A sheet feeding apparatus includes a sheet supporting portion to support a sheet, a feeding member to contact an upper surface of the sheet supported on the sheet supporting portion and feed the sheet, and a drive motor to rotate in a first direction and in a second direction opposite to the first direction. In addition, a lifting mechanism is connected to the drive motor to lift the sheet supporting portion and lower the feeding member in a case where the drive motor rotates in the first direction, and to lower the sheet supporting portion and lift the feeding member in a case where the drive motor rotates in the second direction.

A drive transmission device includes a chassis fixed to an apparatus main body and a driving roller that is driven by a driving source. A belt member transmits rotational force of the driving roller. A tension roller contacts the belt member to apply tension to the belt member. A support member supports the tension roller rotatably and is swingable about a rotational shaft of the chassis. A screw fixes the support member to the chassis at a predetermined position. A retaining member is able to be engaged with the chassis, in which the support member is arranged and fixed between a part of the retaining member and the chassis in an insertion direction of the screw.

An image forming apparatus includes a sheet accommodation unit, a feed roller to feed a sheet along a conveyance path, a first encoder to detect rotation of the feed roller, a conveying roller downstream of the feed roller, a second encoder to detect rotation of the conveying roller, and a motor to drive the feed roller and the conveying roller. A first clutch switches between connecting and disconnecting the paper feed roller to the motor. A second clutch switches between connecting and disconnecting the motor to the conveying roller. A first sensor detects the sheet at a first position. A second sensor detects the sheet at a second position. A control unit controls the motor based on output from the first encoder when the sheet is at the first position and output from the second encoder when the sheet is at the second position.

A drive transmitting device includes a first gear; a second gear in engagement with the first gear; wherein a first tooth which is at least one of teeth of the first gear has a tooth surface contacting a tooth of the second gear, wherein the tooth surface has such a shape that a contact point of the first tooth of the first gear to the tooth of the second gear is in a region of a first gear side with respect to a line of action which is formed by movement of a contact point between a tooth of the second gear and a second tooth of the first gear immediately before the first tooth with respect to a rotational moving direction of the first gear.

A medium feeding apparatus includes a feed roller that feeds media. A separation roller nips the media together with the feed roller to separate it and is rotated in a first direction to feed the media. A motor applies driving torque to the separation roller in a second direction opposite to the first direction. A torque limiter, when rotation torque applied to the separation roller in the first direction exceeds a preset upper torque limit, causes the separation roller to rotate at idle in the first direction independently of the driving torque. During feeding operations, including feeding of first and second media, a controller that controls the motor provides a break period in which the motor is not driven. The break period contains the timing when a rear edge of the first medium leaves a nip position between the feeding and separation rollers.

According to aspects of the present disclosure, there is provided a tray swinging mechanism including a document tray. A movable plate of the document tray is configured to be swingable about a tray shaft and extends leftward. A lifter is configured to be swingable about a lifter shaft extending in the front-rear direction at a position different from the tray shaft. On a lower surface of the movable plate, a cam surface configured to contact a tip of the lifter is formed. The cam surface includes a parallel part parallel to an upper surface of the movable plate and a curved part spaced from the upper surface farther toward a right side. According to a shape of the cam surface, each time the lifter is rotated by a particular angle, the tip of the movable plate moves by a particular amount.

A medium conveying apparatus includes a medium tray, a feed roller, an upper guide, a movement sensor including an arm movably provided by the fed medium on the upper guide and on an upstream side of the feed roller, to generate a movement amount signal corresponding to a movement amount of the arm, a medium sensor to detect a presence of the medium at a predetermined position of the medium tray, a processor to determine whether a feeding abnormality of the medium has occurred based on the movement amount signal, detect a size of the medium placed on the medium tray based on a detection result by the medium sensor, and stop feeding of the medium by the feed roller when the processor determines that the feeding abnormality of the media has occurred and the detected size of the media is equal to or less than a predetermined size.

A document conveying device includes a document tray, a first rotary member, a first motor, a second rotary member, a second motor, a document feed sensor, and a controller. The controller counts a counted time from the time point that the first motor starts to rotate until the leading end of a document reaches the document feed sensor. When the time resulting from subtracting the counted time from a required sheet-to-sheet time interval is longer than the required speed change time, the controller performs deceleration and post-deceleration acceleration for the first motor. The required speed change time is the time required for speed change from the first rotation speed to the second rotation speed.

A media processing device includes: a hopper for supporting a stack of media units (e.g. cards), the hopper including (i) a gate wall configured to abut leading edges of the media units and (ii) an outlet defined at an end of the gate wall; a pick roller at the outlet for engaging an outer one of the media units in the stack and dispensing the outer media unit from the hopper to a media processing path; the gate wall including a flexible gate at the outlet, the flexible gate configured to deflect toward the media processing path responsive to the outer media unit being driven into the flexible gate by the pick roller, wherein the outer media unit deflects when passing by the flexible gate, permitting the outer media unit to be dispensed from the hopper.

A thick document conveying device includes a paper pickup mechanism. The paper pickup mechanism has a pick roller base, a pick roller axle, a pick roller, a switching assembly, a first universal coupling, a driving mechanism, a second universal coupling, a bearing and a gear. The pick roller axle and the pick roller are located in the pick roller base. The switching assembly is located under the pick roller base. The first universal coupling is connected to the pick roller axle. The driving mechanism is sleeved on the first universal coupling. The second universal coupling is connected to the driving mechanism. The bearing is connected to the driving mechanism. The gear is connected to the bearing. As described above, both a thick document and a thin document can be adapted.