A recording medium processing apparatus includes first teeth that are used for binding processing of a recording medium bundle; second teeth that move toward the first teeth and press the recording medium bundle located between the first teeth and the second teeth; and a control unit that moves the second teeth toward the first teeth to press the second teeth against the first teeth in a state in which there is no recording medium bundle between the first teeth and the second teeth.

A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

A sheet conveyer, having a sheet tray, a tray-driving mechanism, a conveyance guide, a feed roller, a conveyer-driving mechanism, a first sensor, and a controller, is provided. The controller controls the tray-driving mechanism and the conveyer-driving mechanism, during a sequential conveying action, when the first sensor detects an upper-surface level being at a lower limit of a correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding a next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

A sheet conveyer, having a sheet tray, a tray-driving mechanism, a conveyance guide, a feed roller, a conveyer-driving mechanism, a first sensor, and a controller, is provided. The controller controls the tray-driving mechanism and the conveyer-driving mechanism, during a sequential conveying action, when the first sensor detects an upper-surface level being at a lower limit of a correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding a next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

A sheet conveyance apparatus includes a drive source, a conveyance portion, a transmission mechanism configured to switch between a first state and a second state, a load detection portion configured to detect a load acting on the drive source, and a control portion configured to control the drive source and the transmission mechanism. The control portion is configured to change, on a basis of a detection result of the load detection portion, a timing in the conveyance operation at which a control signal for switching the transmission mechanism from the first state to the second state is issued, the timing being changed in accordance with a delay time from when the control signal is issued to when change in the load corresponding to the switching of the transmission mechanism from the first state to the second state appears.

An image forming apparatus includes a paper feeding cassette, a first conveying unit, a lift mechanism, a motor, a second conveying unit, and a control unit. The controller drives the motor and, if a value indicating a movement amount of the tray moving from when the lift mechanism starts the lifting of the tray until when a position of the top part reaches a first position is a first value, matches a position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a second position and, if the value indicating the movement amount is a second value larger than the first value, matches the position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a third position lower than the second position.

An image forming apparatus comprises an accommodating unit that accommodates recording materials and a feeding unit that feeds an accommodated recording material, detects a fed recording material, and measures time from a predetermined timing until a recording material is detected. An information processing apparatus receives measured time data from the image forming apparatus, classifies the received plurality of time data into a first group and a second group in accordance with a length of time, selects a group for predicting a remaining life time of the feeding unit from the classified first group and second group, and predicts a remaining life time of the feeding unit using time data included in the selected group.