Patent ID: 6422557
Filing Date: 2002-07-23
Classification: B65H,G03G

Abstract:
An image forming apparatus comprising:image forming means for forming images on sheets; a plurality of sheet stacking means in which the sheets are stacked; selector means for selecting one of the plurality of sheet stacking means; moving means for moving to a predetermined position the selected sheet stacking means; detection means for detecting a sheet-stacked condition of the selected sheet stacking means which positions at the predetermined position; wherein said detection means utilizes a single detector common to said plurality of sheet stacking means; and control means for controlling image forming to a sheet which is to be discharged to said selected stacking means in accordance with a detected result by said detection means; wherein said control means, when the selected sheet stacking means is changed to a newly selected sheet stacking means, causes to move the newly selected sheet stacking means to the predetermined position and to detect the sheet-stacked condition of the newly selected sheet stacking means which positions at the predetermined position and then, controls the starting of image forming to a sheet which is to be discharged to the newly selected sheet stacking means.