| 摘要 |
PROBLEM TO BE SOLVED: To prevent such an abnormal control action that an exposure lamp is fully turned on from being executed and to enhance the reliability of an equipment by turning off the trigger of a switching means in prescribed timing that an identical zero cross signal to the zero cross signal becoming the reference of trigger-on in timing being slower than the prescribed timing is regarded as a reference or corresponding to quicker one of the next zero-cross signal. SOLUTION: When a prescribed timer value is counted by a started phase angle timer(S3), phase angle interruption inputted(b). When the phase angle interruption is inputted, a trigger output is turned on if the turning-on of the exposure lamp is instructed(S12). When the trigger output is turned on, the switching means is turned on in an instant and the exposure lamp is energized. At this time, a voltage impressed on the lamp is sampled by a detection circuit(S 13) and the next phase angle timer value is calculated(S14). Then, a cycle timer is actuated in addition to the phase angle timer and cycle interruption is generated when a previously decided value is counted by the cycle timer. |
