# US 10,502,952 B2 · Light source device, image projection apparatus, and head-up display apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,952 B2 - Document ID: US10502952B2 - Status: Granted - Kind: B2 - Application number: 15/474,036 - Filed: 2017-03-30 - Published: 2017-10-05 - Granted: 2019-12-10 - Earliest claimed: 2016-04-01 - Assignees: Japan Display Inc. - Applicants: Japan Display Inc. - Inventors: Tsutomu Harada - Web page: https://patentgrep.com/patent/US10502952B2 ## CPC - G02B 27/0101: {characterised by optical features (G02B27/0172 takes precedence)} - G02B 3/06: with cylindrical or toric faces - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B 26/101: {with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129)} - G02B 27/0988: {Diaphragms, spatial filters, masks for removing or filtering a part of the beam} - 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)} - G02B 2027/0118: {comprising devices for improving the contrast of the display / brillance control visibility} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract According to an aspect, a light source device includes: a light emitting device that emits a light beam capable of being modulated; and a scanning device that deflects the light beam in a first direction and a second direction intersecting the first direction. The light beam has a light quantity varying region in which a light quantity decreases outward from a center of the light beam in at least one of the first direction or the second direction. The scanning device overlaps the light quantity varying regions of a plurality of the light beams with each other with respect to a scanning direction along directions in which the light quantities of the light beams decrease. ## Claims ### Claim 1 A light source device comprising: a light emitting device that emits a light beam capable of being modulated; and a scanning device that deflects the light beam in a first direction and a second direction intersecting the first direction, wherein the light beam has a light quantity varying region in which a light quantity decreases outward from a center of the light beam in at least one of the first direction or the second direction, wherein the scanning device overlaps the light quantity varying regions of a plurality of the light beams with each other with respect to a scanning direction along directions in which the light quantities of the light beams decrease, and wherein, in the light beam, assuming the light quantity at a center in at least one of the directions of the light beam as a reference value, a distance from the center to a position where the light quantity is halved from the reference value is equal to a distance from the position where the light quantity is halved from the reference value to a position where the light quantity becomes equal to zero, and, with respect to the position where the light quantity is halved from that of the center, a degree of increase in the light quantity toward the center of the light beam has a symmetric relation with a degree of decrease in the light quantity toward the position where the light quantity becomes equal to zero. ### Claim 2 (depends on 1) The light source device according to claim 1, wherein the scanning device overlaps the light quantity varying regions with each other so that the light quantity in the overlapped light quantity varying regions is equal to the light quantity at the center. ### Claim 3 (depends on 1) An image projection apparatus comprising: the light source device according to claim 1; and an image output device that uses the light beam as a light source to output an image. ### Claim 4 (depends on 3) The image projection apparatus according to claim 3, wherein the image output device is a liquid crystal display device. ### Claim 5 A head-up display apparatus comprising: a light source device; and an image projection device, wherein the light source device comprises: a light emitting device that emits a light beam capable of being modulated; and a scanning device that deflects the light beam in a first direction and a second direction intersecting the first direction, wherein the image projection device comprises an image output device that uses the light beam as a light source to output an image, wherein the light beam has a light quantity varying region in which a light quantity decreases outward from a center of the light beam in at least one of the first direction or the second direction, wherein the scanning device overlaps the light quantity varying regions of a plurality of the light beams with each other with respect to a scanning direction along directions in which the light quantities of the light beams decrease, and wherein, in the light beam, assuming the light quantity at a center in at least one of the directions of the light beam as a reference value, a distance from the center to a position where the light quantity is halved from the reference value is equal to a distance from the position where the light quantity is halved from the reference value to a position where the light quantity becomes equal to zero, and, with respect to the position where the light quantity is halved from that of the center, a degree of increase in the light quantity toward the center of the light beam has a symmetric relation with a degree of decrease in the light quantity toward the position where the light quantity becomes equal to zero. ### Claim 6 (depends on 5) The head-up display apparatus according to claim 5, wherein the scanning device overlaps the light quantity varying regions with each other so that the light quantity in the overlapped light quantity varying regions is equal to the light quantity at the center. ### Claim 7 (depends on 5) The head-up display apparatus according to claim 5, wherein the image output device is a liquid crystal display device. ### Claim 8 (depends on 5) The head-up display apparatus according to claim 5, wherein the light beam is configured to be transmitted through or reflected by the image output device, wherein the light beam is configured to be reflected by a mirror and a windshield, and wherein the light reflected by the mirror and the windshield is recognized as the image.