Sheet processing device

Abstract

A posture control device has a posture detecting section, an upstream conveying section, a posture control section, and a downstream conveying section along a conveying path for mail items. The distance from a nip of the upstream conveying section and a nip of the posture control section (D-E distance) is designed to be substantially as long as the longest one of the mail items to be processed by the device which has the greatest length along a conveying direction. The distance from the nip of the posture control section and a nip of the downstream conveying section (E-F distance) is designed to be slightly longer the shortest one of the mail items to be processed by the device which has the shortest length along the conveying direction.

1 . A sheet processing device comprising:
 conveying belts positioned opposite each other across a conveying path and each extending so as to travel in a conveying direction;   a posture control section which receives, at a nip, a sheet conveyed via the conveying path and which rotates while nipping and restraining the sheet to variably control a conveying posture of the sheet while applying a conveying force to the sheet;   a downstream conveying section located downstream of the posture control section in a conveying direction to receive, at a nip, the sheet conveyed from the posture control section via the conveying path, the downstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet,   wherein a distance between the nip of the posture control section and the nip of the downstream conveying section is designed to be longer than a shortest one of sheets to be processed by the sheet processing device which has a shortest length along the conveying direction and to be equal to or shorter than a longest one of the sheets to be processed by the sheet processing device which has a greatest length along the conveying direction.   
   
   
       2 . The sheet processing device according to  claim 1 , wherein the posture control section performs posture control on the sheet of any of the lengths in the same amount of time as that required for the posture control of the shortest sheet. 
   
   
       3 . The sheet processing device according to  claim 2 , wherein the distance between the nip of the posture control section and the nip of the downstream conveying section is designed to be slightly longer than the shortest sheet. 
   
   
       4 . The sheet processing device according to  claim 1 , wherein the posture control section is capable of completing posture control while the shortest sheet is passing through the nip. 
   
   
       5 . The sheet processing device according to  claim 4 , wherein the distance between the nip of the posture control section and the nip of the downstream conveying section is designed to be slightly longer than the shortest sheet. 
   
   
       6 . The sheet processing device according to  claim 1 , further comprising:
 an upstream conveying section located upstream of the posture control section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the upstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet,   wherein a distance between the nip of the upstream conveying section and the nip of the posture control section is designed to be longer than the longest sheet.   
   
   
       7 . The sheet processing device according to  claim 1 , further comprising:
 an upstream conveying section located upstream of the posture control section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the upstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet,   wherein a distance between the nip of the upstream conveying section and the nip of the posture control section is designed to be substantially as long as the length of the longest sheet along the conveying direction.   
   
   
       8 . The sheet processing device according to  claim 7 , further comprising:
 a detecting section located upstream of the upstream conveying section in the conveying direction to detect the conveying posture of the sheet conveyed via the conveying path,   wherein a distance between the detecting section and the nip of the upstream conveying section is designed to be short but still enough to allow the shortest sheet the posture of which has been detected by the detecting section to be nipped and restrained by the nip of the upstream conveying section before the posture of the shortest sheet changes.   
   
   
       9 . The sheet processing device according to  claim 7 , further comprising:
 a second upstream conveying section located downstream of the downstream conveying section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the second upstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet;   a second posture control section located downstream of the second upstream conveying section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the second posture control section rotating while nipping and restraining the sheet to variably control a conveying posture of the sheet while applying a conveying force to the sheet; and   a second downstream conveying section located downstream of the second posture control section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the second downstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet;   wherein a distance between the nip of the second upstream conveying section and the nip of the second posture control section is designed to be substantially as long as the length of the longest sheet along the conveying direction,   a distance between the nip of the second posture control section and the nip of the second downstream conveying section is designed to be greater than the length of the shortest sheet along the conveying direction and to be equal to or shorter than the length of the longest sheet along the conveying direction, and   a distance between the nip of the downstream conveying section and the nip of the second upstream conveying section is designed to be shorter than the length of the shortest sheet along the conveying direction,   
   
   
       10 . The sheet processing device according to  claim 1 , further comprising:
 a second posture control section located upstream of the posture control section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the second posture control section rotating while nipping and restraining the sheet to variably control a conveying posture of the sheet while applying a conveying force to the sheet; and   the upstream conveying section located upstream of the second posture control section in the conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the upstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet;   wherein a distance between the nip of the upstream conveying section and the nip of the second posture control section is designed to be substantially as long as the length of the longest sheet along the conveying direction, and   a distance between the nip of the second posture control section and the nip of the posture control section is designed to be slightly greater than the length of the longest sheet along the conveying direction.   
   
   
       11 . A sheet processing device comprising:
 conveying belts positioned opposite each other across a conveying path and each extending so as to travel in a conveying direction;   a posture control section which receives, at a nip, a sheet conveyed via the conveying path and which rotates while nipping and restraining the sheet to variably control a conveying posture of the sheet while applying a conveying force to the sheet;   an upstream conveying section located upstream of the posture control section in a conveying direction to receive, at a nip, the sheet conveyed via the conveying path, the upstream conveying section rotating while nipping and restraining the sheet to apply a conveying force to the sheet,   wherein a distance between the nip of the upstream conveying section and the nip of the posture control section is designed to be longer than a longest one of sheets to be processed by the sheet processing device which has a greatest length along the conveying direction.   
   
   
       12 . The sheet processing device according to  claim 11 , wherein the distance between the nip of the upstream conveying section and the nip of the posture control section is designed to be substantially as long as the length of the longest sheet along the conveying direction. 
   
   
       13 . The sheet processing device according to  claim 12 , further comprising:
 a detecting section located upstream of the upstream conveying section in the conveying direction to detect the conveying posture of the sheet conveyed via the conveying path,   wherein a distance between the detecting section and the nip of the upstream conveying section is designed to be short but still enough to allow a shortest one of sheets to be processed by the sheet processing device which has a shortest length along the conveying direction the posture of which has been detected by the detecting section to be nipped and restrained by the nip of the upstream conveying section before the posture of the shortest sheet changes.