US2771336A - Image control tube and method of printing - Google Patents

Description

Nov. 20, 1956 J, F, MacGRlFF IMAGE CONTROL TUBE AND METHOD OF PRINTING Filed Feb. 14, 1952 IN V EN TOR.

ATTomYEK United States Patent INIAGE CONTROL TUBE AND METHOD OF PRINTING Jack E. MacGrilf, Detroit, Mich. Application February 14, 1952, Serial No. 271,579 7 Claims. (Cl. 346-74) This invention relates to an image control tube, and more particularly to a cathode ray tube together with mechanism for utilizing said tube for transmitting an image upon a moving web.

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

It is the further object of this invention to provide a novel cathode ray tube adapted for transmitting and effecting the application of an image to a moving web permanently thereon.

It is the further object of this invention to provide a novel cathode ray tube with conductors in the end face thereof for transmitting electron rays from the tube to an electrode spaced therefrom.

It is the further object of this invention to provide a mechanism for utilizing said transmitted electron rays for depositing a permanent image upon a moving web of image receiving material spaced intermediate said conductors and said electrode.

It is the further object of this invention to provide a novel method and apparatus of image printing upon a moving web.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawing in which:

Fig. 1 is a diagrammatic partially sectioned elevational view of the present image control tube as used for printing upon a moving web.

Fig. 2 is a perspective view of the image control tube.

Fig. 3 is an enlarged perspective view of the high voltage electrode used in conjunction with said tube.

Fig. 4 is a diagrammatic illustration of a simple mechanical scanner for producing a video image signal from a permanent image upon a rotatable drum.

Fig. 5 is a fragmentary plan view of a portion of the illustration of Fig. 4 showing the relation between the light shield, the revolving disc and the screen employed in said mechanical scanner device; and

Fig. 6 is a perspective view illustrating the relation between the shield, the disc and the screen.

It will be understood that the above drawing diagrammatically illustrates merely one embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereafter set forth.

Referring to the drawing, the present image control cathode ray tube includes a hollow glass envelope with an enlarged portion 11 terminating at its smallest diameter in the elongated cylindrical shank 12 which is closed at its end as shown in Fig. 1. The enlarged portion 11 terminates in the end face 13 which is arranged substantially at right angles to the longitudinal axis of the tube shank and is relatively thickened with respect to the other portions of the tube. The end face 13 is constructed without a fluorescent screen as commonly used, and instead has formed or molded within said end face a plurality of elongated parallel spaced conductors 14, which are arranged in a row AB across said end face as shown in Fig. 2.

Said conductors are sealed within end face 13 so that their corresponding ends terminate at or adjacent the corresponding inner and outer surfaces of end face 13.

Said conductors are arranged in parallel insulated relation to each other and are parallel to the central longitudinal axis of the tube 11-12. The interior space 15 of the tube is evacuated to a high vacuum in the conventional manner.

The present tube has centrally and axially housed therein adjacent the closed end of the tube shank 12 a standard cathode-electron-gun assembly 16 including the cathode emitting element 17 which is connected by the lead 18 to the power line 19.

Said electron gun assembly also includes the forwardly arranged axially aligned cylindrical control grid 20 and the two forwardly arranged axially aligned accelerating anodes 21 and 22. The voltages of the control grid 20 and the anodes 21 and 22 are progressively increased with respect to each other towards the enlarged end of the tube for controlling the velocity of electron beam 23.

It is understood that the control grid 20 in response to image signals 54 through the lead 26 regulates the quantity of electrons which make up the electron beam 23 at any instant.

The tube or the electron beam 23 is focused by the focusing coil 24 which is suitably energized in a conventional manner. There is also provided a conventional deflection yoke 25 around the tube shank.12 whereby the electron beam may be deflected magnetically in a conventional manner. The upper and lower coils 25 are adapted to bend the electron beam to the right or to the left of the geometrical longitudinal axis of the tube. The other two deflection coils, one of which is shown in dotted lines, arranged on diametrically opposite sides of the tube shank, are adapted to bend the electron beam upwardly or downwardly. In the present embodiment said latter deflection coils are employed to maintain the electron beam in a horizontal plane which passes through the row of conductors AB shown in Fig. 2. It is contemplated that the deflection of the electron beam could also be effected electrostatically, if desired.

As it is the purpose of the presentdevice to effect merely a horizontal deflection of the electron beam for intermittent and successive registry with the various con doctors 14 arranged in the row AB, it is understood 'that no vertical deflection of the beam is contemplated except such as might be necessary to align the beam with the row of conductors AB, Figs. 1 and 2.

