Sheet supply device

Abstract

A sheet supply device has a sheet storing section on which sheets are stacked and stored, a sheet feed unit that feeds the sheets stored in the sheet storing section to a next process, and an air blower that blows air to the sheets stored in the sheet storing section. A force for pushing up the sheets, which is exerted on the sheets by the blown air, is set to be weaker when the sheets are being fed than when they are not being fed.

1 . A sheet supply device, comprising: 
 a sheet storing section on which sheets are stacked and are stored;    a sheet feed unit that feeds the sheets stored in the sheet storing section to a next process; and    an air blower that blows air to the sheets stored in the sheet storing section,    wherein a force for pushing up the sheets, which is exerted on the sheets due to the air blower blowing the air, is made to be weaker when the sheets are being fed than when the sheets are not being fed.    
   
   
       2 . A sheet supply device according to  claim 1 , wherein an air flow rate of the air blower is set at a lower rate when the sheets are being fed than when the sheets are not being fed.  
   
   
       3 . A sheet supply device according to  claim 2 , wherein a time when the air blower is operated corresponds to a time when the sheets are not fed, and a time when the air blower is not operated corresponds to a time when the sheets are fed.  
   
   
       4 . A sheet supply device according to  claim 3 , wherein the air blower is repeatedly alternated between being operated and not operated, and the sheet feed unit is operated after the air blower becomes inoperative.  
   
   
       5 . A sheet supply device according to  claim 2 , wherein the air blower has an air nozzle and a shutter that can adjust an area of the air nozzle, and the shutter increases or decreases the air flow rate of the air blown to the sheets.  
   
   
       6 . A sheet supply device according to  claim 5 , wherein the sheet feed unit is operated after the shutter decreases the air flow rate of the air blown to the sheets.  
   
   
       7 . A sheet supply device according to  claim 2 , wherein the air blower has an air nozzle and a mechanism that can adjust a height of the air nozzle in an up-down direction, and the mechanism increases or decreases the air flow rate of the air blown to the sheets.  
   
   
       8 . A sheet supply device according to  claim 7 , wherein the sheet feed unit is operated after the mechanism decreases the air flow rate of the air blown to the sheets.  
   
   
       9 . A sheet supply device according to  claim 2 , wherein the air blower has a fan, the number of revolutions of which can be changed, and the number of revolutions of the fan is set so as to be lower when the sheets are being fed than when the sheets are not being fed.  
   
   
       10 . A sheet supply device according to  claim 9 , wherein the sheet feed unit is operated after the number of revolutions of the fan is reduced.  
   
   
       11 . A sheet supply device according to  claim 1 , wherein 
 the force for pushing up the sheets exerted by the air blower blowing the air is varied for predetermined periods, and    the sheet feed unit feeds the sheets to a next process in synchronization with the predetermined periods.    
   
   
       12 . A sheet supply device, comprising: 
 a sheet storing section on which sheets are stacked and stored;    a feed unit that feeds the sheets stored on the sheet storing section to a next process;    an air blower that blows air to the sheets stored on the sheet storing section; and    a flow channel moving unit that moves a flow channel for the air blown by the air blower,    wherein a height of the flow channel in a vertical direction is set to be higher when the sheets are being fed than when the sheets are not being fed.    
   
   
       13 . A sheet supply device according to  claim 12 , wherein 
 the flow channel moving unit has an air blocking member that moves in a stacking direction of the sheets so as to block the air, and    the air blocking member is moved so that a height of an upper end of the air blocking member is higher when the sheets are being fed than when the sheets are not being fed.    
   
   
       14 . A sheet supply device according to  claim 12 , wherein 
 the flow channel moving unit has an air blowing position changing unit that changes a height of an air blowing position with respect to the sheets, and    the height of the air blowing position is set to be higher when the sheets are being fed than when the sheets are not being fed.    
   
   
       15 . A sheet supply device according to  claim 12 , wherein 
 the height of the flow channel for the air in the vertical direction is varied for predetermined periods, and    the feed unit feeds the sheets to the next process in synchronization with the predetermined periods.    
   
   
       16 . A sheet supply device, comprising: 
 a sheet storing section on which sheets are stacked and are stored;    a sheet feed unit that feeds the sheets stored on the sheet storing section to a next process; and    an air blower that blows air to the sheets stored on the sheet storing section,    wherein the air blower can adjust a flow rate of the air to be blown to the sheets so that a force pushing up the sheets which is exerted on the sheets when the air is blown is weaker when the sheet feed unit is operated than when it is not operated.    
   
   
       17 . A sheet supply device according to  claim 16 , wherein a time when the air blower is operated corresponds to a time when the sheets are not fed, and a time when the air blower is not operated corresponds to a time when the sheets are fed.  
   
   
       18 . A sheet supply device according to  claim 16 , wherein the air blower has an air nozzle and a shutter which can adjust an area of the air nozzle, and the shutter increases or decreases the air flow rate of the air blown to the sheets.  
   
   
       19 . A sheet supply device according to  claim 16 , wherein the air blower has an air nozzle and a mechanism that can adjust a height of the air nozzle in an up-down direction, and the mechanism increases or decreases the air flow rate of the air blown to the sheets.  
   
   
       20 . A sheet supply device according to  claim 16 , wherein the air blower has a fan, the number of revolutions of which can be changed, and the number of revolutions of the fan is set to be lower when the sheets are being fed than when they are not being fed.