US2415229A - Facsimile apparatus - Google Patents

Description

Feb. 4, 1947. c. J. YOUNG FACS IMILE APPARATUS Filed Sept. 10, 1942 PEcEn/EP 676N491. fiMPl lF/EP INPUT INVENTOR I Q C ZeJcIYB ATTORNEY Patented Feb. 4, 1947 FACSIMILE APPARATUS Charles J. Young, Ardmora-Pa assignor to Radio- Corporation of America, a corporation of Delaware Application September 10, 1942, Serial No. 457,821

3 Claims. 1

This invention is directed to facsimile apparatus and more particularly to apparatus for use in the reception and reproduction of facsimile images, pictures or the like which have been transmitted from a transmitting point to various receiving points via a suitable communication channel, which may be radio or wire line or a combination of both, as desired.

In the disclosed form, the invention is particularly adapted to that form of facsimile recording apparatus wherein the reproduced message is built up in a point by point manner on a recording paper or strip by reason of current flowing through. the strip or paper upon which the message is to be produced. Such forms of systems are usually those where the recording on the record strip takes place. by reason of a current flowing directly through the medium upon which the record is to be produced, and, accordingly, such systems are generally known in. the art as recorders of the so-called electrolytic type, although it is to be understood that in some instances the recordings may develop as a result of heat or the like produced by current flowing between two suitable electrodes with the recording material interposed therebetween.

In apparatus of this general type, it has been customary, as known in the art, to provide a record drum upon which is suitably arranged a helical strip which extends usually from one end of the drum to the other and covers substantially 360 of the drum. Under some circumstances, the helix may cover more than 360, as is also known in the art, but when such systems are used, the use is usually restricted to tape records and the like because certain portions of the message are duplicated with lateral spacing between the duplications corresponding in distance to the pitch of the helix, Under other circumstances, the helical strip or edge may be slightly less than 369 withthe small angular period then being particularly adapted for a framing operation.

Arranged in co-operative relationship to the record drum carrying the helix is a so-called presser bar which is in. the nature of an elongated electrode of a length which is usually somewhat shorter than the total pitch of the helix, whether the, helix extends through 369, or in excess of 360, on, the recorder drum, but which length may, naturally, correspond to the helix pitch under some conditions.

The presser bar is so ar-- of the presser bar relative to the drum and its helix is so regulated that the presser bar causes the recording strip continuously to bear upon both the helix of the recorder drum and the presser bar, so that any current which flows between these two members must flow through the recording strip.

In its application to the so-called electrolytic type of recording, as is illustrated in one form, for instance, by' Young Patent No. 2,215,806, a recording sheet or strip is arranged to be suitably impregnated with a chemical solution which is suitably reduced when picture modulated signal current flows through it in the reproduction of the picture image, so that marking effects are obtained. upon the material of the recording sheet. The impregnated paper is suitably advanced relative to the recording drum and the presser bar so as to bring new sections of the recording stripcontinuously beneath the presser bar. Signal energy, as it is received from the communication channel after being suitably amplified; isv caused to initiate the flow of current between the presser bar on the one hand, serving as one electrode of the system, and the recording helix on the record drum, serving as the other electrode, on the-other hand. The density of the markingin the recording strip is, generally speaking, proportional. to the intensity of the current flowing;

In such systems ofthe prior art, difiiculties have been experienced continuously due to the fact that the record drum must rotate at a relatively rapid speed relative to the presser bar in order to maintain a high speed of recording, and particularly because of the fact that the recording strip,- whenused for electrolyting recordingrnust be damp, or even wet, as it is brought to bear on the presser bar and helix. It is. particularly desirable that a uniform pressure be maintained continuously on the presser bar relative to the recording strip on the helix if even coloration for all like de rees of shade Values is to be maintained.

Inthe past, it has been particularly difficult to prevent bouncing of. the printer or presser bar after its first striking as the helix comes under its, end at the start of each scanning line, and many types of mounting and various damping arrangements, have beentried with only a reasonable degree of success. It is particularly diflicult. to maintain, this uniformity of pressure as the recording speeds are increased and, accordingly, it becomes an object of the present invention to provide a mounting for the presser or printer bar which isrelatively easy to arrange and which, at the same time, will inherently provide the even pressure desired relative to the helix on the recording drum and the paper upon which the record is to be built up.

