US2745032A - Photo-conductive targets for cathode ray devices - Google Patents

Photo-conductive targets for cathode ray devices Download PDF

Info

Publication number
US2745032A
US2745032A US229428A US22942851A US2745032A US 2745032 A US2745032 A US 2745032A US 229428 A US229428 A US 229428A US 22942851 A US22942851 A US 22942851A US 2745032 A US2745032 A US 2745032A
Authority
US
United States
Prior art keywords
target
conductive
photo
light
envelope
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US229428A
Other languages
English (en)
Inventor
Stanley V Forgue
Robert R Goodrich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RCA Corp
Original Assignee
RCA Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE511797D priority Critical patent/BE511797A/xx
Priority to NLAANVRAGE7017469,A priority patent/NL169983B/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US229428A priority patent/US2745032A/en
Priority to FR1058021D priority patent/FR1058021A/fr
Priority to GB12487/52A priority patent/GB707125A/en
Priority to DER9134A priority patent/DE919309C/de
Application granted granted Critical
Publication of US2745032A publication Critical patent/US2745032A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
    • H01J9/233—Manufacture of photoelectric screens or charge-storage screens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/10—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances sulfides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/064—Gp II-VI compounds
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/072—Heterojunctions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
    • Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
    • Y10T428/264—Up to 3 mils
    • Y10T428/265—1 mil or less

