# US 2021/0173084 A1 · Safety laser scanner and related method for adjusting distance measurements to compensate for reflective backgrounds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0173084 A1 - Document ID: US20210173084A1 - Status: Published application - Kind: A1 - Application number: 17/112,457 - Filed: 2020-12-04 - Published: 2021-06-10 - Earliest claimed: 2019-12-06 - Assignees: Datalogic IP Tech S.R.L. - Applicants: Datalogic IP Tech S.r.l. - Inventors: Salvatore Valerio Cani; Enrico Lorenzoni; Lorenzo Girotti - Web page: https://patentgrep.com/patent/US20210173084A1 ## CPC - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 7/4808: {Evaluating distance, position or velocity data} - G01S 7/4817: {relating to scanning} - 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: 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 distance measuring device is disclosed that includes a controller operably coupled with a receiver to receive different amplification channels. The controller includes a time of flight core configured to determine time of flight information for the light pulse; and a decider block configured to determine a measurement correction value for the device based on a determination of a presence of a reflective background that is different than a measurement correction value selected for the device when there exists a diffuse background or an absence of a background into a reading field. ## Claims ### Claim 1 A distance measuring device comprising: a transmitter configured to generate a light pulse; a receiver connected to different amplification channels; and a controller operably coupled with the receiver to receive the different amplification channels, wherein the controller includes: a time of flight core configured to determine time of flight information for the light pulse; and a decider block configured to determine a measurement correction value for the device based on a determination of a presence of a reflective background that is different than a measurement correction value selected for the device when there exists a diffuse background or an absence of a background into a reading field. ### Claim 2 (depends on 1) The device of claim 1, wherein the controller includes: a measurement buffer wherein each cell includes distance and energy values calculated for each pulse and for each channel with stored values corresponding to consecutive transmitted pulses; and a reflector detector buffer wherein each cell includes a binary value indicating the presence of a reflective or diffusive object, each binary value being computed using the information included in more than one measurement buffer. ### Claim 3 (depends on 2) The device of claim 2, wherein the decider block is configured to detect the presence of the reflective background based on selecting data from a different channel for analysis. ### Claim 4 (depends on 2) The device of claim 2, wherein the different amplification channels includes at least one of an auxiliary channel, a diffusive channel, and a reflective channel. ### Claim 5 (depends on 4) The device of claim 4, wherein the auxiliary channel is defined for distances from a minimum distance up to 2500 mm and a target reflectance from 1.8% to 90%. ### Claim 6 (depends on 4) The device of claim 4, wherein the diffusive channel is defined for distances from 2000 mm up to a maximum distance and a target reflectance from 1.8% to 90%. ### Claim 7 (depends on 4) The device of claim 4, wherein the reflective channel is defined for distances from a minimum distance up to a maximum distance and a target reflectance greater than 90%. ### Claim 8 (depends on 1) The device of claim 1, wherein the receiver is a photodetector. ### Claim 9 (depends on 1) The device of claim 1, wherein the decider block is configured to determine the measurement correction value for the device responsive to determining an energy threshold value. ### Claim 10 (depends on 1) The device of claim 1, wherein the decider block is configured to determine the measurement correction value for the device responsive to determining a characteristic curve of an energy value ration of a diffusive channel and a reflective channel. ### Claim 11 (depends on 1) The device of claim 1, wherein the decider block is configured to determine the measurement correction value for the device responsive to a mix method of determining both an energy threshold value and determining a characteristic curve of an energy value ration of a diffusive channel and a reflective channel. ### Claim 12 (depends on 1) The device of claim 1, wherein the decider block is configured to determine the measurement correction value based on a look-up table. ### Claim 13 (depends on 12) The device of claim 12, wherein the look-up table is addressable based on an energy value and raw distance pair received from the time-of-flight core for the selected channel. ### Claim 14 (depends on 1) The device of claim 1, wherein the time-of-flight core and the decider block are implemented in an FPGA of the controller. ### Claim 15 (depends on 1) The device of claim 1, wherein the device is a safety laser scanner. ### Claim 16 (depends on 1) The device of claim 1, wherein the device is a time-of-flight distance measurer without a scanning mechanism. ### Claim 17 (depends on 1) The device of claim 1, wherein the light pulses include laser pulses. ### Claim 18 A method of measuring a distance of an object with a reflective background, the method comprising: generating a light pulse with a transmitter; determining time of flight information with a time of flight core of a controller that receives different amplification channels via a receiver; and determining, via a decider block of the controller, a measurement correction value for the device based on a determination of a presence of a reflective background that is different than a measurement correction value selected for the device when there exists a diffuse background or an absence of a background into a reading field. ### Claim 19 (depends on 18) The method of claim 18, wherein determining the measurement correction value is responsive to at least one of: determining an energy threshold value; determining a characteristic curve of an energy value ration of a diffusive channel and a reflective channel; or responsive to a mix method of determining both an energy threshold value and determining a characteristic curve of an energy value ration of a diffusive channel and a reflective channel. ### Claim 20 (depends on 18) The method of claim 18, wherein determining the measurement correction value is based on a look-up table.