US2863061A - X-ray fluoroscopic device - Google Patents

X-ray fluoroscopic device Download PDF

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Publication number
US2863061A
US2863061A US433185A US43318554A US2863061A US 2863061 A US2863061 A US 2863061A US 433185 A US433185 A US 433185A US 43318554 A US43318554 A US 43318554A US 2863061 A US2863061 A US 2863061A
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United States
Prior art keywords
screen
ray
rays
phosphor
luminescent material
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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
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US433185A
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English (en)
Inventor
Destriau Georges
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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Filing date
Publication date
Priority to CA687632A priority Critical patent/CA687632A/en
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US433185A priority patent/US2863061A/en
Priority to DEW16551A priority patent/DE1032089B/de
Priority to JP1466455A priority patent/JPS354828B1/ja
Application granted granted Critical
Publication of US2863061A publication Critical patent/US2863061A/en
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    • 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
    • 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 X-ray devices and, more pan ticularly, to an X-ray device having improved luminescent response to an X-ray signal.
  • Gudden and Pohl elect which may be described as a momentary luminescence induced by the application of an electric eld across a phosphor which has been previously excited.
  • Fig. 1 is a block diagram illustrating a fluoroscopic apparatus constructed according to this invention
  • Fig. 2 is a plan view of a fluo-roscopic screen as used with the device shown in Fig. l;
  • Fig. 3 is a sectional elevational view taken on III- III of Fig. 2;
  • Fig. 4 is a sectional elevational view, corresponding to Fig. 3, illustrating an alternative embodiment
  • Fig. 5 is a graph of screen brightness vs.fperiods of X-ray excitation for the electroluminescent cells of the prior art
  • Fig. 6 is a graph of screen brightness vs.. 'periods of X-ray excitation for the X-ray device of this invention
  • Fig. 7 is a graph representing the sensitization ratio vs. applied electric field for the preferred fluoroscopic screen as used with this invention.
  • Fig. 8 is another graph representing the sensitization ratio vs. applied electric held for the tluoroscopic screen as used with this invention.
  • the numeral 10 in Fig. l indicates generally a .fluoroscopic apparatus which generally comprises a fluoroscopic screen 12, electric field Voltage supply 14, inspection table 16 and X-ray generating apparatus 18, which X-ray apparatus may be of kv., 3 ma. rated output, for example.
  • Figs. 2 and 3 are illustrated the preferred embodiment of the fluoroscopic screen 12 which comprises generally a substantially planar layer of luminescent material 20 in contact with a substantially planar layer of dielectric material 22, said luminescent material and dielectric being sandwiched between two thin transparent conducting layers or electrodes 24 and 26.
  • a foundation-viewing plate 2S is placed over one of the conducting layers, for example layer 24, and an insulating layer 30 is placed over the other conducting layer in order to minimize shock hazard.
  • Each of the conducting layers 24 and 26 are connected by separate electrical leads 32 and 34 to the field voltage supply 14, as shown in block diagram in Fig. l.
  • a protecting and handling shield 36 is normally provided around the entire periphery of the cell in order to facilitate handling, storage, etc.
  • the luminescent material 20 is preferably positioned next to the foundation-viewing plate 23 in order to improve screen perception and minimize parallax, although for so-me applications it might be preferable to place the dielectric material 22 next to the viewing plate.
  • the luminescent material 20 will be more thoroughly considered in the following paragraphs and for such an application as the the instant one may have a thickness of about V0.2 mm., although this thickness is no way critical.
  • the dielectric may consist of any material which has a high dielectric constant, is transparent to X-rays and will not deteriorate under the action of X-rays. Such materials are well known and, as an example, the dielectric material may consist of a mica sheet about 0.05 mm. thick although this thickness is in no way critical and may be increased or decreased as dictated by the application.
  • the thin transparent conducting electrodes 24 and 26 may be any conducting transparent materials which may readily be coated as a thin sheet, are transparent to visible light in the case of the upper layer 24 and transparent to X-rays in the case of the lower layer 26, and will not deteriorate appreciably under the action of X-rays.
  • the coating 24 may be of tin oxi-de and may be applied as described in Patent No. 2,522,531 to Mochel.
  • the coating 24 may be of an oxide of Zinc, cadmium, aluminum or bismuth.
  • the thin transparent conducting coating 26 may be of tin oxide, or may be a thin reflecting coating of aluminum which may be .applied by the well-known vacuummetallizing techniques, a representative thickness of such Al coating being 0.001 cm.
  • the thin protective layer 30, which is intended to insure against shock hazard and to facilitate handling, may be of any X-ray transparent material which has a relatively high dielectric constant, an example being a polystyrene compound as sold by Dow Chemical Co. under the trademark Styron Another example 'of a satisfactory material is a methyl methacrylate compound, such as sold by E. l. du Pont under the trademark Lucite
