US2905829A - Image amplifier - Google Patents
Image amplifier Download PDFInfo
- Publication number
- US2905829A US2905829A US484002A US48400255A US2905829A US 2905829 A US2905829 A US 2905829A US 484002 A US484002 A US 484002A US 48400255 A US48400255 A US 48400255A US 2905829 A US2905829 A US 2905829A
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- US
- United States
- Prior art keywords
- layer
- image
- radiation
- ray
- transparent
- 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
Links
- 230000005855 radiation Effects 0.000 description 12
- 239000000463 material Substances 0.000 description 9
- 239000007789 gas Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- CJOBVZJTOIVNNF-UHFFFAOYSA-N cadmium sulfide Chemical compound [Cd]=S CJOBVZJTOIVNNF-UHFFFAOYSA-N 0.000 description 4
- 229910052980 cadmium sulfide Inorganic materials 0.000 description 4
- 239000004020 conductor Substances 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- UKUVVAMSXXBMRX-UHFFFAOYSA-N 2,4,5-trithia-1,3-diarsabicyclo[1.1.1]pentane Chemical compound S1[As]2S[As]1S2 UKUVVAMSXXBMRX-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- -1 etc. Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229910052743 krypton Inorganic materials 0.000 description 1
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 230000000638 stimulation Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/30—Transforming light or analogous information into electric information
- H04N5/32—Transforming X-rays
-
- 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
- H01J31/505—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output flat tubes, e.g. proximity focusing tubes
-
- 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
- H01J31/506—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output tubes using secondary emission effect
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
- H01J47/10—Spark counters
Definitions
- My invention relates to radiation image amplifiers and, in particular, to a novel type of image intensifier which makes use of the combined properties of photoconductors and gaseous electrical discharge to eifect its purposes. I illustrate it here by applying its broad principles to an intensifier and converter of images of X-ray or other types of radiation.
- One object of my invention is to provide a novel arrangement for producing visible light images which duplicate the spatial distribution of radiation fields.
- Another object is to provide a novel arrangement for producing gaseous discharges which have intensity distributions which are replicas of the intensity distributions of radiation fields.
- Another object is to convert X-ray images into visible light images by a novel and effective method.
- Another object is to produce an electrical discharge distribution which duplicates the area distribution of varying electrical conductivity in a photoconductor.
- Another object is to provide a novel form of radiation image intensifier which is simple, compact and of low first cost.
- Figure 1 is a schematic mid-sectional view of an electrical discharge device applying the principles of my invention to X-ray image conversion
- Fig. 2 is a similar view of a modified form for such a device.
- a vacuum-tight container 1 having substantially planar end faces carries a first electrode in the form of a layer 2 of transparent conducting material such as may be formed from SnO in ways well known in the art.
- the free face of layer 2 is covered with a layer 3 of a photoconductive material such as cadmium sulphide.
- the other planar end of container 1 bears a second electrode in the form of layer 4 of transparent conductive material also.
- the container 1 has a filling of gas which is chemically inert to the photoconductive layer 3 and end layer 4 at a pressure preferably such that the mean-free path is at least equal to the distance between layers 3 and 4. This gas may, for example, be at a pressure of substantially 0.01 to 10 mm.
- a photoconductive layer 3 may be replaced by a layer of material which is rendered temporarily conductive in the vicinity of the incidence point of any sub-atomic particle such as an electron, proton, neutron or alpha particle; i.e. by what may be termed a bombardment-sensitive conductor.
- any sub-atomic particle such as an electron, proton, neutron or alpha particle; i.e. by what may be termed a bombardment-sensitive conductor.
- the X-rays would, of course, be replaced by an image-field of such sub-atomic particle, and the container wall-portion be transparent thereto.
- the voltage of source 7 would be made such that a luminous discharge would pass through the gas opposite those points of the layer 3 as were rendered conductive by photon or particle incidence, but remained non-luminous opposite points where no particles were incident.
- the luminosity of the gas would thus vary moment by moment opposite each point of the area of layer 3 in substantial proportion to the fluctuations in intensity of the incident radiation field.
- a gaseous atmosphere having a luminosity of such wavelength as not to afiect the photoconductive layer 3; thereby avoiding any feed-back and instability; but where such is not the case, a light shield may be provided between the luminous gas and the layer 3.
- This light shield should conduct electricity in a direction normal to the planar face of layer 3, but not substantially parallel thereto.
- a thin high-resistivity film of some material such as graphite particles may be deposited in contact with the outside of layer 3.
- Fig. 2 A modification of the Fig. 1 arrangement which would give higher light output in some fields appears in Fig. 2.
- the gaseous atmosphere selected is one such as mercury vapor, or argon which would generate ultraviolet radiation in the glow discharge.
- a fluorescent screen 9 is deposited over conductive layer 4 and is stimulated to luminosity point-by-point over its area by the ultraviolet radiation.
- the photoconductor layer 3 might be of a material such as cadmium sulphide, arsenic trisulphide or amorphous selenium which was efficiently sensitive to visible light, and to provide an additional input screen 11 of fluorescent material which generated visible light under stimulus of ultraviolet irradiation.
