| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve paper feeding performance by providing a feeding head sensor in a sheet supporting body, which supports a stack of sheets and can be moved from the operation position to the filling position, and performing control so as to raise the stack height inside the sheet supporting body when sheet stack is reduced. SOLUTION: In a sheet feeder feeding a print sheet to a transfer unit, a feeding head 50 including a light pressure roll 53 touching the uppermost part sheet in a stack 54 is provided, and a sheet in the stack 54 is slightly pushed into a nip constructed of a feeding roll 52 and a speed reducing roll 51. In this process, the light pressure roll 53 is oscillated downward if a stack 54 is emptied, and a sensor flag 150 is turned, and then, a sensor 160 is turned on. On the basis of the output from the sensor 160, an elevator mechanism is operated so as to lift the stack 54, and when the sensor 160 is operated so as to be turned off, the elevator motion is stopped so as to hold a proper stack height.</p> |
