Sheet stacking device and image forming apparatus incorporating the sheet stacking device

Abstract

A sheet stacking device includes a sheet stacker, an image capturing device, and circuitry. The sheet stacker stacks a sheet. The image capturing device captures an image of a whole face of the sheet stacked in the sheet stacker. The circuitry detects a size of the sheet stacked in the sheet stacker, whether the sheet stacked in the sheet stacker is a last sheet, or whether an image is formed on an image forming face of the sheet, based on image data of the image captured by the image capturing device.

What is claimed is: 
     
         1 . A sheet stacking device comprising:
 a sheet stacker to stack a sheet;   an image capturing device to capture an image of a whole face of the sheet stacked in the sheet stacker; and   circuitry to detect a size of the sheet stacked in the sheet stacker based on image data of the image captured by the image capturing device.   
     
     
         2 . The sheet stacking device according to  claim 1 ,
 wherein the circuitry is to:
 cause the image capturing device to capture an image of the sheet stacked in the sheet stacker together with a detection mark formed on the sheet stacking device to detect a position of the sheet in a vertical direction; and 
 detect a sheet stacking amount of the sheet stacked in the sheet stacker based on image data of the image of the detection mark and the sheet stacked in the sheet stacker simultaneously captured together by the image capturing device. 
   
     
     
         3 . The sheet stacking device according to  claim 1 ,
 wherein the circuitry is to detect whether the sheet stacked in the sheet stacker is a last sheet based on the image data of the image captured by the image capturing device.   
     
     
         4 . The sheet stacking device according to  claim 1 ,
 wherein the circuitry is to detect whether an image is formed on an image forming face of the sheet based on the image data of the image captured by the image capturing device.   
     
     
         5 . The sheet stacking device according to  claim 1 , further comprising a restraint to restrict a position of the sheet stacked in the sheet stacker,
 wherein the circuitry is to:
 cause the image capturing device to simultaneously capture an image of the restraint and the sheet stacked in the sheet stacker; and 
 detect a distance between the sheet stacked in the sheet stacker and the restraint based on image data of the image of the restraint and the sheet stacked in the sheet stacker simultaneously captured by the image capturing device. 
   
     
     
         6 . The sheet stacking device according to  claim 1 ,
 wherein a component of the sheet stacking device has an optical difference from the sheet in the image data of the image captured by the image capturing device.   
     
     
         7 . An image forming apparatus comprising:
 the sheet stacking device according to  claim 1 ; and   an image forming device to form an image on the sheet fed from the sheet stacking device.   
     
     
         8 . The image forming apparatus according to  claim 7 , further comprising a notification device to notify a user of information detected based on the image data of the image captured by the image capturing device. 
     
     
         9 . A sheet stacking device comprising:
 a sheet stacker to stack a sheet;   an image capturing device to capture an image of a whole face of the sheet stacked in the sheet stacker; and   circuitry to detect whether the sheet stacked in the sheet stacker is a last sheet based on image data of the image captured by the image capturing device.   
     
     
         10 . An image forming apparatus comprising:
 the sheet stacking device according to  claim 9 ; and   an image forming device to form an image on a sheet fed from the sheet stacking device.   
     
     
         11 . The image forming apparatus according to  claim 10 , further comprising a notification device to notify a user of information detected based on the image data of the image captured by the image capturing device. 
     
     
         12 . A sheet stacking device comprising:
 a sheet stacker to stack a sheet;   an image capturing device to capture an image of a whole face of the sheet stacked in the sheet stacker; and   circuitry to detect whether an image is formed on an image forming face of the sheet based on image data of the image captured by the image capturing device.   
     
     
         13 . An image forming apparatus comprising:
 the sheet stacking device according to  claim 12 ; and   an image forming device to form an image on a sheet fed from the sheet stacking device.   
     
     
         14 . The image forming apparatus according to  claim 13 , further comprising a notification device to notify a user of information detected based on the image data of the image captured by the image capturing device.