  • This protective coating 30 may be dispensed with if desired as it in no way affects the operation of the device. Shock hazard may then be eliminated by grounding thev electrode 26.
  • the foundation glass-viewing plate 28 may be fabricated of any glass which contains heavy atoms which will absorb the X-rays and thus protect the viewer.
  • any ofthe well-known lead or cerium glasses may be used.
  • the protecting shield 36 may be of any suitable plastic material such as the aforementioned polystyrene compound. This protecting shield is in no way necessary to the operation of the device and may be dispensed with if desired.
  • the electrical leads 32 and 34 may be directly connected to the electrodes 24 and 26 respectively or preferably are connected to the electrodes through bus bars 38 and 40 as described in Patent No. 2,628,299 to Gaiser.
  • the field voltage supply may Aconsist of a transformer having an output which is variable between 100 and 2,000 volts, 60 cycles, for example, in order that the eld applied across the electrodes may be adjusted to optimum conditions, as hereinafter explained.
  • Fig. 4 is represented an alternative embodiment of the liuoroscopic screen, as illustrated in Fig. 3, and'all parts of this alternative embodiment are identical with the embodiment as illustrated in Fig. 3 except that the phosphor is embedded throughout the dielectric, to form a homogeneous phosphor-dielectric layer 40.
  • the dielectric in which the phosphor is embedded may consist of any material which is relatively transparent to visible light and X-rays, is stable under the action of X-rays and has a high dielectric constant, a dielectric constant about 4 being generally satisfactory.
  • an equivalent amount of phosphor may be embedded in the dielectric as would form a phosphor layer about 0.2 mm. thick, as described in the preferred embodiment of Fig. 3.
  • This amount of phosphor is only one of choice and the amount may be varied as dictated by the application.
  • Sufiicient dielectric material may be incorporated with the phosphor to cause the phosphordielectric layer to be about 0.3mm. thick. This thickness is given only by way of example and not by way of limitation and may be varied according to the application.
  • Fig. 5 is illustrated a graph of arbitrary brightness units vs. time in minutes of X-ray irradiation for a fluoroscopic screen incorporating a known uoroscopic phosphor .and adapted to have an electric field applied thereacross.
  • the prior art phosphor material utilized in the screen is ZnCdS:Ag of 0.2 mm. thickness, which is a well-known X-ray-sensitive phosphor. In this experiment this phosphor is placed between two electrodes, as illustrated in Fig. 3.
  • the liuoroscopic screen embodying this phosphor is irradiated with X-rays, the brightness increases following the curve OABC.
  • the brightness When a field is applied between the two electrodes, simultaneously with the X-ray irradiation, the brightness may be represented by the curve OA'BC. If the electric field is applied only between the time t1 and t2 there is a sudden drop AD in brightness upon application of the field at t1, after which the brightness slowly increases from its minimum at D to point B', which is the brightness normally expected with both X-ray irradiation and applied field. When the field is removed at time t2, there is experienced a small drop B'E, after which the brightness increases to that normally expected with only X-ray irradiation.
  • a ZnCdS:Mn phosphor is incorporated in the pre- CII ferred embodiment of the screen, as illustrated in Fig. 3, the effect of decreased brightness, as illustrated in Fig. 6, is completely reversed and an increased brightness is obtained.
  • Fig. 6 a graph of arbitrary brightness units vs. periods of X-ray irradiation for the preferred ZnCdS:Mn phosphor incorporated into a fluoroscopic screen, as illustrated in Fig. 3, All brightness measurements referred to were made under the same test conditions and thus represent relative values.
  • this phosphor consists of 2 moles CdS, 7 moles ZnS and activated by 5 10-2 mole Mn.
  • Such a phosphor may be prepared by ball-milling the aforementioned ingredients and firing in an oxygen-free atmosphere for about one hour at l200 C.
  • a specific example of the phosphor which may be used in the fluoroscopic screen consists of 2 moles Cds, 7 moles ZnS and activated by 5x10-2 mole Mn. It has been found that this luminescent material activated by from about 0.01 X10*2 to 6 102 mole Mn per mole of zinc plus cadmium Will be satisfactory and apparently the main constituents of the phosphor which affect its properties regarding increased brightness when irradiated by X-rays and placed within an electric field are CdS and Mn.
  • the ratio of Cd to Zn in the luminescent material should be from between 1 mole CdS; 9 moles ZnS to 7 moles CdS; 3 moles ZnS, if a satisfactory output is to be obtained. Any molar ratio of Cd to Zn within these aforementioned limitations will produce a luminescent material which is generally satisfactory for the disclosed uoroscopic screens.
  • the moles of Mn activator per mole of Cd and Zn are preferably from about '0.3 10-2 to about 1.l l02, although this range may vary from 0.01 to 10-2 to 6 102 mole Mn activator per mole of luminescent material, as heretofore mentioned.
  • the aforementioned phosphor In order to increase the X-ray sensitivity of the luminescent material, there may be added to the aforementioned phosphor from traces, e. g. 0.001X l0-2 mole Ag up to about 1.0)(10-2 mole of Ag activator per mole of Mn activator.
  • This Ag activator addition will not measurably decrease the increase in brightness which is realized thru the screen excitation by both X-ray irradiation and an electric field, but the silver activator addition increases somewhat the X-ray sensitivity of the phosphor.
