Sheet conveying apparatus and image forming apparatus

Abstract

Disclosed is a sheet conveying apparatus. The sheet conveying apparatus includes a conveying roller pair ( 58 ) for conveying a sheet, a registration roller pair ( 57 ) disposed downstream of the conveying roller pair ( 58 ) and a guide portion for guiding the sheet conveyed to the registration roller pair ( 57 ) by the conveying roller pair ( 58 ) such that the sheet is deflected. Further, the guide portion guides the sheet such that a number of deflection nodes changes according to stiffness of the sheet.

What is claimed is: 
     
         1 . A sheet conveying apparatus, comprising:
 a conveying roller pair configured to convey a sheet;   a registration roller pair disposed downstream of the conveying roller pair, for correcting skew feeding of the sheet with a leading end of the sheet conveyed by the conveying roller pair abutting against the registration roller pair; and   a guide portion configured to guide the sheet conveyed to the registration roller pair by the conveying roller pair such that the sheet is deflected,   wherein the guide portion includes a movable guide that is movable from a first position where an abutting portion of the guide portion for abutting the sheet that is conveyed is located on one side of a nip line of the conveying roller pair to a second position where the abutting portion is located on the other side of the nip line.   
     
     
         2 . The sheet conveying apparatus according to  claim 1 ,
 wherein the movable guide is displaced from the first position to the second position when the movable guide is pressed by the sheet having a predetermined or higher stiffness that is conveyed by the conveying roller pair.   
     
     
         3 . The sheet conveying apparatus according to  claim 1 ,
 wherein the guide portion includes:
 a first movable guide configured to displace when the first movable guide is pressed by the sheet having a predetermined or higher stiffness that is conveyed by the conveying roller pair; and 
 a second movable guide disposed downstream of the first movable guide. 
   
     
     
         4 . The sheet conveying apparatus according to  claim 3 ,
 wherein the first movable guide is movable from a first position where an abutting portion of the first movable guide for abutting against the sheet which is conveyed is located on one side of the nip line of the conveying roller pair to a second position where the abutting portion is located on the other side of the nip line when the first movable guide is pressed by the sheet having a predetermined or higher stiffness that is conveyed by the conveying roller pair.   
     
     
         5 . The sheet conveying apparatus according to  claim 3 ,
 wherein the first movable guide is movable from a first position where an abutting portion of the first movable guide for abutting the sheet which is conveyed is located on a side of the nip line of the conveying roller pair with respect to an extended plane of a guide surface of the second movable guide to a second position where the abutting portion is away from the nip line when the first movable guide is pressed by the sheet having a predetermined or higher stiffness that is conveyed by the conveying roller pair.   
     
     
         6 . The sheet conveying apparatus according to  claim 5 ,
 wherein the second movable guide is movable from a first position where an abutting portion of the second movable guide for abutting the sheet that is conveyed is located in a vicinity of a nip line of the registration roller pair to a second position where the abutting portion is away from the nip line when the second movable guide is pressed by the sheet having a predetermined or higher stiffness that is conveyed by the conveying roller pair.   
     
     
         7 . The sheet conveying apparatus according to  claim 3 ,
 wherein a guide surface of the second movable guide intersects with the nip line of the conveying roller pair.   
     
     
         8 . The sheet conveying apparatus according to  claim 3 ,
 wherein the registration roller pair includes:
 a first roller disposed on one side of a sheet conveying path; and 
 a second roller disposed on the other side of the sheet conveying path, stiffness of the second roller being higher than that of the first roller, and 
   wherein the second movable guide is disposed on the other side of the sheet conveying path and a fixed guide is disposed on the one side of the sheet conveying path, the fixed guide being opposed to the second movable guide.   
     
     
         9 . An image forming apparatus, comprising:
 a sheet conveying apparatus; and   an image forming portion configured to form an image on a sheet conveyed by the sheet conveying apparatus,   wherein the sheet conveying apparatus includes:
 a conveying roller pair configured to convey the sheet; 
 a registration roller pair disposed downstream of the conveying roller pair, for correcting skew feeding of the sheet with a leading end of the sheet conveyed by the conveying roller pair abutting against the registration roller pair; and 
 a guide portion configured to guide the sheet conveyed to the registration roller pair by the conveying roller pair such that the sheet is deflected, 
   wherein the guide portion includes a movable guide that is movable from a first position where an abutting portion of the guide portion for abutting the sheet that is conveyed is located on one side of a nip line of the conveying roller pair to a second position where the abutting portion is located on the other side of the nip line.