Patent US3716713A successfully refreshed from Google Patents.
US3716713A
Expired / Lapsed
US
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Input screen for image devices having reduced sensitivity in the cental region
Assignee: Varian Medical Systems Inc
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Filing: 1969-01-09
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Granted: 1973-02-13
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Expires: 1989-01-09
Abstract
Abstract Image device input screen having greater image conversion efficiency in the peripheral region of the screen than in the central region. Preferred embodiments include, separately or in combination, a screen scintillator having the shape of a diverging meniscus, a semi-transparent screen filter layer having the shape of a converging meniscus, and variations in regional compositions of a screen photocathode.
Inventors
- 👤 N Levin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:47
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J29/385
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
80 words
In an image device having an input screen for receiving and converting radiant images to electron image, said input screen including a photocathode layer and having central and peripheral regions, the improvement comprising the composition of the peripheral region of said photocathode being productive of greater efficiency in converting light images to electron images than the composition of the central region of said photocathode, whereby said peripheral region of said screen has greater image conversion efficiency than said central region.
Claim 2
Dependent Claim
80 words
In an image device having an input screen for receiving and converting radiant images to electron image, said input screen including a photocathode layer and having central and peripheral regions, the improvement comprising the composition of the peripheral region of said photocathode being productive of greater efficiency in converting light images to electron images than the composition of the central region of said photocathode, whereby said peripheral region of said screen has greater image conversion efficiency than said central region.
Claim 3
Dependent Claim
80 words
In an image device having an input screen for receiving and converting radiant images to electron image, said input screen including a photocathode layer and having central and peripheral regions, the improvement comprising the composition of the peripheral region of said photocathode being productive of greater efficiency in converting light images to electron images than the composition of the central region of said photocathode, whereby said peripheral region of said screen has greater image conversion efficiency than said central region.
Claim 4
Dependent Claim
80 words
In an image device having an input screen for receiving and converting radiant images to electron image, said input screen including a photocathode layer and having central and peripheral regions, the improvement comprising the composition of the peripheral region of said photocathode being productive of greater efficiency in converting light images to electron images than the composition of the central region of said photocathode, whereby said peripheral region of said screen has greater image conversion efficiency than said central region.
Claim 5
Dependent Claim
21 words
The apparatus of claim 1 wherein the central region has of said photocathode comprises a chemical agent detrimental to photocathodic activity.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |