An image forming apparatus includes a sheet storing cassette, a lift mechanism, a sheet feeding portion, a remaining quantity sensing portion, and a control portion. The control portion, during continuous sheet feeding by the sheet feeding portion, controls the lift mechanism to make a sheet stacking plate ascend to a lifted position where sheets make contact with the sheet feeding portion, and feeds a foregoing sheet and then, at a sheet feeding timing a predetermined time thereafter, starts feeding the following sheet. The control portion makes the sheet feeding timing earlier as the remaining quantity of the sheets sensed by the remaining quantity sensing portion decreases.

An image forming apparatus includes a processing tray, a post-processing controller, and a detection sensor. The processing tray is configured to support a sheet or a sheet bundle on which a post-processing is to be executed. The post-processing controller is configured to execute the post-processing on the sheet positioned on the processing tray. The detection sensor is configured to detect an object in a predetermined detection range including a space above the processing tray. The post-processing controller stops execution of the post-processing when the detection sensor detects the object at a determination timing other than a timing at which passage of the sheet or the sheet bundle through the detection range is estimated.

An image forming apparatus includes a processing tray, a post-processing controller, and a detection sensor. The processing tray is configured to support a sheet or a sheet bundle on which a post-processing is to be executed. The post-processing controller is configured to execute the post-processing on the sheet positioned on the processing tray. The detection sensor is configured to detect an object in a predetermined detection range including a space above the processing tray. The post-processing controller stops execution of the post-processing when the detection sensor detects the object at a determination timing other than a timing at which passage of the sheet or the sheet bundle through the detection range is estimated.

A sheet feeding device includes a pickup roller, a lifting/lowering mechanism, and a driver device. The lifting/lowering mechanism includes a restricting member that releasably restricts the pickup roller from being lowered from a lifted position of the pickup roller at the lifted position. In the sheet feeding device, the driver device drives the lifting/lowering mechanism so that the pickup roller is lowered from the lifted position of the pickup roller, and a drive suspend operation is performed in which the driving of the lifting/lowering mechanism by driver device is suspended after a predetermined time during which the pickup roller does not contact a sheet loading tray or a sheet on the sheet loading tray elapses from a time point when the pickup roller is released from being restricted by the restricting member at the lifted position.

A conveyance device includes a sheet stacker, a pickup roller, a feed roller, a first drive source, a first encoder, a first drive controller, a separation roller, a second drive source, a second encoder, a second drive controller, a separation pressure provider, and a torque estimation device. The torque estimation device estimates a torque of the second drive source with an applied voltage to the second drive source from the second drive controller after calculating a turning angle speed from a rotation amount of the second drive source detected by the second encoder based on a relational expression between a motor rotation speed and an applied voltage that are measured beforehand for the second drive source and a torque of the second drive source.

A method and apparatus for processing documents are provided. The apparatus includes a feeder for receiving a packet of a plurality of documents and separating the documents to serially feed the documents to a scanner. A drop feeder conveys the document packets to the feeder. A sensor provides information related to the thickness of the document packets and the drop feeder is controlled in response to the information related to the thickness of a packet in the feeder. The method includes the control of the drop feeder in response to information related to the thickness of a document packet at the feeder.

A method and apparatus for processing documents are provided. The apparatus includes a feeder for receiving a packet of a plurality of documents and separating the documents to serially feed the documents to a scanner. A drop feeder conveys the document packets to the feeder. A sensor provides information related to the thickness of the document packets and the drop feeder is controlled in response to the information related to the thickness of a packet in the feeder. The method includes the control of the drop feeder in response to information related to the thickness of a document packet at the feeder.

An image recording apparatus including: a recording unit; an accommodation part configured to accommodate therein a plurality of recording media including first and second recording medium and having a support surface on which the plurality of the recording media is supported; a conveying path; a feeder roller contacting the recording medium in the accommodation part from above; a reversing path; a recording medium detection unit located above the support surface and between the feeder roller and a downstream end of the support surface in the conveying direction; and a controller configured to control the feeder roller so as to feed the second recording medium in a manner that a front end portion of the second recording medium overlaps a rear end portion of the first recording medium, when the recording medium detection unit detects the rear end portion of the first recording medium fed by the feeder roller.

A controller drives a floating unit and a conveyor to perform a sheet feed operation, during the sheet feed operation, acquires an amount of received light at a detector during floating of sheets floated by the floating unit each time each sheet is conveyed by the conveyor, and perform a following control of lifting a stacking tray upon the acquired amount of received light being less than a threshold value. The controller, after start of the sheet feed operation, samples amounts of received light at the detector during floating of the sheets floated by the floating unit, performs a threshold value determination process of determining the threshold value by using the sampled amounts of received light, and starts the following control upon determining the threshold value.

An image forming apparatus has a sheet feed portion, a conveying portion, a control portion, a first sensor having the detection position at a first position in the sheet conveying passage, and a second sensor having the detection position at a second position downstream of the first position in the sheet conveying direction. The control portion performs first sensing to sense whether the sheet's rear end has passed the first position within a first time of the start of the feeding and second sensing to sense whether the sheet's rear end has passed the second position within a second time of the start of the feeding. Even if the control portion is unable to sense passage of the sheet's rear end in the first sensing, when it senses passage of the sheet's rear end in the second sensing, it makes the conveying portion continue feeding the sheet.