Patent ID: 8523173

Claim:
A sheet feeder comprising: a sheet containing portion that has a sheet stacking portion to be lifted and lowered and that is detachably attached to an apparatus body; a feed roller that is located above the sheet stacking portion in a manner movable in a vertical direction so as to feed sheets stacked on the sheet stacking portion; a feed roller biasing portion that applies a force to the feed roller in a direction in which the feed roller is brought into press-contact with the sheets, stacked on the sheet stacking portion; a separation member that is brought into press-contact with the feed roller so as to separate the sheets fed by the feed roller one by one; a separating portion that separates the separation member from the feed roller in association with a pulling operation of the sheet containing portion from the apparatus body; a lifting and lowering portion that lifts the sheet stacking portion in such a manner that an upper surface of the sheet is located at a predetermined height during a sheet feeding operation whereas lowers the sheet stacking portion in association with the pulling operation of the sheet containing portion when the sheet containing portion is pulled out of the apparatus body; and a restricting portion that restricts the feed roller being applied a force by the feed roller biasing portion from following the separation member separated from the feed roller and the lowering sheet stacking portion when the sheet containing portion is pulled out of the apparatus body.