# US 8,540,241 B2 · Sheet end detection device, image recording apparatus including the sheet end detection device, and a method for detecting position of sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,241 B2 - Document ID: US8540241B2 - Status: Granted - Kind: B2 - Application number: 12/326,062 - Filed: 2008-12-01 - Published: 2009-08-27 - Granted: 2013-09-24 - Earliest claimed: 2007-11-30 - Assignees: Brother Kogyo Kabushiki Kaisha - Applicants: Hiroto Sugahara - Inventors: Hiroto Sugahara - Web page: https://patentgrep.com/patent/US8540241B2 ## CPC - B65H 7/02: by feelers or detectors - B41J 11/0065: {Means for printing without leaving a margin on at least one edge of the copy material, e.g. edge-to-edge printing} - B41J 11/0095: {Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end} - B65H 5/06: by rollers {or balls, e.g. between rollers (transport by suction rollers B65H5/226)} - B65H 2511/20: Location in space - B65H 2553/26: Piezoelectric sensors - B65H 2553/51: Encoders, e.g. linear - B65H 2801/12: Single-function printing machines, typically table-top machines - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A sheet end detection device includes a cylindrical roller rotatable around an axis; and a phase detection unit configured to detect a phase in a circumferential direction of the roller. A first piezoelectric element band is provided on the peripheral surface of the roller and extending in the circumferential direction and the axial direction, and the first piezoelectric element band is configured to detect a contact of the sheet and extending in an axial direction of the roller over an inside and an outside of a contact area to be contacted with the conveyed sheet on the peripheral surface. A position of an arbitrary point of the first piezoelectric element band in the axial direction of the roller corresponds one-to-one with the phase in the circumferential direction of the roller. ## Claims ### Claim 1 A sheet end detection device comprising: a cylindrical roller rotatable around an axis with conveying of a sheet to be conveyed in a state in which a peripheral surface of the roller contacts one face of the conveyed sheet; a phase detection unit configured to detect a phase in a circumferential direction of the roller, wherein a first piezoelectric element band is provided on the peripheral surface of the roller and extending in the circumferential direction and the axial direction, the first piezoelectric element band being configured to detect a contact of the sheet and extending in an axial direction of the roller over an inside and an outside of a contact area to be contacted with the conveyed sheet on the peripheral surface, and wherein a position of an arbitrary point of the first piezoelectric element band in the axial direction of the roller corresponds one-to-one with the phase in the circumferential direction of the roller; and further comprising a processor and a memory, the memory storing a program that, when executed by the processor, causes the processor to detect a first signal indicating the detection of the contact of the sheet a first time and to determine and end position of the sheet based on detecting a second signal indicating the detection of the contact of the sheet a second time. ### Claim 2 (depends on 1) The sheet end detection device as claimed in claim 1, wherein the first piezoelectric element band spirally formed on the peripheral surface of the roller to extend one round around the axis of the roller. ### Claim 3 (depends on 1) The sheet end detection device as claimed in claim 1, wherein the first piezoelectric element band extends such that a position of the first piezoelectric element opposing a conveying passage of the conveyed sheet moves in a direction from an outer portion of the contact area to an inner portion in response to a rotation of the roller. ### Claim 4 (depends on 1) The sheet end detection device as claimed in claim 1, wherein the first piezoelectric element band extends such that a position of the first piezoelectric element opposed to the conveying passage of the conveyed sheet moves in a direction from an inner portion of the contact area toward an outer portion in response to a rotation of the roller. ### Claim 5 (depends on 3) The sheet end detection device as claimed in claim 3, wherein the roller has an outer circumferential dimension being a half or less of a dimension of the conveyed sheet in the conveying direction. ### Claim 6 (depends on 1) The sheet end detection device as claimed in claim 1, wherein the first piezoelectric element band extends such that a position of the first piezoelectric element opposed to the conveying passage of the conveyed sheet moves in a direction from an outer portion of the contact area to an inner portion and further to an outer portion in response to a rotation of the roller. ### Claim 7 (depends on 6) The sheet end detection device as claimed in claim 6, wherein the roller has an outer circumferential dimension equal to or less than a dimension of the conveyed sheet in the conveying direction. ### Claim 8 (depends on 1) The sheet end detection device as claimed in claim 1, wherein the peripheral surface of the roller contains metal and contacts with a back of the first piezoelectric element band to serve as one electrode, and wherein another electrode is provided on the surface of the first piezoelectric-crystal element band to extend along the first piezoelectric element band. ### Claim 9 (depends on 8) The sheet end detection device as claimed in claim 8, wherein an insulating cover is provided to cover the first piezoelectric element band and the another electrode. ### Claim 10 (depends on 1) The sheet end detection device as claimed in claim 1, further comprising a second piezoelectric element band provided on the peripheral surface of the roller, such that the second piezoelectric element makes a round around the axial direction in an area to be contact with the conveyed sheet. ### Claim 11 (depends on 1) The sheet end detection device as claimed in claim 1, wherein a plurality of the first piezoelectric element bands are arranged on the peripheral surface of the roller along the axial direction. ### Claim 12 (depends on 1) The sheet end detection device as claimed in claim 1, wherein a plurality of the first piezoelectric element bands are arranged on the peripheral surface of the roller along a direction perpendicular to the axial direction. ### Claim 13 (depends on 1) An image recording apparatus comprising; a sheet end detection device as claimed in claim 1; and a recording head for ejecting ink to a recording sheet as the conveyed sheet to form an image, wherein the roller is provided at a midpoint in the conveying passage of the sheet to be conveyed. ### Claim 14 (depends on 1) A method for detecting an end position of a sheet using the sheet end detection device as claimed in claim 1, said method comprising: detecting the phase of the roller by the phase detection unit; detecting a contact state indicating whether the first piezoelectric element band with the sheet; detecting the end position of the sheet in a direction orthogonal to the conveying direction by, when the first piezoelectric element band detects change in the contact state, a position of the roller in the axial direction at which the contact state is changed based on the phase of the roller detected by the phase detection unit. ### Claim 15 (depends on 14) The method as claimed in claim 14, wherein the sheet end diction device further comprises a second piezoelectric element band provided on the peripheral surface of the roller, such that the second piezoelectric element makes a round around the axial direction in an area to be contact with the conveyed sheet, and wherein said method further comprising detecting an end position of the sheet in the conveying direction, based on the phase of the roller detected by the phase detection unit when the second piezoelectric element band detects change in the contact state with the conveyed sheet. ### Claim 16 A sheet end detection device comprising: a cylindrical roller rotatable around an axis with conveying of a sheet to be conveyed in a state in which a peripheral surface of the roller contacts one face of the conveyed sheet; a phase detection unit configured to detect a phase in a circumferential direction of the roller, wherein a first piezoelectric element band is provided on the peripheral surface of the roller and extending in the circumferential direction and the axial direction, the first piezoelectric element band being configured to detect a contact of the sheet and extending in an axial direction of the roller over an inside and an outside of a contact area to be contacted with the conveyed sheet on the peripheral surface, and wherein a position of an arbitrary point of the first piezoelectric element band in the axial direction of the roller corresponds one-to-one with the phase in the circumferential direction of the roller; and further comprising a processor and a memory, the memory storing a program that, when executed by the processor, causes the processor to monitor a detection signal indicating detection of the contact of the sheet and to determine an end position of the sheet when a state of the detection signal changes form a non-contact state to a contact state within one rotation of the roller.