In this way, it becomes a further object of the invention to provide for increased evenness of record reproduction by reason of the establishment of uniform pressure at all times upon the dampened recording paper. This condition is maintained, even at high recording speeds, by having a minimum of mass in the bar itself, and then supporting it in a resilient and selfdamping mounting.

Another object is to provide a method of bar mounting which will reduce the noise in operation by limiting the size of the bar structure, thus reducing radiation of noise.

Other objects and advantages of the invention are those of providing for ready adjustment of the tensioning and pressure of the printer or pressure bar relative to the paper.

Still other objects and advantages are those of overcoming the defects of prior art systems and enabling the recordings to become more uniform than in arrangements heretofore used.

Still other objects and advantages of the invention will be apparent from reading the following specification and its claims in connection with the accompanying drawing, in which,

Fig. 1 illustrates, in schematic form, one form of the invention and shows particularly the manner in which the record strip is fed through the recording machine between the presser bar and the recording drum;

Fig. 2 shows schematically one arrangement for mounting the presser bar relative to the recording drum;

Fig, 3 shows a modification of the arrangement of Fig. 2 but does not illustrate the method of supporting the presser bar in the detail of Fig. 2; and,

Fig. 4 shows a still further modification of the arrangement of Figs. 2 and 3 and provides a form of system where different presser bars may be used in sequence for the recording.

Referring now to the drawing, the general form of the recording system by which messages are provided on a suitable record strip due to the rotation of a recording drum carrying a helix and being moved so that successive points on the helix are brought successively'beneath successive points on a presser or printer bar, has been shown in general by Reissue Patent No. 20,152 dated October 27, 1936 and granted to C. J. Young.

In the arrangement of the patent above named, provision was made for moving the presser bar relative to the recording drum and the recording paper, but, in the present instance, the presser bar is arranged generally to maintain a permanent position so that current applied from a receiver may be caused. to flow between the presser bar and the helical strip, and through the recording material, which was not the case in the reissue patent. In Patent No. 2,215,806 granted to C. J, Young on September 24, 1940, an arrangement was disclosed wherein suitable electrolytic recording on a record strip was provided. The last named patent, however, provided for recording on both sides of the record strip and was not particularly directed to the form of presser bar herein to be set forth and claimed.

The present invention, however, is directly applicable to the arrangement shown by Patent No.

4 2,215,806, notwithstanding the illustration herein making the arrangement particularly applicable to one-side recording, since, by altering the electrode polarity, as in Patent No. 2,215,806, twosided recording may be had with the electrode arrangement herein disclosed.

Reference may be made to the patents hereinabove named for a complete description of the general nature of the apparatus set forth and, therefore, this disclosure refers to such apparatus largely only in schematic nature.

Referring now to the particular arrangement herein disclosed, there is provided a rotating cylindrical drum member H which is adapted to be driven by a suitable prime mover source (not shown) which turns the spindle 13 so as to cause it to rotate in the direction shown by the arrow. The drum is suitably maintained at synchronous speed with a corresponding member of the transmitter by any suitable and desired means, as is known in the art. Carried upon the drum or cylinder H is a helix 15, formed by suitable conducting material, and secured at its ends in any desired and suitable manner to the ends of the drum.

The helix, as illustrated herein, is adapted to wrap around the recording drum or cylinder H and to extend for 360 thereabouts, so that one end of the helix is substantially at one end of the drum and the other end is substantially at the opposite end of the drum. The helix l5 may be formed from conducting material suitably imbedded and secured in a ridge or recess formed in the periphery of the drum, or the helix may be formed in any other convenient way. Connection to an energizing circuit by which electrical energy is supplied for marking may be made in any desired manner, such as by suitable slip rings or the like (not shown). Alternatively, the drum carrying the helix can be conducting, and thus current may be supplied by way of a connection made to the shaft.

Immediately above the helix l5 and in cooperative relation therewith is the presser bar arrangement H, which element forms particularly the subject matter of this invention and which will be described more particularly in connection with the showing of Figs. 2, 3 and 4.

Between the presser bar ll and the helix l5, which is carried on the drum ii, the paper or other suitable form of recording strip I9, upon which the facsimile message is to appear, is passed. This recording strip may be withdrawn directly from a humidor can, in which event the recordingstrip, as it is withdrawn, is suitably impregnated and ready for recording and is of the desired dampness, or the strip may be fed over suitable rollers through a chemical bath 2% within a container 23, so that the paper or recording strip, as it passes through the chemical bath 2!, is suitably impregnated with a solution. The impregnating solution is of such a character that it will, under the influence of current flowing therethrough, be suitably reduced, at the points where current flows, so as to produce the desired recordings.

