A sheet feeding apparatus includes a sheet supporting unit, a sheet feed unit, an air separation unit configured to separate the uppermost sheet by blowing the air onto a side surface of the sheet bundle supported by the sheet supporting unit, a velocity detection unit configured to detect actual velocity of a sheet fed by the sheet feed unit, a drive load detection unit configured to detect an actual drive load for feeding the sheet by the sheet feed unit, and a controller configured to control the sheet feed unit and the air separation unit. In a case where the sheet is fed by the sheet feed unit, the controller is configured to control an operation of the air separation unit depending on the actual velocity of the sheet detected by the velocity detection unit and the actual drive load detected by the drive load detection unit.

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.

A paper sheet processing device includes: an accommodating part that accommodates a paper sheet; and a sliding stage part that is provided within the accommodating part and supports the paper sheet accommodated within the accommodating part, the sliding stage part sliding with respect to the accommodating part to cause a portion of the sliding stage part to protrude to outside of the accommodating part, and the sliding stage part sliding with respect to the accommodating part to push the paper sheet to the outside of the accommodating part and cause a leading end of the paper sheet to protrude to the outside of the accommodating part.

A sheet conveying device includes a sheet tray on which one or more sheets are placed, a pickup roller by which a sheet is picked up from the sheet tray, and an elevating mechanism. The elevating mechanism includes a shaft rotated by a motor, and a cam attached to the shaft and rotated together with the shaft to raise and lower the sheet tray with respect to the pickup roller. The sheet conveying device further includes a load applying mechanism contacting the shaft to apply a load thereto.

A sheet conveying device includes a sheet tray on which one or more sheets are placed, a pickup roller by which a sheet is picked up from the sheet tray, and an elevating mechanism. The elevating mechanism includes a shaft rotated by a motor, and a cam attached to the shaft and rotated together with the shaft to raise and lower the sheet tray with respect to the pickup roller. The sheet conveying device further includes a load applying mechanism contacting the shaft to apply a load thereto.

A sheet feeding apparatus includes an apparatus body including an abutting portion, an opening/closing member, a stacking member, a feeding member, a conveyance unit including a separation portion, and a guide configured to guide a leading edge of the sheet conveyed by the feeding member from the stacking member toward the separation portion. The guide includes a supported portion supported pivotably by the apparatus body and an abutted portion configured to be abutted against the abutting portion. The guide is configured to move in interrelation with an operation of closing the opening/closing member and to be positioned inside the apparatus body with respect to the opening/closing member in the closed state of the opening/closing member. In the opened state of the opening/closing member, the guide is configured to be restricted from pivoting by the abutted portion being abutted against the abutting portion.

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.

An image forming apparatus including: a sheet feeding roller which feeds a sheet accumulated on a tray; and a hardware processor which: detects a movement speed of the sheet currently fed by the sheet feeding roller; and calculates a difference amount between the movement speed and a first reference speed, and determines a life of the sheet feeding roller based on the difference amount, wherein the hardware processor determines whether or not to use the movement speed of a first sheet for life determination based on a relationship between the movement speed of the first sheet and the movement speed of a sheet fed before the first sheet, and if the hardware processor determines not to use the movement speed of the first sheet for the life determination, the hardware processor calculates the difference amount by excluding the movement speed of the first sheet.

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.