US1909142A - Facsimile receiver - Google Patents

Description

y 1933- v. K. ZWORYKIN ET AL 1,909,142

FACSIMILE RECEIVER Filed Jan. 20, 1930 2 Sheets-Sheet l I I I I I I I I I /5 I e O C k L I INVENTORS'.

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ATTORNEY M y 1933. v. K. ZWORYKIN ET AL 1,909,142

FACSIMILE RECEIVER Filed Jan. 20 1950 2 Sheets-Sheet 2 INVENTORS'. ra/d'rn/rKZn/ar ATTORNEY Patented May 16, 1933 UNITED STATES PATENT OFFIOE VLADIMIR K. ZWORYKIN, OF SWISSVALE, AND HOWARD M. ELSEY, OF OAKION'I, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA FACSIMILE RECEIVER Application filed January 20, 1980. Serial N0. 421,965.

Our invention relates to facsimile transmission and particularly to the reproduction, at the receiving station, of drawings, pictures or other messages by electrolytic means.

It has been proposed to reproduce pictures by impregnating paper with a substance which will be discolored under the influence of an electric current and to apply this current at single small areas of the paper at a time, causing said area to progress systematically over the paper and so varying the current that, at each position of said area, it shall be proportional to the degree of darkening necessary to reproduce the picture.

This method has heretofore persented the disadvantage that the paper must be manipulated in a wet condition. It has not proved feasible to operate upon continuous bands of paper because of this condition.

It is an object of our invention to provide a picture-reproducing machine in which a continuous band of paper can be used. The band is to be dry during the greater part of its travel through the machine and is to be wet just previous to its passage between the electrodes.

It is a further object of our invention to provide a combination of electrodes, one helical and the otherv straight, between which the paper passes and to so arrange them that the abrasion of the paper by the electrodes shall be reduced to a minimum.

It is a further object of our invention to provide such a pair of electrodes in which the electrode from which metal is removed by theelectrolytic action may be conveniently replaced.

Other objects of our invention will be apparent from the following detailed description and the accompanying drawings in which:

Figure 1 is a sectional view, showing the course of the paper through the machine, taken along a line' corresponding to the line 1-1 in Fig. 2;

Fig. 2 is a top plan view of the machine, certain parts being shown in section and the paper being omitted;

Fig. 3 is a longitudinal central section of the roller carrying an electrode;

Fig. 4 is a transverse sectional view taken on the line 44 of Fig. 3;

In Fig. 5 is a detail perspective view showing the construction and the mounting of the straight electrode.

A spool 1, carrying a roll of paper 2, is mounted in the upper part of the machine at one end thereof. A drive roller 3 is mounted upon a shaft 4, suitably spaced from the shaft 1 to afford effective delivery of the paper thereto. A friction roller 5 is pressed, by a spring 6, into engagement with the paper as it passes over the roller 3. A continuous and positive tension is thus exerted upon the paper.

Below the roller 3, a tank 7 is provided which contains a guide roller 8. The guide roller is mounted at the lowerpart of a removable framecomprising an upper bar 9, a lower tie rod 10 and side members 11. The bars for the roller 8 are mounted in the lower ends of the side members which extend below the tie rod 10 and reach near to the bottom of the tank 7. At one end of the cross bar 9, the frame is provided with a lug 13 which extends into a dove-tail groove in a boss 14 on the side wall of the machine. At the other end, the cross bar 9 is provided with a tenon 15 which exten into a vertical groove inthe other side wall of the machine. A set screw 16, by engaging the end of the tenon 15, will retain the frame and, therefore, the roller 8 at the selected height.

A guide roller 17 is located on the other side of the frame from the roller 3 and, somewhat higher, this guide roller is supported between the pointed pivots 18 and 19, one of which is adjustable in order to insure the correct connection to the bars and to provide for removal of the roller, when necessary. This adjustment is effected by the screw 20.

