# US 11,112,494 B2 · Photodetector and portable electronic equipment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,494 B2 - Document ID: US11112494B2 - Status: Granted - Kind: B2 - Application number: 16/613,985 - Filed: 2018-03-29 - Published: 2021-05-13 - Granted: 2021-09-07 - Earliest claimed: 2017-05-18 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: Takayuki Shimizu; Takuma Hiramatsu; Yoshiki Ikuta; Hideki Sato - Web page: https://patentgrep.com/patent/US11112494B2 ## CPC - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 7/497: Means for monitoring or calibrating - G01C 3/06: Use of electric means to obtain final indication - G01S 7/4876: {by removing unwanted signals (G01S7/495 takes precedence)} - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - H10F 55/00: Radiation-sensitive semiconductor devices covered by groups H10F10/00, H10F19/00 or H10F30/00 being structurally associated with electric light sources and electrically or optically coupled thereto - 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 - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract Effects of ambient light are suppressed, and distance to a detection object is measured with high precision. A ranging sensor includes a VCSEL, a SPAD array that has multiple SPADs that detect photons of pulse light emitted by the VCSEL, a SPAD array that has multiple SPADs that detect photons of reflected light where the pulse light has been reflected by a detection object, a DLL that measures a time difference between a pulse signal output from the SPADs of the SPAD array and a pulse signal output from the SPADs of the SPAD array, an ambient-light-incident SPAD determining unit that determines a SPAD on which ambient light is incident, based on pulse signals output from SPADs of the SPAD array when the VCSEL is not emitting light, and a SPAD front-end circuit that stops operation of the SPAD for which determination is made that ambient light is incident. ## Claims ### Claim 1 A photodetector, comprising: a light-emitting element; a first light-receiving unit that has a plurality of avalanche photodiodes as a first light-receiving element that detects, in Geiger mode, photons of pulse light emitted by the light-emitting element; a second light-receiving unit that has a plurality of avalanche photodiodes as a second light-receiving element that detects, in Geiger mode, photons of reflected light where the pulse light has been reflected by a detection object; a time difference measuring unit that measures a time difference between a puke signal output from the first light-receiving element of the first light-receiving unit and a pulse signal output from the second light-receiving element of the second light-receiving unit; an ambient-light-incident light-receiving-element determining unit that determines the second light-receiving element on which ambient light is incident, based on pulse signals output from second light-receiving elements of the second light-receiving unit when the light-emitting element is not emitting light; and an operation stopping unit that stops operation of the second light-receiving elements for which determination is made that ambient light is incident. ### Claim 2 (depends on 1) The photodetector according to claim 1, wherein, in a case where a number of pulses per unit time of a pulse signal output from the second light-receiving element is greater than a predetermined value, the ambient-light-incident light-receiving-element determining unit determines that ambient light is incident on the second light-receiving element that has output the pulse signal. ### Claim 3 (depends on 1) The photodetector according to claim 1, further comprising: a coefficient multiplying unit that multiplies a pulse signal of the second light-receiving element by a weighting coefficient corresponding to a position of the second light-receiving element, in the second light-receiving unit, wherein, in a case where a number of pulses per unit time of the pulse signal multiplied by the weighting coefficient is greater than a predetermined value, the ambient-light-incident light-receiving-element determining unit determines that ambient light is incident on the second light-receiving element that has output the pulse signal. ### Claim 4 (depends on 3) The photodetector according to claim 3, wherein the weighting coefficient is smallest at a middle portion of the second light-receiving unit and becomes larger in a direction from the middle portion toward a perimeter portion of the second light-receiving unit. ### Claim 5 (depends on 1) The photodetector according to claim 1, wherein, in a case where a number of pulses of a pulse signal output from the second light-receiving element is greater than a first predetermined value, and a difference or a ratio between the numbers of pulses when the light-emitting element is emitting light and not emitting light is smaller than a second predetermined value, determination is made that ambient light is incident on the second light-receiving element outputting the pulse signal. ### Claim 6 (depends on 5) The photodetector according to claim 5, further comprising: a light-emission intensity control unit that reduces light-emission intensity of the light-emitting element in a case where the difference or the ratio between the numbers of pulses when the light-emitting element is emitting light and not emitting light is greater than a predetermined value. ### Claim 7 (depends on 5) The photodetector according to claim 5, further comprising: a light emission angle control unit that controls a light emission angle of the light-emitting element in a case where the difference or the ratio between the numbers of pulses when the light-emitting element is emitting light and not emitting light is greater than a predetermined value. ### Claim 8 (depends on 1) The photodetector according to claim 1, further comprising: a concentrating lens disposed on a side of the second light-receiving unit on which light is incident. ### Claim 9 (depends on 1) Portable electronic equipment, comprising: the photodetector according to claim 1.