# US 5,619,310 A · System for suppressing one-sided movement and zigzag running of a conveyor belt in an image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,619,310 A - Document ID: US5619310A - Status: Granted - Kind: A - Application number: 08/466,872 - Filed: 1995-06-06 - Granted: 1997-04-08 - Earliest claimed: 1993-03-05 - Assignees: Kabushiki Kaisha Toshiba - Inventors: Tuyoshi Todome - Web page: https://patentgrep.com/patent/US5619310A ## CPC - G03G 15/6558: {Feeding path after the copy sheet preparation and up to the transfer point, e.g. registering; Deskewing; Correct timing of sheet feeding to the transfer point} - G03G 2215/00168: by friction - G03G 2215/00409: Transfer device - G03G 2215/00679: Conveying means details, e.g. roller - G03G 2215/0119: Linear arrangement adjacent plural transfer points - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes an image former for forming an image on an image carrier, a conveyor belt for conveying an image receiving medium to the image carrier, a conveyor roller structure having a first roller with different diameter at both ends and taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, which is more than 2.341.times.10.sup.-3 and a coefficient of static friction is less than 0.26. A second roller is provided opposite to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers, and a transferring structure for transferring the image formed on the image carrier onto the image receiving medium. ## Claims ### Claim 1 An image forming apparatus, comprising: means for forming an image on an image carrier means; a conveyor belt for conveying an image receiving medium to the image carrier means; means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers; and means for transferring the image formed on the image carrier means onto the image receiving medium. ### Claim 2 (depends on 1) An image forming apparatus as claimed in claim 1 further comprising a regulation member for regulating the one-sided movement of the conveyor belt while sliding one end side of the conveyor belt that is positioned at the small diameter side of the first roller. ### Claim 3 (depends on 1) An image forming apparatus as claimed in claim 1 further comprising a regulation guide member provided in one united body with the edge side of the conveyor belt positioned at the large diameter side of the first roller for regulating the one-sided movement of the conveyor belt while sliding on the large diameter portion of the first roller when the conveyor belt is running. ### Claim 4 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the image carrier means includes a plurality of image carriers and the conveyor belt sequentially conveys the image receiving medium to the plurality of image carriers. ### Claim 5 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the first roller has a rotating shaft of which the large diameter side has been tilted by an angle .theta. shown by the following expression against the plane being parallel to the moving direction of the conveyor belt and including the rotating center shaft of the image carrier means: tan .theta.={(D-d)/2}/L. ### Claim 6 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the Young's modulus of the conveyor belt in the direction perpendicular to the moving direction of the conveyor belt is more than 200 kg/mm.sup.2. ### Claim 7 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the length (the belt width) of the conveyor belt in the direction perpendicular to the moving direction of the belt is more than 50 mm. ### Claim 8 An image forming apparatus, comprising: means for forming an image on an image carrier means; a conveyor belt for conveying an image receiving medium to the image carrier means; means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers; means for applying a load set at more than 3 kg to the conveyor belt; and means for transferring the image formed on the image carrier means onto the image receiving medium. ### Claim 9 An image forming apparatus, comprising: means for forming an image on an image carrier means; a conveyor belt for conveying an image receiving medium to the image carrier means; means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers; means for transferring the image formed on the image carrier means onto the image receiving medium; and a first and a second tension applying means for applying a tension to the conveyor belt by giving a force to the small diameter side and the large diameter side of the first roller, wherein the force given to the small diameter side is smaller than the force given to the larger diameter side. ### Claim 10 (depends on 9) An image forming apparatus as claimed in claim 9, wherein a difference between the tensile forces given by the first and the second tension applying means is a value obtained from the following expression: {(Pa-Pb)/Pb}.times.100.gtoreq.10 (where, Pa is a size of load applied by the first tension applying means, Pb is a size of load applied by the second tension applying means, wherein Pa>Pb). ### Claim 11 A conveying apparatus, comprising: a conveyor belt for conveying an image receiving medium on which an image, which is transferred from an image carrier, is carried to the image carrier; and means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers. ### Claim 12 (depends on 11) A conveying apparatus as claimed in claim 11, wherein the first roller has a rotating shaft of which the large diameter side has been tilted by an angle .theta. shown by the following expression against the plane being parallel to the moving direction of the conveyor belt and including the rotating center shaft of the image carrier: tan .theta.={(D-d)/2}/L. 13. ### Claim 13 (depends on 11) A conveying apparatus as claimed in claim 11, wherein the Young's modulus of the conveyor belt in the direction perpendicular to the moving direction of the conveyor belt is more than 200 kg/mm.sup.2. ### Claim 14 (depends on 11) A conveying apparatus as claimed in claim 11, wherein the length (the belt width) of the conveyor belt in the direction perpendicular to the moving direction of the belt is more than 50 mm. ### Claim 15 (depends on 11) A conveying apparatus as claimed in claim 11 further comprising means for applying a load set at more than 3 kg to the conveyor belt. ### Claim 16 (depends on 15) A conveying apparatus as claimed in claim 15 further comprising a first tension applying means for applying a tension to the conveyor belt by giving a force to the large diameter side of the first roller and a second tension applying means for applying a tension to the conveyor belt by giving a force to the small diameter side of the first roller, wherein the force of the first applying means is larger than that of the second applying means. ### Claim 17 (depends on 11) A conveying apparatus as claimed in claim 11 further comprising a regulation member for regulating the one-sided movement of the conveyor belt while sliding one end side of the conveyor belt that is positioned at the small diameter side of the first roller. ### Claim 18 (depends on 11) A conveying apparatus as claimed in claim 11 further comprising a regulation guide member provided in one united body with the edge side of the conveyor belt positioned at the large diameter side of the first roller for regulating the one-sided movement of the conveyor belt while sliding on the large diameter portion of the first roller when the conveyor belt is running. ### Claim 19 An image forming apparatus, comprising: means for forming an image on an image carrier; a conveyor belt for conveying an image formed on the image carrier; and means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers. ### Claim 20 A conveying apparatus, comprising: a conveyor belt for conveying an image formed on an image carrier; and means, having a first roller which has a diameter that is different at both ends and a taper size T expressed by T=(D-d)/L, wherein D is the diameter at the large diameter side, d is the diameter at the small diameter side and L is the length of the first roller, wherein T is more than 2.31.times.10.sup.-3 and a coefficient of static friction is less than 0.26, and a second roller which is opposing to the first roller, for moving the conveyor belt in a prescribed direction by rotating the first and the second rollers in a state where the conveyor belt is put over the first and the second rollers.