| 摘要 |
PURPOSE:To beforehand prevent the abuse of a light source by judging the time of diagnosis completion with an its own device by a recognizing means and a deciding means, and automatically putting out the light source by a light source control means in accordance with the judgement. CONSTITUTION:Video signals A and B held by a sample and hold circuit are inputted to a differential amplifier 4, differentially amplified, and inputted to a comparator 5 as a differential signal A-B. The comparator 5 generates a HIGH voltage value when a prescribed suitably set allowable difference signal value is exceeded by a difference signal and the LOW voltage value when it is not so. The HIGH or LOW signal is inputted through an interface 6 to a CPU 7 and it is judged which is obtained. A CPU 7 is continued for a prescribed time when the HIGH/LOW decision is suitably set, during the period, the diagnosis completion is judged only concerning the case when only the LOW is continuously inputted and a light source putting-out signal is generated. The light source putting-out signal puts out a light source 9 through the interface 6 and a light source control circuit 8. |
