| 摘要 |
The invention relates to carrying out a pre-adjustment, before photographing is started, in panoramic X-ray photography using an X-ray device which performs a rotational movement and supports a moving film and an X-ray source. The object is to achieve a correct positioning of the focus in relation to the patient. This is achieved without moving either the patient or the X-ray apparatus, or more precisely, merely by selecting the correct ratio between the film speed and the movement of the X-ray apparatus, instead of mechanical movement. In the apparatus, a viewing member is used, and the correct speed variation curve for the film during the photographing movement is selected on the basis of the position or reading of the viewing member. The film is reeled preferably by means of an electric motor, in which case a sensor can be connected to the sighting member, and the motor is controlled electronically according to the electric output signal of the sensor by means of, for example, a microprocessor.
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