Provided is an image forming apparatus preventing lowering of continuous printing performance; including plural paper feeding stages in main body; a residual paper quantity detection sensor; a printer part printing on paper; a paper feeding stage searching part functioning every time paper feeding is made; a paper feeding stage selection part determining existence of paper feeding capable stage, on result by paper feeding stage searching part, and selecting a paper feeding stage; a system control part performing stage changeover according to selection result by paper feeding stage selection part; when there exists no paper feeding capable stage, paper feeding stage selection part notifying system control part of it, and when there exists paper feeding capable stage, paper feeding stage selection part altering priority levels in stage searching on detection result by residual paper quantity detection sensor, and number of sheets required for printing, selecting paper feeding stage.

A medium detection mechanism includes a medium guide that holds a medium and an optical sensor including an irradiation section that emits irradiation light to the medium guide and a light receiving section that receives reflected light. An amount of received light that is received by the light receiving section from among reflected light of external light that enters the medium guide and reflected light of the irradiation light is smaller than or equal to a predetermined value.

A medium detection mechanism includes a medium guide that holds a medium and an optical sensor including an irradiation section that emits irradiation light to the medium guide and a light receiving section that receives reflected light. An amount of received light that is received by the light receiving section from among reflected light of external light that enters the medium guide and reflected light of the irradiation light is smaller than or equal to a predetermined value.

A post-processing apparatus includes a first sheet mount section to place sheets in the shape of a bunch, a second sheet mount section to place sheets in the shape of a bunch, a binding processing unit disposed to be able to shift to a first position to bind sheets placed in the first sheet mount section and a second position to bind sheets placed in the second sheet mount section, and a regulation device that does not position the sheets in the shape of a bunch in an area of the binding processing unit when the binding processing unit is not positioned in the second position.

A post-processing apparatus includes a first sheet mount section to place sheets in the shape of a bunch, a second sheet mount section to place sheets in the shape of a bunch, a binding processing unit disposed to be able to shift to a first position to bind sheets placed in the first sheet mount section and a second position to bind sheets placed in the second sheet mount section, and a regulation device that does not position the sheets in the shape of a bunch in an area of the binding processing unit when the binding processing unit is not positioned in the second position.

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

A card feeding apparatus realizes random and selective feeding of cards of different types or kinds. This apparatus includes a card supplying device, a card holding and feeding device, and a controller. The card holding and feeding device includes a table set having tables on which cards from the card supplying device are held, a table set supporting structure (e.g., a frame), a table set moving device (e.g., a lifting mechanism), and a card conveying device that conveys cards held on the tables. In response to a card feeding signal, the table set supporting structure is temporarily stopped using the table set moving device such that a target table designated from the tables by the said signal is located at the card conveying position, and the card holding and feeding device is activated, thereby feeding a card on the target table by the card conveying device.

A card feeding apparatus realizes random and selective feeding of cards of different types or kinds. This apparatus includes a card supplying device, a card holding and feeding device, and a controller. The card holding and feeding device includes a table set having tables on which cards from the card supplying device are held, a table set supporting structure (e.g., a frame), a table set moving device (e.g., a lifting mechanism), and a card conveying device that conveys cards held on the tables. In response to a card feeding signal, the table set supporting structure is temporarily stopped using the table set moving device such that a target table designated from the tables by the said signal is located at the card conveying position, and the card holding and feeding device is activated, thereby feeding a card on the target table by the card conveying device.

A paper feed apparatus includes a paper feeding portion that sends-out a paper placed in a paper placing tray, and is used in an image forming apparatus such as a multifunction machine. The paper feed apparatus comprises a first regulating portion and a second regulating portion that are arranged in the vicinity of a downstream side of a paper feeding position by the paper feeding portion. The first regulating portion is arranged outside a second width paper passage area to regulate a movement of a first width paper such as A4 paper placed in the paper placing tray toward a feeding direction. On the other hand, the second regulating portion is arranged inside the second width paper passage area to regulate a movement of a second width paper such as a name card placed in the paper placing tray toward a feeding direction. Since there are provided with the first regulating portion and the second regulating portion that are arranged outside and inside the second width paper passage area, the second width paper such as a name card can be adequately fed in addition to the first width paper such as A4 paper.