Patent GB-917960-A (GB)
Title: Improvements relating to photographic type composition
IPC: B41B27/00
Filed: 1960-02-23
Abstract: 917,960. Photographic type-composing apparatus. INTERNATIONAL PHOTON CORPORATION. Feb. 23, 1960 [Feb. 24, 1959], No. 6364/60. Drawings to Specification. Class 98 (1). A photographic type-composing machine includes coding means for converting successively characters and for feeding the codes into a character storage memory; a reader for reading successively stored codes from the memory during transcription of a line; a transcription unit adapted to be prepared by a character code read from the storage memory to project an image of the selected character to a common character-image position through which a lightsensitive surface for providing a record of the selected characters may be continuously advanced ; a displacement mechanism for producing continuous relative motion during transcription between the character image position and the surface so that successive character images are suitably spaced thereon; a multiplier unit connected to respond to a first input code from the reader significant of the relative width of a character in numerical form and to a second input code significant of a coefficient proportional to the point set desired for that character to produce an output signal significant of the product of the two inputs and thus of the actual space allocated on the surface to the selected character; a counter for receiving and storing a value significant of said product; a pulse generator adapted to operate in synchronism with the displacement mechanism so that at any instant the number of pulses generated after projection of a character is significant of the relative displacement between its position and the common character-image position; and connections for applying the pulses to the counter progressively to change the value stored therein to a pre-arranged value, the counter being arranged, after having received after projection of the selected character a number of pulses significant of said product, to energize a projection trigger circuit for projecting an image of the next selected character and to energize a counter-resetting circuit for changing the value stored in the counter to an initial value in readiness for receiving from the multiplier a fresh product significant of the actual width allocated to said next selected character. Preferably connections are provided between the reader and the multiplier for changing input applied thereto in response to a code signifying a change in coefficient being read from the memory so that style and point size changes may be effected in the same line. The resetting circuit for the counter may be connected to be energized by the pulse which energizes the projection trigger circuit. A slight delay is provided by means of a delay circuit included in the path of the projection trigger pulse to set up the counter to the complement of the product output of the multiplier and significant of the width of the character just projected so that the counter has time first to return to its pre-arranged value, e.g. empty, and the delayed pulse advances the reader to the next code. Spaces are treated similarly to characters but no exposure is effected. If a justified line is to be produced a second pulse counter in series with that mentioned above is controlled by a justification unit to delay projection of the next selected character following each word space until the relative displacement produced by the displacement mechanism includes an additional space increment determined by the justification unit. As described, the high-speed machine of Specification 735,863 is modified by replacing its simple width decoder unit operated by the codes read from the character memory storage by a multiplier which is fed from the reader with relative width and point set information. The multiplier may be of the kinds described in Specification 754,104, which relates to a machine having escapement-controlled intermittent displacement of the film and the present machine may include such multipliers both in its justification and transcription units as in this prior Specification. Specifications 691,738, 691,761, 691,763 and 807,752 also are referred to.