US2227015A - Picture transmitter - Google Patents

Picture transmitter Download PDF

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Publication number
US2227015A
US2227015A US122032A US12203237A US2227015A US 2227015 A US2227015 A US 2227015A US 122032 A US122032 A US 122032A US 12203237 A US12203237 A US 12203237A US 2227015 A US2227015 A US 2227015A
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Prior art keywords
mosaic
electrons
image
cathode
electron
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US122032A
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English (en)
Inventor
Schlesinger Kurt
Liebmann Gerhard
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LOEWE RADIO Inc
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LOEWE RADIO Inc
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Priority claimed from DEL7402D external-priority patent/DE1033701B/de
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/36—Photoelectric screens; Charge-storage screens
    • H01J29/39—Charge-storage screens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/36—Photoelectric screens; Charge-storage screens
    • H01J29/39—Charge-storage screens
    • H01J29/43—Charge-storage screens using photo-emissive mosaic, e.g. for orthicon, for iconoscope
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/36—Photoelectric screens; Charge-storage screens
    • H01J29/39—Charge-storage screens
    • H01J29/43—Charge-storage screens using photo-emissive mosaic, e.g. for orthicon, for iconoscope
    • H01J29/435—Charge-storage screens using photo-emissive mosaic, e.g. for orthicon, for iconoscope with a matrix of conductors traversing the target
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/26—Image pick-up tubes having an input of visible light and electric output
    • H01J31/265—Image pick-up tubes having an input of visible light and electric output with light spot scanning
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/26—Image pick-up tubes having an input of visible light and electric output
    • H01J31/48—Tubes with amplification of output effected by electron multiplier arrangements within the vacuum space

Definitions

  • the known ikonoscope is a voltage generator, i.
  • the following invention by Kurt Schlesinger and Gerhard Liebmann relates to corresponding modifications of the ikonoscope in which, in contradistinction to the known ikonoscope, electrons are liberated upon the scanning of an accumulating light-electric surface, and in which these electrons are drawn directly on to an anticathode, at which there occurs a current amplification so as known from the multiplier," due to a powerful secondary emission.
  • the currents thus amplified may then be passed further to an additional anticathode and maythus be additionally amplified in the manner already known.
  • the complete operation takes place in the tube according to the invention in a common high vacuum.
  • FIG. 1 and 2 are diagrammatic sectional elevations of electron tubes according to the invention together with a diagrammatic partial showing of the optical and electrical equipment thereof, whereas Fig. 3 is a plan view of a detail of the tube shown in Fig. 2, and
  • Fig. 4 is a diagrammatic elevation of a modification of this detail and its circuits.
  • Fig. 8 is a plan view of a special mosaic structure according to the invention, of which structure Figs. 9 and 10 show a part on an enlarged scale substantially in plan view (9) and in sectional elevation (10).
  • Figs. 11 and 12 again, are showings of a similar type as Figs. 1 and 2 and illustrate certain modifications and improvements according to the invention.
  • Fig. 13 is a plan view of a mosaic structure for use in a tube as shown in Fig. 12.
  • Fig. 1 is illustrated a form of embodiment of the idea according to the invention, in conjunction with which the essential explanations may be given.
  • the image receiving area itself consists of insulated photo-electric particles. These particles lose electrons during the storage period and have the same compensated for by the scanning electron ray In this device, therefore, no new electrons are to be gained during the scanning, but electrons are consumed from the ray. In the arrangements according to the invention these operations, therefore, are modified accordingly.
  • the storage plate must'recover electrons during the period of rest, and these must be liberated point-by-point upon the scanning operation. For this purpose it is proposed first electronoptically to produce on a mosaic surface an electron image of the image-receiving area.
  • Fig. 1 the image receiving area itself consists of insulated photo-electric particles. These particles lose electrons during the storage period and have the same compensated for by the scanning electron ray In this device, therefore, no new electrons are to be gained during the scanning, but electrons are consumed from the ray. In the arrangements according to the
  • the image-receiving area I is a coherent, i. e., undivided photo-electric plate.
