US2555545A - Image intensifier - Google Patents

Image intensifier Download PDF

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Publication number
US2555545A
US2555545A US771112A US77111247A US2555545A US 2555545 A US2555545 A US 2555545A US 771112 A US771112 A US 771112A US 77111247 A US77111247 A US 77111247A US 2555545 A US2555545 A US 2555545A
Authority
US
United States
Prior art keywords
image
screen
intensity
fluorescent
fluorescent screen
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
US771112A
Other languages
English (en)
Inventor
Lloyd P Hunter
Richard L Longini
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.)
CBS Corp
Original Assignee
Westinghouse Electric 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 BE484424D priority Critical patent/BE484424A/xx
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US771112A priority patent/US2555545A/en
Priority to GB18919/48A priority patent/GB652451A/en
Priority to FR970375D priority patent/FR970375A/fr
Priority to GB13979/49A priority patent/GB662569A/en
Priority to NL146672A priority patent/NL71728C/xx
Priority to FR59910D priority patent/FR59910E/fr
Application granted granted Critical
Publication of US2555545A publication Critical patent/US2555545A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/02—Viewing or reading apparatus
    • G02B27/022—Viewing apparatus
    • G02B27/023—Viewing apparatus for viewing X-ray images using image converters, e.g. radioscopes
    • 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
    • H01J31/50—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output
    • 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
    • H01J31/50—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output
    • H01J31/503—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output with an electromagnetic electron-optic system
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2231/00—Cathode ray tubes or electron beam tubes
    • H01J2231/50—Imaging and conversion tubes
    • H01J2231/50005—Imaging and conversion tubes characterised by form of illumination
    • H01J2231/5001—Photons
    • H01J2231/50031—High energy photons
    • H01J2231/50036—X-rays