Many impregnating solutions for this purpose are satisfactory, although those disclosed particularly by co-pending applicatiton of Myer Solomon, filed as Serial No. 178,743 on December 8, I937, now Patent No. 2,306,471, granted December 29, 1942, have been found to be particularly satisfactory.

After the recording strip or paper 19 has been impregnated with the chemical solution in the bath 2!, it is then fed over guide rollers, such as the rollers 25, and drawn in th direction shown by the arrow by means of the pulling rollers 2'! and 29, for instance. Intermediate the bath 2| and the point where the recording strip passes beneath the presser bar ii, suitable drying apparatus may be employed, where desired, and also, subsequent to the recording, the recording strip may be suitably dried, either before or after it passes between the pulling rollers 2! and 2%. One of the rollers 21 and 29 is usually rubber covered so as to readily pull the recording strip or sheet through the machine, although other modified arrangement may be used.

In order to produce facsimile messages upon the recording strip, signals are received at the signal input terminals 3i and, after being suitably amplified and, where necessary, detected in a receiver-amplifier arrangement conventionally illustrated at 33, the output energy is fed by conductors 37 so as to flow between the electrode member ll constituted by the presser bar and the electrode member 65 forming the helix. Usually a direct connection is made to the presser bar IT with conductor 35. The connection between the conductor Bl and the helix i5 is usually, as above stated, by way of slip rings (not shown). The direction in which current flows through the recording strip is determined in accordance with the type of solution used to impregnate the recording strip, so that, in some instances, the presser bar l's' may be made the positive or anode terminal of the system with the helix [5 functioning as the cathode, whereas, un-

der other conditions and for different types of recording solutions, the electrode arrangement may be exactly opposite.

In order to provide for tensioning the presser bar ll relative to the recording drum or cylinder II and 'its associated helix I5, the presser bar is formed in such a manner as to be carried by the arms 39 which are pivoted at pivot points 41 which are upon the supporting frame member (not shown) of the recording machine proper.

A resilient member, such as a spring, is arranged to adjust the pressure with which the presser bar is adapted to bear upon the recording drum or cylinder ll. There is also provided an adjusting screw #35 at the end of the support arm 38 so that when the adjusting screw is moved through a supporting member Ill carried upon the frame member 13, it will exert more or less pressure upon the end of the supporting arm 39 and thus tend to regulate or limit the movement of the presser bar relative to the recording strip upon the recording drum or cylinder so that the bar will not drop too far when it runs off the helix at the end during phasing periods for instance.

Referring now particularly to Fig. 2, there is shown the recording edge 5! which is to bear upon the various points on the helix it to provide the flow of current through the recording strip or paper Hi. This recording edge 5i is formed of a conducting material and, in order to provide so that the presser bar shall exert an even pressure throughout the recording member, is suitably mounted in a resilient mounting support or yoke 51 which may be either rubber, a resilient composition or a soft plastic. This resilient mounting section or member 57, which carries the recording edge 5| suitably molded or clamped therein, is carried in the channeled or slotted end 59 of the arm 39 so as to be suitably clamped therein. It can be seen that by reason of the resilient mounting of the recording edge 5i by means of the resilient packing 51, the member is caused to press easily upon the recording strip l9 as it moves relative to the recording drum.

In this arrangement as it has been shown, the end of the presser bar arrangement H, which is nearest the recording edge 5!, is pressed downwardly toward the helix E5 on the recording drum II by means of a sprin 4! which may have one end attached to the upper surface of the presser bar arrangement II, and the other end secured to the frame member At. This then enables the maintenance of a substantially fixed pressure of the bar and its recording edge against the helix [5.

The complete assembly supporting the presser bar or member is carried from the main support or frame member 46 by means of a pair of supporting elements 553 and 52 which carry the support plate 54 serving to hold the bearing 56, in which is provided the pivotal mounting 4|. The support members 5!) and 52 are suitably fastened into the frame member in any desired and appropriate manner.

At the opposite end of the presser bar arrangement 1?, the adjusting screw E5 is so positioned, as shown, that it may be adjusted to limit the motion of the presser bar. In this way, when the presser bar rides off the helix it is not permitted to fall far enough to damage either it or the drum and helix. Normally, the bar would rest upon the drum and helix, but at times, when the phasing operations take place, the relative position might change were it not for the stop arrangement.