Adjacent to the guide roller 17 is mounted a roller 21 which carries a helical electrode 22. The electrode 22 is preferably of flexible metal. It may, before being inserted into place, be a ring of a diameter which will fit the groove in the cylinder 21 but d m but ta ers, narrowing split at one point. By pulling the ends a art, in adirection at right angles to the an of the ring, it may be deformed into a elix and inserted in the groove 23, which extends helically around the cylinder 21.

e ectrode 22, compelling wall of the groove. he electrode is thus I brought to a true helical shape, even though,

as originally produced from the ring, it is onl approximately helical.

en the filler 24 has been screwed into the groove 23 so far that it p the electrode 22 firmly into lace, it is secured by a set screw 28. An e ongated o ning 29 is provided near one end of the Her 24 for 5 the accommodation of the head of this screw 30 each'side wall of the mac ine.

during the tightening movement of the filler.

A straight electro e 30 is adjustably supported above the c linder 21. The adjustment is provided or by lates 31, one at The plates are provided with vertical slots 32 which cooperate with set screws extending into exterior plates 34. The exterior lates are secured to the outer'faces of t e side walls $5 of the machine, and the side walls are recessed to provide space for the plates 31. The electrode 30, being of thin metal and, therefore, too flexibleto maintain itself in a straight line acrom the machine, is stifiened by a bar 35 which extends beyond the electrode 30 at each end and is received into notches 36 in the plates 31. A second reenforcing bar 37 extends along the other face of the electrode and screws 38, at spaced intervals along the electrode, fasten the bars 35 and 37 together. A lurality of holes are rovided in the electro e in Y sition to register with the screws to enab e them to draw the bars together. Tightening the screws thereby produces a rigid structure, the lower edge of which is the projecting edge of the electrode. The upper edge of the electrode may project above the'upper edges of the bars 35 and 37. The whole structure may then be reversed end for end to bring the upper edge of the electrode into the lower 'tion.

Guide rolls 40 and 41, atthe delivery side of the cylinder 21, serve to put the necessary tension on the paper to insure its motion past the cylinder 21. Each of the rollers 3, 21, 40 and 41 is drivenby gearing on the outer side of the side walls of the machine.

It is unnecessary to describe this gearing 65. in detail. It includes a pulley by which the roller 3 is driven, and a pulley 43 by which the roller, 40 is driven. In order to insure the necessary small slippin movementbetween the paper and the roller 21, a brake is rovided-for controllin the speed of the ro ler 21. The necessary s ip age between the pulleys 42 and 43 and t e belts which drive them is regulated by the action of the brake.

The brake includes a pressing member 45 to cooperate with a gear wheel 46 which meshes with a gear wheel 47 upon the shaft of the cylinder 21. The pressure of the member 45 against the face of the ar wheel 46 is re lated by a magnet 48 which may be contro ed in anysuitable manner.

In the operation of the device, a roll of paper 2 is mounted upon the spool 1, threaded between the rollers 3 and 5, led into the tank 7 and then over the guide roll 17, past the upper surface of the cylinder 21 and between the rollers 40 and 41. The frame, including the cross bar 9 and carrying the roller 8, is then put in place by slipping the dove-tail lug into the slot 13 and the other lug into the slot in the opposite wall. The height of the frame is adjusted until the paper passes very near to, but not in frictional contact with, the bottom of the pan 7.

The electrode assembly, carrying the straight electrode 30, is then put in place, the ends of the bar 35 entering the slots 36. If the adjustment is not already correct, the screws are adjusted in the slots 32 until the contact between the lower edge of the electrode 30 and the paper at the point where it is supported by the projecting electrode 22 is of the right pressure.

The an 7 contains the material with which t 0 paper is to be wet. If the paper is already impregnated with a suitable solution for cooperation with the electrodes, the

pan may be filled merely with water. For example, if the image is to be-formed by the reaction of starch with free'iodine, the paper may have been soaked in a solution containing both starch and potassium iodide, dried and wound upon the roll 2. Then the tank would contain only water.

