Patent GB-668623-A (GB)
Title: Method and apparatus for photographing documents on photosensitive film
IPC: G03B27/68
Filed: 1947-06-12
Abstract: 668,623. Photographic copying apparatus; optical systems. DIEBOLD, Inc. June 12, 1947 [April 30, 1946], No. 15526/47. Classes 97 (i) and 98 (i). A method of photographing documents on continuously movable light-sensitive film includes continuously moving the documents through the illuminated field of view of a lens and projecting the light reflected from the documents through a slit having its longitudinal extent normal to the direction of movement of said. documents and through said lens onto the film and is characterized in that the ratio of the rate of movement of the film to that of the documents is less than the ratio of the distance from the film to the optical centre of the lens to the distance from the documents to said optical centre. As shown in Fig. 4, documents 24, 24a, 24b are illuminated by sources 25 and are continuously carried, by an endless belt 16 entrained around rollers 17, 18, across the field of view of a camera lens 28, which is shielded by a hood 45 from extraneous light and between which and the documents is a mask 22 having a slit 23 therein. Roller 18 is driven through reduction gearing 20 by an electric motor 19 which is energized from the same current source as a motor 41 which, through reduction gearing 40, drives a drum 32 for moving light-sensitive film, in the direction opposite to that of the documents and at a slower rate than that of the documents, from a supply reel 31 to a take-up reel 30. Latent images of the documents, which are shrunk in the direction of the film length, are thus formed in the film as it passes around a drum 34. This apparatus may be used for projecting images of a negative film so formed on to a sensitized film carried by the endless belt 16 by making drum 34 transparent and providing a prism in its interior to direct light therethrough from an external source. Specification 390,503 is referred to. The Specification as open to inspection under Sect. 91 describes also an apparatus whereby images of documents which have been restored to their normal proportions and perhaps enlarged may be reproduced on a screen and also photographed. In this apparatus, Fig. 8 (Cancelled), a negative 60 bearing images formed with the use of the camera of Fig. 1, is continuously moved through a transparent gate 59 and illuminated by light reflected from an apertured lamp housing 52. The light, after passing through the negative, is directed downwardly on to a stainless steel sheet 63 which is mounted on a stand 64 and may be flexed by thumbscrews 65, 66 to form a convex cylindrical mirror, which directs the light on to a plane mirror 67 and then on to the screen 51. The support of the plane mirror 67 also carries a reflecting sheet 68 which may be flexed to form a convex cylindrical mirror from which light from the negative is reflected on to a ground glass positioned in the plane of a block of sensitized papers when this mirror takes up the dotted line position of Fig. 8, the convexity of mirror 68 is adjusted until the image seen on this screen is of the same proportions as the document. Thereafter, the mirror 68 is moved back to its normal position, and the negative is run through the projector until an image, which it is desired to copy appears on screen 51; mirror 68 is then moved to the dotted line position and the negative image is photographed on the sensitized paper 72. This subject-matter does not appear in the Specification as accepted.