| 摘要 |
PROBLEM TO BE SOLVED: To detect paper stably by providing a control means which operates a cleaning means in accordance with a light receive amount of a light- intercepting element of an optical detection means after the discharge operation of recording medium when the light-intercepting amount is below a predetermined reference value. SOLUTION: As a result of paper detection by a validation sensor 11, it is judged that paper powders 20 exist on an optical path of the validation sensor 11 when an output level of the validation sensor 11 is below a reference value, and cleaning of the validation sensor 11 is done by a cleaning device 14. The cleaning device 14 is driven by driving a solenoid 13 of a platen opening and closing means. When the cleaning is done, it is preferable that the paper powders 20 are securely removed by driving and controlling the solenoid 13 several times. |
