A sheet feeding apparatus includes a sheet stacker, an air blower, a suction feeder, a lifting mechanism, an elevation detection sensor, an elevation detection sensor, a feed detection sensor, and processing circuitry. The air blower blows air to float an uppermost sheet of sheets stacked on the sheet stacker. The processing circuitry drives the lifting mechanism such that the sheet stacker is lifted by an elevation amount determined based on a sheet thickness of the sheets stacked on the sheet stacker, each time a sheet is detected when a number of sheets detected is smaller than a threshold number of sheets, and stops lifting of the sheet stacker until a sheet is not detected when the number of sheets reaches the threshold number of sheets, while repeatedly feeding the uppermost sheet and counting the number of sheets.

A sheet feeding apparatus includes a stacking unit including a plate, a feeding unit including a roller, a holder including a detected member, a drive unit and a controller. The detected member is positioned in a first position where the detected member is not detected by a detector in a case that the feeding unit is new, and is moved from the first position to a second position where the detected member is projected so as to be detected by the detector when the new feeding unit is mounted on the holder and the roller is driven. The controller controls the drive unit to perform up-and-down operation of the plate so that the plate is set to a feedable state of the sheet in a case that the feeding unit is mounted, and determines whether or not the feeding unit is new based on a detection result of the detector.

A sheet feeding apparatus includes a stacking unit including a plate, a feeding unit including a roller, a holder including a detected member, a drive unit and a controller. The detected member is positioned in a first position where the detected member is not detected by a detector in a case that the feeding unit is new, and is moved from the first position to a second position where the detected member is projected so as to be detected by the detector when the new feeding unit is mounted on the holder and the roller is driven. The controller controls the drive unit to perform up-and-down operation of the plate so that the plate is set to a feedable state of the sheet in a case that the feeding unit is mounted, and determines whether or not the feeding unit is new based on a detection result of the detector.

An image reading apparatus, includes: a supply tray; a discharge tray; a conveyance guide; a reading sensor; a discharge unit, which includes a discharge opening to discharge the sheet conveyed by the conveyance guide to the discharge tray and is configured to move from a third position to a fourth as the document supported by the paper feed tray is decreased, the fourth position being higher than the third position; a first drive source, which generates a drive force; a first rotation body, which moves the movable plate by transmitting the drive force from the first drive source to the movable plate; and a second rotation body, which moves the discharge unit by transmitting the drive force from the first drive source to the discharge unit, wherein a diameter of the first rotation body and a diameter of the second rotation body are different from each other.

An image reading apparatus, includes: a supply tray; a discharge tray; a conveyance guide; a reading sensor; a discharge unit, which includes a discharge opening to discharge the sheet conveyed by the conveyance guide to the discharge tray and is configured to move from a third position to a fourth as the document supported by the paper feed tray is decreased, the fourth position being higher than the third position; a first drive source, which generates a drive force; a first rotation body, which moves the movable plate by transmitting the drive force from the first drive source to the movable plate; and a second rotation body, which moves the discharge unit by transmitting the drive force from the first drive source to the discharge unit, wherein a diameter of the first rotation body and a diameter of the second rotation body are different from each other.

A feeder includes: a mount board that moves vertically while allowing sheet-shaped media to be stacked thereon; a transport device that allows an uppermost one of the sheet-shaped media stacked on the mount board to be sucked by a suction portion to transport the uppermost sheet-shaped medium to a transporter and to feed the uppermost sheet-shaped medium to a destination; left and right edge air blowers that blow air to left and right edge portions, when viewed from an upstream side in a transportation direction, of upper ones of the sheet-shaped media stacked; and left and right detectors that are disposed on left and right sides of the suction portion at the same position in the transportation direction, and that individually detect downward or upward bend amounts of left and right edge portions of the uppermost sheet-shaped medium.

A sheet conveyer, having a sheet tray, a tray-driving mechanism, a conveyance guide, a feed roller, a conveyer-driving mechanism, a first sensor, and a controller, is provided. The controller controls the tray-driving mechanism and the conveyer-driving mechanism, during a sequential conveying action, when the first sensor detects an upper-surface level being at a lower limit of a correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding a next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

A sheet conveying device includes a sheet placement table, a sheet discharge table, a conveyance mechanism, raising/lowering mechanism, and a raising/lowering control portion. The sheet discharge table is located below the sheet placement table. The conveyance mechanism conveys a sheet placed on the sheet placement table onto the sheet discharge table via an execution position at which image processing is executed by an image processing portion. The raising/lowering mechanism raises and lowers the sheet placement table. The raising/lowering control portion controls the raising/lowering mechanism in accordance with a clearance that is defined by a height from the sheet on the sheet discharge table to the sheet placement table, so as to maintain the clearance to be equal to or higher than a set value.

A sheet stacker includes a sheet stacking portion, a pair of sheet restrictors, a sheet feeder, and a position detector. A bundle of sheets is stacked on the sheet stacking portion in a stacking direction, and the sheet stacking portion moves in the stacking direction. The pair of sheet restrictors move in a width direction to regulate a position of the bundle of sheets in the width direction. The sheet feeder feeds a top sheet of the bundle of sheets at a sheet feeding position in a sheet feeding direction. The sheet feeding position is disposed at a top of the bundle of sheets in the stacking direction. The position detector is disposed between the pair of sheet restrictors in the width direction and above the sheet feeding position in the stacking direction. The position detector detects a position of the pair of sheet restrictors in the width direction.

There is provided a mechanism for determining whether to perform processing of lifting up a document tray upon detection of a document depending on an active application. A method for controlling an image processing apparatus includes lifting up a document tray upon placement of a document on the document tray, conveying the document placed on the document tray lifted up in the lifting, reading the document conveyed in the conveying, and registering, for an application, whether to lift up the document tray upon the placement of the document on the document tray.