Definitions

  • This invention relates to light-sensitive targets for electron discharge devices, and, more particularly, to photoconductive targets for television camera tubes and their method of manufacture.
  • a Vidicon camera tube consists of an electron gun and a target assembly contained in a glass envelope approximately six inches long and one inch in diameter.
  • the electron gun is of the conventional type used in the image orthicon and other television pickup tubes.
  • the target assembly comprises a film of light-transparent, electrically-conductive material on the glass face plate of the envelope, and a layer of photo-conductive material deposited upon the electrically-conductive film.
  • the target and the gun are so arranged within the envelope that the electron beam from the gun scans the photoconductive surface of the target.
  • the photo-conductive material used for Vidicon targets is an electrical insulator in the dark, but becomes electrically-conductive when light is shed upon it.
  • the conductivity is proportional to the amount of light striking the material, and is limited to the immediate area under the influence of the light.
  • Vidicons may be operated at either high or low velocity. That is, they may be operated with the target at suiiicient voltage positive with respect to the cathode so that the electron beam strikes the target with enough force to drive secondary electrons from the photo-conductive material, thereby rendering it more positive. Or, they may have cathode and target at approximately the same potential so that the scanning electron beam deposits electrons on the target with a negligible amount of secondary emission, thereby making the target more negative.
  • the electron beam scans the photo-conductive surface facing the electron gun at a Velocity above first crossover, i. e. at a suiiiciently high velocity so that the number of secondary electrons leaving the surface will be greater than the number of primary electrons which arrive at the surface and cause the secondary emission therefrom.
  • the first crossover potential differs with different target materials and surface conditions. Two hundred volts between target and cathode has given satisfactory results with antimony tri-sulfide targets.
  • This target potential is applied to the electrically-conductive film in contact with the opposite side of the photo-conductive layer from the one scanned by the electron beam.
  • a collector potential about ten volts positive with respect to the target is applied to a metal screen or ring, which is termed the collector electrode and is located immediately in front of the scanned surrice face of the photo-conductive layer.
  • the high velocity beam scans this surface, the resulting secondary electrons are attracted to the collector electrode making the scanned surface more positive until it reaches the potential of the collector electrode and equilibrium is established between them.
  • the scanning electron beam has brought the scanned surface to collector potential, it makes that surface ten volts positive with respect to the conductive film on the other side of the photo-conductive layer.
  • the photo-conductive material becomes conductive in the areas where the light impinges upon it.
  • the effect of this conductivity is to cause a leakage of electrons from the electrically-conductive lm, through the photo-conductor, to the scanned surface.
  • the amount of leakage depends upon the intensity of the light incident upon each area; and its effect is to make the area of the scanned surface affected by the light a volt or so more positive.
  • the scanning electron beam re-scans an area from which the electron charge has leaked, it restores the ten volt difference between the surfaces of the photo-conductor.
  • This leakage and restoration causes an electron current iiow in the circuit between the light-transparent, electrically-conductive lilrn in contact with the photo-conductive target and the source of potential to which it is connected. Variations in the electron current through this circuit, as more or fewer electrons are needed to restore the ditierence in potential become the signal output of the tube.
  • the electrically-conductive tilm is connected to a source of potential approximately ten volts positive with respect to the cathode which is at ground potential.
  • the electron beam scans the photoconductive surface, and, by depositing electrons thereon at a velocity less than first crossover (i. e. where the ratio of secondary electrons leaving the surface when primaries strike it is less than unity), brings the bombarded surface to cathode potential and produces approximately a ten volt difference of potential across the target.
  • Some of the qualities of photo-conductive materials which must be considered in determining their desirability as Vidicon targets are: sensitivity, resistivity in the dark, lag, useful life, and current-to-light response.
  • Sensitivity has reference to the ability of the material to become conductive under the influence of light. It is measured in micro-amperes of video current output per lumen of light on the target.
  • Resis'tivity in the dark has reference to that quality of photo-conductive material which enables it to store an electrical charge in a given spot without leakage from front to back surface as long as there is no light on the target.
  • lag is meant rapidity of response of the target to changes in light, i. e. the ability of the target to erase a signal in a given period of time without showing a shadow or trail of light.
  • the problems arising from lag become acute when a light-colored moving object is televised against a dark background.
  • Useful lite has reference to the hours of operation that can be expected from a target, and its ability to stand up under the handling etc. involved in manufacturing processes.
  • Another and related object of the invention is to provide an improved method of manufacture or such targets.
  • the target assembly thus prepare-d is contained within a glass envelope with an electron gun assembly and the envelope is evacuated and sealed o. Buring evacuation, the assembly is degassed by placing that area of the envelope containing the gun within an RF heating coil. While this heating process is going on, the target assembly is kept cool by an air blast trained upon it.
  • the present inventors have discovered that when red antimony tri-sulfide is heated to more than about 225 C. it undergoes a change of state from the red form to the black form and takes on difierent electrical characteristics, such as lower sensitivity, which make it less desirable as a camera tube target material. They have further discovered that the lag characteristics of the target are due not only to qualities inherent in the target material, but also to the capacitance between the scanned surface of the target material and the electrically-conductive hlm on its opposite side. By carefully following the procedure to be described, they have evaporated red antimony tri-sulde targets of adequate thickness to overcome capacitative lag, and have prevented the red antimony sulfide employed from changing into the less desirable black form.
  • Fig. l is a sectional view, partly diagrammatic, of apparatus used to prepare a photo-conductive target for a cathode ray device after the manner of the invention
  • Fig. 2 is a view in section, partly diagrammatic, of a cathode ray pickup tube with its target being cooled during the degassing process, after the manner of the invention
