Sheet processing apparatus and image forming system including multiple folding members

Abstract

A sheet processing apparatus that forms a folding line on a sheet includes first and second folding rollers that form a folding line on the sheet by rotating a bent sheet while pinching from sheet surfaces and a first pressing unit that presses the second folding roller against the first folding roller in an arbitrary portion in a rotating shaft direction of the second folding roller.

1 . A sheet folding apparatus comprising:
 a first pair of folding members configured to fold a sheet;   a first pair of conveying members configured to convey the sheet that has been folded by the first pair of folding members; and   a sheet detector configured to detect the sheet at a position downstream from the first pair of conveying members in a first sheet conveyance direction, wherein   the sheet folding apparatus is configured to convey the sheet by a distance downstream from the sheet detector in the first sheet conveyance direction after a folding line of the sheet passes through a nip of the first pair of conveying members, and stop the conveyance of the sheet.   
     
     
         2 . The sheet folding apparatus according to  claim 1 , wherein the sheet folding apparatus is configured to cause the first pair of conveying members to reverse rotation to bend a portion of the sheet between the first pair of folding members and the first pair of conveying members. 
     
     
         3 . The sheet folding apparatus according to  claim 1 , further comprising:
 a second pair of folding members configured to fold the sheet that has been folded by the first pair of folding members.   
     
     
         4 . The sheet folding apparatus according to  claim 3 , wherein the second pair of folding members is configured to fold the sheet that has been folded by the first pair of folding members at a position upstream from the first pair of conveying members in the first sheet conveyance direction. 
     
     
         5 . The sheet folding apparatus according to  claim 3 , wherein one member of the first pair of folding members is a member of the second pair of folding members. 
     
     
         6 . The sheet folding apparatus according to  claim 1 , wherein the sheet folding apparatus is configured to adjust the distance based on sheet information. 
     
     
         7 . The sheet folding apparatus according to  claim 6 , wherein the sheet information includes a thickness of the sheet, a type of the sheet or both the thickness of the sheet and the type of the sheet. 
     
     
         8 . The sheet folding apparatus according to  claim 5 , wherein the one member of the first pair of folding members is a driving member. 
     
     
         9 . The sheet folding apparatus according to  claim 8 , wherein another member of the first pair of folding members is a driven member. 
     
     
         10 . The sheet folding apparatus according to  claim 1 , wherein the first pair of folding members and the first pair of conveying members are rollers. 
     
     
         11 . The sheet folding apparatus according to  claim 1 , further comprising:
 a second pair of conveying members configured to convey the sheet to the first pair of folding members.   
     
     
         12 . An image forming apparatus, comprising
 a main body;   an image forming unit configured to form an image on a sheet; and   a sheet folding apparatus, the sheet folding apparatus being in the main body and including,   a first pair of folding members configured to fold the sheet,
 a first pair of conveying members configured to convey the sheet that has been folded by the first pair of folding members, and 
 a sheet detector configured to detect the sheet at a position downstream from the first pair of conveying members in a first sheet conveyance direction, wherein
 the sheet folding apparatus is configured to convey the sheet by a distance downstream from the sheet detector in the first sheet conveyance direction after a folding line of the sheet passes through a nip of the first pair of conveying members, and stop the conveyance of the sheet. 
 
   
     
     
         13 . The image forming apparatus according to  claim 12 , wherein the first pair of folding members and the first pair of conveying members are rollers. 
     
     
         14 . The image forming apparatus according to  claim 12 , further comprising:
 a second pair of conveying members configured to convey the sheet to the first pair of folding members.   
     
     
         15 . The image forming apparatus according to  claim 12 , wherein the sheet folding apparatus is configured to cause the first pair of conveying members to reverse rotation to bend a portion of the sheet between the first pair of folding members and the first pair of conveying members. 
     
     
         16 . The folding apparatus according to  claim 12 , further comprising:
 a second pair of folding members configured to fold the sheet that has been folded by the first pair of folding members.   
     
     
         17 . An image forming system, comprising:
 an image forming apparatus configured to form an image on a sheet; and   a sheet folding apparatus, the sheet folding apparatus being separate from the image forming apparatus and including,
 a first pair of folding members configured to fold the sheet, 
 a first pair of conveying members configured to convey the sheet that has been folded by the first pair of folding members, and 
 a sheet detector configured to detect the sheet at a position downstream from the first pair of conveying members in a first sheet conveyance direction, wherein 
   the sheet folding apparatus is configured to convey the sheet by a distance downstream from the sheet detector in the first sheet conveyance direction after a folding line of the sheet passes through a nip of the first pair of conveying members, and stop the conveyance of the sheet.   
     
     
         18 . The image forming system according to  claim 17 , wherein the first pair folding members and the first pair of conveying members are rollers. 
     
     
         19 . The image forming system according to  claim 17 , further comprising:
 a second pair of conveying members configured to convey the sheet to the first pair of folding members.   
     
     
         20 . The image forming system according to  claim 17 , wherein the sheet folding apparatus is configured to cause the first pair of conveying members to reverse rotation to bend a portion of the sheet between the first pair of folding members and the first pair of conveying members. 
     
     
         21 . The image forming system according to  claim 17 , further comprising:
 a second pair of folding members configured to fold the sheet that has been folded by the first pair of folding members.