Sheet feeder, image reading apparatus and image forming apparatus

Abstract

A paper press member 240 configured to be capable of advancing and retracting with respect to a paper guide 220 is provided between a paper feed roller 234 and the front end in the paper feed direction of paper loaded in a manual feed tray 230 . When a plurality of sheets of paper enter into the press-contact section between the paper feed roller 234 and a reverse roller 235 , the reverse roller 235 is rotated in the reverse direction to retract the sheet on the reverse roller side to the manual feed tray 230 . At this time, by causing the paper press member 240 to project from the upper surface of the paper guide 220 , the sheet to be retracted and the paper press member 240 come into contact with each other, so that the travel amount of the sheet when retracting the sheet is reduced.

1 . A sheet feeder comprising:
 a sheet storing section for storing sheets;   a paper feed roller for feeding a sheet taken out of said sheet storing section to a predetermined supply destination;   a detecting section for detecting a multi-feed in said paper feed roller;   a sheet retracting unit for retracting, when said detecting section detects a multi-feed of sheets, an extra sheet fed by the multi-feed to an upstream side in a sheet feed direction; and   a contact member configured, between said paper feed roller and a front end in the sheet feed direction of the sheet stored in said sheet storing section, so that said contract member is capable of advancing and retracting and capable of coming into contact with an extra sheet fed by a multi-feed.   
   
   
       2 . The sheet feeder according to  claim 1 , wherein said contact member comes into contact with a front surface or a back surface of the extra sheet when retracting the sheet. 
   
   
       3 . The sheet feeder according to  claim 1 , further comprising a driving section for moving, when feeding a sheet to the supply destination, said contact member not to come into contact with the sheet, and for moving, when said detecting means detects a multi-feed of sheets, said contact member to come into contact with the extra sheet fed by the multi-feed. 
   
   
       4 . The sheet feeder according to  claim 1 , wherein said sheet retracting unit includes a reverse roller placed opposite to said paper feed roller, and a torque limiter supported on a driving shaft of said reverse roller, wherein
 when said torque limiter detects an increase in load and said reverse roller is coupled to a drive source and starts to be driven, said detecting section determines that a multi-feed of sheets is detected.   
   
   
       5 . The sheet feeder according to  claim 1 , wherein a travel amount of sheet when retracting the sheet by said sheet retracting unit is restrained by the contact between the sheet and the contact member. 
   
   
       6 . The sheet feeder according to  claim 5 , further comprising a pickup roller arranged to be able to come into contact with the sheet stored in said sheet storing section, wherein
 the sheet feeder restrains a front end in the feed direction of the sheet to be retracted from returning upstream of a contact section between said pickup roller and the sheet stored in said sheet storing section.   
   
   
       7 . The sheet feeder according to  claim 1 , wherein said contact member has elasticity. 
   
   
       8 . The sheet feeder according to  claim 1 , wherein said sheet storing section is a manual feed tray. 
   
   
       9 . An image reading apparatus comprising:
 a sheet feeder as set forth in  claim 1 ; and   an image reading section for reading an image recorded on a sheet fed by said sheet feeder.   
   
   
       10 . An image forming apparatus comprising:
 a sheet feeder as set forth in  claim 1 ; and   an image forming section for forming an image on a sheet fed by said sheet feeder.