Definitions

  • Our invention relates to fluorescent devices and, in particular, covers a method of, in efiect, amplifying the intensity of an optical image produced on a fluorescent screen.
  • Fluorescent screens are devices known in the art by means of which visible light images are produced which are replicas of the energy intensity, point by point, of incident radiation of some known invisible type.
  • flu-- crescent screens are employed with X-ray tubes to make visible the pattern which results when a. stream of X-radiation pases through some material object, such as a part of the human body. While such radiation patterns are frequently recorded by their effect on photographic plates, it is highly desirable, for certain purposes, such as the observation of the movements of the human heart, for an operator to be able to watch the changes in the pattern from instant to instant by causing it to be rendered visible by a fluorescent screen.
  • the intensity of the image produceable today by known fluorescent screen-materials is so low that it is only with great difiiculty that such fluorescent images may be observed in the case of many human organs. It is impossible in these instances to raise the intensity of the image by increasing the X-ray intensity because of the injurious effects of over-intense X-radiation on the human body.
  • One object of our invention is, accordingly, to provide an arrangement for reproducing in greatly amplified intensity an image or pattern on a fluorescent screen.
  • Another object of our invention is to provide an arrangement for reproducing an optical image in greatly amplified intensity.
  • Another object of our invention is to provide an X-ray apparatus which shall produce on a fluorescent screen an image in which the ratio of the intensity of the light image to the intensity of the X-radiation is much higher than has been possible with X-ray apparatus of the prior art.
  • Still another object of our invention is to provide an X-ray apparatus in which visible images are produced instantaneously which are replicas of the pattern of the X-ray field and which are of a much higher order of visibility than was possible with X-ray apparatus of the prior art.
  • Another object of our invention is to provide a method of increasing the intensity of an optical image which is a replica of a given electron image.
  • a further object of our invention is to provide a method of greatly increasing the intensity of the optical-image replica which may be produced from an electron image of a given intensity.
  • Fi 1 illustrates an embodiment of our invention as applied to an X-ray apparatus.
  • Fig. 2 is an enlarged sectional detail view of the end 5 of the tube.
  • Fig. 3 is a similar enlarged sectional detail view of the opposite end 6 of the tube.
  • l symbolizes a source of X-rays which is being used, in a marmer too well known in the art to require detailed description, to irradiate an object 2 and thereby produce upon a fluorescent screen 3 a visible pattern or image indicative of the extent to which X-rays are absorbed in different portions of the object 2.
  • Phosphorescent materials such as are employed to form screen 3, for use in producing visible replicas of X-radiation fields are known in the art and are frequently referred to as X-ray phosphors; for example, screens embodying calcium tungstate are among the most satisfactory known to the prior art for this purpose.
  • a fluorescent screen which is considerably more effective in producing light output for a given intensity of X-radiation can be produced by the employment of zinc sulphide with an admixture of the order of 0.01% of an activator and of about 20% of an alkali halide flux such as sodium chloride.
  • the means for producing an image of amplified intensity in accordance with. our invention comprises a vacuum-tight cylindrical tube 4 having opposite ends 5 and 6 comp-rising thin walls of glass, preferably of uniform thickness.
  • the interior face of the end wall 5 is provided with a conductive coating 5A which is transparent to light. While there are a number of ways in which such coatings may be produced, one method is to coat the glass by sublimation with a coating of metallic gold, or silver, so thin that it is transparent to light.
  • An electric terminal 1 makes it possible to complete an electric circuit to the aforesaid conductive coating A and fix its electrical potential relative to the other surfaces in the interior of tube 4.
  • the surface of the conductive coating is covered in turn by a coating 8 of some suitable photo-electric material, such, for example, as antimony treated with caesium.
  • the opposite end 6 of tube 4 is coated on its interior face with a layer 9 of some substance which produces a luminous image when bombarded with electrons; though many such substances are known, we have found zinc-cadmiumsulphide to be a particularly satisfactory material for this purpose.
  • the zinc-cadmium-sulphide is preferably settled from a water mixture.
  • caesium is employed as a component of the photo-electric layer 8
  • some protective coating H which may, for example, be potassium silicate.
  • the layer [2 may, for example, be produced by evaporation of aluminum in vacuo.
  • the visible image produced on the X-ray phosphor screen 3 by the source i will produce an electron image, which is substantially a replica of it in intensity distribution, over the end wall 5, and by means of a suitable voltage source It, the electrons forming such image may be accelerated and caused to impinge on the layer 9 and produce a luminous image thereon, which is an amplification in intensity of the luminous image produced by the X-rays on the X-ray phosphor screen 3.
  • Such magnetic field when used, may conveniently be produced by a pair of direct-current field coils I5 and i6 fed from a suitable direct-current source, not shown.
  • the use of such field coils in connection with electron images is believed to be too well known in the art to require a detailed description.
