Sheet processing apparatus for determining likelihood of sheets to stick after stacking

Abstract

A sheet processing apparatus comprises a sheet placing section in which recording media are stacked, a storage section configured to record a total amount of toner on the recording media stacked in the sheet placing section, and a control section configured to determine whether or not the recording media stacked in the sheet placing section is likely to stick when a new recording medium is stacked thereon, based on the total amount of toner on the recording media stacked in the sheet placing section.

What is claimed is: 
     
         1 . A sheet processing apparatus, comprising:
 a sheet tray in which recording media are to be stacked;   a storage section configured to record a total number of times an erasing process has been performed on the recording media stacked in the sheet tray; and   a controller configured to determine whether or not the recording media stacked in the sheet tray is likely to stick when a new recording medium is stacked thereon, based on the total number of times an erasing process has been performed on the recording media stacked in the sheet tray.   
     
     
         2 . The sheet processing apparatus according to  claim 1 , wherein the controller is configured to issue a warning message to be displayed when the recording media stacked in the sheet placing section are determined to be likely to stick when a new recording medium is stacked thereon. 
     
     
         3 . The sheet processing apparatus according to  claim 1 , wherein the controller is configured to determine that the recording media stacked in the sheet tray are likely to stick if the total number of times an erasing process has been performed on the recording media stacked in the sheet tray and the new recording medium exceeds a threshold number. 
     
     
         4 . The sheet processing apparatus according to  claim 1 , further comprising:
 an image reading section configured to read image information on the new recording medium,   wherein the controller is configured to determine the number of times an erasing process has been performed on the new recording medium from the image information.   
     
     
         5 . The sheet processing apparatus according to  claim 1 , wherein the image information on the new recording medium includes one or more marks that indicate the number of times an erasing process has been performed on the new recording medium. 
     
     
         6 . The sheet processing apparatus according to  claim 5 , wherein the one or more marks are on both sides of the new recording medium. 
     
     
         7 . A sheet processing apparatus, comprising:
 a sheet tray in which recording sheets are to be stacked;   a conveyance mechanism module configured to convey recording sheets to the sheet tray for stacking;   an image reader section configured to read image information of each recording sheet on a conveyance path of the conveyance mechanism module before the recording sheet is stacked on the sheet tray; and   a controller configured to receive, for each recording sheet to be stacked on the sheet tray, a first value from the image reader corresponding to a number of times an erasing process has been performed on the recording sheet image information and calculate a sum of the first values for recording sheets already stacked on the sheet tray and the first value of a next recording sheet to be stacked in the sheet tray, compare the sum to a predetermined value and stop the stacking of the next recording sheet on the sheet tray when the sum exceeds the threshold value and to continue the stacking of the next recording sheet on the sheet tray when the sum is less than the predetermined value.   
     
     
         8 . The sheet processing apparatus according to  claim 7 , wherein the controller is configured to issue a warning message when the sum exceeds the predetermined value. 
     
     
         9 . The sheet processing apparatus according to  claim 7 , wherein the controller is configured to cause a warning message to be displayed when the sum exceeds the predetermined value. 
     
     
         10 . The sheet processing apparatus according to  claim 7 , wherein the first value for each recording sheet is provided by information respectively printed on each recording sheet. 
     
     
         11 . The sheet processing apparatus according to  claim 10 , wherein the information is one or more marks.