In the modified form of the arrangement shown in 3, provision is made for slightly greater resilience in the vertical direction than does the arrangement of Fig. 2. This is done by providing above the resilient packing 5? a cavity El into Which the resilient packing 5? may be pressed with increased pressure against the recording edge, so that for slight variances in the pull of the recording strip or in alignment of bar and helix, evenness of pressure is maintained by reason of the resilient packing being more or less displace-d into the cavity 55. At the same time, horizontal displacement of the bar edge from its proper position is maintained with the same force as in 2. In the arrangements of Figs. 3 and it it to be understood that the mounting of the support for the presser bar is substantially like that shown by 2, but, for convenience of illustration, this has been illustrated in a mere schematic fashion.

In the arrangement of Fig. 4 a still further adaptation of the system is disclosed. In this arrangement, four separate recording edges 5!, 5?, 55 and iii have been provided on a single assembly formed generally by a series of angular bracket members 53 which extend lengthwise of the recording presser bar for a distance corresponding substantially to the length of the cylindrical recording drum or cylinder I l. The angle members 63 are arranged to carry and support the resilient packing members 57, such as shown for instance by Fig. 2, and, in, turn, support the recording edges.

The complete group of angle members 63 is held by means of a circular end support element 55 provided at each end of the presser bar, so that by positioning the complete assembly upon a central spindle 6?, which is mounted in one end of the arm 39, the complete assembly may be arranged for suitable rotation. The adjustment is such that by rotating the various recording heads through different recording edges may recording strip i9 and caused to permit current to flow through the recording strip to the helix member 35. In each 90 position the assembly of presser bars is securely latched by a detent (not shown) which prevents the edge of the active bar from being dropped out of position by the movement of the recording strip. In this Way, as the recording edges El, 53, 55 or 60 become worn, the recording head may be turned through a 99 angle to the next position of the detent and the recording action continued without replacing the complete presser bar. Under some conditions, however, it may be desirable to shift, from time to time, from one recording head to another, and for this purpose a suitable mechanism may be provided which will act under the receipt of the frame'synchronizing signals whereby, at the completion of each picture or recording area, the recording head will be shifted through a 90 angle so as to distribute wear over all the recording edges in sequence.

Not only is the multiple mounting frequently desirable from the standpoint of distribution of Wear, but by using such multiple mounting and by placing bars of different metals in the various positions it is possible to use different recording compounds more readily. As an example,

an iron presser bar may be provided for use with gallic acid solutions, and a platinum bar may be used with a recording strip impregnated with an azo dye; or bars of difierent metals may be utilized to give different recorded colors from one azo solution. In any case, the recording edge of the printer bar itself is preferably formed always of a metal or alloy so selected as to be re sistant to erosion by the chemicals in the solution which impregnates the paper for recording.

I claim:

1. In facsimile apparatus a rotary drum having a helical member supported thereon, an elongated presser bar arranged to be positioned in co-operative relationship to the drum and helical member so as continuously to bring said elements to bear upon each other, a channelled end support element for said presser bar, resilient means held Within the channelled end of the support element for positioning the presser bar in the support element so that the base-of the presser bar is supported Within the resilient means and. an edge portion of the elongated presser bar protrudes from the resilient means to bear against the helical member on the rotary drum, means to feed a record-receiving strip between the drum and presser bar, and means to provide a predetermined substantially constant pressure between the presser bar and the helical member.

2. In facsimile apparatus, an elongated presser bar, a resilient element for holding said presser bar Withone edge portion only of the said presser bar exposed, a channelled elongated element substantially surrounding the said resilient element for a length thereof corresponding at least substantially to the length of the presser bar so as to hold and position the presser bar and its supporting resilient element, said channelled element having an internal cavity into which the resilient element may be pressed with increased pressure exerted upon the protruding edge of the said presser bar, and a recording member for cooperation with said presser bar.

In facsimile apparatus, an elongated presser car, an elongated support element for said presser bar, said element being of a length corresponding substantially to that'ol the presser bar and having an internal slot extending substantially lengthwise thereof, a resilient body supported within the slot for holding and positioning the said presser bar with the edge of the bar in protruding relationship relative to the resilient body and the complete bar supported resiliently throughout the length thereof relative to the support element and a recording member for cooperating with said presser bar.

CHARLES J. YOUNG.

BEFERENCES CITED The following references are of record in

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