Patent ID: 8991814
Filing Date: 2015-03-31
Classification: B65H

Abstract:
1. A sheet feed device mounted to an image forming apparatus, comprising: a sheet housing portion that can be inserted in and pulled out from an image forming apparatus main body; a sheet stacking plate that is pivotably supported, at an end portion thereof on an upstream side in a sheet feed direction, to a bottom surface of the sheet housing portion and whose end portion on a downstream side in the sheet feed direction moves up and down between a placement position at which sheets are set and a feed position at which the sheets are fed; a pickup roller that comes in contact with an upper surface of a plurality of sheets stacked on the sheet stacking plate and feeds out, one by one, an uppermost one of the sheets in a direction orthogonal to an insertion direction or a pull-out direction of the sheet housing portion; a feed mechanism that feeds, by using a feed roller disposed on the downstream side in the sheet feed direction with respect to the pickup roller, a sheet fed out by the pickup roller; a first bracket that has a first rotary shaft to which the pickup roller is supported so as to be movable in the insertion direction or the pull-out direction of the sheet housing portion, and is swingably supported to the image forming apparatus main body; an arm that is mounted to the image forming apparatus main body, is movable together with the sheet housing portion in the insertion direction or the pull-out direction in accordance with insertion or pulling out of the sheet housing portion, and makes the first bracket swing between a feed position where, when the sheet housing portion is at a first position at which mounting of the sheet housing portion in the image forming apparatus main body is completed, the arm makes sliding contact with the first bracket, and the pickup roller comes into contact with an upper surface of the sheets housed in the sheet housing portion, and a separation position where, when the sheet housing portion is at a second position to which the sheet housing portion has moved from the first position to a downstream side in the pull-out direction, the pickup roller separates from the upper surface of the sheets; and a feed roller mounting shaft that drives the feed roller to rotate and functions as a swing center of the first bracket, wherein at a time of pulling out the sheet housing portion from the image forming apparatus main body, when the sheet housing portion moves from the first position to the second position, the pickup roller moves on the first rotary shaft, through frictional contact with the upper surface of the sheets, to a position on an upstream side in the insertion direction, at a time of inserting the sheet housing portion in the image forming apparatus main body, when the sheet housing portion moves from the second position to the first position, the pickup roller moves on the first rotary shaft, through frictional contact with the upper surface of the sheets, to a position on a downstream side in the insertion direction, and a movable area of the pickup roller in a direction of the first rotary shaft is equal to or larger than a movement amount of the pickup roller between the position on the upstream side and the position on the downstream side.