| 摘要 |
PURPOSE:To detect jam at a purge processing time by providing a discrimination means discriminating whether the jam can be detected or not based on the output of a sensor. CONSTITUTION:It is detected by the sensor of a paper that the paper is passed when a purge function is actuated. The output of the sensor and the output of a timer are inputted to the discrimination means for detecting the jam. The discrimination means is provided with a function discriminating whether a trigger sensor 13-a and a check sensor 12-b are simultaneously turned on by one sheet of paper or not, a function discriminating whether the sensor 13-b is turned on or not and a function discriminating whether the sensor 13-b is turned off after prescribed time or not. Thus, since the states (a) and (b) shown in a figure can be discriminated, the detection of the jam which cannot be executed before in the state (a) of the purge processing time can be executed. Besides, the detecting probability of the jam is enhanced even when the paper already turning on the sensor is jammed before it does not turn on the next sensor at the starting time of the purge processing. |
