US2934673A - Image control tube - Google Patents

Description

April 26, 1960 J. E. M GRlFF IMAGE CONTROL TUBE Filed Aug. :51, 1956 1 INVENTOR.

E. MACGRIFF.

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V the construction and assembly of 1 2,934,673 IMAGE CONTROL TVUBE Jack E. MacGriif, Detroit, Mich. Application August 31, 1956, Serial No. 607,446 Claims. c1. 315-85) to image tubes, and more particularly to the structure of 'an image control tube.

This application is a continuation in part of my copending application Serial No. 271,579 filed February 14, 1952, now U.S. Patent No. 2,771,336 relating to an Image Control Tube and method of printing.

It is the primary object of present invention to provide a novel image control cathode tube.

It is the further object of this invention to provide in such a tube a row of conductors in the end face thereof adapted for transmitting electron rays from the tube. These and other objects will be seen from the following specifications and claims in conjunction with the appendeddrawing in which:

Fig. l is a diagrammatic elevational view of the present image control tube, and certain electrical connections.

Fig. 2 is a right Slde elevation thereof showing itsend v This invention 7 relates wall.

Fig. 3-is a perspective view of one form of the present Fig. 4 is a fragmentary elevational section of the end portion of the tube shown in Fig. 1, on increased scale. Fig. 5 is a vertical section of one form of apparatus employed in making the glass conductor strip for the Fig. 5(a) is a similar view showing the complete apparatus for this purpose. a

Fig. 5(b) is a perspective composite viewillustrating said apparatus.

Fig. 5 (c) is a perspective view of the partly finished conductor strip.

Fig. 6 is an elevational view of the initial step in a different method of constructing the conductor strip.

Fig. 6(a) is a side elevational view thereof.

Fig. 6(b) is an elevational view of the partly finished "conductor strip.

Fig. 6(c) is an end elevational view thereof.

Fig. 6(d) is a similar view of the completed conductor strip- Fig. 7 is a diagrammatic view-of the end face of the tube showing a slightly different method of operation than that shown in Fig. 1.

Fig. 7(a) is a similar view operation of this method.

- Fig. 7(b) is a similar view'of a slightly different method of operation.

Fig. 7 (c) is a similar view illustrating diagrammatically a slightly different method of operation.

Fig. 8 is a diagrammatic view of amultiple tube system for using small tubes-to form a large image.

Fig. 9 is a diagrammatic plan view thereof.

Fig. 10 is a diagrammatic view illustrating the use of the multiple tube system in conjunction with a sensitized tape fragmentarily shown.

It will be understood that the above drawing illustrates merely several preferred embodiments of the invention and several variations in the method of operation. It is understood that the other embodiments are contemplated within the scope of the Referring to the drawing the present image control cathode ray tube includes a hollow evacuated glass envelope 1 which includes the cylindrical shank C and the outwardly flared end portion D. Shank C is closed at further illustrating the 'claims hereafter set forth.

res Fa c deflection of a magnetic deflection system could be substituted if deits end as in Fig. 3; whereas the minates in the upright end face 6 which is arranged in a plane at right angles to the longitudinal axis of'the tube and is relativelythickened with respect to the other sandwich 7 of glass plates and parallel electrical con- 9 therebetween are housed within end face 6 in the manner hereafter described. Said conductors are so sealed within said end that the corresponding ends of said conductors terminate respectively 'at the inside and the outside of the said end face for conduction therethrough selectively of a controlled electron beam. Conductors 9 are arranged in parallel insulated relation to each other, lie in a single planepassing through the longitudinal axis of said tube and are parallel thereto.

A pair of electro-static deflection plates 3 are provided for controlling the horizontal deflection or trace of electron beam 11 shown in Fig. 1. A second pair of electro-static plates 4 are shown for regulating vertical said electron beam. It is contemplated that ductors sired.

An interior conductive coating 5 of copper, graphite, silver, platinum or the like is arranged'upon the inte rior of the walls of the tube towards its enlarged end, and serves as a second anode high-voltage acceleration source for the emitted electron beam 11, as is standard practice in the art.

The electron gun assembly 2 includes the cathode ray emitting element 35 which power line 37.

Said electron gun assembly also includesthe forwardly arranged axially aligned control grid 38 and thetwo forwardly arranged axially aligned accelerating anodes 39 and 40. The voltages of the control grid and the said anodes are progressively increased with respect to each other towardthe enlarged end of the tube for controlling the velocity of electron beam 11 in a conventional manner. Control grid 38 responds to image signals 41 through the lead 42 for regulating the quantity of electrons which make up the electron beam 11 at any instant; Deflection plates 4 are, employed to maintain the electron beam 11 in a horizontal plane which passes through the row of conductors 9 as in Figs. 1 horizontally of said beam is controlled by plates 3.

