# US 2021/0333372 A1 · Distance image capturing device, distance image capturing system, and distance image capturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333372 A1 - Document ID: US20210333372A1 - Status: Published application - Kind: A1 - Application number: 16/619,448 - Filed: 2019-03-20 - Published: 2021-10-28 - Earliest claimed: 2019-03-20 - Assignees: Brookman Technology, Inc. - Applicants: Brookman Technology, Inc. - Inventors: Tomoyuki Akahori - Web page: https://patentgrep.com/patent/US20210333372A1 ## CPC - G01S 7/4865: Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) - G01S 7/4814: {of transmitters alone} - G01S 7/4816: {of receivers alone} - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 7/4876: {by removing unwanted signals (G01S7/495 takes precedence)} - G01S 17/894: Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar - H04N 25/53: Control of the integration time - 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 - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A light source unit, a light receiving unit that includes a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units at a predetermined accumulation timing are arranged in a two-dimensional matrix pattern, a distance image processing unit that is configured to acquire a distance from a subject present in the space that is an imaging target, and a timing determining unit that is configured to determine the accumulation timing in the measurement time interval on the basis of an electric charge amount in each of the electric charge accumulating units in an inspection time interval in which the light pulse is not emitted at the accumulation timing are provided. ## Claims ### Claim 1 A distance image capturing device comprising: a light source unit that is configured to emit an intermittent light pulse into a space that is an imaging target at a predetermined period; a light receiving unit that includes a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units at a predetermined accumulation timing are arranged in a two-dimensional matrix pattern; a distance image processing unit that is configured to acquire a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which the light pulse is emitted in synchronization with the accumulation timing; and a timing determining unit that is configured to determine the accumulation timing in the measurement time interval on the basis of an electric charge amount in each of the electric charge accumulating units in an inspection time interval in which the light pulse is not emitted at the accumulation timing. ### Claim 2 (depends on 1) The distance image capturing device according to claim 1, wherein the timing determining unit is configured to determine the accumulation timing in the measurement time interval in accordance with the electric charge amount accumulated in each of the electric charge accumulating units in the inspection time interval and the accumulation timing in the inspection time interval. ### Claim 3 (depends on 1) The distance image capturing device according to claim 1, wherein the timing determining unit is configured to determine the accumulation timing in the measurement time interval such that an accumulation time interval in which the electric charge is accumulated in the electric charge accumulating unit in which the electric charge amount accumulated in the inspection time interval is a maximum in the inspection time interval and the accumulation time interval of each of the electric charge accumulating units at the accumulation timing in the measurement time interval do not overlap each other in an accumulation period that is a period in which the accumulation time interval is repeated. ### Claim 4 (depends on 1) The distance image capturing device according to claim 1, wherein the timing determining unit is configured to determine the accumulation timing in the measurement time interval on the basis of a timing information table in which identification information of the electric charge accumulating unit in which the electric charge amount accumulated in the inspection time interval is a maximum and information relating to the accumulation timing in the measurement time interval are associated with each other. ### Claim 5 (depends on 1) The distance image capturing device according to claim 1, wherein a length of the inspection time interval is shorter than a length of the measurement time interval. ### Claim 6 A distance image capturing device comprising: a light source unit that is configured to emit a light pulse into a space that is an imaging target at a predetermined period; a light receiving unit that includes a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units in synchronization of emission of the light pulse are arranged in a two-dimensional matrix pattern; a distance image processing unit that is configured to acquire a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which accumulation of the electric charge is executed a predetermined number of electric charge division instances; and an accumulation period changing unit that is configured to change a length of the accumulation period such that there is no change in the length of the measurement time interval before and after change of the length of the accumulation period that is a period in which the electric charge is accumulated in each of the electric charge accumulating units. ### Claim 7 A distance image capturing system comprising: a plurality of distance image capturing devices; and an external control device that is communicatively connected to the plurality of distance image capturing devices, wherein each of the plurality of distance image capturing devices includes: a light source unit that is configured to emit a light pulse into a space that is an imaging target at a predetermined period; a light receiving unit that includes a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units