Patent GB-190828525-A (GB)
Title: Electric Transmission of Visual Images.
Inventor: ANSPACH LUCIEN
Filed: 1908-12-31
Granted: 1909-03-25
Abstract: 28,525. Anspach, L. Dec. 31. Telegraphs.-In a facsimile telegraph system for the reproduction at a distance of drawings, manuscript, &c., exact synchronism of the transmitting and receiving instruments is dispensed with in order to obtain a higher speed of transmission, and the consequent distortion of the received image is rectified by retransmitting the image, at the receiving station, to a second receiver, this process being arranged to produce automatically an inverse or neutralizing distortion. One form of the invention is shown in Figs. 1 and 2, the apparatus for transmission to a distance being shown in Fig. 1 and the apparatus for local retransmission in Fig. 2. The image to be transmitted is mounted on the cylinder T, which receives a helical motion under a collecting-contact c, which sends a current from the battery B to the line L whenever a conductive part of the image comes under it. At the receiving station, these currents actuate a tracer t, which engraves a distorted image on the cylinder R. A second tracer t<1>, which acts on an extension R" of the cylinder R, is not brought into action by the battery B, but is actuated once in each revolution of the transmitter by a battery B', which is connected to line by a contact on a rotating but longitudinally-fixed disk G. The tracer t<1> accordingly marks what is called a "repro- " ducing-line," which is distorted to the same extent as the image on the cylinder R. To reproduce a final undistorted image, the engraved double cylinder R, R<11>, after being treated with ink to differentiate its surface into conducting and non- conducting parts, is mounted, as shown in Fig. 2, in gear with a cylinder R' ; the cylinders, when rotated, receive a lateral motion from oppositelythreaded fixed screws E, E<1> ; the image is transferred electrically to the cylinder R' in the ordinary way, and the distortion is corrected by a stop C which engages once in each revolution with a ridge on the cylinder R' and which releases the cylinder R' electro-magnetically at the instant when the line on the cylinder R" passes under its collecting- contact. To enable this correcting action to take place, the cylinder R<1> is mounted frictionally and is geared to rotate slightly faster than the cylinder R, R". Another arrangement is described in which the "reproducing line " is cut in the form of a projecting ridge and produces its correcting effect by direct mechanical action. Instead of forming a spiral " reproducing line " during each distant transmission, a standard series of helicoidal lines of varying pitch may be selected for each particular case, provided the motion of the transmitter and receiver is rendered uniform by fly-wheels. The invention is also described as applied to a process in which the transmitting-contact and the receiving-stylus are carried by swinging blocks, these being geared together for local re-transmission, the distortion produced during the distant transmission being corrected by the direct mechanical action of the "reproducing line," engraved as a groove, on a pin carried by the receiving-surface. The distant and local transmissions may depend on the use of selenium or on electro-chemical action.