  • Luminescent material compositions according to this invention are given in the following examples:
  • Example 1 2 moles CdS 7 moles ZnS 5 X 10-2 mole Mn
  • Example 2 1.5 moles CdS moles ZnS 2 1O2 mole Mn
  • Example 3 2 moles CdS 7 moles ZnS 5 X10"2 mole Mn 0.01 2 mole Ag
  • the cell brightness is directly proportional to the eld intensity.
  • the iield intensity is at an optimum at about -25 kv. per cm.
  • Fig. 7 a graph of relative intensity vs.
  • P1 is a sensitizing ratio and represents the brightness (b1) of the fluoroscopic screen when the screen is irradiated by X-rays and has 'simultaneously applied thereto an electric iield, dividedrby the brightness (bo) of the same screen when irradiated by X-rays only.
  • P1 b1/ 170.
  • Fig. 8 is represented the sensitizing ratio (P1) vs. eld in applied kv. per cm. for the phosphor given in Example 2.
  • the maximum sensltizing ratio occurs at about 18 kv. per cm. and is about 1.6, after which the sensitizing ratio decreases.
  • This phenomenon of decreasing sensitizing ratio after an optimum has been cached has been generally observed with the luminescent materials of this invention and in all experiments conducted so -far the optimum iield occurs between 15 and 25 kv./cm. ln order to operate at the field of 20 kv./ cm. for the specific example of the embodiment as illustrated in Fig.
  • the applied voltage to the electrodes should be about 500.
  • the applied Voltage to the electrodes sho-uld be about 600.
  • the X-ray in tensity may be decreased from the X-ray intensity required to operate the fluoroscopes of the prior art, and a picture of equivalent brightness may still be obtained.
  • This of course has the advantage of decreasing the hazards encountered in operating X-ray equipment.
  • An X-ray sensitive device comprising, a screen comprising luminescent material sandwiched between two electrodes, means for applying an alternating current pomeans, and means tential between said electrodes, means for irradiating said luminescent material with X-rays, and Said luminescent material consisting of ZnS and CdSwherein the molar ratio of Zn to Cd is from 9 Znzl Cd to 3 Zn:7 Cd and activated by from 0.01 102 to 60x102 mole Mn per mole of luminescent material.
  • An X-ray sensitive device comprising, a screen comprising luminescent material sandwiched between two electrodes, means for applying an alternating current potential between said electrodes, means for irradiating said luminescent material with X-rays, and said luminescent material consisting of ZnS and CdS wherein the molar ratio of Zn to Cd is from 9 Zn:1 Cd to 3 Zn:7 Cd and activated by from 03x10-2 to 1.1)(102 mole Mn per mole of luminescent material.
  • a iiuoroscopic device comprising, a luminescent material and a dielectric sandwiched between two electrodes, means for applying an alternating current potential between said electrodes, means for irradiating said luminescent material with X-rays, said luminescent material consisting of ZnS and CdS wherein the molar ratio Zn to Cd is from 9 Zn:1 Cd to 3 Zn:7 -Cd and activated by one of the group consisting of Mn, and Mn and Ag, said Mn activator being present in amounts of from 0.3 102 to 1.1 102 mole per mole of luminescent material, and said Ag activator being present in amounts of from traces to 1.0 102 mole per mole of Mn activator.
  • An X-ray sensitive device comprising, a screen including luminescent means which exhibits the property of sustained luminescence under excitation by X-rays and sustained enhanced luminescence under the simultaneous inuence of an alternating electric iield, means for applying an alternating electric field across said luminescent for simultaneously irradiating said luminescent means with X-rays.
  • An X-ray sensitive device comprising, a screen of dielectric and luminescent means, said luminescent means exhibiting the property of sustained luminescence under excitation by X-rays and sustained enhanced luminescence under the simultaneous iniiuence of an alternating electric field, means for applying an alternating electric ield across said screen, and means for simultaneously irradiating said screen with X-rays.
  • An X-ray sensitive device comprising, a screen including linely-divided luminescent means which exhibits the property of sustained luminescence under excitation by X-rays and sustained enhanced luminescence under the simultaneous influence of an alternating electric lield, means for applying an alternating electric eld across said luminescent means, and means for simultaneously irradiating said luminescent means with X-rays.
  • An X-ray sensitive device comprising, a screen of dielectric and finely-divided luminescent means, said luminescent means exhibiting the property of sustained luminescence under excitation by X-rays and sustained enhanced luminescence under the simultaneous influence of an alternating electric field, means for applying an alternating electric iield across said'screen, and means for simultaneously irradiating said screen with X-rays.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Luminescent Compositions (AREA)
  • Photo Coupler, Interrupter, Optical-To-Optical Conversion Devices (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
US433185A 1954-05-28 1954-05-28 X-ray fluoroscopic device Expired - Lifetime US2863061A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CA687632A CA687632A (en) 1954-05-28 X-ray fluoroscopic device
US433185A US2863061A (en) 1954-05-28 1954-05-28 X-ray fluoroscopic device
DEW16551A DE1032089B (de) 1954-05-28 1955-04-26 Verfahren und Vorrichtung zum Erzeugen von Roentgenschirmbildern
JP1466455A JPS354828B1 (enrdf_load_stackoverflow) 1954-05-28 1955-05-28

