A sheet feeding apparatus includes a sheet conveyance roller, a retard roller to contact the conveyance roller and separate sheets one by one, a drive input shaft, a retard shaft, and a joint to connect the retard shaft with the drive input shaft and transmit rotary drive force of the drive input shaft to the retard shaft. A first angle formed between a line passing through a first engagement position and the drive input shaft and a line passing through a second engagement position and the retard shaft center is within a range of 80 degrees or greater and 100 degrees or smaller, and a second angle formed between a line passing through the drive input shaft and a first pin axis and a line passing through the retard shaft and a second pin axis is within a range of 50 degrees or greater and 70 degrees or smaller.

A medium conveying apparatus includes a medium tray on which a medium is placed, a skew corrector that rotates the medium in such a manner that a part of an end of the medium is aligned with a predetermined line, a rotating member that contacts with the medium, and a conveyor that conveys the medium in a conveying direction, wherein the rotating member is supported rotatably on the medium tray so that, when the medium moves in a direction different from the conveying direction, the rotating member rotates following the medium.

A medium feeding device includes a medium feeding mechanism switching between a first state in which the medium is fed from the feeding tray and a second state in which the medium is not fed from the feeding tray, a feeding roller rotationally driven in a forward rotation direction, and a separation roller that is rotationally driven in the reverse rotation direction when the feeding roller is rotationally driven in the forward rotation direction, wherein when the separation roller is rotationally driven in the forward rotation direction, the feeding roller is configured to be passively rotatable with respect to the separation roller, and wherein a rotation direction of the first motor when the cam member switches the medium feeding mechanism from the first state to the second state is the same as a rotation direction of the first motor when the separation roller rotates in the forward rotation direction.

A shaft on which a torque limiter is mounted includes a rotation restricting portion. The rotation restricting portion is inserted into and engaged with an engaging portion of the torque limiter. The rotation restricting portion is provided with an outer circumferential portion which is projected in an outer diameter direction from an outer circumference of the shaft and of which an outer circumferential surface is formed parallel with an outer circumferential surface of the shaft and an engaging portion connected to the outer circumferential portion and engaging with the engaging portion of the torque limiter. The engaging portion of the rotation restricting portion is provided with a tip portion of a R shape opposing the engaging portion of the torque limiter, and a width thereof in a direction perpendicular to an inserting direction into the engaging portion of the torque limiter is a width capable of being inserted into the engaging portion of the torque limiter.

A paper feeding device includes a paper feeding roller and a separation roller. The paper feeding roller and the separation roller are arranged in a parallel direction. The paper feeding roller and the separation roller interpose a sheet. The paper feeding device includes a paper feeding roller, a separation roller, a shaft, a holder, and a rotation stopping portion. The paper feeding roller is configured to convey the sheet in a conveyance direction. The separation roller is configured to be pressed against the paper feeding roller. The shaft is configured to rotatably support the separation roller via a torque limiter. The holder is configured to include a supporting portion. The supporting portion is provided with a first guide surface and a second guide surface facing each other and extending in the parallel direction. The rotation stopping portion is configured to be attached to the shaft. The rotation stopping portion is configured to be inserted between the first guide surface and the second guide surface. The rotation stopping portion is configured to include a first sliding surface and a second sliding surface. The first sliding surface faces the first guide surface on the paper feeding roller side of the parallel direction and a downstream side of the conveyance direction with respect to a rotation axis of the separation roller. The second sliding surface faces the second guide surface on an opposite side of the paper feeding roller of the parallel direction and an upstream side of the conveyance direction with respect to the rotation axis of the separation roller.

According to one embodiment, a paper feeding device includes a paper feeding roller and a separation roller. The paper feeding roller and the separation roller are arranged in a parallel direction. The paper feeding roller and the separation roller interpose a sheet. The paper feeding device includes a paper feeding roller, a separation roller, a shaft, a holder, and a rotation stopping portion. The paper feeding roller is configured to convey the sheet in a conveyance direction. The separation roller is configured to be pressed against the paper feeding roller. The shaft is configured to rotatably support the separation roller via a torque limiter. The holder is configured to include a supporting portion. The supporting portion is provided with a first guide surface and a second guide surface facing each other and extending in the parallel direction. The rotation stopping portion is configured to be attached to the shaft. The rotation stopping portion is configured to be inserted between the first guide surface and the second guide surface. The rotation stopping portion is configured to include a first sliding surface and a second sliding surface. The first sliding surface faces the first guide surface on the paper feeding roller side of the parallel direction and a downstream side of the conveyance direction with respect to a rotation axis of the separation roller. The second sliding surface faces the second guide surface on an opposite side of the paper feeding roller of the parallel direction and an upstream side of the conveyance direction with respect to the rotation axis of the separation roller.

A medium feeding apparatus includes a pickup roller that feeds a medium from a medium mount section. A support member supports a pickup roller and swings around a swing axis to switch between a feeding position and a non-feeding position. A separation roller separates the medium from other media. A feed roller feeds the medium toward the downstream end. The separation and feed rollers are disposed downstream of the pickup roller. A control section controls a position of the support member. After the pickup roller and the feed roller start rotating, when the control section determines that the separation roller stops rotating or returns the medium by rotating in a reverse direction, based on a detection signal from a rotation sensing section configured to detect rotation of the separation roller, the control section causes the support member to switch from the feeding position to the non-feeding position.

A transport device includes a transport roller, a nip section, and first and second transport path surfaces. The transport roller transports a transport target material sent from an accommodating unit. The nip section nips the transport target material with the transport roller, and prevents multi-feed of the transport target material. The first transport path surface is disposed upstream of the nip section in a transport direction to face a transport roller side of the nip section. The first transport path surface includes a top portion protruding toward the transport roller side beyond a nip line between the transport roller and the nip section. The second transport path surface is disposed downstream of the nip section in the transport direction to face the transport roller side of the nip section. The second transport path surface includes a top portion protruding toward the transport roller side beyond the nip line.

The 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 starting to rotate the pickup roller. When there is a document set on the lift plate at the time when the pickup roller stops, the control unit automatically resumes the feeding in the manual feed mode.

A sheet feeder includes a separation roller, a retard roller, and a return latch. The separation roller rotates in a forward direction to separate a sheet and transport the separated sheet in a sheet transport direction. The retard roller forms, together with the separation roller, a nip point and rotates in a reverse direction to return a sheet in a direction opposite to the sheet transport direction. The return latch moves from a retracted position to a protruding position to return a sheet remaining after separation by the separation roller to a position upstream of the nip point in the sheet transport direction. The return latch, when at the retracted position, is retracted from a sheet transport path and, when at the protruding position, protrudes to the sheet transport path.