Patent ID: 9670019
Date: 2017-06-06
CPC Classifications: B65H,G03G

Claim:
1. A paper feed device comprising: a paper tray on which one or more sheets of paper are set; a set-state sensor including an actuator which rotates a predetermined rotational angle and returns to a reference position by an urging force of an urging member when no document is set and arranged at a position where any set paper can be detected, the actuator being configured to move when paper is set, the set-state sensor outputting different values depending on the position of the actuator; a paper feed unit configured to feed the paper set on the paper tray by rotating a feeding rotary body; a transport unit configured to transport the paper fed from the paper feed unit; a paper feed sensor configured to detect that the paper has been sent out of the paper tray by the paper feed operation of the paper feed unit; and a control unit configured to detect the presence or absence of paper on the paper tray on the basis of the magnitude of an output value from the set-state sensor, detect whether the paper has been fed by the paper feed operation on the basis of an output from the paper feed sensor, check the output value from the set-state sensor when the paper feed sensor has detected passing of a tail end of the paper, and cause the paper feed unit to perform the paper feed operation for a next page when determining that there is the paper, wherein when the control unit detects on the basis of the output from the paper feed sensor that no paper has been fed, the control unit causes the paper feed unit to perform retry processing of repeating intermittent paper feed of stopping and then resuming the paper feed operation a prescribed number of times until the paper feed sensor detects paper, the control unit checks an output from the set-state sensor each time before the start of the intermittent paper feed and, in the case where no paper feed is detected even after the intermittent paper feed was performed the prescribed number of times, the control unit determines that a non-feed jam has occurred, and in the case where it is detected that there is no paper on the paper tray before the number of repetition of the intermittent paper feed reaches the prescribed number of times, the control unit causes the paper feed unit to terminate the retry processing and determines that, with no paper on the paper tray, it is not the non-feed jam.