Patent GB-669609-A (GB)
Title: Improvements in and relating to photographic type composing machines
IPC: B41B17/10
Filed: 1946-08-13
Abstract: 669,609. Photographic type - composing. HIGONNET, R. A. E., and MOYROUD, L. M. Aug. 13, 1946 [July 11, 1944], No. 1078/50. Divided out of 669,531. Class 98 (i). Relates to photographic type-composing apparatus such as is described in Specification 669,531, comprising in combination a character carrier or matrix member provided or adapted to be provided with characters to be photographically reproduced and which is adapted to carry said characters continuously in a predetermined common path through a projection position, and a light source for photographically reproducing a matrix character as it passes through the projection position on a lightsensitized surface without stopping the matrix member; and consists in a scanning element having a number of scanning slits equal to the number of characters, said scanning element being adapted to carry each scanning slit transversely of its width through the projection position, the movement of the scanning element being synchronized with that of the characters so that as a character passes through the projection position a slit also passes through the projection position adjacent the said character, at the same speed as the character but in the opposite direction, and means for preventing the projection of any image except that of a selected character on the light-sensitized surface, whereby when a selected character passes through the projection position, images of the successive parts thereof traversed by the scanning slit are projected seriatim on to the light-sensitized surface thereby building up a complete image on the latter, which image is stationary with respect to the light-sensitized surface. As shown, a disc 1 bearing doublewidth characters is mounted on the same rotating shaft 2 as a brush 3 sliding over fixed contacts 4, equal in number to the characters. A disc 5 rotates in the opposite. direction to, but at the same speed as, the disc 1, and is coaxial with and as close as possible to the disc 1. Light from a lamp 6 is projected on to the characters. A shutter 8 normally prevents light from falling on the light-sensitized surface 13.. A series of contacts 10 are connected each to one of the contacts 4; and are closed selectively by a keyboard or by a register when a character is to be projected. When the selected character reaches the photographing position, brush 3 makes contact with the brush 4 connected to the closed pair of contacts 10; a circuit is completed from a battery 11 through contacts 10, contact 4, brush 3, and a solenoid 9 actuating shutter 8, so that shutter 8 is opened as long as brush 3 is in contact with contact 4, during which period the selected character crosses the photographing position. During this time a slit of disc 5 sweeps the character and a lens 12 forms an image of the character which is recorded on the sensitized surface 13. Discs 1, 5 may be geared by bevel gears, or by a differential, the cage of which is movable to adjust the relative positions of the discs. The shutter may comprise two plates separated by electromagnets to admit light. Instead of a shutter, a gas discharge tube may be used as a source of light, and energized only when the selected character is passing the photographing position.