Sheet supply device and image forming apparatus

Abstract

According to an embodiment, a sheet supply device includes a stacking unit, a first roller, a second roller, and a stopper. The stacking unit has a stack surface on which sheets are stacked. The first roller conveys a sheet from the stacking unit in a conveying direction. The second roller conveys the sheet conveyed by the first roller. The stopper has an abutting surface. The stopper is rotatable around a rotation shaft along a width direction. The stopper rotates such that a posture of the stopper switches between a first and a second posture. The first posture has a first angle at which an angle between the abutting surface and the stack surface is an obtuse angle. The second posture has a second angle at which an angle between the abutting surface and the stack surface is an obtuse angle, the second angle being more than the first angle.

What is claimed is: 
     
         1 . A sheet supply device, comprising:
 a sheet stacking component having a stack surface on which a plurality of sheets are stacked;   a first roller configured to convey an uppermost sheet of the plurality of sheets from the sheet stacking component toward a downstream side in a conveying direction of the sheet;   a second roller configured to further convey the sheet conveyed by the first roller; and   a stopper rotatable around a rotation shaft along a width direction of the sheet parallel to the stack surface and perpendicular to the conveying direction, the stopper having an abutting surface against which a leading end of the sheet on the downstream side in the conveying direction abuts,   wherein the stopper rotates around the rotation shaft such that a posture of the stopper switches between
 a first posture having a first angle at which an angle between the abutting surface and the stack surface is an obtuse angle, and 
 a second posture having a second angle at which an angle between the abutting surface and the stack surface is an obtuse angle, the second angle being greater than the first angle. 
   
     
     
         2 . The sheet supply device according to  claim 1 ,
 wherein a shaft center of the rotation shaft is present at a height position that is lower than or equal to a height position of the stack surface.   
     
     
         3 . The sheet supply device according to  claim 1 ,
 wherein the stopper is configured to freely adjust the angles of the abutting surface in the first posture and the second posture.   
     
     
         4 . The sheet supply device according to  claim 1 , further comprising:
 a pressing plate configured to press a trailing end of the sheet stacked on the stack surface opposite to the leading end such that the leading end is pressed against the abutting surface.   
     
     
         5 . The sheet supply device according to  claim 4 ,
 wherein the pressing plate has a pressing surface configured to press the trailing end of the sheet, and   a tilt angle of the pressing surface with respect to the stack surface is equal to a tilt angle of the abutting surface when the stopper is in the first posture.   
     
     
         6 . The sheet supply device according to  claim 1 ,
 wherein a plurality of stoppers are provided, and   the stoppers are provided at different positions in the width direction of the sheet.   
     
     
         7 . The sheet supply device according to  claim 1 ,
 wherein a surface material having a coefficient of static friction different from a coefficient of static friction of the abutting surface is attachable to the stopper.   
     
     
         8 . The sheet supply device according to  claim 1 , wherein
 the first roller, the second roller, and stopper are configured to convey a single sheet in the conveying direction, with the proviso that two or more sheets are not conveyed at one time by the first roller, the second roller, and stopper.   
     
     
         9 . An image forming apparatus, comprising:
 a sheet supply device, comprising:
 a sheet stacking component having a stack surface on which a plurality of sheets are stacked; 
 a first roller configured to convey an uppermost sheet of the plurality of sheets from the sheet stacking component toward a downstream side in a conveying direction of the sheet; 
 a second roller configured to further convey the sheet conveyed by the first roller; and 
 a stopper rotatable around a rotation shaft along a width direction of the sheet parallel to the stack surface and perpendicular to the conveying direction, the stopper having an abutting surface against which a leading end of the sheet on the downstream side in the conveying direction abuts, 
 wherein the stopper rotates around the rotation shaft such that a posture of the stopper switches between
 a first posture having a first angle at which an angle between the abutting surface and the stack surface is an obtuse angle, and 
 a second posture having a second angle at which an angle between the abutting surface and the stack surface is an obtuse angle, the second angle being greater than the first angle; and 
 
   an image forming device configured to form an image on a sheet conveyed by the sheet supply device.   
     
     
         10 . The image forming apparatus according to  claim 9 , further comprising a controller configured to control a posture of the stopper. 
     
     
         11 . The image forming apparatus according to  claim 10 ,
 wherein the controller causes the stopper to rotate from the first posture to the second posture along with the start of driving of the first roller.   
     
     
         12 . The image forming apparatus according to  claim 9 ,
 wherein a shaft center of the rotation shaft is present at a height position that is lower than or equal to a height position of the stack surface.   
     
     
         13 . The image forming apparatus according to  claim 9 ,
 wherein the stopper is configured to freely adjust the angles of the abutting surface in the first posture and the second posture.   
     
     
         14 . The image forming apparatus according to  claim 9 , further comprising:
 a pressing plate configured to press a trailing end of the sheet stacked on the stack surface opposite to the leading end such that the leading end is pressed against the abutting surface.   
     
     
         15 . The image forming apparatus according to  claim 14 ,
 wherein the pressing plate has a pressing surface configured to press the trailing end of the sheet, and   a tilt angle of the pressing surface with respect to the stack surface is equal to a tilt angle of the abutting surface when the stopper is in the first posture.   
     
     
         16 . The image forming apparatus according to  claim 9 ,
 wherein a plurality of stoppers are provided, and   the stoppers are provided at different positions in the width direction of the sheet.   
     
     
         17 . The image forming apparatus according to  claim 9 ,
 wherein a surface material having a coefficient of static friction different from a coefficient of static friction of the abutting surface is attachable to the stopper.   
     
     
         18 . The image forming apparatus according to  claim 9 , wherein
 the first roller, the second roller, and stopper are configured to convey a single sheet in the conveying direction, with the proviso that two or more sheets are not conveyed at one time by the first roller, the second roller, and stopper.   
     
     
         19 . A sheet supply method, comprising:
 conveying by a first roller an uppermost sheet of a plurality of sheets from a sheet stacking component having a stack surface on which the plurality of sheets are stacked toward a downstream side in a conveying direction of the sheet;   conveying by a second roller the sheet conveyed by the first roller; and   rotating a stopper around a rotation shaft along a width direction of the sheet parallel to the stack surface and perpendicular to the conveying direction, the stopper having an abutting surface against which a leading end of the sheet on the downstream side in the conveying direction abuts, and switching a posture of the stopper between
 a first posture having a first angle at which an angle between the abutting surface and the stack surface is an obtuse angle, and 
 a second posture having a second angle at which an angle between the abutting surface and the stack surface is an obtuse angle, the second angle being greater than the first angle. 
   
     
     
         20 . The sheet supply method according to  claim 19 , further comprising:
 pressing a trailing end of the sheet stacked on the stack surface opposite to the leading end such that the leading end is pressed against the abutting surface.