GB536036A - Improvements in and relating to apparatus for photographic copying - Google Patents

Abstract

536,036. Photographic copying-apparatus. HALL, J. V. Dec. 6, 1939, No. 31626. Convention date, Jan. 5. [Class 98 (i)] A photographic copying apparatus comprises a lens with means to support it in relation to the object to be copied, masking means of adjustable area in alignment with the lens, and a film carrier movably mounted on the masking means so that it may be moved over the opening in the mask to expose the film, or away from it to allow of focusing and adjustment of the opening in the mask. The apparatus shown comprises a base 10 with a recess 11 in which the matter to be copied is inserted and pressed against a transparent cover plate 13, the base carrying a pair of pillars 15 on which a crosshead 16 carrying the camera apparatus 18, is vertically adjustable. The apparatus 18 includes a housing 21 for the objective and a housing 19 for a lamp 20 used for adjusting and focusing purposes. In the space between the housings 19, 21 is an adjustable masking device shown in Fig. 4 with its cover plate removed. This comprises two pairs of slides 32, 33 adapted to be adjusted in slideways 31 so as to mask off a portion of the width or length of the exposure opening 40 in accordance with the proportions of the matter to be copied. The slides are operated by a rotary disc 28 with an operating lever 29, pins 34, 36 on the slides engaging cam grooves in the disc of such form that movement of the lever to the right of its central position moves the slides 33 inwardly to reduce the length of the opening, whilst movement to the left moves the slides 32 to reduce the width. During this adjustment, the film carrier 44 extending between the film spool compartments 47 is moved forwardly against stops 50, so that a frame 54 secured to it and carrying a transparency with a focusing spot 53 in the horizontal plane of the film coincides with the opening 40. Illumination of the lamp 20 causes the mask opening and the focusing spot to be projected on to the copy, so that the necessary masking and focusing adjustments may be made. The film carrier is then moved backwardly against stops 51, when an exposure window on its underside registers with the mask opening 40.