  • Fig. 3 is a graph showing the current-to-light response of a photo-conductive target prepared in accordance with the invention.
  • Fig. 4 is a sectional View of a portion of the target end of the tube shown in Figure 2 with legends added.
  • the apparatus shown in Fig. l comprises a deinountable evacuation chamber l?. consisting of a glass bell jar resting upon a flat base l5.
  • the base is equipped with a bushing 17 through which a pipe li communicates between the interior of the assembly ll and an evacuating pump assembly 2l.
  • Base l5' is also provided with a plurality of vacuum tight electrical teri minals 23, 23', 24, 24', 2S, 2.5. These terminals provide means for carrying electrical current from external sources (not shown) to points within the evacuation chamber ll.
  • an inverted cup-shaped membei' 27 upon which stands the tube envelope 29 on whose face 3l the layer of photo-conductive target material 33 is evaporated.
  • the red antimony tri-sulfide target material which is to be evaporated to form the layer or coating is contained in a crucible which is formed by twisting a tungsten wire into the conical spiral shown in the drawing and coating it with aluminum oxide. The f ee ends of this wire are connected to the terminals 2.5, 2S in the base Ilz", to permit electrical contact outside the evacuation chamber ll.
  • Sleeves 37 of insulating material prevent these wires from short-circuiting against a cylindrical metal shield 39 which is inserted inside the tube envelope during the evaporation process to prevent the photo-conductive material from condensing any part of the envelope 29 other than the face plate 3l.
  • An auxiliary heating coil 4l is located outside of the tube envelope 25" and close to the face plate 3l upon which the target material is to be evaporated. Current to activate this coil comes through the terminals 23, 23 in the supporting base l5.
  • Antimony tri-sulfide targets in accordance with the invention, may be either evaporated directly onto the glass face plate of the tube envelope, or they may be evaporated onto a separate light-transparent, electrically-conductive surface, later to be mounted within a tube envelope.
  • the invention will be described as applied to the situation where the evaporation takes place directly onto the face plate of the tube.
  • a glass bl or envelope 223 has a light-transparent, electrically-conductive coating of material such as the chloride or oxide of tin deposited on the inside surface of its face plate 3l.
  • the coat makes electrical contact with a conductive ring #ff-5 which passes through the wall of the envelope 29.
  • the envelope 29 and the mounts which are going to become a part of the inished tube, or are going to be used in its processing are given a preliminary baking at 450 C. to drive out occluded gases.
  • the glass envelope 29 is mounted within the evacuation chamber il in a vertical position, resting upon the supporting member Z7 which is positioned over the pipe i9.
  • An auxiliary metal ring if? is inserted between the cylindrical member 27 and the glass envelope 29 to determine the exact height that the tace plate 3l of the envelope Il@ will assume within the bell jar 113, and consequently the distance between the face plate 3l and the Crucible 35 which contains the antimony tri-sulfide to be evaporated.
  • the distance between the crucible 35 and the face plate 3l may be adjusted to obtain targets of suitable thickness and even distribution, and also to prevent peeling. Good targets have been obtained when the Crucible 35 was spaced 1% from the face plate 3l.
  • the chamber lll is evacuated to about 105 mm. of mercury.
  • the evaporated layer showed a tendency to separate into separate plates sliding together and overlapping one another.
  • the peeling 1esulted from the glass supporting surface in some cases contracting to a greater extent or at a faster rate than the antimony tri sulfide coating, or in some cases to a less extent or at a slower rate; and they reasoned that, by a proper pre-heating of the class surface 3l together with a judicious control of temperature during the evaporation and further processing of the tube, they could prevent unequal expansion and contraction and thereby prevent peeling.
  • pre-heating the glass face plate 31 to about 50 C., before evaporation, as described above, and not allowing it to rise above about 60 C. during evaporation provides for a uniform contracting of face plate and photo-conductive layer and prevents peeling.
  • Another aid in preventing peeling is the preliminary baking at about 450 C. referred to above. This permits a closer bond between the evaporated mateiial and the conductive film.
  • thermo-couple 32 held against the glass envelope 29 in the target area by means of a clamping ring 34. Electrical leads from the thermo-couple 32 pass out of the evacuated chamber 11 by way of vacuum-tight terminals 2d, 2d and make contact with temperature indicating instruments (not shown).
  • the current to the auxiliary heating coil 41 is turned off, current is applied to the terminals 25, 25 leading to the Crucible 35, and the evaporating process begins. Evaporation is allowed to continue until the layer 33 of antimony tri-sulde condensing on the face plate 3i has been built up to the proper thickness.
  • the thickness of this layer is determined by two factors. it must be thin enough to ⁇ permit light penetration and thick enough to prevent lag.
  • the lag in a target which has been defined above as therapidity of response to changes in light, is due to two different phenomena.
  • material lag which is different for different photo-conductive materials; and there is capacitative lag, which results from the capacitance of each particular target and is a function of the area, the thickness and the dielectric constant of the target, according to the formula,
  • the capacitative lag is aected by two other factors related to the capacity of the target. These are the amount of charge stored across the target in the dark and the extent towhich this charge leaks through the target and is dissipated under the influence of light.
  • the frame scanning time is m of a second
  • the charge stored by the scanning beam in a single frame is l0 7 %,0 or 3 l09 coulombs.
  • the electron beam When the electron beam scans its next frame, it restores the original potential across the target. This restoring of the original potential causes an electron current flow through the output resistor to the conductive [ilm and produces an output signal. lf the scanning electron beam does not have enough current to restore the charge which has been lost, or if the capacity of the target prevents the charge from being restored in a single frame time, a signal is generated in the output circuit for several frames after the light has been removed from the target. This signal shows up as a shadowy after-image on the viewing screen in a television system.
  • the electron beam in a conventional Vidicon deposits approximately 3x109 coulombs of electrical charge in a l/o second frame time.
  • Q CE or Substituting for the above the values already given This means that an ideally responsive target with no visible ⁇ lag' would have a capacitance of approximately 3X 10-9 farads or 3000 micro-microfarads.
