GB866831A - Improvements in or relating to photographic copying apparatus - Google Patents

Abstract

866,831. Photographic copying apparatus. RICORD, J. June 12, 1959 [June 12, 1958], No. 18846/58. Class 98(2) A photographic copying apparatus includes a thin sheet of transparent material such as polyethylene which is automatically interposed between the original and the printing material to prevent sticking when these are pressed against a platen for exposure. Fig. 1 shows a cylindrical platen 2 of transparent material such as "Perspex", which contains a mercury vapour tube 6, and to which are secured by the metal binding strip 10 a transparent polyethylene film 8 and an opaque blind 24. These latter are tensioned by spring rollers 12 and 28 respectively. A roller 22 is spring-urged towards the platen 2 so that the printing material 32 which is placed between the blind 24 and the separating film 8, and the original 34 which is placed between the film 8 and the platen 2, are simultaneously caught and wound on to the platen by rotating the cranked handle 20. Means for feeding in and extracting the original and copy may be added according to the prior art. For the repeated copying of a single original, that end of the transparent film 8 not attached to the platen 2 is left free to wrap itself round the platen, which is continuously or intermittently rotated in the same (anti-clockwise) direction, and the blind which serves to press the printing material against the film is in the form of a continuous belt, the feeding-in means for the printing material being so adjusted as to present each piece of printing material at the correct location with respect to the original. If a material such as polythene, which has a "clinging" characteristic, is used, slip of the original is resisted during rotation.