Sheet stacking device and sheet processing apparatus

Abstract

In a sheet stacking device including a sheet stacking section, a holding member for holding sheets on the sheet stacking section, and a driving device for moving the holding member to the holding position and retreating position, the holding of the holding member which retreats when a sheet is being fed in and which holds the sheet when the sheet has reached, is canceled on the basis of approaching information of a succeeding sheet.

1 . A sheet stacking device comprising:
 a sheet stacking section;   a holding member for holding a sheet on the sheet stacking section;   a driving device for moving the holding member between a holding position and a retreating position; and   a control device for controlling the driving device,   wherein the control device sets the holding member in the retreating position while a sheet is being conveyed to the sheet stacking section and sets the holding member in the holding position when the sheet has arrived at the sheet stacking section and then sets the holding member in the retreating position based on information of approaching of a subsequent sheet to the sheet stacking section.   
   
   
       2 . The sheet stacking device of  claim 1 ,
 wherein the information of approaching is a sheet detection signal from a first sensor equipped in an upstream position of the sheet stacking section.   
   
   
       3 . The sheet stacking device of  claim 1 ,
 wherein the control device controls to set the holding member in the holding position based on a sheet detection signal of a second sensor equipped in a position which is vicinity of a receiving section of the sheet stacking section and is upstream of the sheet stacking section.   
   
   
       4 . The sheet stacking device of  claim 3 , further comprising:
 a first sensor equipped in an upstream position of the sheet stacking section for transmitting a sheet detection signal which is the information of approaching; and   wherein the first sensor detects a sheet on an upstream side of the second sensor.   
   
   
       5 . The sheet stacking device of  claim 1 ,
 wherein the control device controls to set the holding member from the holding position to the retreating position based on a stop signal for stopping the sheet stacking device and set the holding member in the holding position based on a stop cancelling signal.   
   
   
       6 . A sheet processing apparatus comprising:
 the sheet stacking device of  claim 1 ; and   a processing device for applying processing to a sheet stacked thereon.