US2368739A

US2368739A - Facsimile recorder

Info

Publication number: US2368739A
Application number: US376616A
Authority: US
Inventors: Blain Albert
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1941-01-30
Filing date: 1941-01-30
Publication date: 1945-02-06
Anticipated expiration: 1962-02-06

Description

Feb. 6; 1945. A, B AIN- 2,368,739

FACSIMILE RECORDER Filed Jan. 30, 1941 2 Sheets-Sheet l Feb. 6, 1945. A. BLAIN 2,368,739

FAGSIMILE RECORDER Filed Jan. 30, 1941 2 Sheets-Sheet 2 I I l I l .l

l. 1 l I I I I I I l I. I I l .I I r I Patented Feb. 6, i945 I 2,368,739 mosmmn mzconpsa Albert Blain, Philadelphia, Pa., assignor to Radio Corporation of America, a corporation of Delaware Application January at, 1941, Serial No. 376,616

2 Claims.

more particularly to facsimile recorders.

In facsimile systems wherein a drum having a helical edge is adapted to rotate in synchronism with a drum supporting the record to .be transmitted, the record may be reproduced on a record surface by causing the helical edge to act upon the surface in accordance with the signals received from the facsimile transmitter.

One method of reproducing records by facsimile consists in impregnating paper .by a substance which will he discolored under the influence of an electric current and to apply this current at single small areas of the picture surface at a time, causing said area to progress systematically over the paper and so varying the current that, at each position of the area, it is proportional to the degree 'of darkening necessary to reproduce the record.

In my copendlng application Serial No. 376,615,

filed Jan. 30, 1941, I have described a method of recording which includes a pair of adjacent drums provided with helical electrodes which intersect on a recording surface. By applying a, signal to the helical electrodes and maintaining one of the electrodesmore positive than the other, a record may be made on a surface adjacent the more positive electrode.

According to this invention, at least two spiral electrodes are supplied to each of two adjacent drums which are adapted to revolve about two parallel axes, such that one electrode on each drum provides a recording spot with its corresponding electrode of the other drum. By maintaining one electrode of one drum positiv with respect to its corresponding electrode on the sec- 'ond drum, and maintaining the second electrode of the second drum positive with respect to its corresponding electrode on the first drum, a record may be made. on 'both sides of a sheet passed between the two drums by applying a signal to each set of electrodes.

The primary object of this invention is to provide a facsimile recorder adapted to record on both sides of a'sheet.

Another object of this invention is to simultaneously record a plurality of facsimile signals. Other and incidental objects of the invention I will be apparent to those skilled in the art'from a reading of the following specification considered in connection with the accompanying drawings in which Figure 1 isan end view of a facsimile recorder,

Figure 2 is a sectional view of Fig. 1,

p v (Cl. 234-59) This invention relates to facsimile systems and Figure 3 is a schematic front view showing the printer drums and the helical electrodes,

Figure 4 is an end view of the printer drum,

Figure 5 is a sectional view of the printer drum, and

Figure 6 is a plan view of the facsimile recorder.

Referring to Fig. l, a spool I carries a roll of paper or other recording surface 3. Below the spool I, a tank 5 is provided with a guide roller 1 under which the paper 3 from the spool I is passed so that it will be immersed in a tank '5 containing a liquid adapted to sensitize the paper 3 and cause its color to be changed upon the application of an electric current. This may be accomplished by means and methods such as shown and described in Zworykin Patent 1,909,142, patented May 16, 1933.

The paper 3 then passes up and over a stationary guide tube 9 rotatably mounted on a shaft l0, under a guide rod II and between the drums l3 andli. Drums l3 and I5 are composed of a non-conductive material. Drum I3 i provided with spiral electrodes l1 and i8 and drum l5 with spiral electrodes l9 and 20.

The paper 3 then passes under the guide rod 2| and over the drive roller 23 and between the drive roller 23 and the pressure roller 25 which is forced against the drive roller 23' .by the spring 21.

Drum l5 and gear 29 are mounted on the shaft 33; Drum l3 and gear 3| are mounted on shaft 32. A gear 33 mounted on shaft l0 engages the gears 29 and 3|.

Fig. 2 shows a guard member 35 which covers the drum l3 whereby the spiral electrodes l1 and I3 are guarded from mechanical damage and the operator is protected from receiving an electrical shock from the exposed and charged'helical elec- Fig. 3 shows a front view of the drums I3 and IS. The similar helical electrodes l1 and I8 are supported upon the surface of the drum l3. The

electrodes l1 and I8 are spaced from each other on the surface of the drum l3. The electrodes l9 and 2|] are similarly supported upon the surface of drum l5. It will be noticed that each electrode intersects its corresponding electrode on the adjacent drum. Thus, electrode [1 intersects the electrode I9 and electrode l8 intersects tact between the associated helical electrodes will move from one end of the drums to the other end of the drums. As each point of intersection approaches one edge or the paper, which is interposed between the printer drums, the same electrodes will intersect again at the other edge of the paper.