It is the purpose of the present horizontal deflection of the electron beam for intermittent and successive registry with the various conductors 9 and arranged in the row as shown in Fig. 3. I

In use there is provided closely adjacent the exterior of tube 1 a high-voltage stationary electrode blade144 supported at 44, and having a thin electron receiving edge 45 arranged parallel to and opposite from the row connected to the power source by the 1ead'46.

When the tube is operating, the high-voltage electron beam 11 is caused to scan the row of conductors 9 by the scanning field produced by a suitable deflection means well known in the art. of the scanning field the electron beam 11 willbe so deflected as to intermittently scan the row of conductors 9 starting from one end and moving across to the other end as in Fig. 3.

The horizontal scanning field is actuated by a stand;

ard saw-tooth signal with the electron beam moving: from one end to the other of, said row of conductors the slow moving horizontal signal and returningv during the rapid Ie-trace way."

during to its beginning point back signal in'the conventional manner.

enlarged portion D teris connected by lead 36 to 1 and 3. The deflection.

device to effect a By varying-the intensity High voltage electrode 44 is operated at a higher potential than the accelerating anode 40; which in turn is at a higher potential than anode 39; which latter operates at a higher voltage than emitter 35. Control grid 38 is operated at a lower potential than said emitter. The instantaneous and varying potential of control grid 38 is regulated or modulated by the image signal 41, thus controlling the instantaneous quantity of electron flow in beam 11.

The above described image control tube may be operated from a non-interlaced television type video signal, or may be operated from a simple mechanical scanner, such as shown and described in the above mentioned copending patent application Serial No. 271,579, now US. Patent 2,771,336.

In the construction of the present tube, a slot of rectangular cross-section is cut in end face 6 or formed therein when the tube blank is made, and which extends substantially across the tube end face, as shown in Figs. 3 and 4.

The conductor-sandwich is sealed into the tube end face by a low temperature fusing point glass, such as Corning type 7570, for example. These sealing fillets are shown at 10 in Fig. 4. The sandwich includes a pair of glass strips 8, positioned and immovably retained on opposite sides of the row of electrical conductors 9.

Metal plates or screens of fine wire may be positioned at 12 above and below the conductor assembly 7, and as shown in Fig. 4, and are electrically connected to the interior conducting coating 5 which latter is suitably grounded as at 37, Fig. l.

A strip of material which will fluoresce when struck by the electron beam is arranged upon end wall 6 as at 13. This is in the nature of a standard Phosphor screen which will emit light for example, for focusing and centering electron beam 11. The centering line of the row of conductors 9 is generally designated at 21' in Fig. 2.

To make this tube, the glass and conductor strip 7 is inserted in the slot in end face 6, and sealed with the fillets 10 above described, which is a low temperature fusing glass. The other parts of the tube such as the interior coating 5, the electron gun and grid assembly 2 and the evacuation are standard in the art. The conducting screens 12 Fig. 4 may be inserted before the strip 7 is sealed in place.

Several methods may be employed in the construction of the above mentioned conductor strip. One such method is illustrated in Figs. 5, 5(a), 5(b), 5(0). A carbon block 14 has a slot 15 milled in the top thereof. The carbon block is then put in a lathe and the exterior turned on two sides producing the continuous fragmentary threads 19 as in Figs. 5(a) and 5(b). These threads form a part of a continuous helix and are spaced apart the same as the desired spacing of the wires 9 in the glass sandwich, as for example, 300 to the inch.

A thin strip of glass 16 is placed in the milled slot 15, and fine wire with the same co-eflicient of expansion as the glass is wound around block 14 and glass strip 16, as shown in Fig. 5 (b). When the wire is wound the length of the strip, the ends of said wire are suitably anchored to the block. A second. glass strip 17 is placed on top of the first strip 16 as shown in Figs. 5(a) and 5(b). A carbon plate 18 with a milled opening to fit this second glass strip, is then placed around the strip 17 as in Figs. 5(a) and 5(b); the assembly is then placed in an electric furnace and heated to fusing temperature of the glass. The glass flows together fusing around the wires. Thereafter said wires are cut at the bottom of the carbon block after the unit has cooled and the strip 7 including the individual wires 20 is produced as shown in Fig. 5(a). The wire ends are-then trimmed, and likewise the edges of the-strip 7 are ground to shape. The said wires are then identified as the row of parallel conductors 9 shown in Figs. 1, 2, 3 and 4.

Instead of the glass strips 16 and 17, powdered glass 4 could also be used in the assembly, after the wires are wound around the carbon block to thereby produce the conductor assembly 7 of the Fig. 5(a).