- a tube could also be used for X-ray or other input-radiation fields by employing a screen 11 which responded with visible light to stimulation by said input radiation.
- An X-ray image intensifier comprising a vacuumtight envelope having a wall portion which is substantially transparent to X-rays, a conductive X-ray transparent layer between said wall portion and a substantially planar layer of material which is rendered temporarily more conductive in the vicinity of an incident X-ray photon, a light-transparent conductive layer spaced from said planar layer, in-leads through said envelope for said X-ray transparent layer and said light-transparent conductive layer, and a gaseous atmosphere of substantial pressure within said envelope.
- planar layer material is cadmium sulphide.
- the image intensifier specified in claim 1 in which the gaseous atmosphere comprises helium, neon, argon, krypton, mercury vapor, etc., or mixtures thereof.
- An image converter which comprises a vacuumtight envelope having an input screen comprising a conductive layer having a substantially planar surface of bombardment-sensitive material spaced away from a transparent conductive layer, in-leads for said planar surface and said conductive layer sealed through said envelope, and a gaseous atmosphere therein.
- An image converter which comprises in combination a vacuum-tight envelope, a first substantially planar and substantially transparent electrode within said envelope, a substantially planar layer of photoconductive material for receiving a spatial radiation image and control ionization in said gas so as to generate a luminous discharge image having the pattern of said radiation image.
Description
Filed Jan. 25, 1955 iNVENTOR Edward L. Webb ATTORNEY WITNESSES Uni ed S a v Pat IMAGE AMPLIFIER Edward L. Webb, Baltimore, Md., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 25, '1955, Serial No. 484,002
7 Claims. (Cl. 250-213) My invention relates to radiation image amplifiers and, in particular, to a novel type of image intensifier which makes use of the combined properties of photoconductors and gaseous electrical discharge to eifect its purposes. I illustrate it here by applying its broad principles to an intensifier and converter of images of X-ray or other types of radiation.
One object of my invention is to provide a novel arrangement for producing visible light images which duplicate the spatial distribution of radiation fields.
Another object is to provide a novel arrangement for producing gaseous discharges which have intensity distributions which are replicas of the intensity distributions of radiation fields.
Another object is to convert X-ray images into visible light images by a novel and effective method.
Another object is to produce an electrical discharge distribution which duplicates the area distribution of varying electrical conductivity in a photoconductor.
Another object is to provide a novel form of radiation image intensifier which is simple, compact and of low first cost. 7
Other objects of my invention will become apparent upon reading the following description taken in connection with the drawings, in which:
Figure 1 is a schematic mid-sectional view of an electrical discharge device applying the principles of my invention to X-ray image conversion; and
Fig. 2 is a similar view of a modified form for such a device.
Referring in detail to the drawings, a vacuum-tight container 1 having substantially planar end faces carries a first electrode in the form of a layer 2 of transparent conducting material such as may be formed from SnO in ways well known in the art. The free face of layer 2 is covered with a layer 3 of a photoconductive material such as cadmium sulphide. The other planar end of container 1 bears a second electrode in the form of layer 4 of transparent conductive material also. The container 1 has a filling of gas which is chemically inert to the photoconductive layer 3 and end layer 4 at a pressure preferably such that the mean-free path is at least equal to the distance between layers 3 and 4. This gas may, for example, be at a pressure of substantially 0.01 to 10 mm. of Hg if the layers 3 and 4 are respectively cadmium sulphide and SnO Inleads 5 and 6 enable electric currents to flow from layers 2 and 4 to an external circuit containing a direct current source 7 and a current-limiting resistor 8.
While I have described the principles of my invention as carried out in a tube employing a photoconductive layer 3, the latter may be replaced by a layer of material which is rendered temporarily conductive in the vicinity of the incidence point of any sub-atomic particle such as an electron, proton, neutron or alpha particle; i.e. by what may be termed a bombardment-sensitive conductor. In such case, the X-rays would, of course, be replaced by an image-field of such sub-atomic particle, and the container wall-portion be transparent thereto.
The voltage of source 7 would be made such that a luminous discharge would pass through the gas opposite those points of the layer 3 as were rendered conductive by photon or particle incidence, but remained non-luminous opposite points where no particles were incident. The luminosity of the gas would thus vary moment by moment opposite each point of the area of layer 3 in substantial proportion to the fluctuations in intensity of the incident radiation field.
It will, in many cases, be possible to employ a gaseous atmosphere having a luminosity of such wavelength as not to afiect the photoconductive layer 3; thereby avoiding any feed-back and instability; but where such is not the case, a light shield may be provided between the luminous gas and the layer 3. This light shield should conduct electricity in a direction normal to the planar face of layer 3, but not substantially parallel thereto. For example, a thin high-resistivity film of some material such as graphite particles may be deposited in contact with the outside of layer 3.
