| 摘要 |
The invention relates to a method used in the panoramic X-ray photography of a patient's set of teeth and a device for carrying out constant enlargement also in those spots (21) of the dental arch where the X-ray beam (12) is not perpendicular to the tangent (23) of the dental arch (20). Constant enlargement is achieved by selecting, on the film (13), a speed profile which follows the formula: vf=((A+B/A)xv1x1/ cos (b), where vf is the speed of the film, v1 is a component of the propagation speed of the intersection of the X-ray beam and the spot to be photographed which is perpendicular to the X-ray beam, A is the distance between the focus of the X-ray source and the spot to be photographed, B is the distance between the spot to be photographed and the film, and b is the angle between the tangent (23) of the spot in question of the dental arch and the normal (22) of the X-ray beam.
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