  • On to this plate is projected through the objective 2 by way of a small mirror 4 an image of the object 3.
  • an electron image is projected on to a plate I by means of a simple electrical lens comprising the electrodes and 6/
  • This plate I in turn consists of an insulating sheet of mica 8, which is furnished on the side directed towards the interior of the tube with a layer Ia divided in mosaic fashion and comprising minute photo-cells, and on the opposite side with a coherent. counter-electrode 1b.. The latter is earthed.
  • the primary electrons represented by the rays 9, are caused to traverse magnetic field H), which is to be imagined at right angles to the paper. They are then deflected in the manner shown.
  • an electrode 5a which may be raised to about the same potential as 5, the electrons 9 are slowed before impinging on the mosaic and reach the mosaic with a potential of less than 100 volts. At this low speed they are no longer capable of liberating secondary electrons from the layer la, but merely charge negatively to different potentials the particles of this layer.
  • the layer la is illuminated from an optical scanning line screen II by way of a lens l2 and thereby discharged point by point.
  • the electrons are liberated from the layer by an anode l4. They then meet against a first anticathode I5 in the manner known from the "electron multiplier and liberate there a multiple secondary electrons, the
  • Each additional stage of this nature is furnished with a new, appertaining suction anode, the suction anode in respect of the paths It being designated l8.
  • the potentials of these successive anodes consecutively increase by the same amount respectively in relation to one another.
  • Each accelerating anode is connected with the appertaining plate, i. e., the anode l4 with the anticathode IS, the anode IS with the anticathode l1, etc.
  • the final anticathode, in this case I1 is connected by way of a coupling resistance IS with the final accelerating potential 20, so that to this resistance there may be connected an end amplifier 22.
  • a magnetic field has been employed for spacially separating the primary and secondary currents.
  • there may also be employed in place thereof an electrostatic electron-optical system.
  • a reproduction may be made use of with magnetically or electrically curved rays, wherein such deflecting mirrors may be dispensed with.
  • the screen area ll consisting of luminous points may be produced by a mechanical decomposing machine in conjunction with a technical light source or by the luminous screen of a Braun tube.
  • a tube for converting a light image into an electron image has already been described in a practical form of embodiment in the application Ser. No. 111,815.
  • the described operation of the point-by-point discharge of the stored charges of the photo-cells occurs only in the manner described if there is no appreciable secondary emission from these cells in the dark condition.
  • either the primary ray must be slowed, so that the electrons meet against the layer at a speed of less than 100 volts.
  • This may be performed by the cylinder electron lens as described, or for instance by coating the wall of the tube 8 with a conductive layer. e. 'g., in the form of a graphite spiral and applying the desired terminating potentials to the ends of this spiral (afterretardation).
  • the desired effect may also be accomplished by the use of rays of more than about 2,000 volts, since from a certain speed up wards the secondary emission no longer suflices to cover the current balance between incoming and leaving electrons and a point-by-point charging then occurs in proportion to the intensity of the primary current.
  • FIG. 2 A particularly simple embodiment of the optically scanned ikonoscope in conjunction with a current amplifier is shown in Fig. 2.
  • 23 is a plate having perforations of image-point size
  • 24 is a two-dimensional structure which is situated opposite thereto and consists, so to speak, only of image points, and in which points of silver are arranged on an insulating supporting plate 25.
  • An arrangement of this kind has already been described in a previous application Ser. No. 111,815.
  • Both the perforated plate 23 as well as the point plate 24 are activated with caesium and made photo-sensitive only on the side facing each other.
  • the light from the object 3 to be transmitted passes by way of a reproducing lens 2 through the spaces between the image points 24 onto the activated layer side of the perforated plate 23.
