US2026100A - Image transmission apparatus - Google Patents

Description

Dec. 31, 1935. L H ROBE@ 2,026,100

vIMAGE TRANSMISSION APPARATUS Filed Aug. 19, 1951 2 Sheets-Sheet 1 2a ik a- S Y////A I'F 1 :Q A 1 F v Dec. 31, 1935. H RQBECK I 2,026,100

IMAGE TRAN SMI S S ION APPARATUS Filed Aug. 19, 1951 2 Sheets-Sheet 2 Eg4 .F15/f5,

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PATENT oFElcE MAGE TRANSMISSION APPARATUS Hermann Robeck, Berlin, Germany, assigner to Siemens & lalske, Aktiengesellschaft, Berlin- Siemensstadt. Germany, a corporation of Germany Application August 19, 1931, Serial No. 558,162` In Germany September 1, 1930 s claims. (c1. 17a-s) This invention relates to a process for the transmission and recording of pictures, signs or the like, in which the movable parts at the transmission and receiving end are constituted by` rotatable writing surfaces or the like driven and released entirely independently of each other, an independence of the receiving process from the starting of .the transmitting apparatus being achieved.

Such apparatus are locally synchronized, that is to say, at both ends means are provided such as standard tuning forks, pendulums or the like by means of which the speed of the rotating writing surfaces can be controlledand maintained either constantly the same at both ends or constantly reduced or increased by a multiple (integer number). The standard tuning means are compared with each other at long intervals of time. For the reception of complete pictures it is moreover necessary to synchronize the moments at which thewriting surfaces are released. For this purpose periodically recurring current impulses have been frequently used hitherto; 'these impulses being sent out from the transmitter end and caused to act at the receiving end.

In the process according to the invention, the

devices are no longer brought in step, but inspite of that, one picture is produced at thereceiving end which does not appear cut up Vor interrupted by paper clamping joints, stops or the like. For this purpose the process of transmission or of reception atboth ends or at one end only is shifted in time, the feeling or writing being done doubly.

In the case of ,continuously travelling rotating surfaces, at the 'transmitting end pictures are used which at the outside reach half-way round the circumference, whilst at the transmitting end two writing pencils or stylos which are displaced to the extent of at least one picture width, are

caused to explore the writing surface simule taneously. The stylos are preferably displaced I by an angle of 180 relatively to each other.

If the xing or clampingA slot, for instance of a cylindrical drum, at the receiving end is in the centre of a picture, it is true that this picture will appear cut up, but the adjoining picture will. be

Complete. I i

In systems which work on the start-stop system, the stop is used as is well known after every revolution as the synchronizing means and is released 'from the transmitter end. In the case of local synchronizing, th`is stop can also be used in which case it is released by the said local synchronizing device.

At the receiving end of these stop systems two writing surfaces rotating with the same speed, the stops and stylos of which are displaced in 5 time relatively to each other, can be simultaneously explored or written upon, The picture at the transmitting end must not exceed the time of rotation between the end and beginning of two successive stops of the receiving' end. The most 10 favorable plan is therefore to set these stops at to the rotating surface, as in this case the largest possible picture' dimensions can be transmitted.

An increase of the picture up to half the cir- 15 cumference of the surface of rotation is obtained by arranging at the transmitting end two pictures arranged behind each other, whilst the receiving ends are also caused to work with two writing surfaces, the screens, screen contacts 20 orthe likeof which, as well as their stylos, displaced to the duration of at least one stop, but at the outside of one revolution, release the writing surface.

Also, in this case, the simplest method is to .25 choose the releasewith a time difference of half a. revolution as in this way, for instance in the case of pendulums, stops are obtained by means of contacts at both sides of their deflections without any complicated devices. It is, however,` pos- 30 sible to use only one writing surface at the receiving end by feeling or exploring-the transmitting end also with a picture which comprises halfa circumference of the writing surfaces less 1/2 stop.

Two stylos are then used at the receiving end 35 connected in parallel, which therefore write simultaneously and are displaced relatively to each other to the extent of one picture width.

In the accompanying drawings,

Figures 1 to 3 are diagrammatic representa.- 40 tions of the start-stop system;

Figures 4 and 5 are diagrammatic illustrations of a transmitter and a receiver respectively constructed in accordance with thev principles of the invention; 45

Figure 6 represents a sheet bearing an image for use with the transmitter shown in Figure 4; and

Figure 7 represents the corresponding sheet bearing the image reproduced by the receiver 50 shown in Figure 5.

Referring more specifically to the drawingsl and with particular reference to Figures 1 to 3 inclusive thereof, it will be noted that 2a. is the `time of the revolution of a rotating surface, b 55 the duration of stop, c the lead or the lag of the receiver relatively to the transmitter. The systems are indicated in the lines E I and E II (of the receiver), those ot thetransmitting end in the lines S. X and Y are. the times of the 2' i+1/2b (180) and the picture in the transmitter S equal to a-1/2b that is to say, equal to the time between the end and the beginning` of the stops of E I and 'E II.

In Figure 2, the displacement is equal to b, that is to say equal to onestop. In the transmitter S there are two identical pictures of the width a. In Figure 3, in the transmitter S two rotating take-off or feeler contacts V Z are connected in parallel and displaced to the width of one picture, and the width of the picture in the transmitter is In Figures 4 to 7, the transmitter and receiver have been drawn diagrammatically for the case in which the writing surfaces I and la of the two apparatus are equal in size and have a circumference equal to 2a. The receiver lags behind the transmitter by'c. Two stylos 3 and I, displaced relatively to one another by are arranged on the circumference of the transmitter writing surface. The picture reproducer of the receiver is shown at 2, while 5 and 6 are the brushes situated on the axis of the apparatus and forming the second terminals. The arrows 1 show the direction of rotation. The copy sheet clamped on the transmitter is therefore explored twice at the transmitter and is recorded twice at the receiver la, being recorded once as an intact picture which is displaced by an amount c relatively to the lower edge of the writing surface, while the second picture is cut by the edge 5 of the sheet. l

l. In apparatus for transmitting and recording images, the combination with a transmitter comprising means for scanning each transverse ele- 10 ment of an image to produce corresponding electrical impulses, of a recording device for receiving the impulses, and means for causing said device to record each transverse element` of the image twice in succession in adjacent relation l5 and spaced in the direction of scanning to produce duplicate images, whereby one of the two recorded images will be uninterrupted.

2. In apparatus for transmitting and recording images, the combination with' a transmitter com- 20 prising means for scanning each transverse element of an image twice insuccession to produce corresponding electrical impulses, a recording device for receiving the impulses, and means for causing said device to record each transverse 25 element of the image twice in succession in adjacent relation and spaced in the direction of scanningto produce duplicate images, whereby one of the two recorded images will be uninterrupted.

3. Inapparatus for transmitting and recording images, the combination with a transmitter comprising a rotating drum for supporting an image record, means for scanning each element of the image record. to produce corresponding electrical impulses, a recording device comprising a rotating drum for supporting an image record receiving element, and means cooperating with said record receiving element and responsive to the transmitted electrical impulses for recording each transverse element of the image twice in succession in adjacent relation and spaced in the direction of scanning to produce duplicate images, whereby one of the two recorded images will be uninterrupted.

HERMANN RoBECK. 45

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