Image control lead 26 to the grid 20 is connected with the power source 19 by the lead 27 shown in Fig. 1.

A moving web 28 of paper or other image receiving material is arranged forwardly of the end face 13 of said tube and bears against drum 29 which revolves at a constant speed upon its horizontal axis 30 arranged parallel to and spaced from the row of conductors 14 in the tube end face 13. As shown in Fig. 1 the web 28 is moving upwardly from the drum 29 and as it passes the row A-B of conductors 14 said Web is spaced closely to the outside face of said tube a short distance measured in thousandths of an inch, such as .008 of an inch, for

illustration. 'It is contemplated, however, that this space is variable depending upon the voltages employed and other factors hereafter described.

The high voltage stationary electrode blade 31 has a thin electron receiving edge 32 arranged parallel to and opposite from the row AB of conductors 14 in the tube face 13. Said electrode is positioned upon the inside of the revolving drum and remains in the stationary position shown in Fig. 1.

The formed housing 34 is so arranged and associated with-respect to the end face of said tube and the web .28 as to provide a passageway for a suitable pigment in the form of smoke 36 which is drawn from a smoke pigment generator 34' and is forced between the conductors 14 in the tube face and the moving web of paper.

This smoke pigment may be exhausted or recirculated through the blower 35 and conducted through the continuous housing element 34 which is fragmentarily shown, for illustration. A constant density of smoke pigment is maintained at the space between the row of conductors 14 and the web 28 of image receiving material.

Operation When the tube is operating, the high voltage electron beam 23 is caused to scan the row of conductors 14 by the magnetic scanning field produced by the deflection yoke 25. By varying the intensity of the scanning field the electron beam 23 will be so deflected as to intermittently scan the row of conductors 14 starting at point A and moving across to point B, Fig. 2.

If the row of conductors 14 is horizontal to the base of the device as', in the present embodiment, then only the horizontal scanning field is actuated by the standard saw-tooth signal, with the electron beam moving from point A to point B during the slow moving horizontal signal and returning from point B to point A during the rapid-retrace or flyback signal in the conventional manner.

As above set forth the vertical scanning field of the defiection yoke 25 is used only to position the scanning trace of the electron beam 23 on the row A--B of conductors 14.

As shown in Fig. 1 the Web 28 is adapted to move vertically past the face of the tube. The image signal designated by the numeral 54 is fed to the control grid 20 of the electron-gun-assembly 16 by the lead wire 26. The highvoltage electron beam is emitted from the cathode .17 in the quantity allowed by the instantaneous image signal on the control grid. The electron beam 23 passes through the scanning field controlled by the deflection yoke25 and strikes one conductor 14, passes through the same and through the face of the tube; and then passes through the smoke pigment 36 and the web 28 and completes the electrical circuit to the high voltage electrode 31-32 inside the rotating drum 29.

As the electron beam 23 passes through the smoke pigment 36, particles of the pigment are carried by the beam to the paper and impinge upon the paper and into the surface of the paper or other image receiving material 28 in a permanent manner.

Thesmoke pigment 36 may carry an electrostatic or electromagnetic charge to assist in the image deposition upon the web 28, which charge is formed in a standard and conventional manner.

Thus, with the yoke 25 causing the beam 23 to sue-- cessively scan conductors 14 from one end to the other of row AB of said conductors, it is apparent that particles of the pigment will be deposited upon the web in a row corresponding to the row of conductors. Thus, as the web 28 of paper or other material moves, image lines will be formed across web 28 in such a manner that the image formed on and in the paper by the pigment particles corresponds to the amount of electrons passed by the control grid 20.

Therefore, it follows that the image on and in the web 28 is controlled by the image signal 54 to the electrongun-assembly 16.

The high voltage electrode 31 is operated at a higher potential than the accelerating anode 22; and the latter anode is at a higher potential than accelerating anode 21. Furthermore, the latter anode 21 operates at a higher voltage than the cathode emitter 17. The control grid 20 is operated at a lower potential than said cathode emitter 17. The instantaneous and varying potential of the grid 20 as regulated by the image signal 54, thus controls the deposition of smoke pigment upon the web 28 in a row corresponding to the row of spaced conductors 14.

Magnitudes of the various voltages depend upon various factors such as the dimensions of the tube 11--12, the web thickness, the distance of the row of conductors from the surface of the web on the revolving drum, and the density and substance of the smoke pigment 36.

The image control tube above described may be operated from a non-interlaced television type video signal, or may be operated from the simple mechanical scanner shown in Figs. 4, 5, and 6 for producing image signal 54, for illustration.