  • Fig. 3 is a magnified front view of a portion of the perforated plate, showing that a wire net 26 may further be introduced in such fashion between the apertures in the perforated plate 23 that the wires thereof are finer than the connecting pieces between the apertures of 23, so that when looking from the left in Fig. 2 merely the connecting pieces of the perforated plate 23 and when looking from the right merely the image points of 24 are visible, whilst the anode maximum produced picture frequency is connected between the perforated plate 23 and an auxiliary electrode 21 and is operated by a highfrequency generator at 28.
  • the electrostatic field then provides for the liberation of the electrons from the perforated plate.
  • the same highfrequency generator may also release electrons from the mosaic plate 24 in the opposite direction by way of a push-pull circuit, as illustrated in Fig. 4.
  • a counter-electrode 21a is required.
  • scanning light source there is again employed a mechanical system oi the Nipkow disc type or a Braun tu generally speaking a surface ll over which t ere moves a luminous image point.
  • the electrons which have accumulated at the mosaic 24 are photo-electrically liberated, conveyed outwards towards the perforated plate by means of a fine-mesh net 30' with a positive bias 29, acting as anode, and then concentrated on to an anticathode l5 by means of an electron-optical system, which in its simple form comprises two cylinders 30, 3
  • an electron-optical system which in its simple form comprises two cylinders 30, 3
  • At 15 secondary electrons are liberated in the manner known per se and are concentrated by a further and smaller electron-optical system 33/34 upon a final anode FL
  • the electron-optical system shown is an electrostatic one.
  • a battery 20 is applied with its full voltage of approximately 200 volts relatively to IE to the cylinder 34 and the intercepting plate I! by way of the coupling resistance 13, whilst a medium potential of 20 is adjusted at the reproducing electrode 33, thus effecting focusing.
  • 22 is the input tube of the associated image amplifier.
  • the double-plate arrangement 23/24 contains at least as many image points as indicated by the square of the desired number of lines.
  • the arrangement is preferably produced mechanically, by first stamping a perforated plate 23. With a size of approximately 20 cm. square, and 400 lines, an individual aperture in this plate still has a diameter of 5 mm., which may be readily produced. If there is employed the precision art of producing finest apertures of approximately 50;: in diameter as developed in the production of Nipkow discs, a 400-line screen may even be produced in a plate of 4 cm. square.
  • Fig. 5 is shown an arrangement similar to that of Fig. l.
  • a deviation in direction is assumed amounting to 45.
  • the object 3 to be televised ls reproduced by a lens 2 on the primary cathode I.
  • the cathode l is a coherent photoelectric layer.
  • the image 3 is reproduced by the lens 50-52, the sharpness of which is adjusted at 5
  • a magnet field l0 perpendicular to the plane of the paper deflects all of the reproducing rays 9a to at the point of their maximum construction by the samev angle (45 have beenshown), and accordingly acts as an electron reflector.
  • the reproduction remains sharp in the plane la.
  • a slowing system formed of three rings 53 in conjunction with the resistance l slows the electrons down about 0 volts.
  • a lens l2 reproduces a luminous scanning area, for example the surface of a television cathode ray tube, II, on la. Since la is photo-activated, the illuminated points discharge electrons until they have entirely lost their negative charges.
  • the thus produced oathode rays 13a to I30 are deflected by the same magnetic field ill in the opposite direction and enter into a tubular member 30, being accordingly completely separated from the primary currents.
  • any of the known multiplication systems for a direct amplification of electronic currents there may be employed any of the known multiplication systems for a direct amplification of electronic currents.
  • an electrostatic multiplier As well known, such a multiplier consists of a tubular member so and a tubular member 3i which is positive in relation to 30.
  • the anticathode l5 ismet at the point 59 by the primary rays l3, and the electrons 60 liberated in excess at that point under certain known conditions are concentrated by the tubular member 34, and finally collected by the anode H.
  • FIG. 6 A further embodiment of the idea of the invention is set forth in Fig. 6.
