Patent GB-316668-A (GB)
Title: Process and devices for condensing on films photographic reproductions of printed orother works and for selectively reproducing from these films
IPC: G03B21/11
Filed: 1929-07-22
Abstract: 316,668. Sebille, G. Aug. 2, 1928, [Convention date]. Optical-projection apparatus.-A film on which microscopic images of the pages of printed or engraved works are reproduced in series is provided with markings, distinct from the reproduced pages, but uniformly located in relation thereto, representing the digits or letters of the pagination of the work, so that, on passing the film through an optical projector provided with kinematograph feed mechanism, the markings are readable owing to the persistence of like markings, although the reading of the text of the pages is impossible owing to the speed of the film, and the film may therefore be stopped at any desired page reproduction for visual inspection or photographic reproduction. In a modification, the film is provided, instead of or in conjunction with the markings, with page-indicating means adapted to co-operate with electric selecting mechanism associated with the optical projector, whereby the film may be stopped automatically at any desired page reproduction. The pages of a work may be reproduced on the film in successive lines, each containing a number of page reproductions, as shown in Fig. 1, which may be so arranged that the lines of reproduction read alternately from left to right and right to left, as indicated by the arrows. The margins of the film are provided with feed perforations 3<1>, 3<2>, with a column 11 of figures &c. by which the pages of the work are identified, and with series of perforations 4 - - 7 representing the digits of the various volumes of the work and the hundreds of pages thereof, and intended to control the automatic operation of apparatus in which the film is inspected or reproduced by enlargement. Additional holes 13 and 14 representing the tens and units of the pages are spaced across the film. The various films so produced are reeled and stored in a magazine 50, Fig. 5, in which thev rest in the forks 63 of endless chains 61, whereby any one film may be brought into the uppermost position ready to be fed into the projector. Within the magazine is an intermittent feed-mechanism operating toothed drums 65, a wind-on spool 67, and the clutch shaft 69 of the film roll. Steel strips 66 pass from the wind-on spool 67, and round the drums 65 to sectors 70 adjacent to the film roll, and the end of the film, which is strengthened by a transverse rod 73, is adapted by manipulation of a lever 71 to be hooked on to the strips 66 so that, when the feed mechanism is set into operation, the film will be fed intermittently between a condenser 75 and objective 76 whereby its images may be selectively projected upon a ground-glass screen 53 which may, for the purpose of reproduction, be replaced by a photographic film, ferroprussiate paper, &c. The condenser and objective are mounted on rails 77 along which they may be traversed as a unit across the film by means of chain gearing 78 to project the individual images of a row. The various parts of the apparatus may be actuated by the handwheels shown, or by electric motors controlled by a hand-operated distributing-switch. With this switch is associated an electric selector system whereby, if a particular page of the work is to be consulted, the volume and page references are set up on dials working in conjunction with switch contacts controlled by the perforations 4 - - 7 and 13 and 14 in the film so that, when the electrical driving mechanism is started, the film will be wound until the line of page reproductions containing the particular page rests between the condenser and objective, whereafter the condenser and objective are automatically traversed, back and forth if necessary, until the particular page rests between them, and the drive is then interrupted. Provision is made for working backwards automatically from any page to another page in an earlier part of the work.