TWO-DIMENSIONAL IMAGE DISPLAY DEVICE

• US 20100097674A1
• Filed: 12/22/2009
• Published: 04/22/2010
• Est. Priority Date: 01/29/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Mizuuchi, Kiminori, Morikawa, Akihiro, Kasazumi, Ken'ichi, Yamamoto, Kazuhisa
• Granted Patent: US 8,016,427 B2
• Time in Patent Office: Days
• US Class Current: 359/15
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/1093 for use with monochromatic radiation only, e.g. devices for splitting a single laser source
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• 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 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

There is provided a light source device which can miniaturize a two-dimensional image display device as small as possible. The light source device is provided with three coherent light sources (11a), (11b), and (11c) corresponding to red, blue, and green; prisms (12a) and (12c) for reflecting lights emitted from the coherent light sources (11a) and (11c); and a diffraction part (20) comprising a single volume hologram on which plural gratings are multiply-formed, which gratings diffract the light emitted from the coherent light source (11b), and the lights that are emitted from the coherent light sources (11a) and (11c) and reflected by the prisms (12a) and (12b) so that these lights propagate in the same optical path.

Claims

1-16. -16. (canceled)

17. A light source device comprising:

at least two coherent light sources; and

a diffraction part for diffracting lights emitted from the coherent light sources, such that the lights propagate through the same optical path,

wherein the lights having different incident angles upon contacting the diffraction part, and the diffraction part is for receiving the lights having different incident angles and outputting a coaxial beam comprising said lights,

wherein said diffraction part comprises;

a first diffraction element for receiving at least two lights, and diffracting at least one of the received lights so that the received at least two lights propagate through the same optical path; and

a second diffraction element for diffracting the light emitted from at least one coherent light source among the at least two coherent light sources so that the center axes of the optical propagation paths of the lights emitted from the respective coherent light sources intersect at one point on the first diffraction element,

and wherein said second diffraction element is further provided with a lens function, and said second diffraction element condenses the respective lights emitted from the at least two coherent light sources so that the respective lights diffracted by the second diffraction element irradiate the same region of the first diffraction element.

19. A light source device as defined in claim 17 wherein

said first diffraction element is regionally divided, and

the respective lights that are diffracted in the divided regions of the first diffraction element irradiate the same planar region.

24. A light source device as defined in claim 17 wherein

said diffraction element is regionally divided in a lattice pattern.

18. A light source device comprising:

at least two coherent light sources; and

a diffraction part for diffracting lights emitted from the coherent light sources, such that the lights propagate through the same optical path,

wherein the lights having different incident angles upon contacting the diffraction part, and the diffraction part is for receiving the lights having different incident angles and outputting a coaxial beam comprising said lights;

wherein said diffraction part comprises a single diffraction element, and said diffraction element diffracts the light emitted from at least one coherent light source so that the respective lights emitted from the at least two coherent light sources propagate through the same optical path; and

wherein said diffraction element is regionally divided, and the respective lights that are diffracted in the divided regions of the diffraction element irradiate the same planar region.

20. A light source device as defined in claim 18 wherein

said diffraction element is regionally divided in a lattice pattern.

23. A light source device as defined in claim 18 wherein

said diffraction element is a volume hologram, and

plural gratings are multiplexed on the volume hologram, which gratings receive the respective lights emitted from the at least two coherent light sources, and change the propagation directions of the respective lights.

21. A two-dimensional image display device comprising:

at least two coherent light sources;

a diffraction part for diffracting light emitted from at least one coherent light source so that the respective lights emitted from the at least two coherent light sources propagate in the same optical path; and

a two-dimensional spatial light modulation element for receiving the respective lights that are diffracted by the diffraction part to be coaxial beams, said element being provided in a space above the diffraction part.

22. A two-dimensional image display device as defined in claim 21 further including:

a control part for controlling the operations of the at least two coherent light sources; and

said at least two coherent light sources being a coherent light source that emits red light, a coherent light source that emits green light, and a coherent light source that emits blue light; and

said control part controlling the three coherent light sources so that the coherent light sources are time-shared to sequentially emit lights.