To produce the same image many times upon a web of paper, such as in printing, a master image 37 is secured to the rotatable drum 38 having a longitudinal axis 39.

Light from a lamp 40 illuminates a strip 41 of the image parallel to the axis 39 of the revolving image drum 38.

This strip 41 of image is focused by the lens 42, which is spaced forwardly of said drum 38, unto a suitable rectangular screen 43 which may be constructed of milk glass, said screen being suitably spaced from lens 42 as diagrammatically indicated in Fig. 4.

A revolving disc 44 is driven by the motor 45 and has formed therein adjacent its periphery a plurality of circumferentially spaced radial slots 46.

A rectangular light shield 47 with elongated longitudinal slot 48 is spaced forwardly of the revolving disc 44 as shown in Fig. 4 and in Fig. 6. Thus, the revolving disc so moves its slots 46 with respect to the light shield slot 48 as to permit only a spot 49 of the image line 41 to be focused by the lens 42 upon the screen 43 at any instant.

Thus, a moving spot of light is produced upon the screen 43 formed by the shielding effect of the slots 46 in the revolving disc 44 and the slot 48 of light shield 47 in the manner illustrated in Fig. 6.

A suitable lens 50 spaced from the screen 43 focuses all points 49 on the moving line traced by the moving spot of light on to the mirror 50 which in turn reflects the same on to the sensitive photocathode of a photo multiplier tube 51. Variations in light intensity received by the photomultiplier are transformed into variations in electrical current, which are directed by the lead 52 to the amplifier 53 and are fed as image control signals 54 to the grid 20 of the image control tube by means of the lead 26 shown in Fig. 1.

The master image drum 38 is synchronized with the movement of the web 28. The horizontal scanning frequency of the deflection yoke 25 is synchronized with the revolving disc slots 46 to reproduce on the moving web 28 the image lines 41 scanned by the device on the master image drum 38.

I A light beam from the lamp 55 shown in Fig. 6 is allowed to fall upon the photo-tube 57 arranged upon the opposite side of disc 44 from lamp 55, as each shutter slot 46 passes. The pulse-signal from photo-tube 57 is used as a synchronizing signal for the horizontal scanning electronic circuit for the deflection yokes 25 in the image control tube 11ll2, and locks the scanning oscillator of said deflection yoke in step with rotating disc 44.

The speed of the scanning disc 44 is fixed as operated by motor 45 and depends on the number of shutter slots 46 and the desired number of image trace lines per picture or image.

As one shutter slot 46 completes its travelpast the horizontal slot 48 of light shield 47, another shutter slot 46 is just beginning to travel past slot 48 at its opposite end. Thus, a continuous series of trace line signals are scanned from the master image drum.37'-38 and are reproduced instantaneously by the high voltage electron beam 23 passing through the individual conductors 14 and forcing particles of the smoke pigment 36 into and upon the moving web 28, which may be paper or some other image receiving material.

Instead of the simple mechanical scanner diagrammatically illustrated in Fig. 5, the image signal producing device may be any standard television type pick-up tube, such as an image dissector, iconoscope, or image orthicon, With a non-interlaced trace.

Having described my invention, reference should now be had for determining the scope thereof.

I claim:

1. In an image control cathode ray tube, an evacuated glass envelope having an elongated cylindrical shank closed at one end and having an enlarged portion at its other end terminating in an end face at right angles to the longitudinal axis of said shank, an electron gun assembly within the closed end of said shank, a plurality of straight elongated spaced conductors within said end face parallel to said longitudinal axis and arranged in a row, a deflection yoke surrounding said shank adjacent said enlarged portion exteriorly energized electrically to produce a continuously changing field, the electron beam from said gun assembly being deflectable from a path in alignment with said longitudinal axis for transversely scanning said row of conductors throughout its length for separate transmission through each of said conductors to the exterior of said tube, a stationary electrode blade spaced from the face of said tube on its exterior and arranged parallel to and opposite from said row of conductors, a moving web of image receiving material positioned between said blade and said row of conductors in spaced relation, and a confined smoke pigment of constant density between said row of conductors and said web, whereby the scanning electron beam as it passes through said conductors successively to said blade carries particles of said pigment to said web for impingement thereon in a permanent manner, to thereby form a row of pigmented elements and a plurality of :such rows upon continued movement of said Web, the quantity of particles deposited in a row upon said web corresponding proportionately to the quantity of electrons passed through a particular conductor controlled by the instantaneous image signal applied to said electron gun assembly.

