# US 2021/0240108 A1 · Apparatus for use in an electrographic printer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0240108 A1 - Document ID: US20210240108A1 - Status: Published application - Kind: A1 - Application number: 17/230,328 - Filed: 2021-04-14 - Published: 2021-08-05 - Earliest claimed: 2019-10-15 - Assignees: HP Indigo B.V. - Applicants: HP Indigo B.V. - Inventors: Shachar Berger; Shmuel Borenstain; Regina Guslitzer; Gregory Katz - Web page: https://patentgrep.com/patent/US20210240108A1 ## CPC - G03G 15/104: {Preparing, mixing, transporting or dispensing developer} - G03G 15/065: {Arrangements for controlling the potential of the developing electrode} - G03G 15/2017: {Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence)} - G03G 15/5045: {Detecting the temperature} - G03G 2215/0658: Liquid developer devices - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract In one aspect an apparatus for use in an electrographic printer is described. The apparatus includes a housing defining a cavity, a developer roller, a developer electrode for developing printing substance onto the developer roller, the electrode being arranged within the cavity, and a heater for heating printing substance to be developed onto the developer roller, the heater being arranged in the cavity. ## Claims ### Claim 1 An apparatus for use in an electrographic printer, the apparatus comprising: a developer roller; a developer electrode for developing printing substance onto the developer roller; and a heater for heating printing substance to be developed onto the developer roller, the heater being disposed on the developer electrode. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the heater is arranged to directly heat the printing substance in use. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the heater is arranged to indirectly heat the printing substance by heating the developer electrode. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the printing substance to be developed is ink. ### Claim 5 (depends on 5) The apparatus of claim 5, wherein the apparatus comprises an ink inlet through which ink may be supplied to the apparatus, the inlet being surrounded by a portion of the developer electrode. ### Claim 6 (depends on 5) The apparatus of claim 5, further comprising a channel in the developer electrode leading from the inlet to the developer roller. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the heater is configured to have a surface temperature of greater than or equal to 30° C. in use. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the heater is configured to have a power output of greater than or equal to 200W in use. ### Claim 9 An apparatus for use in an electrographic printer, the apparatus comprising: a housing defining a cavity; a developer roller; a developer electrode for developing printing substance onto the developer roller, the electrode being arranged within the cavity, the developer electrode surrounding an inlet for the printing substance into the cavity of the housing, the developer electrode structured to direct printing substance from the inlet to the developer roller; and a heater for heating printing substance to be developed onto the developer roller. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the heater is disposed on the developer electrode. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the heater is arranged to directly heat the printing substance in use. ### Claim 12 (depends on 10) The apparatus of claim 10, wherein the heater is arranged to indirectly heat the printing substance by heating the developer electrode. ### Claim 13 (depends on 10) The apparatus of claim 10, wherein the heater comprises two heating elements disposed on opposite sides of a printing substance path defined by the developer electrode. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein the printing substance to be developed is ink. ### Claim 15 (depends on 9) The apparatus of claim 9, wherein the heater is configured to have a surface temperature of greater than or equal to 30° C. in use. ### Claim 16 (depends on 9) The apparatus of claim 9, wherein the heater is configured to have a power output of greater than or equal to 200W in use. ### Claim 17 A method of heating a printing substance to be developed by a developer roller, the method comprising: with a heater that is thermally bridged to a developer electrode, heating the developer electrode; with the developer electrode, guiding a printing substance from an inlet to the developer roller, thereby heating the printing substance with the heated developer roller; and with a potential difference between the developer electrode and developer roller; developing the printing substance to the developer roller. ### Claim 18 (depends on 17) The method of claim 17, wherein, in addition to heating the developer electrode, flowing the printing substance over the heater to directly heat the printing substance. ### Claim 19 (depends on 18) The method of claim 18, wherein the heater comprises multiple heating elements disposed in different positions with respect to the developer electrode. ### Claim 20 (depends on 17) The method of claim 17, further comprising heating the developer electrode with multiple heating elements of the heater, the multiple heating elements disposed in different positions with respect to the developer electrode.