On the other hand, the paper may be impregnated with one of the two constituents needed to make the sensitive electrol and the pan 7 may contain a solution of t e other ingredient. In the illustration chosen, the paper may be impregnated with starch and the pan 7 may contain a solution of potassium iodide.

It is also feasible to have, in the pan 7, a solution of the sensitive electrolyte, in which case, unimpregnated paper is provided on the roll 2.

For example, the electrode 30 which, in this case, should'be the anode, may be made of silver, and the pan 7 may contain a properly proportioned solution of ammonium nitrate, potassium bromide, potassium iodide and pyrocatechin in water. With the passage of current, thesilver at the ed e of the anode, where it makes contact wit the paper as pushed up by the helical cathode 22, dissolves in proportion to the current passed, in accordance with Faradays law. The dissolved silver at once reacts with the bromide and iodide ions to form silver bromide and iodide, which are-very insoluble in the solution impregnatng the paper, and, seemingly, are adsorbed on the surface of the paper so tightly, as soon as formed, that the outlines of the record do not run or smear. The silver bromide and iodide, which are only slightly colored, later react with one or more of the other ingredients in the solution to form a more highly colored image.

Though we have secured our best results with the above solution and a silver anode, we have also had very good success using an iron anode, whichalso dissolves with the passage of current and the formation of a good image in a solution containing ammdnium nitrate, ammonium chloride and gallic acid in water. With this last solution, the iron anode may be replaced by one of konel or any one of several other metals. It is not our wish to be limited in this .disclosure by the nature either of the electrodes used or the solution, for we are primarily concerned in this application with a special procedure and mechanism by which satisfactory pictures may be continuously received by an electrolytic process.

After passing through the pan 7, the aper is supported by the surface of the cy lnder 21,-but is lifted from this surface, over a portion of its width, by the electrical electrode 22 which projects slightl from said surface. The straight electro e 30 makes contact only with the lifted portion of the paper and makes contact firmly with only that portion of the paper between it and the helical electrode. Current from the one electrode to the other flows only in that portion of the paper which is between the elec-- trodes and flows, in a perceptible amount, only in the very small area which is sub- ]ected to pressure by the electrodes. Only a very small area of the paper is discolored by the action of the current upon the electrolyte in the aper.

The pitch 0 the helix is such that, during one revolution of the cylinder 21, the point at WlllCh the electrodes affect the paper, travels the width of the paper. The cylinder 21 is caused to rotate at a considerably higher s than the longitudinal electrode 22 have a. dul edge to avoid too great a scraping action upon the paper, but

the electrode 30 may have a sharp edge without producing an objectionable amount of scraping of the surface of the paper, even though the paper he wet. To roduce this sharp edgewithout requiring t e electrode to be ground to a'knife edge is a reason why the electrode is thin and, because of this thinness, it must be reenforced, as described in connection with the bars 35 and 37 The provision of a helical electrode cooperating with a straight electrode to provide a motion of the working point across the paper for each revolution of the cylinder has been proposed before, but the mounting of such electrodes whereby they are replaceable, the provision for wetting the paper just before its passage between the electrodes and many details of instruction and operation are new. Certain features of this invention which we believe to be new are expressed in the following claims, but no limitation is intended except as may be stated in the claims or maybe imposed by the prior art.

We claim as our invention:

1. In combination, a helical electrode, a thing straight electrode for cooperation therewith, a reenforcing strip extending along said straight electrode and securing means for maintaining said straight electrode against said reenforcing strip, whereby said straight electrode is prevented from flexing.

2. In combination, a helical electrode a thin straight electrode for cooperatlon therewith, a reenforcing strip extending along said straight electrode, and means for adjusting the spacing of said straight electrode from said helical electrode and for supporting said straight electrode in the adjusted position.

In testimony whereof, we have hereunto subscribed our names this 10th day of January, 1930.

VLADIMIR K. ZWORYKIN. HOWARD M. ELSEY.

movement of t e paper. Many lines across the paper are thus traced by the working point of the electrodes for each unit of length of paper. If, for example, it is desired to make a picture with a fineness of

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