# US 11,079,666 B2 · Light source device and projector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,666 B2 - Document ID: US11079666B2 - Status: Granted - Kind: B2 - Application number: 16/919,563 - Filed: 2020-07-02 - Published: 2021-01-07 - Granted: 2021-08-03 - Earliest claimed: 2019-07-05 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Tomoko Akagawa; Hidefumi Sakata - Web page: https://patentgrep.com/patent/US11079666B2 ## CPC - G03B 21/204: {using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197)} - H10H 20/855: Optical field-shaping means, e.g. lenses - G02B 27/283: {used for beam splitting or combining} - G03B 21/2013: {Plural light sources} - G03B 21/206: {Control of light source other than position or intensity} - G03B 21/2066: {Reflectors in illumination beam (in projection beam G03B21/28)} - G03B 21/2073: {Polarisers in the lamp house (peculiar to electronic spatial light modulators H04N9/3197)} - G03B 33/12: using beam-splitting or beam-combining systems, e.g. dichroic mirrors - H01S 5/0087: {for illuminating phosphorescent or fluorescent materials, e.g. using optical arrangements specifically adapted for guiding or shaping laser beams illuminating these materials} - H04N 9/3155: {for controlling the light source (light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406)} - H04N 9/3158: {for controlling the spectrum} - H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)} - H04N 9/3164: {using multiple light sources} - H04N 9/3167: {for polarizing the light beam (polarizing optical systems per se G02B27/28)} - H04N 9/3194: {including sensor feedback} - H10H 20/851: Wavelength conversion means - G03B 21/208: {Homogenising, shaping of the illumination light} - H01S 5/005: {Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping (H01S5/026, H01S5/18388 take precedence)} - H01S 5/32341: {blue laser based on GaN or GaP} - H01S 5/4025: {Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S5/42 takes precedence)} - 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) - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A light source device according to the present disclosure includes a light emitting section configured to emit first light in a first wavelength band, a wavelength conversion layer configured to convert a part of the first light into second light in a second wavelength band, and a polarization split element configured to reflect third light having the first wavelength band and a first polarization direction, transmit fourth light having the first wavelength band and a second polarization direction, reflect fifth light having the second wavelength band and the first polarization direction, and transmit sixth light having the second wavelength band and the second polarization direction. Light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer and light intensity of light having the second polarization direction. ## Claims ### Claim 1 A light source device comprising: a light emitting section configured to emit first light having a first wavelength band; a wavelength conversion layer having two opposite surfaces including a first surface which the first light enters first, and a second surface different from the first surface, and configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band, emit the second light from the second surface, and transmits another part of the first light from the second surface; and a polarization split element which is disposed so as to be opposed to the second surface of the wavelength conversion layer, and is configured to reflect third light having the first wavelength band and a first polarization direction and emitted from the second surface, transmit fourth light having the first wavelength band and a second polarization direction different from the first polarization direction and emitted from the second surface, reflect fifth light having the second wavelength band and the first polarization direction and emitted from the second surface, and transmit sixth light having the second wavelength band and the second polarization direction and emitted from the second surface, wherein light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer, and light intensity of light having the second polarization direction out of the first light entering the wavelength conversion layer. ### Claim 2 (depends on 1) The light source device according to claim 1, further comprising: a detection section configured to detect the fourth light and the sixth light transmitted through the polarization split element; and a control section configured to compare a detection result by the detection section with a predetermined value to thereby control the light intensity of the light having the first polarization direction out of the first light entering the wavelength conversion layer, and the light intensity of the light having the second polarization direction out of the first light entering the wavelength conversion layer. ### Claim 3 (depends on 2) The light source device according to claim 2, further comprising: a wave plate which is disposed between the light emitting section and the wavelength conversion layer, and which the first light emitted from the light emitting section enters, wherein the control section rotates the wave plate to thereby control the light intensity of the light having the first polarization direction out of the first light entering the wavelength conversion layer, and the light intensity of the light having the second polarization direction out of the first light entering the wavelength conversion layer. ### Claim 4 (depends on 2) The light source device according to claim 2, wherein the light emitting section is made rotatable around a rotational axis crossing the first polarization direction and the second polarization direction, and the control section rotates the light emitting section to thereby control the light intensity of the light having the first polarization direction out of the first light entering the wavelength conversion layer, and the light intensity of the light having the second polarization direction out of the first light entering the wavelength conversion layer. ### Claim 5 (depends on 1) The light source device according to claim 1, further comprising: an optical element disposed so as to be opposed to the first surface of the wavelength conversion layer, and configured to transmit the first light and reflect the second light. ### Claim 6 A light source device comprising: a light emitting section configured to emit first light having a first wavelength band; a wavelength conversion layer having a first surface which the first light enters, and a second surface different from the first surface, and configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band, and emit the second light and another part of the first light from the second surface; and a polarization split element which is disposed so as to be opposed to the second surface of the wavelength conversion layer, and is configured to reflect third light having the first wavelength band and a first polarization direction and emitted from the second surface, transmit fourth light having the first wavelength band and a second polarization direction different from the first polarization direction and emitted from the second surface, reflect fifth light having the second wavelength band and the first polarization direction and emitted from the second surface, and transmit sixth light having the second wavelength band and the second polarization direction and emitted from the second surface, wherein light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer, and light intensity of light having the second polarization direction out of the first light entering the wavelength conversion layer, and the third light reflected by the polarization split element enters the wavelength conversion layer from the second surface of the wavelength conversion layer to be converted into the second light. ### Claim 7 A light source device comprising: a light emitting section configured to emit first light having a first wavelength band; a wavelength conversion layer having a first surface which the first light enters, and a second surface different from the first surface, and configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band, and emit the second light and another part of the first light from the second surface; and a polarization split element which is disposed so as to be opposed to the second surface of the wavelength conversion layer, and is configured to reflect third light having the first wavelength band and a first polarization direction and emitted from the second surface, transmit fourth light having the first wavelength band and a second polarization direction different from the first polarization direction and emitted from the second surface, reflect fifth light having the second wavelength band and the first polarization direction and emitted from the second surface, and transmit sixth light having the second wavelength band and the second polarization direction and emitted from the second surface, wherein light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer, and light intensity of light having the second polarization direction out of the first light entering the wavelength conversion layer, and the fifth light reflected by the polarization split element enters the wavelength conversion layer from the second surface of the wavelength conversion layer, and a part of the fifth light entering the wavelength conversion layer from the second surface is converted into the sixth light. ### Claim 8 (depends on 1) A projector comprising: the light source device according to claim 1; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 9 (depends on 2) A projector comprising: the light source device according to claim 2; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 10 (depends on 3) A projector comprising: the light source device according to claim 3; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 11 (depends on 4) A projector comprising: the light source device according to claim 4; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 12 (depends on 5) A projector comprising: the light source device according to claim 5; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 13 (depends on 6) A projector comprising: the light source device according to claim 6; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 14 (depends on 7) A projector comprising: the light source device according to claim 7; a light modulation device configured to modulate light from the light source device in accordance with image information; and a projection optical device configured to project the light modulated by the light modulation device. ### Claim 15 (depends on 1) The light source device according to claim 1, further comprising: a homogenization illumination system into which the fourth light and the sixth light transmitted from the polarization split element enter, wherein the wavelength conversion layer, the polarization split element and the homogenization illumination system are arranged on a straight line.