  • the thickness of target may be measured in several ways. A rough approximation is made by controlling the time of the evaporation process. If this is done, an evaporation time of about one-half hour produces a target of the proper thickness. Another method of determining proper target thickness is to count the interference fringesfrom the evaporated layer as it is illuminated during its formation by a monochromatic light, such as a sodium lamp. Still another method, is to use a previously fabricated target of satisfactory thickness as a guide and compare densities by means of parallel light beams. When the evaporation process has brought the target in process to the same optical density as the standard or reference target the evaporation process is terminated.
  • the envelope 2@ is removed from the vacuum for further processing of the tube.
  • a screen electrode l9 is inserted into the tube and welded to a conductive ring Si which passes through the wall of the envelope 29 (see Fig. 2).
  • the electron gun assembly 53 is inserted into position within the envelope and the tube is put onto the evacuating pumps for the sealing process.
  • an RF coil 55 for degassing purposes, is placed around the tube in the vicinity of the electron gun assembly 53 and bakes that assembly for one to one and one-half hours at a temperature of about 150 C. to 175 C. Care must be taken that the photo-conductive film 53 of red antimony tri-suliide never is eX- posed to a temperature of more than 225 C. to prevent it from converting to the undesirable black form.
  • an air blast from an external source 57 is played upon the face of the target during the sealing and degassing operation.
  • Photo-conductive targets prepared in the manner described have been found to be much more sensitive than similar targets previously known to the art. Sensitivities of several thousand micro-amperes per lumen have been noted in some targets, and several hundred micro-amperes per lumen is quite common. These targets have been found to have useful lives of several thousand hours at temperatures even above those likely to be encountered in normal television camera operation. And they have good qualities of resistivity and lag.
  • Fig. 3 they aiord approximately a square root current-to-light response. While a material with a linearresponse (plot A) could cover only a little more than three units of shading in light intensity for the tenth of a micro-ampere change in current between .15 and .25 micro-ampere, a target prepared i1 accordance with the invention (plot B) could cover sixteen such units. in practical results this means that these targets make it possible to reproduce more delicate shadings of light in a television system.
  • a photo-conductive target for a cathode ray device comprising a supporting member, a layer of electricallyconductive material, and a layer of evaporated red antimony tri-sullide.
  • a cathode ray tube including an evacuated envelope containing an electron gun assembly and a light-sensitive target assembly, said target assembly comprising: a supporting member, electrically conductive coating on said supporting member, and a layer of evaporated red antimony tri-sulfide on said conductive coating.
  • a light sensitive target assembly for a cathode ray tube comprising, a supported member, a layer of evap- During this part of orated red antimony tri-sulfide on said support member substantially of a thickness determined by the formula 0.0885KA C' Where K is the dielectric constant or" red antimony trisulfide, A is the area of the antimony tri-sulfide layer in square centimeters, and C is the desired capacitance of the target in micro-microfarads.
  • a light sensitive target assembly for a cathode ray tube comprising, a support member, a layer of evaporated red antimony tri-sulfide on said support member whose surface area and thickness are in such relationship With each other that where K is the dielectric constant of red antimony trisulde, A is the area of the antimony tri-sulfide layer in square centimeters, and D is the thickness of the red antimony tri-sulfide layer in centimeters.
  • a light sensitive target assembly for a cathode ray tube comprising, a support member, a layer of evaporated red antimony tri-sulfide on said support member whose surface area and thickness are in such relationship with each other that 0.0885KA D where K is the dielectric constant of red antimony trisulde, A is the area of the antimony tri-sulfide layer in square centimeters, and D is the thickness of the red antimony tri-suitide layer in centimeters.
  • a light-sensitive element containing red antimony tri-sulfide the step which comprises cooling said element during the processing of said device so that said element does not rise above the temperature at which red antimony tii-sulide converts to the black form.
  • the method of making a photo-conductive target for an electron discharge device which comprises: evaporating, in vacuo, red antimony tri-sulfide upon an electrically conductive foundation surface, and subsequently maintaining said red antimony tri-sulfide at a temperature of less than 225 C.
  • the method of preparing photo-conductive targets for cathode ray devices including the steps of heating an electrically-conductive support structure in a vacuum, evaporating a coating of red antimony tri-sulfide on a heated surface of said structure, sealing said coated structure surface in an evacuated envelope containing an electron-gun, degassing said gun with heat during said sealing, and keeping said coated surface at a temperature below that at which red antimony tri-sulfide converts to the black form during said sealing and degassing.
  • the method of preparing a photo-conductive target for a cathode ray device which comprises: heating to approximately 50 C. in a vacuum an envelope having a glass race plate coated on its surface interior to said envelope a iayer of light-transparent, electrically-conductive material; evaporating from a source within said envelope a coating of red antimony tri-sulfide upon said surface,
  • D (thickness in centimeters) :less than 4,000 miero-microfarads :3,000 micro-microfarads heating said target to a temperature of approximately 60 C. during said evaporation, allowing said coated surface to cool to room temperature, removing said envelope from said vacuum, mounting an electron gun in said envelope, evacuating and sealing said envelope and simultaneously de-gassing said electron gun with heat, and keeping said coated surface at a temperature below 225 C. by means of an air blast during said sealing and degassing.
  • a light-sensitive element comprising, a support member, a layer of evaporated red antimoney tri-sulfide on said support member, and a conducting element in contact with a portion of said evaporated layer.
  • a photoconductive element comprising, a support member, a conductive element on a surface of said support member, and a layer of evaporated red antimony trisulde in contact with said conductive element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
  • Physical Vapour Deposition (AREA)
US229428A 1951-06-01 1951-06-01 Photo-conductive targets for cathode ray devices Expired - Lifetime US2745032A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BE511797D BE511797A (en, 2012) 1951-06-01
NLAANVRAGE7017469,A NL169983B (nl) 1951-06-01 Werkwijze voor het desinfecteren van water, dat levende bacteriecellen bevat, met behulp van sterk basische anion-uitwisselharsen in polyhalogenide-vorm.
US229428A US2745032A (en) 1951-06-01 1951-06-01 Photo-conductive targets for cathode ray devices
FR1058021D FR1058021A (fr) 1951-06-01 1952-04-29 Perfectionnements aux cibles photoconductrices pour dispositifs à rayon cathodique
GB12487/52A GB707125A (en) 1951-06-01 1952-05-16 Improvements in photo-conductive targets for cathode ray devices
DER9134A DE919309C (de) 1951-06-01 1952-05-28 Photoleitfaehiger Schirm fuer Kathodenstrahlroehren

