US2005017A

US2005017A - Facsimile telegraph system

Info

Publication number: US2005017A
Application number: US691044A
Authority: US
Inventors: Watson Edward Fisk
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp; Owens Corning Intellectual Capital LLC
Priority date: 1933-09-26
Filing date: 1933-09-26
Publication date: 1935-06-18
Anticipated expiration: 1952-06-18

Description

June 18, 1935. E. F. WATSON 2,005,017-

FACSIMILE TELEGRAPH SYSTEM Filed Sept. 26, 1955 5 FIG.

iaal

INVENTOR E. F. WA 7 SON B r A TTORNE V Patented June 18, 1935 UNITED STATES PATENT OFFICE FACSIMILE TELEGRAPH SYSTEM Application September 26, 1933, Serial No. 691,044

7 Claims.

v The present invention relates to telegraph systems in which each letter or symbol to be transmitted is scanned or analyzed into a succession of constituent elemental or unit areas of positive and negative surfaces. The positive or negative nature of each such elemental or unit area is then communicated by a telegraphic signal from the sender to the receiver, where it is recorded upon a suitable receiving surface such as a paper ta e, for example, according to the nature of the signal, and in directly intelligible form such as lines which constitute letters and/or figures.

An object of this invention is to reduce the width of the band of frequencies necessary to transmit individual lines of letters and figures when the letters occupy one horizontal line and the figures occupy another horizontal line which runs parallel with the first line, but is spaced or offset therefrom.

A further object is to reduce the speed of response required of the recording device and the work which it is required to do.

The receiver includes a printing wheel which is provided on its circumferential surface with symmetrical spiral edges which are adapted to print or record letters and figures upon a receiving tape when said tape is being pressed upon the edges by a platen number which has the form of a knife edge and which is driven toward the paper tape in accordance with the current fluctuations flowing through a movable coil integral with the platen member.

This type of receiving unit is particularly adapted to receive broadcast messages such as news bulletins and stock quotations. In the recording of stock quotations it is customary to print or record the symbols identifying the issues involved in a transaction on a horizontal row, whereas the price or quotation of the issue is printed or recorded on a row parallel thereto, usually offset or below to the right of the letter symbols. Although this printing receiver is particularly well adapted to receive stock quotations, for such a printer to print stock quotations on a receiving tape with the letters and figures offset from each other requires a considerably wider range of frequencies than would be the case if the letters and figures were printed in the same row. If the offset is to be then the range of frequencies required for transmitting letters and figures would be twice the frequency range required for transmitting a single row of letters and/or figures.

In accordance with the present invention, letters and figures may be printed on a receiving tape with a 100% offset without its being necessary to transmit a range of frequencies wider than that required for one row of printed matter. This is accomplished by the provision of two platen members instead of one, one platen being designed for reproducing characters in one line and the other for reproducing characters in the second or offset line, the edges of these platen members being in a line and operating against a widened printing wheel. Two transmitters are required at the transmitting station, one for sending the characters of one line and the other for sending the characters of the other line. One of the transmitters is so connected into the circuit as to apply positive impulses to the line, and the other so as to apply negative impulses to the line. At the receiving station, the moving coil operated by the transmitted current which 0perates one of the platen members is designed to respond to positive impulses, and the moving coil operating the other platen is designed to respond to negative impulses. In this manner one of the moving coil units will reproduce the characters in one horizontal row, while the other moving coil unit will reproduce characters in a horizontal row parallel to said first row, and the width of the range of frequencies required is thus considerably reduced.

The invention may be more fully understood from the following description when read with reference to the attached drawing of which:

Figure 1 shows a schematic drawing of the system;

Fig. 2 shows a perspective view of the receiving apparatus; v

Fig. 3 shows a side and partial sectional view of the receiving apparatus;

Fig. 4 shows a portion of the tape with symbols recorded thereon; and

Fig. 5 shows the details of a typical transmitting cam for generating current impulses representing the symbols to be transmitted.

