A sheet feeder includes: a feed roller; a shutter movable between a restricting position restricting a leading edge of a sheet and a non-restricting position releasing the restriction on the sheet; and a controller configured to control rotation of the feed roller and movement of the shutter. The controller is configured to perform: a first feeding process of controlling the feed roller to rotate at a first rotational speed while the shutter is at the restricting position and of controlling the shutter to move to the non-restricting position from the restricting position no earlier than rotation of the feed roller at the first rotational speed: a reduction process of controlling a rotational speed of the feed roller to be less than the first rotational speed; and a second feeding process of controlling the feed roller to rotate at a second rotational speed.

A sheet feeder includes: a sheet feeding assembly including: a shaft having an insertion part; and a feed roller; and a main body including: a rotary part; and first and second bearings. The main body supports the sheet feeding assembly. The rotary part rotates upon transmission of a drive force and receives the insertion part. The bearings support the shaft. An opening of an open portion of the first bearing has a circumferential dimension greater than a diameter of the shaft. The shaft supported by the bearings is movable between a mounted position and a retracted position. The feed roller is supported by the shaft, and movable as the shaft moves between the mounted position and the retracted position. The insertion part is separated from the rotary part when the shaft is in the retracted position, and inserted into the rotary part to place the shaft in the mounted position.

In an image reading apparatus, in a first process, first and second motor rotate feed and conveyance rollers with circumferential speeds of first and second speeds, respectively. In the first process, the reverse roller has a first separation performance for separating a sheet from another sheet. In a second process, after a detector detects a leading edge of the sheet, the controller stops the first motor, and decelerates the second motor, and the reverse roller has a second separation performance lower than the first separation performance. In a third process, after a trailing edge of the sheet reaches a specific position, the first motor starts rotating the feed roller with the circumferential speed of the first speed. In a fourth process, after the trailing edge of the sheet passes through a reading end position, the controller accelerates the second motor.

A medium conveying apparatus includes a loading tray to place media, a feed roller to separate and sequentially feed the media placed on the loading tray, a motor to drive the feed roller, a sensor located on a downstream side of the feed roller in a medium conveying direction to detect a medium, and a processor to control the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, the processor controls the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, the processor controls the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

Provided is a medium conveying apparatus to enable suitable feeding of a plurality of types of media. A medium conveying apparatus includes a guide member including an opening or a notch and configured to form a conveyance surface of a medium, a feed roller located inside the opening or the notch and configured to feed the medium, a separation roller located to face the feed roller, and protruding parts located on left and right sides of the separation roller relative to a medium conveying direction. The guide member includes recessed parts positioned on left and right sides of the feed roller relative to the medium conveying direction. The protruding parts are located at positions facing the opening or the notch, or the recessed parts in such a way that the medium is conveyed between the protruding parts and the recessed parts. A tip of each of the protruding parts is positioned on the feed roller side of a nip part of the feed roller and the separation roller.

A medium conveying apparatus includes a loading tray to place media, a feed roller to separate and sequentially feed the media placed on the loading tray, a motor to drive the feed roller, a sensor located on a downstream side of the feed roller in a medium conveying direction to detect a medium, and a processor to control the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, the processor controls the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, the processor controls the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

A scanner includes a reading unit that reads an image of a paper, a medium feeding portion that is capable of selecting a first feeding mode in which a separation feeding for separately feeding a paper bundle in which a plurality of sheets of paper is overlapped with each other is performed and a second feeding mode in which a non-separation feeding for collectively feeding the paper bundle without separating is performed, and a pair of first transporting rollers and a pair of second transporting rollers that transport the paper fed by the medium feeding portion, in a case in which the medium feeding portion feeds the paper in the second feeding mode, a first driven roller and a second driven roller respectively constituting the pair of first transporting rollers and the pair of second transporting rollers are driven in a rotation direction where the paper is transported.