| 摘要 |
PROBLEM TO BE SOLVED: To raise a manufacturing efficiency and to improve quality by a method wherein a face of a lens of a sensor for detecting a print timing mark is maintained in a clean condition and occurrence of shift in a printing position due to erroneous detection or misdetection is prevented. SOLUTION: A large production printer is equipped with the sensor (1) for detecting the timing mark printed on a recording medium (2). The printer comprises a mechanism (4) for cleaning the lens face by blowing an air to the lens section of the sensor for detecting the timing mark. |