Referring now to Fig. l, S represents the sending station connected to a receiving station R by the telegraph line I. The transmitter at the sending station S has two sets of transmitting cams 3 and 4 mounted on shaft 2. Shaft 2 is rotated by a motor through suitable gearing and clutches which are not shown since they form no part of the present invention. Cams 3 are connected to positive battery 9 through brushes l l, switches 5 and resistance 1. In a similar manner cams 4 are connected to negative battery It! through brushes I2, switches 6 and resistance 8. Switches 5 and. 6 represent a method of selecting the various cams and may be controlled in any suitable manner, such as a keyboard or tape. The cams may also be selected by other means such as friction clutches and latches or by raisingand lowering the brushes associated with each cam which in turn could be controlled by a tape or a keyboard. As shown these cams are connected through shaft 2 to collector ring l3. Ring 13 is connected to line I by brush I4.

The receiving apparatus located at the receiving station R comprises a printing wheel i5, mounted on shaft I6. Shaft l6 may be continuously rotated in synchronism with shaft 2 at the sending station S or

shafts

2 and 16 may be controlled by appropriate start-stop mechanisms. However, since these various methods or" controlling shafts 2 and [6 form no part of the present invention, they have not been illustrated. Printing wheel I5 is provided with a plurality of spiral printing edges or ridges l7. Two sharp edged platens I8 and I9 are supported adjacent this printing Wheel on coils 2i] and 2|, respectively. These coils are supported in radial magnetic fields by spring members 22 and 23 (see Figs. 2 and 3). Paper tape 24 and ink ribbon 25 are pulled between platen l8 and printing wheel I5 through suitable guides (not shown) in any convenient manner.

Coils

20 and 2| aresuspended in radial magnetic fields due to

electromagnets

26 and 2! having

windings

29 and 30 through which a current is passed by battery 28 as shown in Fig. 1.

Coils

20 and 2| are connected to line I so that one of them moves toward printing wheel 15 when a positive impulse is applied to line I at the sending station S and the other coil moves toward printing wheel I 5 when a negative impulse is applied to line I atv sending station S. When coil 20 moves platen 18 towards printing wheel I5 so that the ink ribbon 25 and tape 24 are compressed between platen I8 and printing wheel 45, a mark will be made on tape 24 in one line and when platen l9 presses ink ribbon and tape 24 against printing wheel [5 marks will be made upon tape 24 in the other line. Thus by sending appropriate positive impulses over line I from station S, one of the platen members, say platen l8,will force ink ribbon 25 and tape 24 against printing wheel [5 in accordance with said impulses and thus print the symbol represented by said impulses on the right half of tape 24 as seen in Fig. 1. In a similar manner negative impulses will cause the symbol which they represent to be printed on the left half of tape 24.

The manner in which the impulses are sent which represent various symbols to be recorded will now be described with reference to Figs. 4 and 5. Fig. 4 shows a section of tape with the letter A recorded in the upper row and the numerals in the lower row. As shown, the space on the tape allotted to each symbol is divided up into small unit areas of which there are sixteen along the tape and eighteenacrossthe tape allotted toeach symbol to be transmitted. An impulse is transmitted representing each space if that space is to be darkened or printed in and no impulse is transmitted if there is to be no mark in that space. Time is allotted to transmit the impulses representing these spaces starting with space 32 across the tape to space 33 and then from 34 across the tape to space 35, etc. Fig. 5 shows the manner in which these impulses are transmitted by a typical cam cut to transmit the letter A as printed in Fig. 4. The cam is started to rotate, brushes H or l2 lowered, or switches i and 6 closedat the point marked start 32A on the cam in Fig. 5. As the cam rotates in a clockwise direction as viewed in Fig. 5 the brushes will pass from point 32A to point 33A, but since the cam is cut away no marking impulses will be transmitted so that spaces 32 to 33 would be blank as shown in. Fig. 4. In a similar manner since cam A is cut from point 34A to point 35A, the correspondin spaces 34 to 35 on the tape in Fig. 4 will also be blank. The raised portion 36A will transmit marking impulses which will mark the receiving tape as shown at 36. Raised portion 31A will similarly transmit a series of marking impulses shown at 31 on Fig. 4.. Thus by sending impulses for each space or unit area allotted to each symbol, that is to be marked the entire symbol may be transmitted.

