US1954691A - Process of making alpha layer containing alpha fluorescent material - Google Patents

Process of making alpha layer containing alpha fluorescent material Download PDF

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Publication number
US1954691A
US1954691A US563650A US56365031A US1954691A US 1954691 A US1954691 A US 1954691A US 563650 A US563650 A US 563650A US 56365031 A US56365031 A US 56365031A US 1954691 A US1954691 A US 1954691A
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Prior art keywords
fluorescent material
alpha
making
layer
layer containing
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Expired - Lifetime
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US563650A
Inventor
Boer Jan Hendrik De
Dippel Cornelis Johannes
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Koninklijke Philips NV
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Philips Gloeilampenfabrieken NV
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens

Definitions

  • This invention relates to a method of making a layer containing a fluorescent material.
  • fluorescing layers are used for various purposes, for example, as X-ray intensifying screens.
  • the fluorescent material is volatilized and precipitated in a vacuum.
  • fluorescing layers having such a thickness that they are transparent to light.
  • the method according to the invention is particularly suitable.
  • a fluorescing layer formed by means of this method may be given a greater thickness than a fluorescing layer which does not have such a uniform structure without the transparency being unfavourably affected thereby.
  • An additional advantage of the method according to the invention consists in that the nature 0 of the grain of the fluorescent material precipitated may be varied by modifying the rate of volatilization. As a rule the-size of the grains will be small at a quick volatilization which is of great importance, for example, in the -manufac-' ture of X-ray intensifying screens. It is found that the image taken on such a screen will be sharper as the size of the grains of the fluorescent material is reduced.
  • Figure 1 is a sectional view of apparatus that may be used to carry out the improved process according to the invention.
  • Fig. 2 is a plan view of the base or sheet on which the fluorescent layer is to be formed showing the filament from which the sensitive material is volatilized.
  • the apparatus comprises a glass vessel or bulb 1 closed by a stopper 2.
  • the wire 8 is coated with fluorescent material, such as zinc sulphide .or calcium tungstate, which is volatilized by the heating of said wire and precipitates in the form of a layer on the upper surface of the sheet 'I.
  • a fluorescent layer having a fine, uniform structure and improved sensitivity is thereby produced.
  • the sheet '1 may, if desired, be first coated with a layer, consisting of a material by which the fluorescent material is perfectly adsorbed, before it is subjected to the described coating process.
  • the fluorescent layer on the sheet 7 may comprise a mixture of fluorescent substances which i may be volatilized simultaneously.
  • This layer may also contain other substances in addition to the fluorescent material. These substances may be incorporated into the layer, for example, by volatilizing them simultaneously with the fluorescent material in the bulb 1.
  • the fluorescent layer formed in this manner is found to have novel and unexpected properties.
  • the layer has a more uniform structure, is much more transparent and possesses enhanced sensitivity.
  • the fluorescence obtained is greatly increased while the light absorption is decreased.
  • i 1 A method of making an X-ray intensifying screen, in which a suitable base together with a quantity of fluorescent material is introduced into 4.
  • a method of making a ray-sensitive screen comprising volatilizing and precipitating calcium ungstate on a sheet or base in a vacuum.

Description

April 10, 1934. J. H. DE BOER ET AL PROCESS OF HAKING A LAYER CONTAINING A FLUORESCENT MATERIAL Filed Sept. 18, 1951 Patented Apr. 10, 1934 UNITED STATES rnocass' OF MAKING A LAYER CONTAIN- me A FLUORESCENT MATERIAL Jan Hendrik de Boer and Cornelis J ohannw Dippel, Eindhoven, Netherlands, assisnors to N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands Application September 18, 1931, Serial No. 563,650 In the Netherlands September 2'], 1930 4 Claims.
This invention relates to a method of making a layer containing a fluorescent material. Such fluorescing layers are used for various purposes, for example, as X-ray intensifying screens.
When making such a layer according to the invention the fluorescent material is volatilized and precipitated in a vacuum.
It has been found that a fluorescing layer formed in this manner has a very uniform structure. In fact, all of the molecules precipitated appear to have the same orientation. By this uniform structure the fluorescence of the layer is increased.
In some cases it is desired to obtain fluorescing layers having such a thickness that they are transparent to light. For this purpose the method according to the invention is particularly suitable. In fact, a fluorescing layer formed by means of this method may be given a greater thickness than a fluorescing layer which does not have such a uniform structure without the transparency being unfavourably affected thereby.
An additional advantage of the method according to the invention consists in that the nature 0 of the grain of the fluorescent material precipitated may be varied by modifying the rate of volatilization. As a rule the-size of the grains will be small at a quick volatilization which is of great importance, for example, in the -manufac-' ture of X-ray intensifying screens. It is found that the image taken on such a screen will be sharper as the size of the grains of the fluorescent material is reduced.
. For a better understanding of the present invention, reference should be had to the accompanying drawing, wherein Figure 1 is a sectional view of apparatus that may be used to carry out the improved process according to the invention; and
Fig. 2 is a plan view of the base or sheet on which the fluorescent layer is to be formed showing the filament from which the sensitive material is volatilized.
The apparatus comprises a glass vessel or bulb 1 closed by a stopper 2. Leading-in wires 3 and a suitable source, such as a transformer 9, so as to be heated to incandescence-after the bulb 1 has been evacuated through the connection 10. The wire 8 is coated with fluorescent material, such as zinc sulphide .or calcium tungstate, which is volatilized by the heating of said wire and precipitates in the form of a layer on the upper surface of the sheet 'I. A fluorescent layer having a fine, uniform structure and improved sensitivity is thereby produced. The sheet '1 may, if desired, be first coated with a layer, consisting of a material by which the fluorescent material is perfectly adsorbed, before it is subjected to the described coating process.
The fluorescent layer on the sheet 7 may comprise a mixture of fluorescent substances which i may be volatilized simultaneously. This layer may also contain other substances in addition to the fluorescent material. These substances may be incorporated into the layer, for example, by volatilizing them simultaneously with the fluorescent material in the bulb 1.
The fluorescent layer formed in this manner is found to have novel and unexpected properties.
In comparison with the layers formed by the processes hitherto employed, the layer has a more uniform structure, is much more transparent and possesses enhanced sensitivity. The fluorescence obtained is greatly increased while the light absorption is decreased. I I What we claim is: i 1. A method of making an X-ray intensifying screen, in which a suitable base together with a quantity of fluorescent material is introduced into 4. A method of making a ray-sensitive screen comprising volatilizing and precipitating calcium ungstate on a sheet or base in a vacuum.
' JAN HENDRIK as BOER.
- CORNELIS JOHANN'ES DIPPEL.
US563650A 1930-09-27 1931-09-18 Process of making alpha layer containing alpha fluorescent material Expired - Lifetime US1954691A (en)

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Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2451292A (en) * 1943-12-20 1948-10-12 Rca Corp Dark trace screen
US2462517A (en) * 1942-09-29 1949-02-22 Rca Corp Method of manufacture of luminescent materials
US2497140A (en) * 1946-03-28 1950-02-14 Sylvania Electric Prod Method of manufacture of luminescent materials
US2511572A (en) * 1946-09-07 1950-06-13 Sylvania Electric Prod Luminescent screen and method of manufacture
US2538562A (en) * 1945-05-30 1951-01-16 Westinghouse Electric Corp Electrostatic coating method and apparatus
US2600579A (en) * 1946-06-05 1952-06-17 Rca Corp Method of making phosphor screens
US2616057A (en) * 1950-05-20 1952-10-28 Westinghouse Electric Corp Black screen television cathode-ray tube
US2616817A (en) * 1944-01-11 1952-11-04 Hartford Nat Bank & Trust Co Luminescent screen
US2673816A (en) * 1949-12-27 1954-03-30 Leitz Ernst Gmbh Process for making monocrystal actinic screen
US2690979A (en) * 1951-02-07 1954-10-05 Rca Corp Method of powder-coating television screens
US2998323A (en) * 1957-04-05 1961-08-29 Davohn Corp Method for making luminescent screens
DE977171C (en) * 1952-01-29 1965-05-06 Gen Electric Process for the production of a practically grainless fluorescent screen
US3961182A (en) * 1970-02-03 1976-06-01 Varian Associates Pick up screens for X-ray image intensifier tubes employing evaporated activated scintillator layer
US5600200A (en) * 1992-03-16 1997-02-04 Microelectronics And Computer Technology Corporation Wire-mesh cathode
US5601966A (en) * 1993-11-04 1997-02-11 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5612712A (en) * 1992-03-16 1997-03-18 Microelectronics And Computer Technology Corporation Diode structure flat panel display
US5675216A (en) * 1992-03-16 1997-10-07 Microelectronics And Computer Technololgy Corp. Amorphic diamond film flat field emission cathode
US5679043A (en) * 1992-03-16 1997-10-21 Microelectronics And Computer Technology Corporation Method of making a field emitter
US5697824A (en) * 1994-09-13 1997-12-16 Microelectronics And Computer Technology Corp. Method for producing thin uniform powder phosphor for display screens
US5763997A (en) * 1992-03-16 1998-06-09 Si Diamond Technology, Inc. Field emission display device
US5861707A (en) * 1991-11-07 1999-01-19 Si Diamond Technology, Inc. Field emitter with wide band gap emission areas and method of using
US6127773A (en) * 1992-03-16 2000-10-03 Si Diamond Technology, Inc. Amorphic diamond film flat field emission cathode
US6629869B1 (en) 1992-03-16 2003-10-07 Si Diamond Technology, Inc. Method of making flat panel displays having diamond thin film cathode

