Patent GB-706690-A (GB)
Title: Improvements in photographic type-composing machines
IPC: G02B13/08
Filed: 1950-07-06
Abstract: 706,690. Photographic type - composing. HIGONNET, R. A. E., and MOYROUD, L. M. July 6, 1951 [July 6, 1950], No. 16914/50. Class 98(1)FIG.3. In photographic type-composing machines of the kind described in Specifications 669,531 and 691,738, the matrix member comprises a disc mounted centrally for rotation in its own plane and carrying, concentrically, a number of rings of characters and a ring of marks. each ring of characters representing at least one fount and each mark being at the centre of a circular arc similarly associated with a character in each ring thereof; fount-changing means for displaying the disc about an axis intersecting said ring of marks, thereby to locate a selected ring of characters for passage through a projection position spaced from the axis by the radius of the arcs, and means for initiating the illumination of a selected character in the projection position in response to the interception of the axis by the mark associated with the character. As shown in Figs. 2 and 3, a matrix disc D1, carrying a number of founts of characters in concentric rings, is mounted on a shaft D2 rotatable in a sleeve D3 and carrying a gearwheel D4. Sleeve D3 is connected to a sleeve D11 rotatable about a fixed shaft D12, which is aligned with a shaft D8 driven by a motor D15 and which carries a decoder drum D16 and a gearwheel D5 meshing with gearwheel D4. A cam D19 with eight faces acts on an arm D21 extending from sleeve D3 so as to rotate the sleeve and disc D1 about shaft D12. All like characters of the founts lie on an arc of a circle centred on the axis of shaft D12 when any one of the like characters is in the projection position, so that when the sleeve D3 is swung about shaft D12 like characters in the several founts are in projection position in any given angular position of disc D1. A series of slits D23 is formed on the periphery of the disc. Light from a lamp passing through a lens, the optical axis of which lies on the axis of shaft D12, and then falls on to a photo-electric cell, so that when a given slit crosses the optical axis, one of a set of like characters on disc D1 is in projection position. An arm D30 on sleeve D11 carries brushes for the drum D16. The electric impulses from the drum and from the photo-electric cell are utilized, in the manner described in Specification 669,556, [Group XL(b)], to energize a flash tube D18 to give a brief flash of light when the selected character is in position. Shaft D8 rotates at twice the speed of shaft D2, so that each ring of disc D1 may have two complete founts. The selected character is projected on to a photographic film. In order to produce different sizes of type on the developed film, a lens turret D31 is provided so that eight lenses of various magnifications can be brought into position for projection. Both the lens turret D31 and the cam D19 are operated by means controlled by cams D51a, D51 operating contacts represented at D52a, D52. Cams D51 are mounted on the shaft D20 of cam D19, which also carries a gearwheel D35 meshing with a gearwheel D36. The ratio of these gears is 1:4, so that half a revolution of wheel D36 causes # of a revolution of shaft D20 and cam D19. A continuously driven shaft D37 may be brought into driving engagement with gearwheel D36 by an electromagnetic device. The contacts D52 are connected to switches which are set according to the fount required, so that when the cam reaches the required position, a circuit is completed through contacts D52 and the switches to actuate a relay breaking the circuit to the electromagnetic device, which releases gearwheel D36 from shaft D37. The lens turret D31 is rotated for lens selection in the same way. Smaller characters are usually required to be thicker in proportion to their height than larger characters, and this effect may be obtained by providing cylindrical components in the projection lenses. Condensed or expanded characters may similarly be obtained. In these cases, the spacing between characters will have to be varied. Oblique or italic characters can be obtained by providing a cylindrical component tilted with respect to the character, but a rotation of the image is required to provide correct alignment. To this end, the character spacing mechanism described in Specification 691,763 may be modified as shown in Fig. 12. The image of a character D71 illuminated by the flash tube D18 is focused by lenses D27, D73 and a reflecting prism D75 on to a photographic film D76. Since the light rays between lenses D27, D73 are parallel, the lens D73 and prism D75 may be mounted on a carriage D74 which is movable to effect character spacing. To produce an inclined image of the character, a cylindrical lens D72 is introduced, and the rotation of the image is compensated by rotating prism D75 about the axis ST. Specification 691,910 is referred to.