Patent ID: 8517373

Claim:
A sheet feeder, comprising: a housing; a tray which is attached to the housing and on which a sheet to be fed is to be placed; a pickup roller for feeding a sheet on the tray to a predetermined processing position; an arm member supported on the housing to be pivotal in a predetermined range and, on the other hand, rotatably supporting the pickup roller; a rotary shaft supported on the housing to be rotatable about an axis thereof; a coupling member which is a member for coupling the arm member and the rotary shaft and transmits a torque of the rotary shaft to the arm member in a range where a pivotal movement of the arm member is not restricted while not transmitting the torque of the rotary shaft to the arm member in a state where the pivotal movement of the arm member is restricted; a pivoting mechanism for pivoting the arm member via the rotary shaft so that the pickup roller shifts its position between a feeding position where it is in contact with the upper surface of a sheet on the tray and a retracted position spaced upward from the upper surface of the sheet; an input unit for receiving an instruction to perform the feeding operation of a sheet a controller for controlling the operation of the pivoting mechanism; and a detector for detecting placement of a sheet on the tray; wherein the controller controls the arm member to pivot in such a direction that the pickup roller moves toward the retracted position when the detector detects placement of a sheet in a state before starting a feeding operation of the sheet, and thereafter, when the input unit receives instruction to perform the feeding operation, the controller controls the arm member to pivot in such a direction that the pickup roller moves toward the feeding position.