Another method of making the conductor strip is shown in Figs. 6, 6(a), 6(1)), 6(0), and 6(d). A glass strip 8 is coated with a metallic conductor diagrammatically indicated at 21, which may be silver, platinum, copper of any other standard metal. The strip may be coated by evaporation in vacuum or by painting on a liquid solution of the metal and firing in a furnace in standard manner well known in the art.

After the metallic coating has been applied to the glass strip in Fig. 6, the surface of this metal is then coated with a photo-resist, and thereafter exposed to a light image of stripes. The photo-resist is developed and the metal etched off where there is no image leaving a row of parallel spaced conductors 9 Fig. 6(b). This etching method is commonly employed for printed circuits in the electronic trade. A second glass strip 8 is then fused over the metal conductors 9 and the first glass strip 8 completing the assembly shown in Fig. 6(d).

A third method of preparing these strips is by using a photo-sensitive glass, such as manufactured by Corning Glass Company, and which can be etched after exposure to ultra-violet light. Grooves or holes so etched, can be filled with a conducting metal, and the surfaces ground smooth. The grooves can also be made in a ruling machine if desired, such as used to produce diffraction gratings.

One method of operation of this tube in reproduction apparatus is to modulate the electron beam 11 which passes through the conductors 9 and tube end face 6 by a standard grid control assembly 2 such as shown in Fig. 1. The control grid 38 in response to image signals 41, Fig. 1 through the lead 42 regulates the quantity of electrons which make up the electron beam 11 at any instant, as more fully described herein above. When using a control grid to modulate the electron beam, the beam is cut off intermittently, as in shutting a gate, to stop the electron flow at any particular time or to any particular conductor in the time path of the horizontal sweep across the conductor row 9.

Another method of operation is shown in Fig. 7 wherein the end face of the control tube is designated at 6, and 21' designates the center line of the row of conductors 9. The path of the electron beam as it sweeps across the tube face with horizontal deflection controlled by a saw-toothed wave form in a standard manner, is. designated at '22, Fig.7. The electron beam is swept across the tube face just below the row of conductors, as also shown at B-B in Fig. 4. To produce current flow through any conductor 9, the vertical deflection is actuated and beam trace is moved up to impinge on a conductor or series of conductors as desired. See the path A-A of Fig. 4.

In Fig. 7(1)) a variation of this is shown. The vertical deflection system is actuated by a sine wave of high frequency, the frequency depending on the number of conductors and the sweep time, but so arranged that the peak of each sine wave is just below each conductor. To produce current flow, the vertical deflection is actuated, as in Fig. 7(a), to move the peaks of the sine waves up to impinge on any particular conductor desired, as shown at 22(0).

Fig; 7(a) is a further variation, with the sine-wave systern on the vertical deflection system, but instead of the vertical deflection system being actuated to move the electron trace up, the amplitude of the sine-wave oscillations is increased, so that the peaks of the trace impinge on the conductors through the end face as at 22( b). Of course, all electrons that do not pass through the end faceare collected by the wire mesh or metal plates at (12) .and the interior coating (5).

, By using these systems, full beam current is maintained at -,all times, even though only a portion of the electron being in the second 7 fed to separate sets of image tubes, 30 and 31 such as in Y forming a large obtain an image resolution of beam passes through the conductors depending on the signal on the vertical deflection system of the amplitude of the sine wave oscillator output, as described. In small tubes the design can be flat at shown at D in Fig. 3 but in big tubes they must be round to withstand atmospheric pressure dueto the evacuated interior.

One difliculty in constructing these tubes is in getting large tubes with perfect conductor rows, and the expense of large tubes and the impossibility of practically constructing tubes over a certain size, due to mechanical considerations and the force exerted by atmospheric pressure on the evacuated envelope. One solution to this is shown in Figs. 8-10.

In 'Fig. 8, a revolving drum (23) illuminated at 24 with the image to be reproduced is set up in front of a lens (25), image-splitting mirror (26) and two rows of image pick-up tubes, such as iconoscopes or image orthicons, etc., at (27) and (28). A top view of this is shown in Fig. 9. The tubes are so staggered and arranged that portions from the various image areas designated 1-2-- 3-4-5-6-7-etc., are focused on particular pick-up I tubes such as 27(a), 27(b), 27(c) Fig. 9, or the other tubes numbered 1, 3, and 7, with every second tube row. Signals from these tubes are Fig. at 1--2-3-4-56-7. As the image receiving web (29') passes the image tubes, by a suitable pigment deposition system (see my application 271,579) or by using electro-sensitive paper, the entire image is reproduced. Each of the sets of tubes 30 and 31 correspond to the tube 1 above described with respect to Fig. 1. The spacing between XY is equal to one image length, so that in one image length the tube-image-traces match up on the receiving web and form a complete image. The various signals from the signal tubes 27, 28 can be properly positioned on the image deposition tubes 30, 31 by proper width and centering controls, as is standard in the electronic art.