It is also obvious that if it is desired to transmit and record symbols in two lines, each of which must be divided up into unit areas and transmitted over the line, twice as many unit areas must be represented by impulses so that it would take twice as long, or the impulses would need to be transmitted twice as: fast and thus require twice the frequency band asthat required to transmit and record the symbols in one line. However, by employing positive impulses tocause marking in theunit areas of one line and negative impulses to cause marking in the unit areas of the other line on said tape, the symbols may be transmitted at the same speed and with the same frequency band as that required to transmit and record the symbols in a single line, or the time required to transmit the signals, and record them in two lines will be cut in two, or the frequency band cut in two, and thus effect a considerable saving in line time.

A further advantage of this arrangement is that the platens may be smaller and lighter than a single one of double width so that they will respond more readily and faster thana single platen of double width.

The above description of a specific embodiment of the invention is to illustrate rather than restrict the invention, since there may be many modifications of this specific embodiment of the invention within the scope of the appended claims. For example, two separate circuits or radio channels might be employed to transmit the two groups of signals separately. to the two receiving coils, or the signals-might be recorded directly by pressure on a wax coated paper instead of using an inking ribbon and ordinary paper.

What is claimed is:

1. In a facsimile telegraphsystem, means for recording successive series signal impulses whichrepresent elemental areas of symbols in any one of a plurality of rows on a single tape which comprises a plurality of receiving mechanismseach of which comprises impulse receiving means, a platen member controlled thereby, and printing means for receiving and recording impulses representing symbols in the respective rows, and circuit instrumentalities connecting said mechanisms to the telegraph system for controlling said mechanisms in accordance with received signal impulses.

2. A facsimile telegraph system for transmitting stock quotations which comprises a transmitting device, a group of cams connected therewith for transmitting groups of impulses representing unit areas of the stocksymbols, a second group of cams connected with said transmitting device for transmitting other groups ofimpulses representing unit areas of the stock quotations,

a transmission line connected to said two groups of cams and extending to receiving apparatus for recording said impulses on a tape, said receiving apparatus having receiving and recording means for receiving and recording the impulses representing the stock symbols in one row on said tape and having other receiving and recording means for receiving and recording impulses representing the quotation on a second row on said tape which is parallel to but displaced from said first row.

3. In a facsimile telegraph receiver adapted for the reception of letter characters and figure characters, a rotating printing wheel provided with a plurality of spiral printing edges, means actuated by the received current impulses for reproducing letters and figurespnd an ink ribbon and a paper tape intermediate said printing wheel and said means, said means having a plurality of independently actuated platen members arranged offset one from the other.

4.. In a facsimile telegraph system adapted to record stock quotations, a receiver having a drivon printing wheel provided with a plurality of spiral printing edges, a plurality of platen members offset each from the other, means for individually moving said platen members toward and away from the circumference of said printing wheel, an impression recording tape intermediate said wheel and said platen members, and means connected to said platen moving means whereby the quotations are recorded in one row and the symbols representing the stool: are recorded in a second row offset from said first row.

5. In a stock quotation system, a facsimile telegraph system having means for reducing the time required and record symbols representing the stock in one row and the quotations in another row offset from said first row with at least as narrow a frequency band as required to transmit and record both types of symbols in a single row which comprises a receiving mechanism having two independent platens one of which records the stock symbols and the other the quotation, independent means for controlling said platens, and circuit instrumentalities connecting said controlling means to said system whereby said platens are actuated in accordance with received impulses representing said symbols.

6. A facsimile telegraph system comprising a transmitter having means for translating symbols into positive telegraph impulses and other means for translating symbols into negative telegraph impulses, a receiver having means for ranslating negative telegraph impulses into the corresponding symbols and for recording said symbols in a straight line, said receiver having other means for translating positive impulses and recording the corresponding symbols in a second row offset from said first row of symbols, and a telegraph transmission channel connecting said transmitter and said receiver.

'7. A facsimile telegraph receiver comprising a rotatable printing wheel provided with a plurality of spiral printing edges, a platen member adjacent thereto, means for actuating said platen in response to positive telegraph impulses, a second platen adjacent said printing wheel, means for actuating said second platen in response to negative telegraph impulses, a tape and ink ribbon between said printing edges and said platens whereby said positive impulses are recorded on one portion of said tape and said negative impulses are recorded on another portion of said tape.

EDWARD F. WATSON.