  • the trajectories followed by the electrons composing the electron image in traversing the space between screens 3 and 9 may be controlled in such .a way as to contract the dimensions of the image at the screen 9.
  • the trajectories of the electron paths to form such a contracted image are symbolized by the dotted lines ii, iii inside the tube 4.
  • the brightness of the light image produced on the screen 9 may be made much greater than that of the light image on the screen 3, and this brightness may be increased through a wide range by contracting the radial dimensions of the image through adjustment of the above-mentioned magnetic field due to coils I5 and IS, the image on the screen 9 may be inconveniently small, although very bright, when so contracted. Under such circumstances, it is desirable to View this image through a suitable magnifying optical system which is symbolized by the lens 19. It will be understood that the showing of the lens 19 is merely symbolical of much more elaborate optical systems which are conventional in the optical art.
  • the optical system I 9 may be so formed, in ways well known in the optical art, to produce, for an observer using the optical system, a virtual image 2! which is a magnified replica of the intense light image on the screen 9.
  • a hemispherical lens 23 covering the image on the screen 9 may be used to minimize halation and increase the optical efficiency.
  • B 82 sin where B2 is the brightness of the object and 0 is the total angle the converging light subtended at the retina. If additional optical elements are used such that 0 is still determined by the eye, the brightness of the image on the retina is substantially unchanged. Such an additional optical system may magnify the image size many times.
  • the brightness B2 of the image generated. by the electron impact on the screen 9 can, in turn, be shown by the laws of electron optics to be given by the following equation:
  • D1 is the diameter of image on screen 3 and D2 is the diameter of the electron phosphor image on screen 9.
  • B1 is the brightness of the image on screen 3 and a is a factor of proportion ality depending on the photo-electric sensitivity.
  • Equation 3 the brightness B of the image on the retina of the observer is increased as the diameter D2 of the image produced by electron impact on screen 9 is reduced. It is correspondingly highly advantageous to adjust the electron optical system by means of regulating the form and strength of the magnetic field set up by coils I 5 and IE to contract greatly the diameter D2 of the image produced by electron impact on the screen 9. It would, in fact, be possible theoretically thus to attain substantially any desired ratio of intensity between the brightness of the image seen by the observer in the optical system l9 to the brightness of the image on fluorescent screen 3 by sumciently reducing the diameter D2. In actual practice there are limitations set by distortion of the electron image when the attempt is made to too greatly reduce the value of D2, and.
  • the image on screen l2 can be contracted to a very high degree making it brighter inversely proportional to its area. This bright image may then be photographed at high speed making no attempt at this time to increase the image size. It is obvious to those versed in the art that such resulting photograph may be enlarged or directly viewed at much greater magnification. In this case the intensity of the accompanying light source for viewing or projecting can make up for a small aperture of the viewing or projecting means. The reduction in size of the image at the electron phosphor will later be counteracted by the projector or viewer. Moving pictures may be possible with the abovementioned device that are not possible without it.
  • An electronic system adapted to be aligned with a source of X-rays, said system including a first fluorescent screen, then in order, a photoelectric screen and a second fluorescent screen spaced from said first fluorescent screen, a condensing electronic lens adjacent said screens for projecting an image from said photoelectric screen of contracted size and increased brilliancy upon said second fluorescent screen and a magnilying optical system adjacent said second flucrescent screen for magnifying the image on said second fluorescent screen.
  • an electronic system adapted to be aligned therewith and including a first fluorescent screen, then in order, a photoelectric screen and a second fluorescent screen spaced from said first fluorescent screen, a condensing electronic lens adjacent said screens for projecting an image from said photoelectric screen of contracted size and increased brilliancy upon said second fluorescent screen and a magnifying optical system adjacent said second fluorescent screen for magnifying the image on said second fluorescent screen.
  • An electronic system adapted to be aligned with a source of X-rays, said system including a first fluorescent screen, then in order, a photoelectric screen closely adjacent and parallel with said first fluorescent screen and a second fluorescent screen spaced from said first fluorescent screen, a condensing electronic lens adjacent said screens for projecting an image from said photoelectric screen of contracted size and increased brilliancy upon said second fluorescent screen and a magnifying optical system adjacent said second fluorescent screen for magnifying the image on said second fluorescent screen.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Transforming Electric Information Into Light Information (AREA)
US771112A 1947-08-28 1947-08-28 Image intensifier Expired - Lifetime US2555545A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
BE484424D BE484424A (xx) 1947-08-28
US771112A US2555545A (en) 1947-08-28 1947-08-28 Image intensifier
GB18919/48A GB652451A (en) 1947-08-28 1948-07-14 Improvements in or relating to electron optical systems
FR970375D FR970375A (fr) 1947-08-28 1948-08-12 Dispositif pour intensifier des images
GB13979/49A GB662569A (en) 1947-08-28 1949-05-25 Improvements in or relating to electron optical systems
NL146672A NL71728C (xx) 1947-08-28 1949-05-27
FR59910D FR59910E (fr) 1947-08-28 1949-07-12 Dispositif pour intensifier des images

