A paper sheet sensing device includes: a sheet thickness sensor that includes a reference member and a displacement sensor, and senses a sheet thickness of a conveyed recording medium by bringing the reference member into contact with the recording medium and sensing a position of a height of the reference member with the displacement sensor, the position of the height having changed with the recording medium; a first attacher to which the sheet thickness sensor is attached; a conveyor that nips and conveys the recording medium, and is disposed adjacent to the sheet thickness sensor at a predetermined distance equal to or shorter than a length of the recording medium being conveyed, in a conveyance direction of the recording medium; and a displacement preventer that prevents a change in an output of the displacement sensor due to a shift of a relative position of the height of the reference member.

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 sheet feeding device includes a roller pair being mutually non-separable; and a roller pair being mutually separable. The sheet feeding device temporarily stops a sheet in a registration position of the non-separable roller pair and then resumes feeding the sheet. The sheet feeding device feeds sheets such that a following sheet reaches the registration position from the separable roller pair after completion of ejection of a preceding sheet.

A timing specifying device includes count processing circuitry to count an input reference clock; and timing control circuitry configured to set a parameter having an integer part and a fractional part in the count processing circuitry. The count processing circuitry counts the reference clock, outputs a timing signal indicating that a time corresponding to an integer value has passed, and counts a value corresponding to the fractional part at a timing at which the timing signal is output. The integer value is a value indicated by the integer part. The count processing circuitry stops counting of the reference clock when a value obtained by counting the value corresponding to the fractional part carries over from a fraction.

In a case where feeding of a subsequent sheet by a feed roller is started after the trailing edge of a preceding sheet is detected by a post-registration sensor, a control unit of a sheet feeder controls the feed roller to rotate at a first feeding speed, and in a case where the leading edge of the subsequent sheet has passed through a nip position between the feed roller and a separation roller, the control unit controls the feed roller to rotate at a second feeding speed.

In a case where feeding of a subsequent sheet by a feed roller is started after the trailing edge of a preceding sheet is detected by a post-registration sensor, a control unit of a sheet feeder controls the feed roller to rotate at a first feeding speed, and in a case where the leading edge of the subsequent sheet has passed through a nip position between the feed roller and a separation roller, the control unit controls the feed roller to rotate at a second feeding speed.

A document feeder includes a lift plate, a pickup roller, a lift motor, a retard roller, and a control unit. In a manual feed mode, the control unit rotates the retard roller to feed a document in a document conveyance direction. Further, the control unit causes the lift motor to start lowering the lift plate while the pickup roller is feeding a document after the rotation of the pickup roller is started.

A sheet conveyance apparatus includes a conveyance unit and first and second moving members respectively including first and second projection portions. When the first projection portion contacts a sheet, the first moving member is moved from a first projection position, where the first projection portion projects to a conveyance path, to a first retraction position, where the first projection portion is retracted from the first projection position. When the first moving member moves to the first retraction position, the second moving member moves from a second retraction position, where the second projection portion is retracted from the second projection position, to a second projection position, where the second projection portion projects to the conveyance path. When a sheet pushes the second projection portion, the second moving member is moved from the second projection position to the second retraction position with the first moving member located at the first retraction position.

A transportation apparatus includes a plurality of transportation members that are arranged in a transportation direction for a medium and transport the medium, a plurality of actuators that drive the plurality of transportation members, and a processor that controls the plurality of actuators in such a manner as to increase transportation velocities of the plurality of actuators in order from actuators for driving transportation members on a downstream side in the transportation direction to actuators for driving transportation members on an upstream side in the transportation direction.

A transportation apparatus includes a plurality of transportation members that are arranged in a transportation direction for a medium and transport the medium, a plurality of actuators that drive the plurality of transportation members, and a processor that controls the plurality of actuators in such a manner as to increase transportation velocities of the plurality of actuators in order from actuators for driving transportation members on a downstream side in the transportation direction to actuators for driving transportation members on an upstream side in the transportation direction.