The signal images can be recorded on magnetic tape, and fed to the image producing tubes 30, 31 in a similar manner.

I have now described my improved tube, several methods of construction of the conductor strip, and several methods of operation. I have also described a multiple tube system for using a plurality of small tubes for image. An additional advantage in the use of such small tubes is that with this system we can 7 500 to 600 lines per linear inch of images regardless of image size; and this is extremely important. Such a construction also cuts down the frequencyor maximum frequencies necessary to pass through the signal amplifier.

While the enevelope has been described as made of glass, it is contemplated that it could be made of any other suitable material such as metal, or ceramics, for illustration. While the envelope has been specifically described as having a cylindrical shank, and an enlarged end portion, it is contemplated that other shapes could also be employed.

Referring to Fig. 1, image control lead 42 to the grid 38 is connected with the power source 37 by the lead 43.

Having described my invention reference should now be had to the following claims.

1. In an image control cathode ray tube including an evacuated envelope having an elongated cylindrical shank closed atone end and having an enlarged portion at its other end terminating in an end wall at right angles to the longitudinal axis of said shank, an electron gun assembly within the closed end of said shank, said gun assembly consisting of an electron emitting element, beam forming and focusing elements which confine said beam to circular cross section, a beam current control grid, and an accelerating anode, and a conductive coating upon the interior of said envelope serving as a high voltage acceleration electrode; the improvement consisting of a glass plate, a series of straight parallel coplanar closely spaced elongated conductors aflixed in insulated position to said plate and arranged in a row, the respective ends of said conductors terminating at the respective inner and outer edges of said glass plate, said glass plate sealed in said tube end wall with said conductors substantially parallel to the longitudinal axis of the tube and with the one end of each conductor exposed to the interior of the tube and the other end of each conductor exposed to the exterior of said tube, so that electrons impressed on the inner ends of said conductors by said electron beams from said gun assembly escape the exterior ends of said conductors to pass through space towards an external accelerating electrode, said electron beam being modulated by said electron gun assembly in response to an exterior signal transmitted thereto, and a deflection system intermediate the ends of said tube exteriorly energized to produce a continuously changing field, the electron beam from said gun assembly being deflectable for scanning said row of conductors throughout its length to provide transmission of electrons through each of said conductors to the exterior of said tube.

2. In the image control tube of claim 1, each of said conductors being of uniform cross section throughout its length.

3. In an image control tube of claim 1, said deflection system being adapted to deflect said beam in a path displaced from and parallel to said row of conductors and being actuated intermittently to displace said beam of electrons to selectively register with and pass electrons through said conductors in quantities determined by the instantaneous signal applied to said electron gun assembly.

4. In the image control tube of claim 1, said deflection system adapted to deflect said beam in a path displaced from and parallel to said row of conductors, said deflection system actuated by a continuous sine wave of high frequency proportional to the number of conductors and to the sweep time to correspondingly deflect said beam in a sinusoidal path, the peaks of said sinusoidal path being displaced from said conductors, said deflection systern being actuated to selectively move the path for registry of individual peaks with said row of conductors.

5. In the control tube of claim 1, said deflection system adapted to deflect said beam in a path displaced from and parallel to said row of conductors, said deflection system actuated by a continuous sine wave of high frequency proportional to the number of conductors and to the sweep time to deflect said beam in a sinusoidal path, the peaks of said path being displaced from said conductors, the amplitude of individual cycles of said sine wave being controlled to determine the length of time the electron beam scans the corresponding conductor and the amount of electrons passing therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 1,579,626 Banta Apr. 6, 1926 2,015,570 Sabbah et a1. Sept. 24, 1935 2,053,268 Davis Sept. '8, 1936 2,097,392 Finch Oct. 26, 1937 2,223,001 Farnsworth Nov. 26, 1940 2,244,260 Power June 3, 1941 2,273,433 Bruce Feb. 17, 1942 2,273,793 Ekstrand Feb. 17, 1942 2,283,148 Bruce May 12, 19.42 2,291,476 Kernkamp July 28, 1942 2,420,846 Strutt et al May 20, 1947 2,526,703 Smith Oct. 24, 1950 2,658,311 Goddard Nov. 10, 1953 2,706,366 Best Apr. 19, 1955 2,829,025 Clemens et a1 Apr. 1, 1958 FOREIGN PATENTS 1,010,023 France Mar. 12, 1952

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