# US 2020/0401065 A1 · Image sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401065 A1 - Document ID: US20200401065A1 - Status: Published application - Kind: A1 - Application number: 16/965,026 - Filed: 2018-03-16 - Published: 2020-12-24 - Earliest claimed: 2018-03-16 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Ido Finkelman; Rivay Mor; Eitan Kichli; Iliya Shahamov; Pavel Shulga-Raz - Web page: https://patentgrep.com/patent/US20200401065A1 ## CPC - G03G 15/104: {Preparing, mixing, transporting or dispensing developer} - G03G 15/105: {Detection or control means for the toner concentration} - G03G 15/0131: {for transferring a pattern to a second base} - G03G 15/5062: {by measuring the characteristics of an image on the copy material} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An example printer comprises an impression cylinder arranged to receive an impression medium thereon and an intermediate transfer member arranged to transfer printing fluid onto a substrate received on the impression medium. The printer further comprises an image sensor arranged to sense an accumulation of printing fluid on the impression medium as sensor data and a controller. The controller is configured to determine, based on the sensor data, an accumulation level of the printing fluid on the impression medium and determine if the accumulation level meets a threshold. ## Claims ### Claim 1 A printer, comprising: an impression cylinder arranged to receive an impression medium thereon; an intermediate transfer member arranged to transfer printing fluid onto a substrate received on the impression medium; an image sensor arranged to sense an accumulation of printing fluid on the impression medium as sensor data; and a controller to: determine, based on the sensor data, an accumulation level of the printing fluid on the impression medium; and determine if the accumulation level meets a threshold. ### Claim 2 (depends on 1) A printer according to claim 1, wherein the controller is further to: send a user a notification to indicate that the impression medium should be replaced, responsive to determining that the accumulation level meets the threshold. ### Claim 3 (depends on 1) A printer according to claim 1, wherein the controller is further to: increment a count each time printing fluid is transferred from the intermediate transfer member to a substrate received on the impression medium; and send a user a notification to indicate that the impression medium should be replaced, responsive to: determining that the accumulation level meets the threshold; and determining that the count meets a second threshold. ### Claim 4 (depends on 1) A printer according to claim 1, wherein the controller is further to: send a user a notification to indicate that the impression medium should be replaced, responsive to: determining, based on the sensor data, that at least a portion of printing fluid has detached from the impression medium. ### Claim 5 (depends on 4) A printer according to claim 4, wherein determining that at least a portion of printing fluid has detached from the impression medium comprises: determining that the accumulation level is less than a previously determined accumulation level, the previously determined accumulation level corresponding to an accumulation level of printing fluid on the same impression medium at an earlier time. ### Claim 6 (depends on 4) A printer according to claim 4, wherein determining that at least a portion of printing fluid has detached from the impression medium comprises: determining that the accumulation level of the printing fluid on the impression medium is non-uniform across a region of the impression medium. ### Claim 7 (depends on 1) A printer according to claim 1, wherein the controller is further to: determine that the accumulation level meets the threshold; receive second sensor data from the image sensor; determine, based on the second sensor data, a second accumulation level; determine that the second accumulation level does not meet the threshold; and based at least in part on determining that that the second accumulation level does not meet the threshold: determine that the impression medium has been replaced. ### Claim 8 (depends on 7) A printer according to claim 7, wherein the controller is further to: send a user a notification to indicate that an exposed surface of the image sensor should be cleaned, responsive to determining that the second accumulation level meets a third threshold. ### Claim 9 (depends on 1) A printer according to claim 1, wherein the image sensor is a camera, and the camera is further arranged to sense one or more registration marks on the substrate. ### Claim 10 A method of monitoring an impression medium, comprising: depositing printing fluid on to an impression medium received on an impression cylinder; determining an accumulation level of printing fluid on the impression medium; and determining if the accumulation level meets a threshold. ### Claim 11 (depends on 10) A method according to claim 10, further comprising: sending a user a notification to indicate that the impression medium should be replaced responsive to determining that the accumulation level meets the threshold. ### Claim 12 (depends on 10) A method according to claim 10, further comprising: incrementing a count each time printing fluid is transferred to a substrate received on the impression medium; and sending a user a notification to indicate that the impression medium should be replaced responsive to: determining that the accumulation level meets the threshold; and determining that the count meets a second threshold. ### Claim 13 (depends on 10) A method according to claim 10, further comprising: sending a user a notification to indicate that the impression medium should be replaced responsive to: determining that at least a portion of printing fluid has detached from the impression medium. ### Claim 14 (depends on 10) A method according to claim 10, further comprising: determining that the accumulation level meets the threshold; determining a second accumulation level; determining that the second accumulation level does not meet the threshold; and based at least in part on determining that that the second accumulation level does not meet the threshold: determining that the impression medium has been replaced. ### Claim 15 A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors in a printer, cause the one or more processors to: cause an intermediate transfer member to transfer printing fluid onto a substrate received on an impression medium; obtain sensor data by causing an image sensor to sense an accumulation of printing fluid on the impression medium; determine, based on the sensor data, an accumulation level of the printing fluid on the impression medium; and determine if the accumulation level meets a threshold.