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US771112A US2555545A (en) 1947-08-28 1947-08-28 Image intensifier
US662569XA 1948-07-14 1948-07-14

Publications (1)

Publication Number Publication Date
US2555545A true US2555545A (en) 1951-06-05

Family

ID=26746538

Family Applications (1)

Application Number Title Priority Date Filing Date
US771112A Expired - Lifetime US2555545A (en) 1947-08-28 1947-08-28 Image intensifier

Country Status (5)

Country Link
US (1) US2555545A (xx)
BE (1) BE484424A (xx)
FR (2) FR970375A (xx)
GB (2) GB652451A (xx)
NL (1) NL71728C (xx)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2648776A (en) * 1951-03-22 1953-08-11 Westinghouse Electric Corp Optical system for image intensifiers
US2650310A (en) * 1952-10-10 1953-08-25 Gen Electric X-ray image intensification and method
US2667585A (en) * 1951-02-15 1954-01-26 Hartford Nat Bank & Trust Co Device for producing screening images of body sections
US2681868A (en) * 1949-08-10 1954-06-22 Westinghouse Electric Corp Image amplifier
US2697182A (en) * 1948-12-09 1954-12-14 Sheldon Edward Emanuel Tube for intensification of images
US2717971A (en) * 1949-03-30 1955-09-13 Sheldon Edward Emanuel Device for storage of images of invisible radiation
US2751504A (en) * 1951-06-14 1956-06-19 Hartford Nat Bank & Trust Co Support for image amplifiers
US2761084A (en) * 1949-03-30 1956-08-28 Sheldon Edward Emanuel Device for intensifying images of invisible radiation
US2768307A (en) * 1952-07-26 1956-10-23 Texas Co Scintillometers
US2804561A (en) * 1948-03-09 1957-08-27 Sheldon Edward Emanuel X-ray camera
US2837660A (en) * 1958-06-03 Glass -
US2853619A (en) * 1951-08-16 1958-09-23 Westinghouse Electric Corp Image amplifier phototimer
US2884528A (en) * 1956-03-05 1959-04-28 Rca Corp Stereoscopic x-ray intensification
US2917645A (en) * 1954-09-20 1959-12-15 Julius Cato Vredenburg Inglesb Control method and means
US2951898A (en) * 1953-05-25 1960-09-06 Gen Electric Iconoscope
US2955888A (en) * 1958-10-16 1960-10-11 Alfreda E Graves Detachable extension table top
US2960416A (en) * 1952-07-29 1960-11-15 Rauland Corp Method of manufacturing screens for electron-discharge devices
US3001098A (en) * 1954-03-17 1961-09-19 Westinghouse Electric Corp X-ray image intensifying device
US3015731A (en) * 1954-08-21 1962-01-02 Philips Corp Radiation indicating device
US3089956A (en) * 1953-07-10 1963-05-14 Westinghouse Electric Corp X-ray fluorescent screen
US3184753A (en) * 1962-11-05 1965-05-18 Bunker Ramo Apparatus for exposing photosensitive material
US3482104A (en) * 1965-05-24 1969-12-02 Jack Finkle System for televising radiant energy images employing image transducer device with radiant energy image responsive photocathode
US3580151A (en) * 1968-10-17 1971-05-25 Us Air Force Low light level color photography
US4164657A (en) * 1976-05-17 1979-08-14 N.V. Optische Industrie "De Oude Delft" Apparatus for tomography
FR2536871A1 (fr) * 1982-11-29 1984-06-01 Hamamatsu Photonics Kk Agrandisseur radiographique

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2131185A (en) * 1935-03-01 1938-09-27 Telefunken Gmbh Electrooptical device
US2143095A (en) * 1937-06-07 1939-01-10 Albert G Thomas Electronic device
US2151785A (en) * 1937-06-26 1939-03-28 Emi Ltd Electron discharge device
US2158853A (en) * 1937-10-30 1939-05-16 Gen Electric Image reproduction
GB514881A (en) * 1937-02-15 1939-11-20 Standard Telephones Cables Ltd X-ray converter
US2189322A (en) * 1937-01-19 1940-02-06 Rca Corp Photoelectric cathode
US2189321A (en) * 1936-10-28 1940-02-06 Rca Corp Electro-optical device
US2344043A (en) * 1941-07-03 1944-03-14 Kailmann Hartmut Israel Method and device for depicting objects by means of neutrons or x-rays

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2131185A (en) * 1935-03-01 1938-09-27 Telefunken Gmbh Electrooptical device
US2189321A (en) * 1936-10-28 1940-02-06 Rca Corp Electro-optical device
US2189322A (en) * 1937-01-19 1940-02-06 Rca Corp Photoelectric cathode
GB514881A (en) * 1937-02-15 1939-11-20 Standard Telephones Cables Ltd X-ray converter
US2143095A (en) * 1937-06-07 1939-01-10 Albert G Thomas Electronic device
US2151785A (en) * 1937-06-26 1939-03-28 Emi Ltd Electron discharge device
US2158853A (en) * 1937-10-30 1939-05-16 Gen Electric Image reproduction
US2344043A (en) * 1941-07-03 1944-03-14 Kailmann Hartmut Israel Method and device for depicting objects by means of neutrons or x-rays

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2837660A (en) * 1958-06-03 Glass -
US2804561A (en) * 1948-03-09 1957-08-27 Sheldon Edward Emanuel X-ray camera
US2697182A (en) * 1948-12-09 1954-12-14 Sheldon Edward Emanuel Tube for intensification of images
US2717971A (en) * 1949-03-30 1955-09-13 Sheldon Edward Emanuel Device for storage of images of invisible radiation
US2761084A (en) * 1949-03-30 1956-08-28 Sheldon Edward Emanuel Device for intensifying images of invisible radiation
US2681868A (en) * 1949-08-10 1954-06-22 Westinghouse Electric Corp Image amplifier
US2667585A (en) * 1951-02-15 1954-01-26 Hartford Nat Bank & Trust Co Device for producing screening images of body sections
DE940775C (de) * 1951-02-15 1956-03-29 Philips Nv Vorrichtung zur Herstellung von Durchleuchtungsbildern von Koerperschnitten
US2648776A (en) * 1951-03-22 1953-08-11 Westinghouse Electric Corp Optical system for image intensifiers
US2751504A (en) * 1951-06-14 1956-06-19 Hartford Nat Bank & Trust Co Support for image amplifiers
US2853619A (en) * 1951-08-16 1958-09-23 Westinghouse Electric Corp Image amplifier phototimer
US2768307A (en) * 1952-07-26 1956-10-23 Texas Co Scintillometers
US2960416A (en) * 1952-07-29 1960-11-15 Rauland Corp Method of manufacturing screens for electron-discharge devices
US2650310A (en) * 1952-10-10 1953-08-25 Gen Electric X-ray image intensification and method
US2951898A (en) * 1953-05-25 1960-09-06 Gen Electric Iconoscope
US3089956A (en) * 1953-07-10 1963-05-14 Westinghouse Electric Corp X-ray fluorescent screen
US3001098A (en) * 1954-03-17 1961-09-19 Westinghouse Electric Corp X-ray image intensifying device
US3015731A (en) * 1954-08-21 1962-01-02 Philips Corp Radiation indicating device
US2917645A (en) * 1954-09-20 1959-12-15 Julius Cato Vredenburg Inglesb Control method and means
US2884528A (en) * 1956-03-05 1959-04-28 Rca Corp Stereoscopic x-ray intensification
US2955888A (en) * 1958-10-16 1960-10-11 Alfreda E Graves Detachable extension table top
US3184753A (en) * 1962-11-05 1965-05-18 Bunker Ramo Apparatus for exposing photosensitive material
US3482104A (en) * 1965-05-24 1969-12-02 Jack Finkle System for televising radiant energy images employing image transducer device with radiant energy image responsive photocathode
US3580151A (en) * 1968-10-17 1971-05-25 Us Air Force Low light level color photography
US4164657A (en) * 1976-05-17 1979-08-14 N.V. Optische Industrie "De Oude Delft" Apparatus for tomography
FR2536871A1 (fr) * 1982-11-29 1984-06-01 Hamamatsu Photonics Kk Agrandisseur radiographique

Also Published As

Publication number Publication date
BE484424A (xx)
FR59910E (fr) 1954-09-21
FR970375A (fr) 1951-01-03
NL71728C (xx) 1953-02-16
GB652451A (en) 1951-04-25
GB662569A (en) 1951-12-05

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