# US 7,609,746 B2 · Light source device, image display device, projector, illumination device, and monitor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,746 B2 - Document ID: US7609746B2 - Status: Granted - Kind: B2 - Application number: 11/987,494 - Filed: 2007-11-30 - Published: 2008-08-07 - Granted: 2009-10-27 - Earliest claimed: 2006-12-01 - Assignees: Seiko Epson Corporation - Inventors: Taisuke Yamauchi; Takashi Takeda - Web page: https://patentgrep.com/patent/US7609746B2 ## CPC - G02B 1/118: having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures - G02B 1/115: Multilayers - G02B 27/425: {in illumination systems (mask illumination systems in photolithographic systems G03F7/70158)} - G03B 21/2033: {LED or laser light sources} - G03B 21/204: {using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197)} - G03B 21/208: {Homogenising, shaping of the illumination light} - G03B 33/12: using beam-splitting or beam-combining systems, e.g. dichroic mirrors - H04N 9/3105: {for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators (simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10)} - H04N 9/3152: {for shaping the light beam (beam shaping per se G02B27/09)} - H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)} - H04N 9/3197: {using light modulating optical valves} - G02B 5/0278: {used in transmission} - G02B 27/149: {using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes} - G02B 27/48: Laser speckle optics - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A light source device generates irradiation light that is irradiated onto a predetermined face, the light source device including: a laser light source that emits laser light; a diffractive optical element that diffracts the laser light; a diffusion optical element that has an incidence face into which the laser light is incident and a light emission face from which the laser light from the incidence face is emitted, and that diffuses the laser light; and unit structures that are two-dimensionally arrayed on at least one of the incidence face and the light emission face of the diffusion optical element, and that cause the light which is perpendicularly incident into the diffusion optical element to refract at one time, and then emit this light toward the predetermined face. ## Claims ### Claim 1 A light source device that generates irradiation light that is irradiated onto a predetermined face, the light source device comprising: a laser light source that emits laser light; a diffractive optical element that is located between the laser light source and the predetermined face, and that diffracts the laser light; a diffusion optical element that is located between the laser light source and the predetermined face, that is located between the diffractive optical element and the predetermined face, that has an incidence face into which the laser light is incident and a light emission face from which the laser light from the incidence face is emitted, and that diffuses the laser light; and unit structures that are two-dimensionally arrayed on at least one of the incidence face and the light emission face of the diffusion optical element, and that cause the light which is perpendicularly incident into the diffusion optical element to refract at one time, and then emit this light toward the predetermined face, wherein the laser light from the diffractive optical element is incident into the incidence face of the diffusion optical element. ### Claim 2 (depends on 1) The light source device according to claim 1, wherein the shape of the unit structures is set so that directions of travel of the laser light that is emitted from each of positions of the unit structure are mutually different. ### Claim 3 (depends on 2) The light source device according to claim 2, wherein the shape of the unit structures is set so that the laser light that has passed through the diffractive optical element and the diffusion optical element is incident at a predetermined incidence angle into a predetermined area of the predetermined face. ### Claim 4 (depends on 1) The light source device according to claim 1, wherein the unit structures include at least one of recessed portions and protruding portions. ### Claim 5 (depends on 4) The light source device according to claim 4, wherein the unit structures include at least one of recessed portions and protruding portions that are two-dimensionally and regularly arrayed along a face which is substantially parallel to the light emission face. ### Claim 6 (depends on 4) The light source device according to claim 4, wherein the unit structures include at least one of recessed portions and protruding portions whose surfaces are shaped as curved surfaces. ### Claim 7 (depends on 4) The light source device according to claim 4, wherein the unit structures include arc-shaped grooves which are depressed relative to the predetermined face in a cross-sectional view which is substantially perpendicular to the light emission face, and the grooves are formed in a predetermined direction of the face that is substantially perpendicular to the light emission face. ### Claim 8 (depends on 1) The light source device according to claim 1, wherein the diffusion optical element diffuses laser light by refracting the laser light at the incidence face, and the incidence face has a shape that controls the direction of travel of the laser light so that the post-incident laser light travels toward the light emission face. ### Claim 9 (depends on 1) An image display device in which irradiation light is radiated from the light source device according to claim 1, and an image is displayed by light that has passed through the predetermined face, wherein the predetermined face includes an incidence face of a spatial light modulation device that optically modulates the irradiated light in accordance with image signals. ### Claim 10 (depends on 9) A projector comprising: the image display device according to claim 9; a display screen; and a projection system that projects onto the display screen light that contains image information and has passed through the predetermined face. ### Claim 11 (depends on 1) An illumination device comprising: the light source device according to claim 1. ### Claim 12 (depends on 1) A monitor device comprising: the light source device according to claim 1. ### Claim 13 A light source device that generates irradiation light that is irradiated onto a predetermined face, the light source device comprising: a laser light source that emits laser light; a diffractive optical element that is located between the laser light source and the predetermined face, and that diffracts the laser light; a diffusion optical element that is located between the laser light source and the predetermined face, that is located between the diffractive optical element and the predetermined face, that has both an incidence face into which the laser light is incident and which has a shape that controls the direction of travel of the laser light so that the post-incident laser light travels toward a light emission face, and the light emission face from which the laser light from the incidence face is emitted, and that diffuses the laser light by refracting the laser light at the incidence face, wherein the laser light from the diffractive optical element is incident into the incidence face of the diffusion optical element. ### Claim 14 (depends on 13) A projector comprising: the image display device according to claim 13; a display screen; and a projection system that projects onto the display screen light that contains image information and has passed through the predetermined face. ### Claim 15 A light source device that generates irradiation light that is irradiated onto a predetermined face, the light source device comprising: a laser light source that emits laser light; a diffractive optical element that is located between the laser light source and the predetermined face, and that diffracts the laser light; and a diffusion optical element that is located between the laser light source and the predetermined face, that is located between the diffractive optical element and the predetermined face, that has an incidence face into which the laser light is incident and a light emission face from which the laser light from the incidence face is emitted, and that diffuses the laser light, wherein unit structures that include at least one of recessed portions and protruding portions whose surfaces are shaped as curved surfaces and that are two-dimensionally arrayed on at least one of the incidence face and the light emission face of the diffusion optical element, and the laser light from the diffractive optical element is incident into the incidence face of the diffusion optical element. ### Claim 16 (depends on 15) The light source device according to claim 15, wherein an angle between an optical axis of light that is emitted from the light emission face of the diffusion optical element and a normal line of the light emission face is less than or equal to 1.2°. ### Claim 17 (depends on 15) The light source device according to claim 15, wherein if a radius of a circle forming a diffusion range of the light which is created by the diffusion optical element is taken as “d”, and if a length of a diagonal line of a rectangle forming an illumination area on the predetermined face is taken as “L”, then a formula 2d≦L is satisfied for light that is incident into a center of the illumination area on the predetermined face when the diffusion optical element is not provided. ### Claim 18 (depends on 17) The light source device according to claim 17, wherein if a radius of a circle forming a diffusion range of the light which is created by the diffusion optical element is taken as “d”, and if a length of a short side of a rectangle forming an illumination area on the predetermined face is taken as “S”, then a formula 2d≦S is satisfied for light that is incident into a center of the illumination area on the predetermined face when the diffusion optical element is not provided. ### Claim 19 (depends on 18) A projector comprising: the image display device according to claim 18; a display screen; and a projection system that projects onto the display screen light that contains image information and has passed through the predetermined face.