Patent GB-733614-A (GB)
Title: Improvements in and relating to photographic type-composing machines
IPC: B41B17/10
Filed: 1951-08-27
Abstract: 733,614. Photographic type-composing. HIGONNET, R. A. E., and MOYROUD, L. M. Aug. 25, 1952 [Aug. 27, 1951], No. 20177/51. Class 98 (1). [Also in Group XL (b)] In a photographic type-composing machine of the kind in which master characters carried by a continuously moving matrix member pass seriatim through a projection position in which selected characters are illuminated by a light flash to project images thereof on to a photosensitive surface, the matrix member 44 bears a number of groups of master characters 50, characters of the same width being arranged in the same group and the groups being disposed to pass through the projection position in order of character width; a group mark 96 associated with each group of characters and a character mark 46 associated with each master character, each group mark 96 being located on the member 44 in a position such that it co-operates with a first impulse generator 70 to produce an electrical impulse immediately prior to the passage of the first character of its associated group through the projection position, and each character mark 46 being located on member 44 in a position such that it co-operates with a second impulse generator 64 to produce an electrical impulse at the instant its associated character is in the projection position, a group counter 76 for counting the impulses produced by the first impulse generator 70 and adapted to be pre-set to a number so related to the position of a selected character on the member 44 that will respond to the impulse produced by the first impulse generator 70 when the group containing the selected character is about to pass through the projection position; and a character counter 78 for counting the impulses produced by the second impulse generator 64, the character counter 78 being activated by the response of the group counter 76 and adapted to be pre-set to a number so related to the position of a selected master character in the group containing the character that it responds to the impulse produced by the second impulse generator 64 when the selected character is in the projection position, the response of the character counter 78 initiating illumination of the selected character. As shown, characters are registered by a keyboard 72 in a register 74 in code form, and after registration of a line the code combinations are decoded by a reader 80, the keyboard, register and reader being, for example, of the kind described in Specification 691,761..The character and group marks 46, 96 consist of transparent slits in an opaque character-bearing disc (or alternatively, opaque marks on a transparent disc), and the impulse generators 64, 70 consist of photo-electric cells receiving light from a lamp 66, lens 68 and a slit 56 in front of which the marks pass. The register stores for each character two numbers, one corresponding to the width of the character and the other to its position in its group. These numbers are registered in counters 76, 78 respectively in such a way that each number is subtracted from the capacity of the respective counter. At the beginning of a cycle, a set of group marks 48 exceeding in number by one the width of the narrowest characters in elementary width units, passes in front of the slit 56. A further group mark 96 passes in front of the slit immediately before each group of characters begins to pass through the projection position. Since, however, the width of the last group exceeds the width of the preceding groups by three units, whereas in the other groups the width is exceeded by one unit, three group marks 96 pass in front of the slit just before the last group reaches projection position. Just before the group containing the selected character begins to be projected, the capacity of counter 76 is exceeded by one and an impulse is carried over to counter 78, which thereupon begins to count the character impulses. When the selected character arrives at the projection position, the capacity of.counter 78 is exceeded and the last impulse is carried over to initiate the generation of a light flash from a lamp 90, which illuminates the selected character and causes it to be projected by a lens 60 on to a photographic film 92. In modifications, the impulses are generated by means of magnetized spots on member 44, or the group impulses may be generated by contacts operating in connection with a brush or multi-lobed cam. The member 44 may .be in the form of a drum, instead of a disc as shown. The counters may be binary or decimal. Specifications 669,531, 669,556, [Group XL (b)], and 691,738 also are referred to.