| 摘要 |
1338307 Acoustic imaging systems; X-ray apparatus DR JOHANNES HEIDENHAIN 19 April 1971 [6 Nov 1970] 20667/71 Headings H4D and H5R [Also in Division G2] Halo in an image produced by ultrasonic waves or X-rays, by a zone plate ZP is reduced by scanning the object in such a way that at each instant light from a selected area only of the object is passed through the zone plate, and the image of that area is screened to remove at least a major part of the unwanted orders of diffraction, the image being built up sequentially. The selected area may be defined, as shown, by a slit Sp-1, or by an area of illumination. The area may be a single slit, a plurality of slits or a plurality of holes. The image may be scanned by a similar area, the object and image areas being mechanically linked, or the interconnection being by a servo-system controlled photomechanically. |
