# US 2019/0170866 A1 · Photoreceptor, flight time measurement device, and optical radar > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170866 A1 - Document ID: US20190170866A1 - Status: Published application - Kind: A1 - Application number: 16/208,386 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: KATSUJI IGUCHI; HIDENORI KAWANISHI; KOJI TAKAHASHI; NORIAKI FUJII - Web page: https://patentgrep.com/patent/US20190170866A1 ## CPC - G01S 7/499: using polarisation effects - G01S 7/4812: {transmitted and received beams following a coaxial path} - G01S 7/484: Transmitters - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - G01S 7/4817: {relating to scanning} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A photodetector measures flight time by an imaging optical element imaging reflected light from an illuminated illumination region of an object illuminated by pulse light, and a light detection portion receiving the imaged light. The light detection portion is formed larger than a projection region reflected at the illumination region of the object and imaged on the light detection portion. In the light detection portion, a portion overlaying the projection region is activated as a light-detection region. ## Claims ### Claim 1 A photodetector, comprising: a light detection portion, wherein the photodetector measures flight time by detecting reflected light from an illumination region of an object illuminated by pulse light, and the illumination region is imaged on the light detection portion as a projection region by an imaging optical element, wherein the light detection portion is formed larger than the projection region, and wherein, in the light detection portion, a portion overlaying the projection region is activated as a light-detection region. ### Claim 2 (depends on 1) The photodetector according to claim 1, further comprising: a storage unit storing the light-detection region beforehand. ### Claim 3 (depends on 1) The photodetector according to claim 1, wherein the light-detection region includes no defective portions. ### Claim 4 (depends on 1) The photodetector according to claim 1, wherein the light detection portion has photon detection elements configured of single photon avalanche diodes (SPADs) laid out as an array. ### Claim 5 (depends on 4) The photodetector according to claim 4, wherein the light-detection region is set in increments of rows and columns of the array. ### Claim 6 (depends on 4) The photodetector according to claim 4, wherein the light-detection region is set in increments of the SPADs. ### Claim 7 (depends on 4) The photodetector according to claim 4, further comprising: a binary counter adding pulse outputs from the SPADs. ### Claim 8 (depends on 1) The photodetector according to claim 1, wherein the light detection portion includes a plurality of light-detection regions, the light-detection region to be applied being selectable situationally. ### Claim 9 (depends on 1) The photodetector according to claim 1, wherein the photodetector includes a plurality of the light detection portion. ### Claim 10 (depends on 1) A flight time measurement device, comprising at least: a pulse emitter; a polarizing beam splitter; an imaging optical element; and the photodetector according to claim 1, wherein the pulse emitter causes pulse light to pass through the polarizing beam splitter and the imaging optical element in that order and illuminate an object, wherein reflected light from the object passes through the imaging optical element and polarizing beam splitter in that order and is imaged at the photodetector, and wherein the pulse emitter and the photodetector are each disposed at a focal position on one side of the imaging optical element. ### Claim 11 (depends on 1) A flight time measurement device, comprising at least: a pulse emitter; a collimation lens; a polarizing beam splitter; an imaging optical element; and the photodetector according to claim 1, wherein the pulse emitter causes pulse light to pass through the collimation lens and the polarizing beam splitter in that order and illuminate an object, wherein reflected light from the object passes through the polarizing beam splitter and the imaging optical element in that order and is imaged at the photodetector, wherein the pulse emitter is disposed at a focal position on one side of the collimation lens, and wherein the photodetector is disposed at a focal position on one side of the imaging optical element. ### Claim 12 (depends on 1) A flight time measurement device, comprising at least: a pulse emitter; a collimation lens; an imaging optical element; and the photodetector according to claim 1, wherein the pulse emitter causes pulse light to pass through the collimation lens and illuminate an object, wherein reflected light from the object passes through the imaging optical element and is imaged at the photodetector, wherein the pulse emitter is disposed at a focal position on one side of the collimation lens, and wherein the photodetector is disposed at a focal position on one side of the imaging optical element. ### Claim 13 (depends on 9) A flight time measurement device, comprising at least: a pulse emitter; a polarizing beam splitter; an imaging optical element; and the photodetector according to claim 9, wherein the pulse emitter includes a plurality of light emitting portions, wherein each light emitting portion of the pulse emitter causes pulse light to pass through the polarizing beam splitter and the imaging optical element in that order and illuminate object, wherein reflected light from the objects pass through the imaging optical element and polarizing beam splitter in that order and is imaged at one of light detection portion of the photodetector, wherein the pulse emitter and the photodetector are each disposed at a focal position on one side of the imaging optical element, and wherein the light emitting portion and the light detection portion correspond in a one-on-one manner. ### Claim 14 (depends on 9) A flight time measurement device, comprising at least: a pulse emitter; a collimation lens; a polarizing beam splitter; an imaging optical element; and the photodetector according to claim 9, wherein the pulse emitter includes a plurality of light emitting portions, wherein each light emitting portion of the pulse emitter causes pulse light to pass through the collimation lens and the polarizing beam splitter in that order and illuminate object, wherein reflected light from the objects pass through the polarizing beam splitter and the imaging optical element in that order and is imaged at one of light detection portion of the photodetector, wherein the pulse emitter is disposed at a focal position on one side of the collimation lens, wherein the photodetector is disposed at a focal position on one side of the imaging optical element, and wherein the light emitting portion and the light detection portion correspond in a one-on-one manner. ### Claim 15 (depends on 9) A flight time measurement device, comprising at least: a pulse emitter; a collimation lens; an imaging optical element; and the photodetector according to claim 9, wherein the pulse emitter includes a plurality of light emitting portions, wherein each light emitting portion of the pulse emitter causes pulse light to pass through the collimation lens and illuminate object, wherein reflected light from the objects pass through the imaging optical element and is imaged at one of light detection portion of the photodetector, wherein the pulse emitter is disposed at a focal position on one side of the collimation lens, wherein the photodetector as disposed at a focal position on one side of the imaging optical element, and wherein the light emitting portion and the light detection portion correspond in a one-on-one manner. ### Claim 16 (depends on 10) An optical radar, comprising: the flight time measurement device according to claim 10. ### Claim 17 (depends on 11) An optical radar, comprising: the flight time measurement device according to claim 11. ### Claim 18 (depends on 12) An optical radar, comprising: the flight time measurement device according to claim 12. ### Claim 19 (depends on 13) An optical radar, comprising: the flight time measurement device according to claim 13. ### Claim 20 (depends on 15) An optical radar, comprising: the flight time measurement device according to claim 15.