Patent ID: 9181053
Filing Date: 2015-11-10
Classification: B41J,B65H,G03G,G06K

Abstract:
1. A paper-feeding device adapted to feed paper to a main body section of an image forming apparatus for printing and outputting paper, the paper-feeding device comprising: a conveyance path for conveying the paper towards the main body section; a paper detection section that has a paper sensor for detecting paper on the conveyance path, and that, on the basis of an output value of the paper sensor, generates a paper detection signal, the paper detection signal being a signal indicating a length of time that elapses after a leading edge of paper arrives at a paper sensor installation location until a trailing edge of the paper that has arrived at the paper sensor installation location passes by the same paper sensor installation location, the paper detection signal being a signal showing the state of conveyance of the paper; and an output section for outputting the paper detection signal to the main body section, the main body section recognizing the state of conveyance of the paper on the basis of the paper detection signal; wherein, during a paper leading edge detection interval that includes an expected point in time of arrival of a paper leading edge at a paper sensor installation location, and during a paper trailing edge detection interval that includes an expected point in time of passage of a paper trailing edge through the paper sensor installation location, the paper detection section allowing the signal level of the paper detection signal that the output section outputs to the main body section to fluctuate on the basis of an actual output value of the paper sensor, and even when an actual output value of the paper sensor varies during conveyance of the paper in a transition interval from the paper leading edge detection interval to the paper trailing edge detection interval, the paper detection section generates, as the paper detection signal which the output section outputs to the main body section, a signal having a level equal to a signal level of the paper detection signal at an end of the paper leading edge detection interval, the paper sensor has a light-emitting section, a light-receiving section, and an actuator that rotates by coming into contact with the paper, when the paper is not present at the paper sensor installation location, the actuator obstructs an optical path between the light-emitting section and the light-receiving section, and when the paper is present at the paper sensor installation location, the actuator rotates not to obstruct the optical path between the light-emitting section and the light-receiving section, whereby the output value of the paper sensor changes depending on whether the paper is present at the paper sensor installation location or not.