A sheet conveyance apparatus includes a drive transmission mechanism configured to transmit a driving force from a driving source to a rotary conveyance member. The drive transmission mechanism includes a shaft, a first rotary member supported on the shaft and configured to rotate by being driven by the driving source, a second rotary member supported on the shaft and configured to rotate the rotary conveyance member, a drive transmission member provided movably in an axial direction of the shaft, and configured to transmit the driving force between the first rotary member and the second rotary member, and a moving unit configured to move the drive transmission member to a transmission position and a release position. The drive transmission member engages the first and second rotary members with each other at the transmission position, and releases engagement of the first and second rotary members at the release position.

A sheet conveyance apparatus includes a drive transmission mechanism configured to transmit a driving force from a driving source to a rotary conveyance member. The drive transmission mechanism includes a shaft, a first rotary member supported on the shaft and configured to rotate by being driven by the driving source, a second rotary member supported on the shaft and configured to rotate the rotary conveyance member, a drive transmission member provided movably in an axial direction of the shaft, and configured to transmit the driving force between the first rotary member and the second rotary member, and a moving unit configured to move the drive transmission member to a transmission position and a release position. The drive transmission member engages the first and second rotary members with each other at the transmission position, and releases engagement of the first and second rotary members at the release position.

A sheet material feeding apparatus includes: a cassette configured to internally contain a sheet material; a push-up plate that is mounted on an inner bottom surface of the cassette and that is a plate on top surface of which the sheet material is mounted; a push-up plate displacement mechanism configured to include push-up plate biasing members and to change a posture of the push-up plate using a biasing force of one of the push-up plate biasing members; a width regulating member configured to be displaced in a width direction intersecting with a feeding direction and to regulate a position of the sheet material; and a biasing member selecting mechanism that includes a switching unit configured to switch application and release-application of the biasing force of one of the push-up plate biasing members to a posture change of the push-up plate, in interlocking with displacement of the width regulating member.

A sheet material feeding device includes: a housing; a cassette configured to internally house a sheet material, and capable of being pulled out of the housing and housed into the housing; a rear-end regulating member provided inside the cassette and configured to regulate a position of an upstream end of the sheet material in a sheet material feeding direction; a rear-end displacing member supported by the rear-end regulating member and configured to swing along the sheet material feeding direction; a sliding member provided for the cassette, having an engagement part to be engaged with the rear-end displacing member, and configured to slide toward a downstream side in the sheet material feeding direction to displace the rear-end displacing member toward the downstream side in the sheet material feeding direction; and a first energizing member configured to energize the sliding member toward an upstream side in the sheet material feeding direction.

Examples relating to determining stack height in imaging devices are described herein. According to one example, an imaging device includes an input roller assembly to transport a print medium towards an image-forming assembly of the imaging device. The input roller assembly can include a pinch roller for drawing the print medium from a media stack. The imaging device further includes a pressure plate movably coupled to a body portion of the imaging device and biased towards the pinch roller. The pressure plate may hold the media stack between itself and the pinch roller and is movable by a first distance from a neutral position when the media stack is there between. The first distance is measured from a fixed point to a measurement region on the pressure plate and can indicate an instantaneous stack height of the media stack.

Examples relating to determining stack height in imaging devices are described herein. According to one example, an imaging device includes an input roller assembly to transport a print medium towards an image-forming assembly of the imaging device. The input roller assembly can include a pinch roller for drawing the print medium from a media stack. The imaging device further includes a pressure plate movably coupled to a body portion of the imaging device and biased towards the pinch roller. The pressure plate may hold the media stack between itself and the pinch roller and is movable by a first distance from a neutral position when the media stack is there between. The first distance is measured from a fixed point to a measurement region on the pressure plate and can indicate an instantaneous stack height of the media stack.

An image forming apparatus and roller separation device are provided. The image forming apparatus including a main body having a print unit, a first paper feeding unit containing print paper and insertable in or pullable from the main body, a feed roller in the main body feeding the print paper from the first paper feeding unit to the print unit and comprising a driven roller contacting a driving roller, an elastic member applying an elastic force to the driven roller in a direction to contact the driving roller, a handle member in the main body movable to a first position and a second position, and a separation member connected to the handle member and switched to a normal position separated from the driven roller and a separation position separating the driven roller from the driving roller.

An image forming apparatus and roller separation device are provided. The image forming apparatus including a main body having a print unit, a first paper feeding unit containing print paper and insertable in or pullable from the main body, a feed roller in the main body feeding the print paper from the first paper feeding unit to the print unit and comprising a driven roller contacting a driving roller, an elastic member applying an elastic force to the driven roller in a direction to contact the driving roller, a handle member in the main body movable to a first position and a second position, and a separation member connected to the handle member and switched to a normal position separated from the driven roller and a separation position separating the driven roller from the driving roller.

A sheet stacking portion for stacking sheets is provided on a cover openably/closably supported on an apparatus body. The sheet stacking portion is guided between a first position and a second position along the cover by a guide portion. A sheet staked on the sheet stacking portion at the first position is fed via a sheet feeding portion. The sheet stacking portion is moved in conjunction with a cover closing action from the first position to the second position not interfering with the sheet feeding portion via a moving portion. A first end side of the moving portion is turnably supported on the apparatus body and a second end side is connected to the sheet stacking portion.

A sheet stacking portion for stacking sheets is provided on a cover openably/closably supported on an apparatus body. The sheet stacking portion is guided between a first position and a second position along the cover by a guide portion. A sheet staked on the sheet stacking portion at the first position is fed via a sheet feeding portion. The sheet stacking portion is moved in conjunction with a cover closing action from the first position to the second position not interfering with the sheet feeding portion via a moving portion. A first end side of the moving portion is turnably supported on the apparatus body and a second end side is connected to the sheet stacking portion.