| 摘要 |
This device has a pinhole camera, a collimator (60, 62), means for closing off or obturating the camera, a luminescent or phosphor screen, a camera optically coupled to the screen and is characterized in that the collimator comprises two half-collimators (60, 62) rotatable about a common rotation axis (AA'), each half-collimator comprising: - a large (64, 66) and a small (68, 70) aperture, the small and large apertures being centred on the common rotation axis and being located in a planar surface (P, P') perpendicular to said axis, - a circular arc spotfacing (72, 74) of angle .alpha. centred on the common rotation axis (AA') and issuing into the plane defined by the small aperture, - a pin or peg (76, 78) which can be incorporated into the circular arc spotfacing of the other half-collimator, and in that the obturating means are in the form of a lamella (80) located between the two planar surfaces (P, P') and extending from one pin to the other.
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