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CA687632T
US1032089XA 1954-05-28 1954-05-28
US433185A US2863061A (en) 1954-05-28 1954-05-28 X-ray fluoroscopic device

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US2863061A true US2863061A (en) 1958-12-02

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JP (1) JPS354828B1 (enrdf_load_stackoverflow)
CA (1) CA687632A (enrdf_load_stackoverflow)
DE (1) DE1032089B (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3010043A (en) * 1956-07-03 1961-11-21 Du Pont Image storage elements and process
US3043979A (en) * 1958-12-17 1962-07-10 Philips Corp Electroluminescent element
US3056898A (en) * 1959-07-09 1962-10-02 Westinghouse Electric Corp Lighting unit and method of manufacture
US3155324A (en) * 1961-08-23 1964-11-03 Westinghouse Electric Corp Ceiling lighting fixtures
US4045676A (en) * 1974-03-15 1977-08-30 Ortec Incorporated Determining element concentrations in samples

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566349A (en) * 1950-01-28 1951-09-04 Sylvania Electric Prod Electroluminescent lamp
US2650310A (en) * 1952-10-10 1953-08-25 Gen Electric X-ray image intensification and method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE658295C (de) * 1934-03-28 1938-03-28 Fritz Schroeter Dr Verfahren zur Herstellung von Lumineszenzbildern mittels Roentgendurchleuchtung

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566349A (en) * 1950-01-28 1951-09-04 Sylvania Electric Prod Electroluminescent lamp
US2650310A (en) * 1952-10-10 1953-08-25 Gen Electric X-ray image intensification and method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3010043A (en) * 1956-07-03 1961-11-21 Du Pont Image storage elements and process
US3043979A (en) * 1958-12-17 1962-07-10 Philips Corp Electroluminescent element
US3056898A (en) * 1959-07-09 1962-10-02 Westinghouse Electric Corp Lighting unit and method of manufacture
US3155324A (en) * 1961-08-23 1964-11-03 Westinghouse Electric Corp Ceiling lighting fixtures
US4045676A (en) * 1974-03-15 1977-08-30 Ortec Incorporated Determining element concentrations in samples

Also Published As

Publication number Publication date
JPS354828B1 (enrdf_load_stackoverflow) 1960-05-10
CA687632A (en) 1964-06-02
DE1032089B (de) 1958-06-12

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