GB750271A - Improvements in or relating to apparatus for photographing printing forms and like copy material - Google Patents

Abstract

750,271. Photographic apparatus. LUDLOW TYPOGRAPH CO. Aug. 29,1952, No. 13612/54. Divided out of 750,218, Class 98 (1). For photographing relief printing forms to obtain a positive or negative for use in preparing a gravure or other photo-mechanical printing surface as by the method described in Specification-750,218, the apparatus comprises, Fig. 2, a copy board 13 for supporting the relief printing form in the optical axis 27 of a camera 11 which is provided with ground glass focusing plate or sensitive material at position 25, and with a light source 15 surrounding the camera lens 19, the light source being of greater area than the working surface of the copy board 13 and being arranged for rotation during exposure by means of motor 47 and driving belt 49. The light source may have lamps 33 disposed in greater frequency when further from the lens as shown in Fig. 5. An alternative light source (Fig. 6, not shown) is a rectangular bank of fluorescent lamps surrounding the lens and arranged to be reciprocated a short distance during exposure; and in a further arrangement indicated diagrammatically (Fig. 7, not shown) a transparent mirror is interposed at 45 degrees between the light source and copy board, whereby light through the mirror is reflected back thereby to give a laterally reversed image on sensitive material placed at right angles to the light source.