| 摘要 |
PROBLEM TO BE SOLVED: To control driving of a paper feeding tray by optimal lifting operation in response to weight of paper placed on the paper feeding tray in positioning operation. SOLUTION: This paper feeder includes: an upper limit sensor 60 for detecting that the uppermost paper upper surface in the paper placed on the paper feeding tray 11 is positioned in a paper feeding starting position; an upper limit sensor processing part 110 for calculating a paper detecting time t by the upper limit sensor 60 in the positioning operation for moving the paper up to the paper feeding starting position when starting printing and outputting a comparing result by a comparison between the detected paper detecting time t and a preset paper detecting time discriminating threshold value T as detecting time discriminating information; and a control processing part 140 for controlling driving of a paper feeding tray driving part 13 by intermittent driving or continuous driving by switching and controlling ON/OFF of PWM (Pulse Width Modulation) control being a driving control method of the paper feeding tray driving part 13 based on the detecting time discriminating information from the upper limit sensor processing part 110 when performing follow-up operation in printing processing. COPYRIGHT: (C)2011,JPO&INPIT |