A modification of the Fig. 1 arrangement which would give higher light output in some fields appears in Fig. 2. In this arrangement, the gaseous atmosphere selected is one such as mercury vapor, or argon which would generate ultraviolet radiation in the glow discharge. A fluorescent screen 9 is deposited over conductive layer 4 and is stimulated to luminosity point-by-point over its area by the ultraviolet radiation.
Where it was desired to employ an intensifier for ultraviolet radiation image-fields, the photoconductor layer 3 might be of a material such as cadmium sulphide, arsenic trisulphide or amorphous selenium which was efficiently sensitive to visible light, and to provide an additional input screen 11 of fluorescent material which generated visible light under stimulus of ultraviolet irradiation. Such a tube could also be used for X-ray or other input-radiation fields by employing a screen 11 which responded with visible light to stimulation by said input radiation.
I claim as my invention:
1. An X-ray image intensifier comprising a vacuumtight envelope having a wall portion which is substantially transparent to X-rays, a conductive X-ray transparent layer between said wall portion and a substantially planar layer of material which is rendered temporarily more conductive in the vicinity of an incident X-ray photon, a light-transparent conductive layer spaced from said planar layer, in-leads through said envelope for said X-ray transparent layer and said light-transparent conductive layer, and a gaseous atmosphere of substantial pressure within said envelope.
2. The X-ray image intensifier specified in claim 1 in which said planar layer material is cadmium sulphide.
3. The image intensifier specified in claim 1 in which the gaseous atmosphere comprises helium, neon, argon, krypton, mercury vapor, etc., or mixtures thereof.
4. An image converter which comprises a vacuumtight envelope having an input screen comprising a conductive layer having a substantially planar surface of bombardment-sensitive material spaced away from a transparent conductive layer, in-leads for said planar surface and said conductive layer sealed through said envelope, and a gaseous atmosphere therein.
5. The image intensifier specified in claim 1 in which said conductive layer is coated with a fluorescent layer.
6. An image converter which comprises in combination a vacuum-tight envelope, a first substantially planar and substantially transparent electrode within said envelope, a substantially planar layer of photoconductive material for receiving a spatial radiation image and control ionization in said gas so as to generate a luminous discharge image having the pattern of said radiation image. V
7. The apparatus of claim 6 in which said first electrode and said second electrode are connected to an external source of electrical potential.
References Cited in the iile of'this patent UNITED STATES, PATENTS 1,724,298 Miller Aug. 13, 1929 2,120,765 Orvin June 14, 1938 2,258,294 Lubszynski Oct. 7, 1941 2,605,335 Greenwood et al July 29, 1952 2,824,986 Rome Feb. 25, 1-958
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US484002A US2905829A (en) | 1955-01-25 | 1955-01-25 | Image amplifier |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US484002A US2905829A (en) | 1955-01-25 | 1955-01-25 | Image amplifier |
DES0109232 | 1967-04-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2905829A true US2905829A (en) | 1959-09-22 |
Family
ID=25998763
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US484002A Expired - Lifetime US2905829A (en) | 1955-01-25 | 1955-01-25 | Image amplifier |
Country Status (1)
Country | Link |
---|---|
US (1) | US2905829A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3337733A (en) * | 1962-12-27 | 1967-08-22 | Ct Nat De La Recherche | Image amplifying device having a pulse generator applied to parallel electrodes separated by an ionizable gas |
FR2335035A1 (en) * | 1975-12-10 | 1977-07-08 | Bosch Gmbh Robert | IMAGE TRANSFORMER |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1724298A (en) * | 1927-07-20 | 1929-08-13 | John A Dienner | Surface lamp |
US2120765A (en) * | 1934-05-31 | 1938-06-14 | Orvin Lars Jorgen | Infrared ray viewing means |
US2258294A (en) * | 1938-03-29 | 1941-10-07 | Emi Ltd | Photoelectric device |
US2605335A (en) * | 1949-05-25 | 1952-07-29 | Gen Precision Lab Inc | Light amplifier |
US2824986A (en) * | 1954-04-19 | 1958-02-25 | Westinghouse Electric Corp | Increasing contrast of the image intensifier |
-
1955
- 1955-01-25 US US484002A patent/US2905829A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1724298A (en) * | 1927-07-20 | 1929-08-13 | John A Dienner | Surface lamp |
US2120765A (en) * | 1934-05-31 | 1938-06-14 | Orvin Lars Jorgen | Infrared ray viewing means |
US2258294A (en) * | 1938-03-29 | 1941-10-07 | Emi Ltd | Photoelectric device |
US2605335A (en) * | 1949-05-25 | 1952-07-29 | Gen Precision Lab Inc | Light amplifier |
US2824986A (en) * | 1954-04-19 | 1958-02-25 | Westinghouse Electric Corp | Increasing contrast of the image intensifier |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3337733A (en) * | 1962-12-27 | 1967-08-22 | Ct Nat De La Recherche | Image amplifying device having a pulse generator applied to parallel electrodes separated by an ionizable gas |
FR2335035A1 (en) * | 1975-12-10 | 1977-07-08 | Bosch Gmbh Robert | IMAGE TRANSFORMER |
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