Patent US3852131A successfully refreshed from Google Patents.
US3852131A
Expired / Lapsed
US
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Method of manufacturing x-ray image intensifier input phosphor screen
Assignee: General Electric Co
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Filing: 1973-07-19
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Granted: 1974-12-03
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Expires: 1993-07-19
Abstract
Abstract The surface of a waffle-like metal substrate forms an array of cells for the support for the input phosphor screen of an x-ray image intensifier tube. The hollow projecting walls of the metal surface substantially reduce degradation of image resolution due to lateral scattering of light in the phosphor and thereby permits use of a thicker phosphor screen for higher x-ray absorption and, or higher image resolution. The method of fabricating the phosphor screen includes the intermediate steps of forming rubber and plastic replicas of a metal master of the waffle surface. The plastic replicas are nickel plated to form low cost metal replicas with the plastic being dissolved whereby the projecting walls are hollow.
Inventors
- 👤 J Houston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:56
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
203 words
A METHOD FOR NANUFACTURING AN IMPROVED X-RAY IMAGE INTENSIFIER INPUT PHOSPHOR SCREEN COMPRISNG THE STEPS OF FORMING AN ELECTRICALLY CONDUCTIVE PLASTIC REPLICA HAVING WALL-LIKE PROJECTIONS FORMING A WAFFLE-LIKE SURFACE ON A FIRST MAJOR SIDE THEREOF AND A SMOOTH SURFACE ON A SECOND MAJOR SIDE, FORMING A THIN, RELATIVELY HIGH REFLECTIVITY METAL LAYER ON THE WAFFLE-LIKE SURFACE OF THE PLASTIC REPLICA, DISSOLVING THE PLASTIC MATERIAL THEREBY LEAVING A THIN METAL REPLICA HAVING WALL-LIKE PROJECTIONS FORMING A WAFFLE-LIKE SURFACE ON A FIRST MAJOR SIDE THEREOF AND THE SECOND MAJOR SIDE HAVING INDENTATIONS CORRESPONDING TO THE WALL-LIKE PROJECTIONS ON THE FIRST SIDE, TRANSFERRING THE METAL REPLICA TO THE FIRST PLATE OF AN X-RAY IMAGE INTENSIFIER TUBE, AND POSITIONING THE METAL REPLICA ON THE INNER SURFACE OF THE FACE PLATE, FIRMLY ATTACHING THE METAL EPLICA TO THE FACE PLATE, DEPOSITING A PHOSPHOR LAYER ON THE WAFFLE-LIKE SURFACE OF THE METAL REPLICA TO A THICKNESS WHEREIN THE PHOSPHOR LAYER EXTENDS SLIGHTLY BEYOND THE ENDS OF THE WALL-LIKE PROJECTIONS, SMOOTHING THE OUTER SURFACE OF THE PHOSPHOR LAYER TO OBTAIN A SURFACE SUBSTANTIALLY PARALLEL TO THE INNER SURFACE OF THE FACE PLATE, AND DEPOSITION A THIN UNIFORM COATING OF A PHOTOEMITTER MATERIAL ON THE OUTER SURFACE OF THE PHOSPHOR LAYER.
