Patent ID: 7850169

Claim:
An automatic original feeder comprising: a rotatable feed roller having a plurality of feed convex portions on a surface of the feed roller; a rotatable separation roller that rotates in an opposite direction to a direction of rotation of the feed roller, the separation roller having a plurality of separation convex portions on a surface of the separation roller, the feed roller and the separation roller being arranged so that the feed convex portions and the separation convex portions engage with each other alternately and feed an original from the engaged portion to a unit on downstream side in a direction of feeding of the original; and a changing member that changes an amount of engagement between the feed roller and the separation roller, wherein the changing member includes an operating unit, wherein a person can operate the operating unit to change the amount, wherein the operating unit includes: a knob unit; a generally fan-shaped abutment unit coupled to the knob unit, wherein the abutment unit has at least two portions having different radii of curvature near the wide edge of the fan; and a rotational shaft that rotatably holds the abutment unit, the wide edge of the fan of the abutment unit abuts on a separation roller shaft of the separation roller, and when the knob unit is operated, the abutment unit rotates with the rotational shaft as center, and the portions having different radii of curvature of the abutment unit push the separation roller shaft away from the feed roller depending on the radii of curvature, wherein the operating unit is provided on one end of the separation roller, an interlocked unit is provided on other end of the separation roller, and the operating unit and the interlocked unit operate in an interlocked manner through a transmission shaft, and further comprising a gear that is integrally fitted to the rotational shaft of the operating unit so that rotation of the operating unit is transmitted to the transmission shaft through the gear.