| 摘要 |
PURPOSE:To provide ideal feedback control corresponding to actual bone structure by sensing special penetration of sensor regardless of surface ratio of transmitted X-ray residual amount receiving surface of sensor and special part, and conpensating the amount of feedback, in a dental diagnostic panoramic X-ray picture unit. CONSTITUTION:A block 1 is an X-ray tube drive circuit and a feedback control circuit, and a power source 1 and an X-ray tube 3 are connected to the block 1. The residual amount of X-ray transmitted through a patient C and X-ray film 4 is detected with a sensor 5 and feedbacked to the block 1 through a compensating circuit 6 and an adder 7. The sensor 5 is divided into multiple sensor segments 5a-5f to take out each segment output. Since each compensating circuit 6 is connected to each segment output line, even if metal fixing object is small compared with transmitted X-ray residual amount receiving surface and catched with only several sensor segment, sensor segment in region corresponding to metal fixing object is saturated and its output is compensated and added to sensor segment output in other region. Therefore, accuracy of sensor is increased. |
