Abstract: A medical X-ray image detecting device wherein the fluorescent surface of a narrow belt-shaped X-ray fluorescen plate which emits light at the time of irradiation of X-ray through a slit is divided to rectangular units, optical fiber bundles are distributed alternately right and left and arranged vertically, the one end surface of each optical fiber bundle is attached to one of the divided fluorescent surface unit, the other end surface of each optical fiber bundle is attached to the image pickup surface of a solid-state image pickup device to make image formation possible, and the solid-state image pickup device is disposed behind an X-ray shielding member by which the slit is formed.

Abstract: A patient positioning device in a medical panorama X-ray photographing apparatus in which after data of the relative position of the subject to the X-ray photographing apparatus supplied from a sensor is compared with data of the relative position of a tomographic zone to the X-ray photographing apparatus thus to produce comparison data which is in turn transmitted to a drive circuit, a tomograph forming assembly and/or the subject is moved from coinciding with each other. The device further includes a comparing arithmetic circuit in which the detected position data of the subject and position data of the tomographic zone are arithmetically compared in order to improve operatability and positioning accuracy. The device furthermore includes a sensor which is adjustable for angular and vertical setting with the use of sensing position changing means in order to improve adaptability to individualities of the subject.

Abstract: A pre-ignition type X-ray apparatus including a mode changeover switch which changes a pre-heat mode to an X-ray irradiation mode and vice versa, a tube current control circuit for feedback control of the X-ray tube's filament heating current to a target value, and pre-heat control circuit for controlling the filament heating current in the pre-heat mode to a target value lower than the target value in the X-ray irradiation mode. The pre-heat control circuit includes a differential amplifier which amplifies the difference between the detected voltage corresponding to a source voltage and the reference voltage determining the lower target value, so that the control signal is outputted from the differential amplifier.

Abstract: An automatic exposure device for obtaining X-ray pictures with superior quality and constant contrast by feedback of both tube voltage and tube current according to the residual X-ray dose which penetrates the body of a patient. This device is further characterized in that the feedback control is compensatingly done according to the changes in the tube voltage and tube current caused by fluctuations of the power supply.

Abstract: A dental panoramic X-ray photographing apparatus including a rotary arm having an X-ray generator disposed at one end thereof and having an X-ray film cassette holder disposed at the other end thereof in an opposite relation with each other around an object disposed therebetween. The apparatus comprises a first control means for controlling the rotation speed of the arm by detecting the rotation position of the arm and a second control means for controlling the tube voltage and the tube current of the X-ray generator by comparing the feeding speed of the X-ray film at the X-ray film cassette holder with the residual X-ray dose which has passed the object and the film, whereby it is intended to provide the simultaneous control function of the tube voltage and the tube current, the function for automatic exposure throughout the entire teeth and the function for compensating for the density of the central portion of the front tooth region of a dental arch at the same time.

Abstract: The present invention relates to a medical X-ray radiation power supply apparatus wherein a DC-operated switching circuit is connected at the primary side of a high voltage transformer, and a comparator circuit compares the voltage predetermined by a tube voltage setting circuit with an actual tube voltage detected by a tube voltage detector circuit, then the gain of a comparison voltage is raised so that the actual tube voltage can quickly reach the predetermined tube voltage value, thereby tube voltage errors, which are caused by short photographing time in a medical or breast X-ray photographing apparatus, are eliminated.

Abstract: The device makes it possible to expose a patient to an approximate flux of X-ray beams without the interference of light and X-rays from outside in the X-rays from an X-ray's generation source (X-ray tube) during irradiation of the X-rays upon the patient and to detect the dose of X-rays in the form of an electrical signal. In such a process, it uses the signal as a detection medium to a normal dose of X-rays so as to permit the irradiation of an exact and normal amount of X-rays upon the affected part.

Abstract: A device for controlling the amount of X-ray irradiation in an X-ray photographing apparatus wherein the dose of X-rays actually administered from an X-ray tube to a patient is determined or measured in an X-ray irradiation amount measuring circuit. The measured value is compared with a set point of X-ray irradiation amount. When the measured value is in agreement with the set point, the operation of the X-ray tube is inactivated.