GB475000A - Improvements in guiding rollers for strip-shaped records, for use for instance in television and sound film apparatus and optical systems employing such rollers - Google Patents

Abstract

475,000. Sound - film apparatus. ZEISS IKON AKT.-GES. Sept. 8, 1936, No. 24494. Convention date, Oct. 12, 1935. [Class 40 (ii)] [Also in Group XL] Relates to an optical system for television or sound-film apparatus in which a scanning, - reproducing or recording light beam is to be passed through a record carrier as it passes round a guiding roller. According to the invention, at least that portion or region of the guiding roller through which the scanning, reproducing or recording light beam passes comprises a solid body of transparent material, e.g. glass or artificial resin, extending over the whole cross-section of the roller. Fig. 1 shows one form of roller which consists of a cylindrical glass body 1 provided at each end with a glass or metal shoulder 2 for laterally guiding the film 3. The shoulder nearer to the driving mechanism may be made so heavy, e.g. of lead, or so large that it acts as a flywheel. According to modified constructions, Figs. 3-6, (not shown), the central part of the roller may be undercut or the surface of the glass body may be made concave or convex. The roller may also be mounted on a shaft carrying a large and/or heavy flywheel. Fig. 7 shows an optical system in which a line-like slit 13 is illuminated by a light source 11 through the condenser 12, the slit being reproduced on the film 3 by means of the guiding roller 1 acting as a cylindrical lens. The light modulated by the film passes to a photo-cell 14. A slit-like stop 15 secured to the projector housing 16 is arranged as shown between the roller and film so as to cut off the marginal rays. According to a modification of this system, Fig. 9 (not shown), the slit 13 is reproduced on the film 3 by a suitable lens, the guiding roller 1 being arranged behind the film. Fig. 8 shows a further modification of the system shown in Fig. 7, adapted for television film reproduction in which the modulated light issuing from the film 3 is reproduced by lens 20 on the scanning disc 19 and from there on to the photocell 14 by a further lens 17. If desired, the disc 19 may be replaced by some other form of analyzing device, such as rotating mirrors or prisms. The slit 13 may also be replaced by a suitable light source (strip or wire shaped).