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US229428A US2745032A (en) 1951-06-01 1951-06-01 Photo-conductive targets for cathode ray devices

Publications (1)

Publication Number Publication Date
US2745032A true US2745032A (en) 1956-05-08

Family

ID=22861208

Family Applications (1)

Application Number Title Priority Date Filing Date
US229428A Expired - Lifetime US2745032A (en) 1951-06-01 1951-06-01 Photo-conductive targets for cathode ray devices

Country Status (6)

Country Link
US (1) US2745032A (en, 2012)
BE (1) BE511797A (en, 2012)
DE (1) DE919309C (en, 2012)
FR (1) FR1058021A (en, 2012)
GB (1) GB707125A (en, 2012)
NL (1) NL169983B (en, 2012)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2829074A (en) * 1954-07-27 1958-04-01 Emi Ltd Manufacture of evaporated layers
US2900280A (en) * 1955-07-23 1959-08-18 Emi Ltd Formation of layers of photo-conductive materials
US2905843A (en) * 1955-02-15 1959-09-22 Emi Ltd Electron discharge devices employing photo-conductive target electrodes
US3027218A (en) * 1958-02-21 1962-03-27 Philips Corp Manufacture of electron discharge tubes having a photo-conductive target
US3054917A (en) * 1956-12-03 1962-09-18 Itt Heat imaging device
US3315108A (en) * 1963-12-17 1967-04-18 Rca Corp High lag, high sensitivity target having solid antimony oxysulphide and porous antimony trisulphide layers
US3966512A (en) * 1973-09-10 1976-06-29 Hitachi, Ltd. Method of manufacturing targets of pickup tubes

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4097775A (en) 1955-08-04 1978-06-27 Rca Corporation Infrared sensitive photoconductive pickup tube

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2093699A (en) * 1932-03-08 1937-09-21 Farnsworth Television Inc Cathode ray tube
US2162209A (en) * 1937-05-17 1939-06-13 Alfred Hofmann & Company Lamp sealing-in and exhausting machine
US2236172A (en) * 1936-03-04 1941-03-25 Bell Telephone Labor Inc Electro-optical system
US2254073A (en) * 1938-03-07 1941-08-26 Emi Ltd Photoelectrically sensitive surface
US2303930A (en) * 1936-03-04 1942-12-01 Bell Telephone Labor Inc Electro-optical system
US2401737A (en) * 1942-03-14 1946-06-11 Rca Corp Phototube and method of manufacture
US2401734A (en) * 1940-10-08 1946-06-11 Rca Corp Photoelectric electron multiplier
US2404098A (en) * 1941-06-27 1946-07-16 Rca Corp Television transmitting system
US2431401A (en) * 1940-06-25 1947-11-25 Rca Corp Method of manufacturing photoelectric tubes
US2642367A (en) * 1947-01-09 1953-06-16 Us Sec War Method of protecting lenses
US2654852A (en) * 1951-06-01 1953-10-06 Rca Corp Photoconductive target for cathode-ray devices
US2687484A (en) * 1951-02-24 1954-08-24 Rca Corp Photoconductive target