  • the image to be transmitted is reproduced on the photo-cathode l by means of the lens 2.
  • the photo-cathode is represented as being perpendicular to the axis of the tube and the direction of the light falling thereon, and must accordingly be assumed to be transparent. It may, however, also be inclined to the axis of the tube (with correspondingly modified arrangement of the lens2) in Fig. 7.
  • the electronoptical reproducing system in the manner known per se, may consist of a system of rings 6
  • the potentiometer which serves to impart to the said electrodes the potentials necessary for obtaining a good reproduction is not shown in the drawings.
  • the electronoptical reproduction in the manner known per se, can also be performed by magnetic means or by a combination of electrostatic and magnetic means.
  • the electrode 63 represents a mosaic composed of electrically conductive metallic pellets embedded in a highly insulated fashion in a conductive net. The production of this electrode will be described later. It separates the aforesad electron-optical reproducing system mechanically and electrically from the scanning system 64.
  • the side of the mosaic electrode facing the photo-cathode I is preferably furnished with a coating due to which the metallic pellets insulated one against the other, assume the property that the number of secondary electrons liberated per oncoming primary electron is considerably smaller than i.
  • each of the insulated metallic pellets is charged to a potential which is somewhat more negative than the potential of the supporting conductive net, which is the same as that of the final electrode of the reproducing system 6
  • the potential up to which the metallic pellets are charged is proportional to the light intensity values of the light that impinges on the corresponding points of the primary cathode.
  • the individual pellets are to a high degree screened off electrically one against the other; in addition the capacity is considerably greater than in the case of the known mosaic screens deposited on mica, which reduces the danger of self-discharge, the potential of each element remaining comparatively low.
  • the side of the mosaic screen 63 facing away from the photo-cathode l, or in other words the rear sides of the negatively charged metallic pellets, are scanned in the example shown by means of a cathode ray, in the manner known per se.
  • a cathode ray there is employed the electrode system 64, and for per- 40 forming the scanning the deflecting system 65,
  • the axis of the cathode ray system 64 is disposed vertically to the 5 mosaic screen 63. If the photo-cathode I is inclined in relation to the axis of the tube the axis of the scanning system is preferably inclined in such fashion that the resulting scanned image is again undistorted.
  • the accelerating potential of the cathode ray scanning system is so chosen that each electron of the scanning ray liberates more than one secondary electron. This eifect may be further improved upon by sensitizing the metallic pellets on the side facing the cathode ray, for example by means of caesium. In this case the accelerating potential may be adjusted to 2,000 volts. This potential, however, as all potentials given in the drawings, are merely quoted by way of example.
  • the secondary electron current impulses released upon the scanning by the cathode ray and the discharging of the pellets to the equilibrium potential correspond in their strengths to the charges of the scanned metallic pellets, and accordingly to the light intensities of the image elements of the image projected on to the photocathode I.
  • These secondary electronic impulses are now amplified in a current multiplier of the known kind, applied somewhat obliquely to the main tube, and are conducted by way of the terminal anode l1 and the resistance ii! to the final amplifying tube 22.
  • current multiplying means there may be employed any of the known arrangements, for example those with magnetic or electrostatic deflection of the secondary currents supplied by diiferentplates, or' those with a superimposed auxiliary oscillation of ultra-high frequency, which hurls the electrons repeatedly against suitable secondary electron cathodes.
  • the most suitable for thepresent embodiment of the invention is the use of a multiplier which consists of a series of grids 6B, 66", etc., suitable for supplying secondary electrons, which are provided with increasing potentials.
  • I is the photo-cathode, which is inclined at an angle of 45, and on to which the image 01 the scene to be transmitted is projected by means of the lens IS.
  • the electrons which are liberated at the photo-cathode l in correspondence with the light intensity of the individual points of the image, and constituting the current Ip, are projected by the electronoptical reproducing system 61', 61", on to the metallic plate 68, which is likewise inclined at an angle of 45.
