US4339659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image converter having serial arrangement of microchannel plate, input electrode, phosphor, and photocathode
Assignee: ITT Inc
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Filing: 1980-10-20
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Granted: 1982-07-13
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Expires: 2000-10-20
Abstract
Abstract Radiant energy images are converted into visual images or video signals by the image converter of the present invention. Input radiant energy images impinge upon a photocathode which is formed on a radiant energy sensitive phosphor that is in turn deposited on the input electrode of a microchannel plate (MCP). A mesh or ring electrode is disposed adjacent the photocathode and biased negative with respect to the MCP input electrode to reflect photoelectrons produced at the photocathode into the MCP. The photoelectrons at the output of the MCP are focused onto a readout device to provide the visual images or video signals. This structure provides high quantum efficiency and improves image quality while retaining relatively high limiting-resolution and high gain.
Inventors
- 👤 Charles B. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:54
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J31/506; H01J31/507
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
191 words
A radiant energy image converter comprising: a vacuum envelope having a longitudinal axis; input means for radiant energy images disposed coaxial of said axis at one end of said envelope; a microchannel plate disposed coaxial of said axis within said envelope in a spaced relationship with said input means, said plate including an input electrode; a radiant energy sensitive phosphor means applied directly to said input electrode; a photocathode applied to said phosphor means; a radiant energy transparent mesh electrode disposed within said envelope coaxial of said axis between and spaced from said input means and said photocathode; means coupled between said mesh electrode and said input electrode to provide a retarding field therebetween to reflect photoelectrons produced at said photocathode into said plate; a readout means disposed coaxially of said axis at the other end of said envelope; and an electron lens means disposed within said envelope coaxially of said axis between an output of said plate remote from said input means and said readout means to focus photoelectrons emanating from said output of said plate onto said readout means to provide a discernible output related to said radiant image.
Claim 2
Dependent Claim
191 words
A radiant energy image converter comprising: a vacuum envelope having a longitudinal axis; input means for radiant energy images disposed coaxial of said axis at one end of said envelope; a microchannel plate disposed coaxial of said axis within said envelope in a spaced relationship with said input means, said plate including an input electrode; a radiant energy sensitive phosphor means applied directly to said input electrode; a photocathode applied to said phosphor means; a radiant energy transparent mesh electrode disposed within said envelope coaxial of said axis between and spaced from said input means and said photocathode; means coupled between said mesh electrode and said input electrode to provide a retarding field therebetween to reflect photoelectrons produced at said photocathode into said plate; a readout means disposed coaxially of said axis at the other end of said envelope; and an electron lens means disposed within said envelope coaxially of said axis between an output of said plate remote from said input means and said readout means to focus photoelectrons emanating from said output of said plate onto said readout means to provide a discernible output related to said radiant image.
Claim 3
Dependent Claim
16 words
A converter according to claim 1, wherein said radiant energy is in the X-ray spectral region.
Claim 4
Dependent Claim
23 words
A converter according to claim 2, wherein said photocathode is composed of cesium antimony, and said phosphor means is composed of cesium iodide.
Claim 5
Dependent Claim
20 words
A converter according to claim 1, wherein said radiant energy is in the alpha, beta and gamma particle spectral region.
Claim 6
Dependent Claim
23 words
A converter according to claim 4, wherein said photocathode is composed of cesium antimony, and said phosphor means is composed of cesium iodide.
Claim 7
Dependent Claim
16 words
A converter according to claim 1, wherein said radiant energy is in the neutron spectral regions.
Claim 8
Dependent Claim
23 words
A converter according to claim 6, wherein said photocathode is composed of cesium antimony, and said phosphor means is composed of cesium iodide.
Claim 9
Dependent Claim
14 words
A converter according to claim 1, wherein said radiant energy includes high energy radiation.
Claim 10
Dependent Claim
22 words
A converter according to claim 8, wherein said photocathode is composed of cesium-antimony, and said phosphor means is composed of cesium iodide.
Claim 11
Dependent Claim
16 words
A converter according to claim 1, wherein said radiant energy is in the ultraviolet spectral region.
Claim 12
Dependent Claim
23 words
A converter according to claim 10, wherein said photocathode is composed of a bialkali, and said phosphor means is composed of sodium iodide.
Claim 13
Dependent Claim
14 words
A converter according to claim 11, wherein said bialkali includes cesium, potassium and antimony.
Claim 14
Dependent Claim
16 words
A converter according to claim 1, wherein said radiant energy is in the visible spectral region.
Claim 15
Dependent Claim
24 words
A converter according to claim 13, wherein said photocathode is composed of a multialkali; and said phosphor means is composed of a phosphorus compound.
Claim 16
Dependent Claim
15 words
A converter according to claim 14, wherein said multialkali includes sodium, potassium, cesium and antimony.
Claim 17
Dependent Claim
20 words
A converter according to claim 1, wherein said input means includes an input window transparent to said radiant energy images.
Claim 18
Dependent Claim
23 words
A converter according to claim 1, wherein said readout means includes a phosphor screen to provide visual images of said radiant energy images.
Claim 19
Dependent Claim
19 words
A converter according to claim 1, wherein said readout means provides video signals related to said radiant energy images.
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) | 1985-07-12 | 1986-01-11 | 1986-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-12 | 1990-01-11 | 1990-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-12 | 1994-01-11 | 1994-07-13 | $7700.00 | Window Closed / Lapsed |