| 摘要 |
Apparatus for panoramic radiography of a curved surface such as the dental arch, comprising an oscillating arm (17) that sustains an X-ray source (18) at one end and a film-holder at the other end. In the apparatus of the invention the arm (17) is mounted idle on a shaft (16), called tertiary shaft, that a mechanism forces to move according to an elliptic trajectory adapted to the jaw of the patient. The arm is further driven rotatingly around the tertiary shaft by a mechanism (pin 11, groove 24) connected to the primary shaft (4) of the mechanism generating the ellipse so as to be always orthogonal to the ellipse. The film (19) is driven in such a manner that it avoids the deformations of the panoramic projection; the ellipse is described at variable speed to compensate for the absorption due to the cervical column.
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