GB888961A - Still picture projector with device for enlargement of sections of the projected image - Google Patents

Abstract

888,961. Projectors. AGFA A.G. Oct. 1, 1958 [Oct. 18, 1957], No. 31355/58. Class 97(1). A projector having an objective 9 has a second objective 11 of shorter focus arranged for alternative passage therethrough of the light beam, with means for holding a transparency in the path in this alternative passage; this means can be moved in its own plane in two directions at right-angles, so that different sections of the transparency may be brought into the light beam for projection on to the same screen of an enlarged image of that particular portion. In the embodiment of Fig. 1, light from lamp 2 passes through condenser' lenses 4, 5, and out through an aperture 6 in the lamp house 1. Here is disposed a transparency in a slider 8. A normal objective 9 throws an image of the whole transparency on a screen. To produce a magnified image of any part of the transparency, the whole objective housing 10 is moved upwards so that the shorter focus lens 11 occupies the objective position. The transparency is transferred to a slider 13, which can be moved in two directions at right-angles, so that any portion can be brought within the light beam for magnified projection. Behind this slider is a masking frame 12, and the slider is so positioned relative to the front wall of the housing 10 that the whole of the light beam 7 passes through it and the objective 11. Thus the enlarged section, as projected, has the same brightness as the whole projected image. In the alternative form of Fig. 3, the two objectives 9 and 11 are both fixed, the light beam being deflected from one path to the other by means of mirrors 14, 16.