Sheet-feed separation mechanism, sheet feeding device, image reading device, and image forming apparatus

Abstract

A sheet feeding device that draws out a sheet from a pile of sheets, including: a sheet tray on which the pile of sheets is placed; a sheet feeding roller whose peripheral surface is pressed to abut on a top surface of an uppermost sheet in the pile of the sheets at a downstream end in a sheet feeding direction of the pile of sheets; a friction pad disposed oppositely to the sheet feeding roller to form a nip portion for the sheet with the sheet feeding roller; and a pushing member that pushes the friction pad in a direction opposite to the sheet feeding direction.

1 . A sheet-feed separation mechanism, comprising:
 a sheet feeding roller that draws out a sheet;   a friction pad disposed oppositely to the sheet feeding roller to form a nip portion for the sheet with the sheet feeding roller; and   a pushing member that pushes the friction pad in a direction opposite to the sheet feeding direction.   
   
   
       2 . The sheet-feed separation mechanism according to  claim 1 , further comprising:
 a pad holder that supports the friction pad with a top portion being exposed; and   a seat that holds the pad holder in a manner so as to be able to move in forward and reverse directions with respect to the sheet feeding direction.   
   
   
       3 . The sheet-feed separation mechanism according to  claim 2 , wherein:
 an accommodation concave portion to accommodate the pad holder in a movable manner is provided by making a recess in a top surface of the seat.   
   
   
       4 . The sheet-feed separation mechanism according to  claim 1 , wherein:
 the pushing member is one of a coil spring, a plate spring, and an elastomer.   
   
   
       5 . A sheet feeding device that draws out a sheet from a pile of sheets, comprising:
 a sheet tray on which the pile of sheets is placed;   a sheet feeding roller whose peripheral surface is pressed to abut on a top surface of an uppermost sheet in the pile of the sheets at a downstream end in a sheet feeding direction of the pile of sheets;   a friction pad disposed oppositely to the sheet feeding roller to form a nip portion for the sheet with the sheet feeding roller; and   a pushing member that pushes the friction pad in a direction opposite to the sheet feeding direction.   
   
   
       6 . The sheet feeding device according to  claim 5 , further comprising;
 a pad holder that supports the friction pad with a top portion being exposed; and   a seat that holds the pad holder in a manner so as to be able to move in forward and reverse directions with respect to the sheet feeding direction.   
   
   
       7 . The sheet feeding device according to  claim 6 , wherein:
 an accommodation concave portion to accommodate the pad holder in a movable manner is provided by making a recess in a top surface of the seat.   
   
   
       8 . The sheet feeding device according to  claim 5 , wherein:
 the pushing member is one of a coil spring, a plate spring, and an elastomer.   
   
   
       9 . An image reading device, comprising:
 a device body including an image reading portion; and   a document feeding device that feeds a document sheet from which image information is read to the image reading portion, wherein   the document feeding device includes:
 a sheet tray on which a pile of the document sheet is placed; 
 a sheet feeding roller whose peripheral surface is pressed to abut on a top surface of an uppermost sheet in the pile at a downstream end in a sheet feeding direction of the pile; 
   a friction pad disposed oppositely to the sheet feeding roller to form a nip portion for the sheet with the sheet feeding roller; and   a pushing member that pushes the friction pad in a direction opposite to the sheet feeding direction.   
   
   
       10 . The image reading device according to  claim 9 , further comprising:
 a pad holder that supports the friction pad with a top portion being exposed; and   a seat that holds the pad holder in a manner so as to be able to move in forward and reverse directions with respect to the sheet feeding direction.   
   
   
       11 . The image reading device according to  claim 10 , wherein
 an accommodation concave portion to accommodate the pad holder in a movable manner is provided by making a recess in a top surface of the seat.   
   
   
       12 . The image reading device according to  claim 9 , wherein
 the pushing member is one of a coil spring, a plate spring, and an elastomer.   
   
   
       13 . An image forming apparatus forming an image according to image information, comprising:
 a first sheet feeding device that feeds a transfer sheet;   and/or   a second sheet feeding device that feeds a document sheet from which the image information is read,   wherein one or both of the first sheet feeding device and the second sheet feeding device include:   a sheet tray on which a pile of the transfer sheet or the document sheet is placed;   a sheet feeding roller whose peripheral surface is pressed to abut on a top surface of an uppermost sheet in the pile at a downstream end in a sheet feeding direction of the pile;   a friction pad disposed oppositely to the sheet feeding roller to form a nip portion for the sheet with the sheet feeding roller; and   a pushing member that pushes the friction pad in a direction opposite to the sheet feeding direction.   
   
   
       14 . The image forming apparatus according to  claim 13 , further comprising:
 a pad holder that supports the friction pad with a top portion being exposed; and   a seat that holds the pad holder in a manner so as to be able to move in forward and reverse directions with respect to the sheet feeding direction.   
   
   
       15 . The image forming apparatus according to  claim 14 , wherein:
 an accommodation concave portion to accommodate the pad holder in a movable manner is provided by making a recess in a top surface of the seat.   
   
   
       16 . The image forming apparatus according to  claim 13 , wherein:
 the pushing member is one of a coil spring, a plate spring, and an elastomer.