# US 11,029,391 B2 · System for determining a distance to an object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,391 B2 - Document ID: US11029391B2 - Status: Granted - Kind: B2 - Application number: 16/337,327 - Filed: 2017-10-03 - Published: 2020-01-30 - Granted: 2021-06-08 - Earliest claimed: 2016-10-03 - Assignees: Xenomatix NV - Applicants: Xenomatix NV - Inventors: Rik Paesen; Dirk Van Dyck - Web page: https://patentgrep.com/patent/US11029391B2 ## CPC - G01S 7/4815: {using multiple transmitters} - G01S 7/4816: {of receivers alone} - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - 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 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - G01S 17/36: with phase comparison between the received signal and the contemporaneously transmitted signal - 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 - G01S 17/931: of land vehicles - 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 The invention pertains to a system for determining a distance, comprising: a light source for projecting a pattern of discrete spots of laser light towards the object in a sequence of pulses; a detector comprising picture elements, for detecting light representing the pattern as reflected by the object in synchronization with the sequence of pulses; and processing means to calculate the distance to the object as a function of exposure values generated by said picture elements. The picture elements generate exposure values by accumulating a first amount of electrical charge representing a first amount of light reflected during a first time window and a second electrical charge representing a second amount of light reflected during a second time window. The solid-state radiation source emits substantially monochromatic light having a wavelength spread of less than ±20 nm and the detector is equipped with a corresponding narrow bandpass filter. ## Claims ### Claim 1 A system for determining a distance to an object comprising: a solid-state light source arranged for projecting a pattern of discrete spots of laser light towards said object in a sequence of pulses; a detector comprising a plurality of picture elements, said detector being configured for detecting light representing said pattern of discrete spots as reflected by said object in synchronization with said sequence of pulses; and processing means configured to calculate said distance to said object as a function of exposure values generated by said picture elements in response to said detected light based on the amount of temporal overlap between the pulse emission window and the arrival of the reflected pulse by applying range gating to said sequence of pulses; wherein said picture elements are configured to generate said exposure values by accumulating, for all of the pulses of said sequence, a first amount of electrical charge representative of a first amount of light reflected by said object during a first predetermined time window overlapping with the pulse emission time window and a second electrical charge representative of a second amount of light reflected by said object during a second predetermined time window, said second predetermined time window occurring after said first predetermined time window; wherein each of said plurality of picture elements comprises at least two charge storage wells; wherein said detecting of said first amount of light and said detecting of said second amount of light occurs at respective ones of said at least two charge storage wells; and wherein the solid-state radiation source emits substantially monochromatic light having a wavelength spread of less than ±20 nm and the detector is equipped with a corresponding narrow bandpass filter. ### Claim 2 (depends on 1) The system according to claim 1, wherein said solid-state light source is adapted to emit said pattern of discrete spots such that different spots have different respective wavelengths (λ1, λ2), said different respective wavelengths (λ1, λ2) corresponding to the maximum of the passband of the narrow bandpass filter under different angles of incidence. ### Claim 3 (depends on 2) The system according to claim 2, wherein said solid-state light source comprises a plurality of tiles emitting light at said different respective wavelengths (λ1, λ2). ### Claim 4 (depends on 3) The system according to claim 3, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 5 (depends on 2) The system according to claim 2, wherein said solid-state light source comprises a VCSEL array equipped with micro-electrical-mechanical systems arranged to adapt an emission wavelength of individual VCSELs among said VCSEL array so as to obtain said different respective wavelengths (λ1, λ2). ### Claim 6 (depends on 5) The system according to claim 5, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 7 (depends on 2) The system according to claim 2, wherein said solid-state light source comprises a VCSEL array equipped with piezo-electrical transducers arranged to adapt an emission wavelength of individual VCSELs among said VCSEL array so as to obtain different respective wavelengths (λ1, λ2). ### Claim 8 (depends on 7) The system according to claim 7, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 9 (depends on 2) The system according to claim 2, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 10 (depends on 1) The system according to claim 1, further comprising optics arranged so as to modify an angle of incidence onto said narrow bandpass filter, to confine said angle of incidence to a predetermined range around a normal of a main surface of said narrow bandpass filter, wherein said plurality of picture elements is arranged on a substrate having a curvature corresponding to the focal plane. ### Claim 11 (depends on 10) The system according to claim 10, wherein said optics comprise an image-space telecentric lens. ### Claim 12 (depends on 11) The system according to claim 11, wherein said optics comprise two lenses with approximately the same focal length arranged in an image space telecentric configuration. ### Claim 13 (depends on 12) The system according to claim 12, wherein said optics further comprise a first minilens array arranged between said two lenses and said narrow bandpass filter so as to direct substantially all light beams incident on said first minilens array from said two lenses into said predetermined range. ### Claim 14 (depends on 13) The system according to claim 13, wherein said optics further comprise a second minilens array arranged between said narrow bandpass filter and said at least one detector, wherein individual minilenses of said minilens array focus incident light on respective light-sensitive areas of individual pixels of said at least one detector. ### Claim 15 (depends on 12) The system according to claim 12, wherein said optics further comprise a second minilens array arranged between said narrow bandpass filter and said at least one detector, wherein individual minilenses of said minilens array focus incident light on respective light-sensitive areas of individual pixels of said at least one detector. ### Claim 16 (depends on 11) The system according to claim 11, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 17 (depends on 10) The system according to claim 10, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 18 (depends on 1) The system according to claim 1, wherein said first predetermined time window and said second predetermined time window are of substantially equal duration and occur back-to-back. ### Claim 19 (depends on 1) A vehicle comprising a system according to claim 1 arranged to operatively cover at least a part of an area surrounding said vehicle. ### Claim 20 (depends on 1) A camera, the camera comprising a system according to claim 1, whereby the system is adapted to add 3D information to the camera image based on information obtained from the system, making it possible to create a 3D image.