Sheet stacking apparatus, method for controlling sheet stacking apparatus, and storage medium

Abstract

A sheet stacking apparatus includes a lowering control unit, a determination unit, and a control unit. The lowering control unit lowers a sheet stacking unit according to a stacked sheet amount. The determination unit determines whether the sheet stacking unit cannot be lowered by the lowering control unit. The control unit performs control to store a position of the sheet stacking unit and stop stacking of the sheet when the determination unit determines that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit. The control unit performs control to raise the sheet stacking unit when the stacked sheet is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit based on the stored position.

What is claimed is: 
     
         1 . A sheet stacking apparatus comprising:
 a lowering control unit configured to lower a sheet stacking unit according to an amount of a sheet that is stacked;   a determination unit configured to determine that the sheet stacking unit cannot be lowered by the lowering control unit; and   a control unit configured to perform control to store a position of the sheet stacking unit in a storage unit and stop stacking of the sheet on the sheet stacking unit when the determination unit determines that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit,   wherein the control unit is configured to perform control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit based on the position stored in the storage unit.   
     
     
         2 . The sheet stacking apparatus according to  claim 1 , wherein the control unit is configured to perform control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit at the position stored in the storage unit. 
     
     
         3 . The sheet stacking apparatus according to  claim 1 , wherein the control unit is configured to perform control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit at a position higher than the position stored in the storage unit. 
     
     
         4 . The sheet stacking apparatus according to  claim 1 ,
 wherein the control unit is configured to perform control to resume the stacking of the sheet on the sheet stacking unit when an obstacle placed below the sheet stacking unit is removed in the state where the stacking of the sheet on the sheet stacking unit is stopped, and   wherein the lowering control unit is configured to lower the sheet stacking unit from the position at which the stacking of the sheet is stopped, instead of the control unit performing control to raise the sheet stacking unit.   
     
     
         5 . The sheet stacking apparatus according to  claim 1 , wherein the control unit is configured to cancel a job for stacking the sheet, when an instruction to cancel the job for stacking the sheet is received in the state where the stacking of the sheet on the sheet stacking unit is stopped. 
     
     
         6 . The sheet stacking apparatus according to  claim 1 , further comprising a notification unit configured to instruct removal of the sheet stacked on the sheet stacking unit or the obstacle placed below the sheet stacking unit when the determination unit determines that the sheet stacking unit cannot be lowered while the stacking of the sheet on the sheet stacking unit is being performed. 
     
     
         7 . The sheet stacking apparatus according to  claim 1 , wherein the control unit is configured to perform control to display, on a display unit, a screen for calling a serviceman when the sheet stacking unit cannot be raised while the sheet stacking unit is being raised after the sheet stacked on the sheet stacking unit is removed. 
     
     
         8 . The sheet stacking apparatus according to  claim 1 , further comprising a printing unit configured to print an image onto the sheet,
 wherein the sheet on which the image is printed by the printing unit is stacked on the sheet stacking unit.   
     
     
         9 . The sheet stacking apparatus according to  claim 8 , further comprising a read unit configured to read an image on a document,
 wherein the printing unit is configured to print the image read by the read unit.   
     
     
         10 . A sheet stacking apparatus comprising:
 a lowering control unit configured to lower a sheet stacking unit according to an amount of a sheet that is stacked;   a determination unit configured to determine that the sheet stacking unit cannot be lowered by the lowering control unit; and   a control unit configured to perform control to stop stacking of the sheet on the sheet stacking unit at a first position at which the determination unit has determined that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit,   wherein the control unit is configured to perform control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped at the first position, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit at a second position that is higher than the first position by a predetermined height.   
     
     
         11 . The sheet stacking apparatus according to  claim 10 , further comprising a reception unit configured to receive the predetermined height from a user. 
     
     
         12 . A sheet stacking apparatus comprising:
 a lowering control unit configured to lower a sheet stacking unit to a lowermost position according to an amount of a sheet that is stacked;   a determination unit configured to determine that the sheet stacking unit cannot be lowered by the lowering control unit at a first position that is different from the lowermost position; and   a control unit configured to perform control to stop stacking of the sheet on the sheet stacking unit at the first position at which the determination unit has determined that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit,   wherein the control unit is configured to perform control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped at the first position, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit at the first position.   
     
     
         13 . A method for controlling a sheet stacking apparatus having a lowering control unit configured to lower a sheet stacking unit according to an amount of a sheet that is stacked and a determination unit configured to determine that the sheet stacking unit cannot be lowered by the lowering control unit, the method comprising:
 performing control to store a position of the sheet stacking unit in a storage unit and stop stacking of the sheet on the sheet stacking unit when the determination unit determines that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit; and   performing control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit based on the position stored in the storage unit.   
     
     
         14 . A computer readable storage unit storing a program to cause a computer to execute a method for controlling a sheet stacking apparatus having a lowering control unit configured to lower a sheet stacking unit according to an amount of a sheet that is stacked and a determination unit configured to determine that the sheet stacking unit cannot be lowered by the lowering control unit, the method comprising:
 performing control to store a position of the sheet stacking unit in a storage unit and stop stacking of the sheet on the sheet stacking unit when the determination unit determines that the sheet stacking unit cannot be lowered while the sheet is being stacked on the sheet stacking unit; and   performing control to raise the sheet stacking unit when the sheet stacked on the sheet stacking unit is removed in a state where the stacking of the sheet on the sheet stacking unit is stopped, stack the sheet on the raised sheet stacking unit, and stop lowering of the sheet stacking unit based on the position stored in the storage unit.