Sheet feeding apparatus and image forming apparatus with sheet feeding apparatus therein
First Claim
Patent Images
1. A sheet feeding apparatus comprising:
- a sheet stack tray on which sheets are stacked;
a drive unit configured to move said sheet stack tray up;
a feeding unit configured to feed an uppermost sheet of the sheets stacked on said sheet stack tray at a feeding position;
a first sensor configured to sense the uppermost sheet of the sheets stacked on said sheet stack tray or said sheet stack tray at the feeding position;
a second sensor configured to sense the uppermost sheet of the sheets stacked on said sheet stack tray at a position which is lower than the feeding position; and
a control part configured to effect a temporary stop or a speed reduction of said drive unit according to sensing of the second sensor while the drive unit moves said sheet stack tray up, and after the temporary stop or the speed reduction, said control part controls said drive unit to move said sheet stacking tray up until the first sensor detects the uppermost sheet at the feeding position,wherein the control part determines that a sheet is not present on the sheet stack tray in a case where the second sensor does not sense the uppermost sheet and the first sensor detects the sheet stack tray.
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Abstract
The sheet feeding apparatus includes a sheet stack tray on which sheets to be fed are stacked, a drive motor for moving up the sheet stack tray, a detection sensor for detecting the position of an uppermost sheet stacked on the sheet stack tray, and a control part for controlling the function of the drive motor, wherein, when the detection sensor detects that the uppermost sheet reaches a predetermined height while the drive motor executes a drive so as to move up the sheet stack tray, the control part tentatively stops or decelerates the drive motor and thereafter drives the drive motor so as to move up the sheet stacked on the sheet stack tray to a feed position.
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Citations
6 Claims
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1. A sheet feeding apparatus comprising:
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a sheet stack tray on which sheets are stacked; a drive unit configured to move said sheet stack tray up; a feeding unit configured to feed an uppermost sheet of the sheets stacked on said sheet stack tray at a feeding position; a first sensor configured to sense the uppermost sheet of the sheets stacked on said sheet stack tray or said sheet stack tray at the feeding position; a second sensor configured to sense the uppermost sheet of the sheets stacked on said sheet stack tray at a position which is lower than the feeding position; and a control part configured to effect a temporary stop or a speed reduction of said drive unit according to sensing of the second sensor while the drive unit moves said sheet stack tray up, and after the temporary stop or the speed reduction, said control part controls said drive unit to move said sheet stacking tray up until the first sensor detects the uppermost sheet at the feeding position, wherein the control part determines that a sheet is not present on the sheet stack tray in a case where the second sensor does not sense the uppermost sheet and the first sensor detects the sheet stack tray. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification