X-RAY IMAGE DETECTOR FOR MEDICAL TREATMENT WITH AUTOMATIC EXPOSING FUNCTION

摘要

PURPOSE:To decrease or remove the unnecessary irradiation with X-rays and to obtain an X-ray image having good sharpness and resolution by disposing an X-ray intensity detecting element in proximity to an X-ray phosphor on a ceramic substrate for fixing a CCD element and controlling the time for irradiation with the X-rays with X-ray intensity output. CONSTITUTION:The X-ray intensity detecting element 6 is fixed in line up with the transverse direction of the wafer of the CCD element 4 in proximity to the phosphor 2 of the X-ray image sensor to the ceramic substrate 5 and the X-rays transmitted near the desired tooth part transmit the X-ray phosphor 61 so that the phosphor emits light. The electric signal proportional to the light intensity is generated by a photodetecting element 62 and is transmitted to a controller 8 on the outside of the device by a cable 7 contg. lead wires. The anode current of an X-ray tube is shut off when the transmitted X-ray quantity which is detected by the X-ray intensity detecting element 6 and is calculated by integration with the time for the irradiation with the X-rays in an integrating circuit attains equal to the set transmitted X-ray quantity. The image signal accumulated in the CCD element or the memory element in the controller 8 is reproduced by a monitor 81 at the point of this time.