in synchronization of emission of the light pulse are arranged in a two-dimensional matrix pattern; a distance image processing unit that is configured to acquire a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which accumulation of the electric charge is executed a predetermined number of electric charge division instances; and an information acquiring unit that is configured to acquire information from the external control device, and wherein the external control device includes a timing control unit that is configured to perform control such that an accumulation timing at which the electric charge accumulating unit accumulates the electric charge in a first distance image capturing device among the plurality of distance image capturing devices and the accumulation timing in a second distance image capturing device other than the first distance image capturing device do not overlap each other with respect to time. ### Claim 8 (depends on 7) The distance image capturing system according to claim 7, wherein the timing control unit is configured to control the accumulation timing such that the accumulation timing of the second distance image capturing device comes in a time interval other than the accumulation timing of the first distance image capturing device. ### Claim 9 (depends on 7) The distance image capturing system according to claim 7, wherein the timing control unit is configured to control the accumulation timing such that the measurement time interval of the second distance image capturing device starts after the measurement time interval of the first distance image capturing device ends. ### Claim 10 A distance image capturing method comprising: a process of emitting, by a light source unit, an intermittent light pulse into a space that is an imaging target at a predetermined period; a light receiving process of receiving light by a light receiving unit including a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units at a predetermined accumulation timing are arranged in a two-dimensional matrix pattern; a distance image processing process of acquiring, by a distance image processing unit, a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which the light pulse is emitted in synchronization with the accumulation timing; and a timing determining process of determining, by a timing determining unit, the accumulation timing in the measurement time interval on the basis of an electric charge amount in each of the electric charge accumulating units in an inspection time interval in which the light pulse is not emitted at the accumulation timing. ### Claim 11 A distance image capturing method comprising: a process of emitting, by a light source unit, a light pulse into a space that is an imaging target at a predetermined period; a light receiving process of receiving light by a light receiving unit including a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units in synchronization of emission of the light pulse are arranged in a two-dimensional matrix pattern; a distance image processing process of acquiring, by a distance image processing unit, a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which accumulation of the electric charge is executed a predetermined number of electric charge division instances; and an accumulation period changing process of changing, by an accumulation period changing unit, a length of the accumulation period such that there is no change in the length of the measurement time interval before and after change of the length of the accumulation period that is a period in which the electric charge is accumulated in each of the electric charge accumulating units. ### Claim 12 A distance image capturing method in a distance image capturing system including a plurality of distance image capturing devices and an external control device that is communicatively connected to the plurality of distance image capturing devices, the distance image capturing method comprising: a process of emitting, by a light source unit in each of the plurality of distance image capturing devices, a light pulse into a space that is an imaging target at a predetermined period; a light receiving process of receiving light by a light receiving unit in each of the plurality of distance image capturing devices including a distance image sensor in which a plurality of pixels each including a photoelectric conversion device generating electric charge corresponding to incident light and a plurality of electric charge accumulating units accumulating the electric charge and dividing and accumulating the electric charge among the electric charge accumulating units in synchronization of emission of the light pulse are arranged in a two-dimensional matrix pattern; a distance image processing process of acquiring, by a distance image processing unit in each of the plurality of distance image capturing devices, a distance from a subject present in the space that is an imaging target on the basis of an electric charge amount in each of the electric charge accumulating units in a measurement time interval in which accumulation of the electric charge is executed a predetermined number of electric charge division instances; an information acquiring process of acquiring, by an information acquiring unit in each of the plurality of distance image capturing devices, information from the external control device; and a timing control process of performing, by a timing control unit in the external control device, control such that an accumulation timing at which the electric charge accumulating unit accumulates the electric charge in a first distance image capturing device among the plurality of distance image capturing devices and the accumulation timing in a second distance image capturing device other than the first distance image capturing device do not overlap each other with respect to time.