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2093699A (en) * 1932-03-08 1937-09-21 Farnsworth Television Inc Cathode ray tube
US2236172A (en) * 1936-03-04 1941-03-25 Bell Telephone Labor Inc Electro-optical system
US2303930A (en) * 1936-03-04 1942-12-01 Bell Telephone Labor Inc Electro-optical system
US2162209A (en) * 1937-05-17 1939-06-13 Alfred Hofmann & Company Lamp sealing-in and exhausting machine
US2254073A (en) * 1938-03-07 1941-08-26 Emi Ltd Photoelectrically sensitive surface
US2431401A (en) * 1940-06-25 1947-11-25 Rca Corp Method of manufacturing photoelectric tubes
US2401734A (en) * 1940-10-08 1946-06-11 Rca Corp Photoelectric electron multiplier
US2404098A (en) * 1941-06-27 1946-07-16 Rca Corp Television transmitting system
US2401737A (en) * 1942-03-14 1946-06-11 Rca Corp Phototube and method of manufacture
US2642367A (en) * 1947-01-09 1953-06-16 Us Sec War Method of protecting lenses
US2687484A (en) * 1951-02-24 1954-08-24 Rca Corp Photoconductive target
US2654852A (en) * 1951-06-01 1953-10-06 Rca Corp Photoconductive target for cathode-ray devices

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2829074A (en) * 1954-07-27 1958-04-01 Emi Ltd Manufacture of evaporated layers
US2905843A (en) * 1955-02-15 1959-09-22 Emi Ltd Electron discharge devices employing photo-conductive target electrodes
US2900280A (en) * 1955-07-23 1959-08-18 Emi Ltd Formation of layers of photo-conductive materials
US3054917A (en) * 1956-12-03 1962-09-18 Itt Heat imaging device
US3027218A (en) * 1958-02-21 1962-03-27 Philips Corp Manufacture of electron discharge tubes having a photo-conductive target
US3315108A (en) * 1963-12-17 1967-04-18 Rca Corp High lag, high sensitivity target having solid antimony oxysulphide and porous antimony trisulphide layers
US3966512A (en) * 1973-09-10 1976-06-29 Hitachi, Ltd. Method of manufacturing targets of pickup tubes

Also Published As

Publication number Publication date
NL169983B (nl)
BE511797A (en, 2012)
DE919309C (de) 1954-10-18
GB707125A (en) 1954-04-14
FR1058021A (fr) 1954-03-12

Similar Documents

Publication Publication Date Title
US2654853A (en) Photoelectric apparatus
US3350595A (en) Low dark current photoconductive device
US2507958A (en) Mosaic screen for cathode-ray tubes
US2077442A (en) Cathode ray tube
US2177736A (en) Television transmitting apparatus
US2745032A (en) Photo-conductive targets for cathode ray devices
US2710813A (en) Cadmium selenide-zinc selenide photoconductive electrode and method of producing same
US2744837A (en) Photo-conductive targets for cathode ray devices
US2403239A (en) Target electrode for electron discharge tubes
US2967254A (en) Composite photoconductive layer
US3271608A (en) X-ray vidicon target assembly
US2212923A (en) Picture transmitter
US2875359A (en) Photoconductive device
US2810087A (en) Photoconductive orthicon
US2373396A (en) Electron discharge device
US2149455A (en) Television transmitting apparatus
US2175691A (en) Photovoltaic target
US3148297A (en) Electron device with storage capabilities
US2869010A (en) Interference type optical filters utilizing calcium fluoride
US3437860A (en) Image orthicon glass target with aluminum-tantalum oxide coating
US3268764A (en) Radiation sensitive device
US3020432A (en) Photoconductive device
US3034010A (en) Radiation detection
US2506742A (en) Storage tube and target therefor
US2289921A (en) Photosensitive electrode