2. In an image control cathode ray tube, an evacuated glass envelope having an elongated cylindrical shank closed at one end and having an enlarged portion at its other end terminating in an end face at right angles to the longitudinal axis of said shank, an electron gun assembly within the closed end of said shank, a plurality of straight elongated spaced conductors within said end face parallel to said longitudinal axis and arranged in a row, a deflection yoke surrounding said shank adjacent said enlarged portion exteriorly energized electrically to produce a continuously changing field, the electron beam from said gun assembly being deflectable from a path in alignment with said longitudinal axis for transversely scanning said row of conductors throughout its length for separate transmission through each of said conductors to the exterior of said tube, a stationary electrode blade spaced from the face of said tube on its exterior and arranged parallel to and opposite from said row of conductors, a continuously rotating drum with its axis parallel to said row of conductors, said electrode being on the interior of said drum, a web of image receiving material on the outside of said drum and movable therewith positioned between said blade and said conductors in spaced relation, and'a confined smoke pigmentof con stant density between said row, of conductors and said web, whereby the scanning, electron beam as. it passes through said conductors successively to saidblade carries particles of said pigment to said webfor impingement thereon in a permanent manner, to thereby form a row of pigmented elements and a plurality of suchrows upon continued movement of said web.

3. In' an image control cathode ray tube, an evacuated g ass envelope having an elongated cylindrical shank closed at one end and having an enlarged portion at its other end terminating in an end face at right angles to the longitudinal axis of said shank, an electron gun assembly within the closed end of said shank, a plurality of straight elongated spaced conductors within said end face parallel to said longitudinal axis and arranged in a row, a deflection yoke surrounding said shank adjacent said enlarged portion exteriorly energized electrically to produce a continuously changing field, the electron beam from said gun assembly being deflectable from a path in alignment with said longitudinal axis for transversely scanning said row of conductors throughout its length for separate transmission through each of said conduc tors to the exterior of said tube, a stationary electrode blade spaced from the face of said tube on its exterior and arranged parallel to and opposite from said row of conductors, a continuously rotating drum with its axis parallel to said row of conductors, said electrode being on the interior of said drum, a web of image receiving material on the outside of said drum and movable therewith positioned between said blade and said conductors in spaced relation, a confined smoke pigment of constant density between said row of conductors and said web, whereby the scanning electron beam as it passes through said conductors successively to said blade carries particles of said pigment to said Web for impingement thereon in a permanent manner, a formed housing adjacent said web and end face of said tube for delivering a moving smoke pigment of constant density between said row of conductors and said web, and a blower in said housing for circulating said smoke pigment.

4. A method of printing comprising movably positioning an image receiving web With a high voltage electrode spaced from one side thereof, arranging an image signal receiving cathode ray tube upon the other side of said web with its end face spaced therefrom, passing a confined pigment in smoke form of constant density between said Web and end face, focusing the electron rays from said tube to pass to said end face in a line lying in a plane extending through the longitudinal axis of said tube, successively deflecting the image signal controlled electron rays in a direction parallel to said web, conducting said rays through said end face, through said smoke to said electrode whereby particles of said pigment are impinged in spaced relation in a corresponding line upon said Web in a permanent manner.

5. In a printing device adapted for use with a cathode ray tube constructed for transmitting electron beams beyond its end face; a stationary electrode blade spaced from the face of said tube and adapted to receive said electron beam, a movable Web of image receiving material interposed in spaced relation between said blade and said tube end face, and a confined smoke pigment of constant density between said end face and web, whereby said electrom beam scanning said end face and in passing to said conductor carries particles of said pigment to said web for impingement thereon in a permanent manner to thereby form a row of pigmented elements and a plurality of such rows upon longitudinal movement of said Web past said conductor.

6. The printing device of claim 5, and a continuously rotating drum with its axis lying in the plane of said electrode, and with said electrode arranged upon the interior of said drum, said web being movably mounted 1 7 upon the outside of said drum, spaced from said endface and in contact with said smoke pigment.

' 7. The printing device of claim 5, a continuously rotating drum with its axis lying in the plane of said electrode, and with said electrode arranged upon the interior of said drum, said web being movably mounted upon the outside of said drum, spaced from said end face and in contact with'said smoke pigment, a formed housing adjacent said web and end face for delivering said smoke pigment between said end faceand web, and a blower in said housing for circulating said smoke pigment.

, References Cited in the file of thispatent UNITED STATES PATENTS Selenyi Aug. 11, 1931 Sabbah et a1 Sept. 24, 1935 Finch Oct. 26, 1937 Bruce May 12, 1942 Kernkamp July 28, 1942 Salz June 21, 1949

Images