Patent ID: 7513496

Claim:
A sheet supply device comprising: a device main body; a storage cassette that has a stacking portion capable of moving up and down, on which sheets are stacked, the storage cassette being configured to be pulled out of the device main body; a delivery roller that is provided to be movable up and down and is rotated in a state where the delivery roller is brought into contact with the sheet stacked on the stacking portion, so as to deliver the sheet to a downstream side of a conveying direction thereof; a separation unit that is provided at the downstream side of the conveying direction with respect to the delivery roller; a separation roller that is rotated in a state where the sheet delivered by the delivery roller is interposed between the separation unit and the separation roller, so as to separate and supply the sheets one by one a stacking portion lifting mechanism that lifts the stacking portion while the delivery roller is placed at a delivery position where the delivery roller is brought into contact with the sheet stacked on the stacking portion, on the condition that the delivery roller is moved lower than a predetermined height; a gear mechanism that receives a sheet supply start signal to rotate and control the delivery roller; a delivery roller switching unit that receives the sheet supply start signal to displace the delivery roller from an initial position, where the delivery roller is separated from the stacking portion, to the delivery position and then returns the delivery roller to the initial position while the sheet passes between the separation unit and the separation roller; and a delivery-roller forcibly-displacing unit that forcibly displaces the delivery roller from the initial position to the delivery position, when the storage cassette is attached to the device main body, wherein the delivery roller switching unit comprises a cam, which is interlocked with the gear mechanism and is rotated by a driving force of the gear mechanism, and a moving unit which is brought into contact with the cam and moves the delivery roller between the initial position and the delivery position by a rotation of the cam, the cam is provided to have a clearance with respect to a rotation of the gear mechanism in a rotation direction thereof, and the delivery-roller forcibly-displacing unit comprises a cam rotating unit that rotates the cam through the clearance in an attaching process of the storage cassette so as to move the delivery roller to the delivery position.