  • the reproducing system consists in the manner known per se of rings 61', 61", 61", 61 to which, by means of a potentiometer (not shown) there are imparted suitable potentials which increase in the direction from the cathode to the metallic plate 68.
  • the first ringiil may be adapted in its form to the inclined position of the photo-cathode I, and in accordance with the invention may consist of a thin-wire metallic fabric in order not appreciably to weaken the image light possibly projected through the same.
  • the final reproducing electrode 61 of the said system is preferably maintained at the same potential as the metallic plate 68 and the first ring of the electron-optical reproducing system 69', 69", This potential in relation to the photo-cathode l is so chosen potential each liberate a multiple number of secondary electrons. These form the current Is, and produce the image on the mosaic screen 63 owing to the electron-optical system consisting of the rings, 69', 69", 69, 69.
  • the charges of the mosaic elements correspond to the light intensity of the individual corresponding points of the photo-cathode I, and accordingly of the original image.
  • the charges of the mosaic 63 are compensated 'in the manner known per se, and image impulses are accordingly generated, which flow from the coherent conductor by way of the resistance l9 to earth and accordingly control the grid of the input tube 22 of the subsequent amplifier.
  • the mosaic screen 63 is so inclined in relation to the scanning electron ray that the image distortion is compensated which is caused by the inclined position of the photo-cathode i.
  • the image transmission tube set out in Fig. 6 is free from these disadvantages, as only the primary photo-electrons, which have a very low starting speed, are once reproduced electronoptically.
  • the multiplication by secondary electron liberation does not take place before, by means of an electron ray or a ray of light, electron impulses have been produced, the strength of which corresponds to the local light intensity of the image.
  • the multiplying device then no longer requires to have point by point reproducing properties.
  • An essential component part of the present invention is represented by the embodiment of the two-sided mosaic employed.
  • Two-sided mosaics have already been proposed previously, which consist of an arrangement of small aluminium bars coated electrolytically with aluminium oxide.
  • the mosaic consists of a metallicpreferably tungsten-net, whichis coated with aluminium oxide. Silver pellets are fused into the meshes thus insulated.
  • the procedure is preferably as follows: Preliminarily burnt, ground, pure aluminium oxide, which is mixed with collodion and amyl acetate, is sprayed on to the tungsten net from both sides by a. spray gun, which requires to have a very fine nozzle, so that, while the meshes are not yet closed, all wires are well imbedded. After drying the net mately 1,800 C. In this way the aluminium oxide is sintered to form a firmly adhering, highly insulating coating on the wires of the net. Following thereon the pores are filled out with powdered silver, or a certain amount of silver amalgam is painted into the meshes and the mercury expelled by heating.
  • the net is then heated in vacuum to a temperature above the melting point of the silver. Owing to the surface tension the silver'forms into small pellets, so that there is one silver pellet in each mesh. This operation is repeated until the pellets have assumed such a size that they completely fill out the pores.
  • Fig. 8 shows the finished mosaic 03 fitted into the tube.
  • the net is stretched over small metal plates 10 and insulating plates II, which after the production may be metallizeda They are held together by the rivets 12. In this manner the mosaic fills out the entire cross-section of the tube and separates the discharge spaces.
  • Fig. 9 shows a piece of the mosaic, Fig. 10 a sectional elevation of this piece.
  • 13 are the individual tungsten wires of the net
  • 14 is the surrounding insulating aluminium oxide coating
  • 15 are the fused in silver pellets.
  • 16 are particles of soot, which are applied to the one side in order to suppress there the emission of secondary electrons
  • 11 are coatings which are applied to the opposite side and favour the emission of secondary and photo-electrons.
  • concentration ring which preferably consists of a comparatively large-mesh, extremely thinwire metallic fabric (both in the case of light ray as well as electronic ray scanning). It is apparent that this measure of intermediate concentration is also important quite generallv in electron multiplying systems.
