Sheet feeding device and image forming apparatus

Abstract

Provided are a sheet feeding device and an image forming apparatus which can separately feed a sheet with safety without causing the length of an adsorption member to be increased. One end of a flexible adsorption member ( 29 ) is fixed to a holding member ( 24 ) which is disposed on the upper side of a storing unit to store the sheet and rotated in a sheet feeding direction. Then, when the holding member ( 24 ) is rotated, the rigidity of a second region ( 29 b ) of the adsorption member ( 29 ) is set to be lower than that of a first region ( 29 a ) of the adsorption member ( 29 ) which comes into surface contact with the sheet stored in the storing unit and adsorbs the sheet by an adsorbing force by static electricity.

1 . A sheet feeding device comprising:
 a loading portion configured to be loaded with a sheet;   a rotation member configured to be disposed on an upper side of the loading portion; and   an adsorption member configured to have ends and to be provided such that a part of the adsorption member is fixed to the rotation member and the sheet loaded on the loading portion is electrically adsorbed,   wherein the adsorption member includes an adsorption portion which comes into contact with the sheet loaded on the loading portion, and a support portion which is provided at a position near the rotation member from the adsorption portion and has a rigidity lower than that of the adsorption portion with respect to a force applied from a sheet feeding direction.   
     
     
         2 . The sheet feeding device according to  claim 1 , further comprising:
 a detection unit configured to detect a rotation angle of the rotation member;   a power source configured to apply a voltage to apply an adsorbing force by static electricity onto the adsorption member; and   a control unit configured to apply a voltage from the power source to the adsorption member when it is determined that the adsorption portion comes into contact with the sheet based on a signal from the detection unit   
     
     
         3 . The sheet feeding device according to  claim 1 ,
 wherein the support portion and the adsorption portion of the adsorption member are set to have the same thickness, and a volume of the adsorption member of the adsorption member is set to be smaller than that of the adsorption portion.   
     
     
         4 . The sheet feeding device according to  claim 3 ,
 wherein at least one of a notch, a tapper, and an opening is formed in the support portion of the adsorption member so as to make the volume of the adsorption member smaller than that of the adsorption portion by the amount of the notch, the tapper, and the opening which are formed.   
     
     
         5 . The sheet feeding device according to  claim 1 ,
 wherein a thickness of the support portion of the adsorption member is thinner than that of the adsorption portion.   
     
     
         6 . The sheet feeding device according to  claim 1 ,
 wherein the support portion of the adsorption member is formed of a material having a Young's modulus lower than that of a material of the adsorption portion.   
     
     
         7 . The sheet feeding device according to  claim 2 ,
 wherein the adsorption member is a dielectric having two electrodes in a surface or the inside of a flexible base material, and   wherein the power source includes a first power source which applies a positive voltage to one of the two electrodes and a second power source which applies a negative voltage to the other one of the two electrodes.   
     
     
         8 . The sheet feeding device according to  claim 7 ,
 wherein the electrode is provided in the adsorption portion.   
     
     
         9 . The sheet feeding device according to  claim 7 ,
 wherein the rotation member is formed of a conductive material, one of the first power source and the second power source is connected to one of the two electrodes of the adsorption member through the rotation member, and the other one of the first power source and the second power source is connected to the other one of the two electrodes of the adsorption member.   
     
     
         10 . A sheet feeding device comprising:
 a loading portion configured to be loaded with a sheet; and   a flexible adsorption member configured to include an adsorption portion which abuts on the sheet loaded on the loading portion from an upper side and comes into surface contact with the sheet loaded on the loading portion to adsorb the sheet by an adsorbing force by static electricity, and a non-adsorption portion which has a low rigidity compared to that of the adsorption portion.   
     
     
         11 . The sheet feeding device according to  claim 10 , further comprising
 a rotation member configured to be provided on the upper side of the loading portion to be rotatably in a sheet feeding direction,   wherein one end of the non-adsorption portion of the adsorption member is fixed to the rotation member, and when the rotation member is rotated, the adsorption portion comes into surface contact with the sheet loaded on the loading portion to adsorb the sheet.   
     
     
         12 . An image forming apparatus comprising:
 an image forming section;   a loading portion configured to be loaded with a sheet;   a rotation member configured to be disposed on an upper side of the loading portion; and   an adsorption member configured to have ends and to be provided such that a part of the adsorption member is fixed to the rotation member and the sheet loaded on the loading portion is electrically adsorbed,   wherein the adsorption member includes an adsorption portion which comes into contact with the sheet loaded on the loading portion, and a support portion which is provided at a position near the rotation member from the adsorption portion and has a rigidity lower than that of the adsorption portion with respect to a force applied from a sheet feeding direction.