A roller drive transmission device includes a drive input gear, a drive transmission gear, a roller unit and a ratchet mechanism. When a rotational drive force is input to the drive input gear and the drive transmission gear is slid to a first position, the drive input gear, the drive transmission gear and the roller unit are integrally rotated in a first rotational direction. When the input of the rotational drive force to the drive input gear is cut off and the roller unit is rotated, following a sheet, the drive transmission gear is slid to a second position and the roller unit and the drive transmission gear are decoupled. The ratchet mechanism includes a load adjustment mechanism configured to make a rotational load in the first rotational direction of the drive transmission gear arranged at the second position larger than a movement load in an axial direction.

A drive transmission device includes a rotatable driving member; a rotatable follower member, and an elastic member. The drive transmission device includes a first rotatable member and a second rotatable member. The first rotatable member includes first and second driving portions and a limiting portion. The second rotatable member includes a first driven portion, a second driven portion and a contact portion contacting the limiting portion. The second driving portion is adjacent to the limiting portion with respect to a rotational axis direction of the first rotatable member. The second driven portion is adjacent to the contact portion with respect to a rotational direction of the second rotatable member.

A sheet feeding device includes a feeder, a contact member, a movement restricting member, a moving mechanism, and control circuitry. The feeder is configured to feed a sheet. A leading end of the sheet in a feeding direction is to contact the contact member. The movement restricting member is configured to lock the contact member to restrict movement of the contact member from a contact position where the contact member contacts the sheet. The moving mechanism is configured to move the movement restricting member between a locking position and a lock releasing position. The contact member is configured to take the contact position by gravity or a biasing force of a biasing part. The control circuitry is configured to control the moving mechanism to move the movement restricting member to the lock releasing position and then to the locking position when a feeding operation of the sheet is finished.

A sheet feeding apparatus includes a document tray configured to support a document, a pickup roller configured to feed the sheet supported on the document tray, a separation roller pair configured to separate the sheets fed by the pickup roller one by one, a paddle arranged between the pickup roller and the separation roller pair in a sheet feeding direction and feeding the sheet supported on the document tray, and a drive motor capable of driving the pickup roller, the separation roller pair and the paddle. The paddle feeds the sheet supported on the document tray with a conveyance force weaker than the pickup roller.

A sheet feeding apparatus, including: a stacking unit; a feed unit having a contact portion to be brought into contact with a sheet stacked on the stacking unit and a noncontact portion kept out of contact with the sheet, the feed unit being configured to feed the sheet in a contact state in which the contact portion is in contact with the sheet, and then turn into a noncontact state in which the noncontact portion faces the sheet so as to be kept out of contact with the sheet; a conveyance unit arranged downstream of the feed unit; and a drive unit configured to drive the conveyance unit at a first speed in the contact state and to drive the conveyance unit at a second speed higher than the first speed in the noncontact state.

A recording material feeding device includes a stacking portion, a driving source, a holding member, a torque limiter for limiting transmission of a driving torque from the driving source to the stacking portion in a case that the driving source rotates in a state in which the holding member holds the position of the stacking portion; a storing portion for storing information on a holding state of the holding member; and a controller for controlling the driving source to rotate at a rotational speed slower when the information is information indicating that the holding member holds the position of the stacking portion than when the information is information indicating that the holding member does not hold the position of the stacking portion.

According to an embodiment, a paper-length detection device includes: a moving mechanism and an angle sensor. The moving mechanism supports a magnet. The moving mechanism causes a first regulatory member to move closer to or further from a second regulatory member in accordance with movement of the first regulatory member. The moving mechanism further causes the magnet to rotate in accordance with the movement of the first regulatory member closer to or further from the second regulatory member. The angle sensor faces the magnet and outputs a signal corresponding to an absolute angle with the magnet.

An image reading device includes: a transport unit configured to transport a medium; an emission unit configured to emit an ultrasonic wave in accordance with a driving voltage and a reception unit configured to receive the ultrasonic wave, the emission unit and the reception unit being disposed so that a transport path for the medium transported by the transport unit is interposed therebetween; a reading unit configured to read the medium; and a control unit configured to detect presence or absence of multi-feed of the medium on the basis of a signal received by the reception unit. The image reading device is configured to switch a posture into any of a first posture or a second posture. The first posture is a posture in which the transport path is sloped relative to a mounting surface. The second posture is a posture in which an angle of the transport path relative to the mounting surface is smaller than that in the first posture. The control unit sets a first driving voltage as the driving voltage when the posture is the first posture, and sets a second driving voltage lower than the first driving voltage as the driving voltage when the posture is the second posture.

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 conveyance unit includes a cassette removably attached to an apparatus body and a conveyance interlocked part provided in the apparatus body. The cassette includes a sheet storage part for storing a sheet, a lift plate liftably provided between a lowered position and a raised position and a biasing member for biasing the sheet to contact with a pickup roller. The conveyance interlocked part includes a lever for engaging with the lift plate when the cassette is attached to the apparatus body and being liftable together with the lift plate, a pressing mechanism for pressing the lever downward, and a support member provided between the apparatus body and the lever so as to suppress a drop of the lever disengaged from the lift plate when the cassette is detached from the apparatus body.