If it is desired to have the drums rotate in opposite directions, it is necessary that the electrodes on one drum curve around their associated drum in a direction opposite to that direction which the electrodes of the other drum curve around their associated drum.

If a signal is applied between the electrodes i1 and I9, and the electrode I1 is maintained positive with respect to electrode I3, a record in accordance with the signal will be applied to the surface of the sheet'adjacent the positive electrode H or upon the upper surface of the sheet. If a second signal is applied between the electrodes l8 and 20, and in this case electrode 2|] of the lower drum I is maintained positive with respect to its associated electrode I8, the record will appear on the lower side of the sheet adjacent the more positive electrode 20. Thus, it follows that records may be made simultaneously on both sides of the sheet.

Fig. 4 shows an end view of the printer drum and shows in more detail the slip rings 31 and Each of the slip rings 31 and 39 are connected to one of the spiral electrodes on its associated drum.

Fig. 5 shows a sectional view of the drum and indicates one method in which the cylindrical electrodes I1 and I8 may be attached to the printer drum i3 and to their associated slip rings 31 and 39, respectively. The screw 4| makes con tact with slip ring 39 and the metallic member 43 into which the screw 45 is engaged to support the electrode IS. A screw 41 supports and connects the electrode 31 to the metallic member 49 into which the screw 5| is engaged to support the electrode I1. The two metallic members 43 and 49 are insulated from one another by the insulating strip 53. At the end of the drum opposite to that end on which is mounted the slip rings, there is provided a pair of mutually insulated metallic members 55 and 51 which support the other ends of the electrodes 18 and I1, respectively.

Figure 6 shows the paper and drum drive mechanism. A motor 59, maintained in synchronism with the motor at the facsimile transmitter, is Y mechanically coupled to the shaft l0 upon which The lower gear :9 drives the drum l5 which is.

fixed to the shaft 30 upon which is mounted a worm gear 6| which engages the gear 63 mounted on the shaft 62 supporting a worm gear 53 which, in turn, engages the gear 65 on the shaft including the sheet drive roller 23.

As the paper is passed through the solution contained in the tank 5, it is sensitized so thatif an electric current is passed therethrough, a mark will appear at the point of contact and on the side adjacent the electrode charged positively with respect to its corresponding electrode. The paper thus sensitized passes between the drums l3 and [5 which are rotating in directions shown by the arrows'at the same predetermined rate.

The terminals or brush members 69 and 10 are adapted to make contact with the slip rings 31 and 33, respectively, so that the incoming signals may be applied to the electrodes l1 and IS. The lower drum 15 has a set of similar electrodesbo cooperate with its slip rings for contact during movement of the drums. This is not shown on the drawings.

A transmitter adapted to transmit facsimile signals of the type which may be recorded by a recorder improved in accordance with this invention is one such as shown and described in an article entitled "Facsimile transmission and reception by Maurice Artzt in the Electrical Engineers Handbook. A recorder designed in accordance with this invention is adapted to record two signals such as can be transmitted by such a facsimile transmitter.

Such a signal is applied to each set of electrodes and as the paper slowly moves between the rotating drums l3 and IS, the point of intersection between the paper and the associated electrodes scans the paper from one side to the other and forms a continuous image on both sides of the paper, each image being representative of its respective train of facsimile signals.

While one system for carrying this invention into effect has been indicated and described, it will be apparent to one skilled in the art that this invention is by no means limited to the particular organization shown and described, but that many modifications may be made without departing from the scope of this invention as set forth in the appended claims.

I claim as my invention:

1. In a facsimile recording system, the combination of a pair of adjacent drums adapted to rotate about parallel axes and each of which supports a plurality of mutually insulated helical electrodes, means for feeding a record receiving sheet between said drums and in contact'with adjacent points on corresponding electrodes of each of said drums, means for applying a signal representative of a record to be reproduced between an electrode on the first of said drums and a corresponding electrode on the second of said drums, and means for applying a second signal of opposite polarity to said first mentioned signal and representative of a second record to be reproduced between another electrode on the first of said drums and a corresponding electrode on the second of said drums.

2. In a facsimile recording system, the combination of a pair of adjacent drums adapted to rotate about parallel axes and each of which supports a plurality of mutually insulated helical electrodes, means for feeding a record receiving sheet between said drums and in contact with adjacent points on corresponding electrodes of each of said drums, means for applying a signal of a given electrical characteristic representative of arecord to be reproduced between an electrode on the first of said drums and a corresponding electrode on the second of said drums, and means for applying a second signal having an electrical characteristic which differs from the electrical characteristic of said first mentioned signal and representative of a second record to be reproduced between another electrode on the first of said drums and a corresponding electrode on the second of said drums.

I ALBERT BLAIN.