  • An additional improvement consists in the fact that the axis of the multiplying system coincides with the axis of the electron-optical system causing the reproduction of the photo-cathode on the mosaic plate.
  • favourable conditions are provided in respect of the sucking ofi of the electrons liberated at the mosaic plate and entering the multiplier.
  • the bundle of cathode rays or light rays necessary for liberating these electrons falls on to the mosaic plate in an inclined direction and the spacing between the first net of the multiplier and the mosaic electrode is so large that there is no interference with the scanning bundle of cathode or light rays.
  • the portion between the mosaic plate and the first secondary cathode may be furnished with a semi-conductive transparent coating.
  • the axes of the reproducing bundle of light and the scanning bundle of cathode or light rays'again form such an angle that thtei resulting image distortions compensate each ot er.
  • a simplification which is independent of the aforesaid improvements, which are capable of being employed separately, consists in the fact that there is not employed an electron-optical reproducing system for reproducing the photo-cathode on the mosaic plate, but that a conductive net is provided just in front of the mosaic electrode, and is photo-electrically sensitized on the side facing away from the mosaic screen.
  • the weak field caused by the discharge of the mosaic points upon the scanning operation extends through the meshes of this net and sucks the liberated photo-electrons on to the storage elec-" trode.
  • FIG. 11 An exemplary embodiment of the stated improvements and simplifications is set forth-in Fig. 11.
  • 18 is the mosaic electrode
  • 19 the photo-cathode net situated closely in front of the same
  • 84 the scanning cathode ray system.
  • the scanning movement of the cathode ray is produced by the coils 65.
  • the electron-multiplying system consists of the nets 66, 66', 66", disposed one behind the other with intermediately disposed concentration rings 80, 80, 80" and the pick-up electrode H.
  • is applied in a suitable manner to the multiplier stages by means of the potentiometer 82.
  • the current impulses developed are conducted to the end amplifying tube 22 by way of the grid resistance IS.
  • the reproduction on the photo-cathode 19 of the image 3 to be transmitted is produced by the lens system 2.
  • the light ray and cathode ray axes are preferably inclined at an angle of 45 in relation to the mosaic screen, in the manner shown.
  • a further embodiment of the invention is 11- lustrated in Fig. 12.
  • 8 is the mica plate of an ikonoscope
  • la the mosaic which in the known manner is illuminated from the object 3 through the optical device 2 and is scanned by means of the cathode ray system 64.
  • a coherent grid which consists of a fine network 83. Behind this first net 83 there follow a plurality of other nets 66, 86' etc.
  • the amplified electron current is picked up, to be converted at the resistance l9 into fluctuations in potential which excite the amplifier 22.
  • the rear mosaic 1c is illuminated by a constant light source 84, possibly with a condensing lens 85.
  • the grids 86, 86'l1 are given increasing positive potentials in a manner such as known from the multiplier designed by Weiss.
  • This final efiect has the advantage that it becomes zero in the case of black points of the image.
  • the illuminating light 84 should liberate electrons not from the nets 83, 66, 66' but only from the mosaic 1c. Since the anticathodes 66, 66 etc., also consist of silver and caesium, the light is to be so guided that it does not meet against the meshes, i. e., enters obliquely. By the way, the emission of subsequent anticathodes is not dangerous, as it is not multiplied.
  • the sheet of mica 8 must cause an optical and an electrical separation of the two discharge spaces. It is made larger than the scanned area. In place of mica there may also be employed black glass and the like.
  • FIG. 13 shows a plan view of the rear mosaic 1c consisting of insulated particles, which are photo-electrically activated and of the net 83 which is preferably made of a noble metal, gold, platinum and the like, so that it will notemit electrons by itself.
