Belt driving device, transfer device, and image forming apparatus

Abstract

A belt driving device includes an annular belt member, rotary members, a protrusion, and a removing member. The rotary members extend in parallel and rotate. The belt member is wound around the rotary members. The protrusion protrudes from an inner peripheral surface of the bel member. The protrusion extends along an edge of the belt member. The protrusion and each rotary member are arranged in an extending direction of the rotary member. The removing member includes a plate-shaped portion. The plate-shaped portion is in contact with an outer peripheral surface of the belt member at a location where the removing member faces one of the rotary members with the belt member being interposed therebetween, so as to remove unnecessary matters from the outer peripheral surface of the belt member. The removing member extends to an outside of end portions of the rotary members in the extending direction.

What is claimed is: 
     
         1 . A belt driving device comprising:
 an annular belt member;   a plurality of rotary members that extend in parallel and rotate, the belt member being wound around the rotary members, the belt member circulating:   a protrusion that protrudes from an inner peripheral surface of the belt member, the protrusion extending along an edge of the belt member, the protrusion and each rotary member being arranged in an extending direction of the rotary member; and   a removing member comprising a plate-shaped portion, wherein   the plate-shaped portion of the removing member is in contact with an outer peripheral surface of the belt member at a location where the removing member faces one of the rotary members with the belt member being interposed therebetween, so as to remove unnecessary matters from the outer peripheral surface of the belt member, and   the removing member extends to an outside of end portions of the rotary members in the extending direction.   
     
     
         2 . The belt driving device according to  claim 1 , wherein an end portion of the removing member in the extending direction is in stronger contact with the outer peripheral surface than a central portion of the removing member in the extending direction. 
     
     
         3 . The belt driving device according to  claim 1 , wherein an end portion of the removing member in the extending direction has higher rigidity than a central portion of the removing member in the extending direction. 
     
     
         4 . The belt driving device according to  claim 2 , wherein the end portion of the removing member is harder than at the central portion of the removing member, due to partial surface treatment. 
     
     
         5 . The belt driving device according to  claim 4 , wherein the removing member has been subjected to the surface treatment at a contact portion with the belt member. 
     
     
         6 . The belt driving device according to  claim 2 , wherein
 the removing member comprises
 a first portion that is in contact with the outer peripheral surface of the belt member, and 
 a second portion that holds the first portion and has a higher rigidity than the first portion, and 
   the second portion has a shorter distance to the outer peripheral surface at the end portion than at the central portion.   
     
     
         7 . The belt driving device according to  claim 2 , wherein the removing member is thicker at the end portion than at the central portion. 
     
     
         8 . The belt driving device according to  claim 2 , wherein
 a boundary between the central portion and the end portion of the removing member is located on an inner side relative to a first location, and   the first location is located on an outer side, in the extending direction, of an end surface position of the one of the rotary members and is located at a distance equal to a width of the protrusion.   
     
     
         9 . The belt driving device according to  claim 2 , wherein
 a boundary between the central portion and the end portion of the removing member is located on an outer side of a second location, and   the second location is located on an inner side, in the extending direction, of an end surface position of the one of the rotary members and is located at a distance equal to a width of the protrusion.   
     
     
         10 . The belt driving device according to  claim 1 , wherein the one of the rotary members is a rotary member having the largest force that changes a position of the belt member in the extending direction among the plurality of rotary members. 
     
     
         11 . The belt driving device according to  claim 10 , wherein the one of the rotary members has the largest length in the extending direction among the plurality of rotary members. 
     
     
         12 . The belt driving device according to  claim 10 , wherein the one of the rotary members is the thickest rotary member among the plurality of rotary members. 
     
     
         13 . The bell driving device according to  claim 10 , wherein the one of the rotary members drives the removing member by rotating under a driving force. 
     
     
         14 . The belt driving device according to  claim 11 , wherein the one of the rotary members drives the removing member by rotating under a driving force. 
     
     
         15 . The belt driving device according to  claim 12 , wherein the one of the rotary members drives the removing member by rotating under a driving force. 
     
     
         16 . A transfer device comprising:
 an annular belt member comprising an outer peripheral surface, the annular belt member being configured to transfer an image onto a recording material by (i) the outer peripheral surface coming into contact with the recording material and (ii) receiving a voltage;   a plurality of rotary members that extend in parallel and rotate, the belt member being wound around the rotary members, the belt member circulating;   a protrusion that protrudes from an inner peripheral surface of the belt member, the protrusion extending along an edge of the belt member, the protrusion and each rotary member being arranged in an extending direction of the rotary member; and   a removing member having a plate-shaped outer shape, wherein   a portion of the removing member, where the removing member faces one of the rotary members with the belt member being interposed therebetween, is in contact with the outer peripheral surface of the belt member, so as to remove unnecessary matters from the outer peripheral surface of the belt member, and   the removing member extends to an outside of end portions of the rotary members in the extending direction.   
     
     
         17 . An image forming apparatus comprising:
 a transport unit configured to transport a recording material;   an image forming unit configured to form an image on the recording material transported by the transport unit; and   a belt driving device assembled to at least one of the transport unit or the image forming unit, wherein   the belt driving device comprises
 an annular belt member, 
 a plurality of rotary members that extend in parallel and rotate, the belt member being wound around the rotary members, the belt member circulating, 
 a protrusion that protrudes from an inner peripheral surface of the belt member, the protrusion extending along an edge of the belt member, the protrusion and each rotary member being arranged in an extending direction of the rotary member, and 
 a removing member having a plate-shaped outer shape, 
   a portion of the removing member, where the removing member faces one of the rotary members with the belt member being interposed therebetween, is in contact with an outer peripheral surface of the belt member, so as to remove unnecessary matters from the outer peripheral surface of the belt member, and   the removing member extends to an outside of end portions of the rotary members in the extending direction.