Sheet stacking device with air cushion

Abstract

An air blowing unit is arranged so as to blow air toward a side edge of a sheet discharged from a discharging port. Alternatively, the air is blew from below the discharged sheet.

What is claimed is:  
     
         1 . A sheet stacking device comprising: 
 a sheet discharging port from which a sheet is discharged;    an air blowing unit for blowing air toward the sheet discharged from the sheet discharging port; and    a stacker on which the blew sheet is stacked.    
     
     
         2 . The sheet stacking device as set forth in  claim 1 , wherein the air blowing unit is arranged so as to blow the air toward a side edge of the discharged sheet.  
     
     
         3 . The sheet stacking device as set forth in  claim 2 , wherein the air blowing unit is arranged at least one of downstream and along the sheet discharging direction such that the air is blew toward the center portion of the discharged sheet in the widthwise direction thereof.  
     
     
         4 . The sheet stacking device as set forth in  claim 2 , wherein the air blowing unit blows the air intermittently.  
     
     
         5 . The sheet stacking device as set forth in  claim 4 , wherein a cycle of the intermittent blowing is determined in accordance with the length of the sheet having been discharged.  
     
     
         6 . The sheet stacking device as set forth in  claim 5 , wherein the air blowing unit blows the air every time 5 to 20 cm of the sheet has been discharged.  
     
     
         7 . The sheet stacking device as set forth in  claim 1 , wherein the air blowing unit is arranged so as to blow the air from below the discharged sheet.  
     
     
         8 . The sheet stacking device as set forth in  claim 7 , wherein the air blowing unit is arranged in the vicinity of the sheet discharging port.  
     
     
         9 . The sheet stacking device as set forth in  claim 8 , wherein the air blowing unit blows the air intermittently.  
     
     
         10 . The sheet stacking device as set forth in  claim 1 , further comprising: 
 a sensor for detecting that the sheet has been discharged from the sheet discharging port,    wherein the air blowing unit starts to blow the air upon the detection of the sensor and continues blowing the air until the sheet is stacked on the stacker.    
     
     
         11 . The sheet stacking device as set forth in  claim 1 , wherein the stacker is arranged so as to support one corner portion of the blew sheet independent from the size of the sheet.  
     
     
         12 . A method of stacking sheets discharged from a sheet discharging port, comprising the steps of: 
 blowing air toward the discharged sheet; and    supporting the blew sheet at a predetermined position.    
     
     
         13 . The sheet stacking method as set forth in  claim 12 , wherein the air is blew toward a side edge of the discharged sheet.  
     
     
         14 . The sheet stacking method as set forth in  claim 13 , wherein the air is blew from at least one of a downstream area and a side area of the sheet discharging direction such that the air is blew toward the center portion of the discharged sheet in the widthwise direction thereof.  
     
     
         15 . The sheet stacking method as set forth in  claim 13 , wherein the air is blew intermittently.  
     
     
         16 . The sheet stacking method as set forth in  claim 15 , wherein a cycle of the intermittent blowing is determined in accordance with the length of the sheet having been discharged.  
     
     
         17 . The sheet stacking method as set forth in  claim 16 , wherein the air is blew every time 5 to 20 cm of the sheet has been discharged.  
     
     
         18 . The sheet stacking method as set forth in  claim 12 , wherein the air is blew from below the discharged sheet.  
     
     
         19 . The sheet stacking method as set forth in  claim 18 , wherein the air is blew from the vicinity of the discharging port.  
     
     
         20 . The sheet stacking method as set forth in  claim 19 , wherein the air is blew intermittently.  
     
     
         21 . The sheet stacking method as set forth in  claim 12 , further comprising the steps of: 
 detecting that the sheet has been discharged from the sheet discharging port,    wherein the air blowing is started upon the detection of the sensor and continued until the supporting step is conducted.    
     
     
         22 . The sheet stacking method as set forth in  claim 12 , wherein one corner portion of the blew sheet is supported independent from the size of the sheet.