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2462517A (en) * 1942-09-29 1949-02-22 Rca Corp Method of manufacture of luminescent materials
US2451292A (en) * 1943-12-20 1948-10-12 Rca Corp Dark trace screen
US2616817A (en) * 1944-01-11 1952-11-04 Hartford Nat Bank & Trust Co Luminescent screen
US2538562A (en) * 1945-05-30 1951-01-16 Westinghouse Electric Corp Electrostatic coating method and apparatus
US2497140A (en) * 1946-03-28 1950-02-14 Sylvania Electric Prod Method of manufacture of luminescent materials
US2600579A (en) * 1946-06-05 1952-06-17 Rca Corp Method of making phosphor screens
US2511572A (en) * 1946-09-07 1950-06-13 Sylvania Electric Prod Luminescent screen and method of manufacture
US2673816A (en) * 1949-12-27 1954-03-30 Leitz Ernst Gmbh Process for making monocrystal actinic screen
US2616057A (en) * 1950-05-20 1952-10-28 Westinghouse Electric Corp Black screen television cathode-ray tube
US2690979A (en) * 1951-02-07 1954-10-05 Rca Corp Method of powder-coating television screens
DE977171C (en) * 1952-01-29 1965-05-06 Gen Electric Process for the production of a practically grainless fluorescent screen
US2998323A (en) * 1957-04-05 1961-08-29 Davohn Corp Method for making luminescent screens
US3961182A (en) * 1970-02-03 1976-06-01 Varian Associates Pick up screens for X-ray image intensifier tubes employing evaporated activated scintillator layer
US5861707A (en) * 1991-11-07 1999-01-19 Si Diamond Technology, Inc. Field emitter with wide band gap emission areas and method of using
US5703435A (en) * 1992-03-16 1997-12-30 Microelectronics & Computer Technology Corp. Diamond film flat field emission cathode
US5612712A (en) * 1992-03-16 1997-03-18 Microelectronics And Computer Technology Corporation Diode structure flat panel display
US5675216A (en) * 1992-03-16 1997-10-07 Microelectronics And Computer Technololgy Corp. Amorphic diamond film flat field emission cathode
US5679043A (en) * 1992-03-16 1997-10-21 Microelectronics And Computer Technology Corporation Method of making a field emitter
US5686791A (en) * 1992-03-16 1997-11-11 Microelectronics And Computer Technology Corp. Amorphic diamond film flat field emission cathode
US5600200A (en) * 1992-03-16 1997-02-04 Microelectronics And Computer Technology Corporation Wire-mesh cathode
US5763997A (en) * 1992-03-16 1998-06-09 Si Diamond Technology, Inc. Field emission display device
US6127773A (en) * 1992-03-16 2000-10-03 Si Diamond Technology, Inc. Amorphic diamond film flat field emission cathode
US6629869B1 (en) 1992-03-16 2003-10-07 Si Diamond Technology, Inc. Method of making flat panel displays having diamond thin film cathode
US5614353A (en) * 1993-11-04 1997-03-25 Si Diamond Technology, Inc. Methods for fabricating flat panel display systems and components
US5652083A (en) * 1993-11-04 1997-07-29 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5601966A (en) * 1993-11-04 1997-02-11 Microelectronics And Computer Technology Corporation Methods for fabricating flat panel display systems and components
US5697824A (en) * 1994-09-13 1997-12-16 Microelectronics And Computer Technology Corp. Method for producing thin uniform powder phosphor for display screens

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