A medium-transporting device includes: a medium-mounting section on which a medium is mounted; a feeding unit that includes a feeding roller and that is configured to be displaced between a contact posture and a separation posture; a first restricting member that is provided downstream of the feeding roller in the transport direction and that is configured to switch between a restriction posture in which the first restricting member restricts movement of the medium and a retreat posture in which the first restricting member permits the movement of the medium; a first motor configured to generate power for rotating the feeding roller; and a second motor configured to generate power for switching a posture of the first restricting member, in which an operation of rotating the feeding roller and an operation of switching the first restricting member from the restriction posture to the retreat posture are performed in parallel.

An image forming apparatus includes a paper feeding cassette, a first conveying unit, a lift mechanism, a motor, a second conveying unit, and a control unit. The controller drives the motor and, if a value indicating a movement amount of the tray moving from when the lift mechanism starts the lifting of the tray until when a position of the top part reaches a first position is a first value, matches a position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a second position and, if the value indicating the movement amount is a second value larger than the first value, matches the position of the first conveying unit, which comes into contact with the top part to thereby rise together with the tray, with a third position lower than the second position.

A sheet feeding apparatus includes an opening/closing unit including a stacking portion, a moving unit including a feed roller and a moving member supporting the feed roller, an urging portion, and a transmitting portion configured to transmit urging force of the urging portion to the moving member. The opening/closing unit is configured to press and move the moving unit in the second direction against the urging force while the opening/closing unit moves from the open position to the closed position. A force that the opening/closing unit receives from the moving unit in a state where the opening/closing unit is at the closed position is smaller than a maximum force that the opening/closing unit receives from the moving unit that is urged in the first direction by the urging portion while the opening/closing unit moves from the open position to the closed position.

A sheet feeding device includes a door movable between an opened position and a closed position relative to an apparatus body, a stacking portion for a sheet, a cover portion configured to be situated at a first position when the door is situated at the opened position and to be situated at a second position when the door is situated at the closed position, and a moving unit including a feeding roller and a moving member supporting the feeding roller. The moving member is movable with respect to the stacking portion in a first direction in which the feeding roller comes close to the stacking portion and in a second direction which is opposite to the first direction. In a state in which the cover portion is situated at the first position, the moving unit is situated between the cover portion and the door.

An auto-adjusting separation mechanism, comprising: a bracket with at least one side arm, a sensor module arranged on the side arm, a rotary shaft arranged at the front end of the bracket; a separation roller set pivotally arranged on the rotary shaft, a sensor wheel arranged to couple with the sensor module, and a torque limiter arranged at the front end of the bracket; wherein, by monitoring the rotation of the sensor wheel with the sensor module, the separating force of the separation roller set is adjustable via a microcontrollers which is capable to adjust the transmission gear set.

A power transmission apparatus includes a drive source, a power transmission switching section configured to switch between a transmission state in which power of the drive source is transmitted to a driven section and a non-transmission state in which power of the drive source is not transmitted to the driven section, a load switching section configured to switch between a first load state, which is a load while the driven section is driven, and a second load state, which is a load smaller than the load of the first load state, and a control section, wherein the control section switches the power transmission switching section from the non-transmission state to the transmission state while the load is in the second load state, and then uses the load switching section to switch the load from the second load state to the first load state.

A sheet conveying device includes a pair of rollers, a biasing member, a guide member, a biasing support, and a biasing force changer. The pair of rollers includes a first roller and a second roller disposed in contact with the first roller. The pair of rollers is configured to hold a sheet between the first roller and the second roller. The biasing member is configured to bias the first roller toward the second roller. The biasing support is configured to support the biasing member and has a guide target member configured to slide along the guide member to move the biasing support. The biasing force changer is configured to change a biasing force of the biasing member along with movement of the biasing support. The guide target member has a portion projecting into a sheet conveyance passage through which the sheet is conveyed by the pair of rollers.

A drive unit includes a drive source and a driving force transmitter that includes a plurality of rotators, an endless belt stretched by the plurality of rotators, a pressing member to press the endless belt, a first support shaft, a first link member to hold the pressing member, a second support shaft, a second link member to press the first link member, a biasing member to bias the second link member. A relation of L1 to L2 satisfies L1>L2, where L1 denotes a distance between the second support shaft and a biasing position and L2 denotes a distance between the second support shaft and a first pressing position. A relation of L3 to L4 satisfies L3>L4, where L3 denotes a distance between the first support shaft and the pressing position and L4 denotes a distance between the first support shaft and a second pressing position.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

A document feeder includes a device body, and an opening and closing cover which is provided to be openable and closable with respect to the device body, and including a paper feed roller and a paper feed roller drive shaft on the device body. The document feeder includes a guide member, which is mounted rotatably to the paper feed roller drive shaft on an outer side of the paper feed roller in a roller axis direction thereof. The guide member guides a document being conveyed, in a state where the opening and closing cover is closed, by being opposed to the paper feed roller drive shaft in a predetermined orientation.