Claim 2
Independent Claim
203 words
A METHOD FOR NANUFACTURING AN IMPROVED X-RAY IMAGE INTENSIFIER INPUT PHOSPHOR SCREEN COMPRISNG THE STEPS OF FORMING AN ELECTRICALLY CONDUCTIVE PLASTIC REPLICA HAVING WALL-LIKE PROJECTIONS FORMING A WAFFLE-LIKE SURFACE ON A FIRST MAJOR SIDE THEREOF AND A SMOOTH SURFACE ON A SECOND MAJOR SIDE, FORMING A THIN, RELATIVELY HIGH REFLECTIVITY METAL LAYER ON THE WAFFLE-LIKE SURFACE OF THE PLASTIC REPLICA, DISSOLVING THE PLASTIC MATERIAL THEREBY LEAVING A THIN METAL REPLICA HAVING WALL-LIKE PROJECTIONS FORMING A WAFFLE-LIKE SURFACE ON A FIRST MAJOR SIDE THEREOF AND THE SECOND MAJOR SIDE HAVING INDENTATIONS CORRESPONDING TO THE WALL-LIKE PROJECTIONS ON THE FIRST SIDE, TRANSFERRING THE METAL REPLICA TO THE FIRST PLATE OF AN X-RAY IMAGE INTENSIFIER TUBE, AND POSITIONING THE METAL REPLICA ON THE INNER SURFACE OF THE FACE PLATE, FIRMLY ATTACHING THE METAL EPLICA TO THE FACE PLATE, DEPOSITING A PHOSPHOR LAYER ON THE WAFFLE-LIKE SURFACE OF THE METAL REPLICA TO A THICKNESS WHEREIN THE PHOSPHOR LAYER EXTENDS SLIGHTLY BEYOND THE ENDS OF THE WALL-LIKE PROJECTIONS, SMOOTHING THE OUTER SURFACE OF THE PHOSPHOR LAYER TO OBTAIN A SURFACE SUBSTANTIALLY PARALLEL TO THE INNER SURFACE OF THE FACE PLATE, AND DEPOSITION A THIN UNIFORM COATING OF A PHOTOEMITTER MATERIAL ON THE OUTER SURFACE OF THE PHOSPHOR LAYER.
Claim 3
Dependent Claim
39 words
The method set forth in claim 1 wherein the step of forming the thin metal layer on the plastic replica consists of electroplating the plastic replica with nickel to a thickness in the range of 0.0002 to 0.0005 inch.
Claim 4
Dependent Claim
62 words
The method set forth in claim 1 wherein the step of firmly attaching the metal replica to the face plate consists of applying a thin coating of silicone resin to the second major side of the metal replica and pressing the coated surface against the concave-shaped inner surface of the face plate of the x-ray image intensifier tube to cause bonding therebetween.
Claim 5
Dependent Claim
192 words
The method set forth in claim 1 wherein the step of forming the electrically conductive plastic replica comprises the steps of photetching a predetermined number of thin metal sheets to produce an array of small holes therein forming a mesh, superimposing the sheets of metal mesh in precise hole alignment upon a heavy planar substrate, diffusion bonding the sheets of metal mesh to the planar substrate to obtain an array of rectangular shaped wall-like projections in vertical section through the solid portions of the sheets of metal mesh, chemically etching the bonded metal mesh-substrate assembly to obtain a waffle-like surface having thin wall projections which define an array of cells of the same shape as the photoetched holes and thereby form a metal master, forming at least one silicone rubber replica from the metal master, coating the wall indentation surface of the rubber replica with a plastic material, drawing the plastic-coated surface of the rubber replica to a support member, hardening the plastic material, removing the rubber replica from the hardened plastic structure which forms a plastic replica of the metal master, and treating the plastic material to render it electrically conductive.
Claim 6
Dependent Claim
62 words
The method set forth in claim 4 wherein the step of drawing the plastic coated surface of the rubber replica to a support member consists of drawing the rubber replica to a support member having the concave shape of the face plate of the x-ray image intensifier tube whereby the hardened plastic replica conforms to the concave shape of the face plate.
Claim 7
Dependent Claim
73 words
The method set forth in claim 4 wherein the step of drawing the plastic coated surface of the rubber replica to a support member consists of drawing the rubber replica to a planar support member, and sagging the metal replica into the concave shape of the face plate of the X-ray image intensifier tube upon transferring the metal replica to the face plate whereby the replication process is accomplished with simpliied planar geometry.
Claim 8
Dependent Claim
116 words
The method set forth in claim 4 wherein the step of photoetching thin metal sheets consists of photoetching sheets of the metal each being of thickness in the order of 1 to 2 mils to thereby precisely photoetch holes with a depth at least a factor of two smaller than the hole diameter to obtain the array of small holes of equal size and equal shape having a center-to-center spacing of approximately 6 mils and separation of approximately 1.5 to 2 mils from which the array of rectangular shaped wall-like projections is formed, and the step of chemically etching the bonded metal mesh-substrate assembly results in the wall projections beiNg thinned to approxiately 0.5 mil thickness.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |