Paper feeding device and paper feeding method

Abstract

Provided are a paper feeding device that can stably feed one sheet of paper at a time to a paper feeding unit hopper of a printer or die cutting device. A paper feeding device comprising a paper feeding tray on which a plurality of sheets are stacked in the vertical direction, a sheet feeding means that sends, in the horizontal direction, the sheet that is located at the top of the plurality of sheets stacked on the paper feeding tray, and a pair of feeding rollers that deliver the sheet by grasping the leading edge of the sheet that is sent by the sheet feeding means, wherein the feeding rollers are variable speed rollers for which the circumferential speed can be increased and decreased while sending one sheet from the leading edge to the trailing edge.

1 . A paper feeding device comprising:
 a paper feeding tray on which multiple sheets are stacked in a vertical direction;   sheet feeding means for horizontally feeding one sheet located on the top of the multiple sheets stacked on the paper feeding tray;   a pair of feeding rollers that is disposed adjacent to the paper feeding tray, and that grasps a leading edge in a moving direction of the sheet fed by the sheet feeding means so as to deliver the sheet in a direction away from the paper feeding tray; and   a transporting conveyor that transports the sheet delivered from the feeding rollers,   wherein the feeding rollers are variable speed rollers which can increase and decrease circumferential speed while one sheet is delivered entirely from the leading edge in the moving direction to a trailing edge in the moving direction,   wherein the transporting conveyor is a variable speed conveyor in which the transporting speed of the transporting conveyor is set to be slower than an average circumferential speed obtained from when the feeding rollers grasp the sheet until the feeding rollers grasp the subsequent sheet, so that the subsequent sheet presses a trailing edge of the previously supplied sheet by causing the subsequent sheet to partially overlap an upper side of the sheet previously supplied onto the transporting conveyor, and   wherein the transporting speed of the transporting conveyor is changed in accordance with the length, size, thickness, or weight of the sheet so as to adjust an overlapping amount between the previously supplied sheet and the subsequent sheet, and a falling posture of the sheet is controlled so that the sheet is supplied to other devices.   
     
     
         2 . The paper feeding device according to  claim 1 ,
 wherein the feeding roller is the variable speed roller that maintains the circumferential speed which is the same as speed of the sheet fed by the sheet feeding means when the sheet feeding means grasps the sheet, that increases the speed from the circumferential speed which is the same as the speed of the sheet fed by the sheet feeding means after the sheet feeding means grasps the sheet, and that decreases the speed down to the feeding speed of the sheet until the sheet feeding means subsequently grasps the subsequent sheet.   
     
     
         3 . (canceled) 
     
     
         4 . The paper feeding device according to  claim 1 ,
 wherein the sheet feeding means transports the sheet by fixing a rear portion of the sheet.   
     
     
         5 . (canceled) 
     
     
         6 . A paper feeding method in which sheet feeding means takes out multiple stacked sheets one by one starting from a sheet located on the top and transfers the sheet to a pair of feeding rollers so as to supply one sheet to another device via the feeding rollers, the method comprising:
 a first step of causing circumferential speed when the feeding rollers grasp the sheet to coincide with speed of the sheet fed by the sheet feeding means;   a second step of increasing the circumferential speed of the feeding rollers while the subsequent one sheet is delivered entirely from a leading edge to a trailing edge; and   a third step of decreasing the speed so that the circumferential speed of the feeding rollers coincides with the speed of the sheet fed by the sheet feeding means until the feeding rollers subsequently grasp the subsequent sheet,   wherein the transporting speed of the transporting conveyor is set to be slower than an average circumferential speed obtained from when the feeding rollers grasp the sheet until the feeding rollers grasp the subsequent sheet, so that the subsequent sheet presses a trailing edge of the previously supplied sheet by causing the subsequent sheet to partially overlap the sheet delivered from the feeding rollers on an upper side of the sheet previously supplied onto the transporting conveyor, and   wherein the transporting speed of the transporting conveyor is changed in accordance with the length, size, thickness, or weight of the sheet so as to adjust an overlapping amount between the previously supplied sheet and the subsequent sheet, and the falling posture of the sheet is controlled so that the sheet is supplied to other devices.   
     
     
         7 . (canceled)