  • a television system for translating an optical image into one electrical representation thereof comprising a substantially planar mosaic formed of a multiplicity of electrically isolated individual elements, a foraminate grid electrode element positioned in a plane parallel to the mosaic and relatively adjacent thereto, the opposed surfaces only of both the mosaic and the grid element being light responsive, optical means for projecting and focusing an optical image through the mosaic onto the light responsive surface of the grid element to release therefrom electrons and to produce thereby an electronic current replica of the optical image, means including a source of high frequency for producing an alternating high frequency electrostatic field between the mosaic and the grid element for directing the electronic current replica onto the mosaic to produce a substantially complete electrostatic image thereof over the surface of the mosaic, a beam of light of substantially elemental crosssectional area, means to scan the light responsive surface of the mosaic according to a pre-established scanning pattern by directing the beam of light through the foraminate grid element to liberate, as a result of scanning, electrons from the individual elements of the mosaic, the number of electrons liberated being proportionally related to the variance of the electro
  • a television system for translating an optical image into one electrical representation thereof comprising a substantially planar mosaic formed of a multiplicity of electrically isolated individual elements, a foraminate grid electrode element positioned in a plane parallel to the mosaic and relatively adjacent thereto, the opposed surfaces only of both the mosaic and the grid element being light responsive, optical means for projecting and focusing an optical image through the mosaic onto the light responsive surface of the grid element to release therefrom electrons and to produce thereby an electronic current replica of the optical image, means including a source of high frequency for producing an alternating high frequency electrostatic field between the mosaic and the grid element for directing the electronic current replica onto the mosaic during each half cycle of a predetermined polarity, to produce a substantially complete electrostatic image thereof over the surface of the mosaic, a beam of light of substantially elemental cross-sectional area, means to scan the light responsive surface of the mosaic according to a pre-established scanning pattern by directing the beam of light through the foraminate grid element to liberate, as a result of scanning, electrons from the individual elements of the mosaic, the number of

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US122032A 1936-01-29 1937-01-23 Picture transmitter Expired - Lifetime US2227015A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE493043X 1936-01-29
DEL7402D DE1033701B (de) 1936-03-03 1936-03-03 Speichernde Fernsehaufnahmeroehre

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2552386A (en) * 1947-06-27 1951-05-08 Rca Corp Color television camera
US2585044A (en) * 1945-02-05 1952-02-12 Farnsworth Res Corp Gain control apparatus
US2760096A (en) * 1952-01-29 1956-08-21 Westinghouse Electric Corp Television pickup tube
US2777970A (en) * 1950-10-03 1957-01-15 Paul K Weimer Television camera storage tube
US2803768A (en) * 1955-01-27 1957-08-20 Du Mont Allen B Lab Inc Cathode ray tube

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE743480C (de) * 1938-02-08 1943-12-27 Fernseh Gmbh Bildzerlegerroehre mit Photoelektronenabtastung einer einseitigen Mosaikelektrode
US2213174A (en) * 1938-07-30 1940-08-27 Rca Corp Television transmitting tube
DE750071C (de) * 1939-06-21 1944-12-12 Verfahren zur Herstellung von Elektronenvervielfachern mit Elektroden verschiedenen Sekundaeremissionsgrades

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2585044A (en) * 1945-02-05 1952-02-12 Farnsworth Res Corp Gain control apparatus
US2552386A (en) * 1947-06-27 1951-05-08 Rca Corp Color television camera
US2777970A (en) * 1950-10-03 1957-01-15 Paul K Weimer Television camera storage tube
US2760096A (en) * 1952-01-29 1956-08-21 Westinghouse Electric Corp Television pickup tube
US2803768A (en) * 1955-01-27 1957-08-20 Du Mont Allen B Lab Inc Cathode ray tube

Also Published As

Publication number Publication date
GB493043A (en) 1938-09-29
CH212753A (de) 1940-12-15
CH211394A (de) 1940-09-15
GB492961A (en) 1938-09-29
BE419718A (en))
FR816963A (fr) 1937-08-21

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