US4097761A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image tube cathode
Assignee: RCA Corp
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Filing: 1966-02-16
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Granted: 1978-06-27
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Expires: 1986-02-16
Abstract
Abstract Photocathode having a transparent conductive undercoating to provide a radial voltage distribution across the cathode surface. The conductive undercoating is in the form of radially spaced rings made of chromium deposited on a glass substrate. Over the substrate and the conducting undercoating is provided a resistive layer comprising chromium having a thickness of about 50 Angstroms. Over the resistive chromium layer is deposited a photoemissive layer of antimony, potassium, sodium and cesium. The radially spaced conductive rings are connected to sources of different voltage to produce a desired voltage distribution across the resistive chromium layer.
Inventors
- 👤 John E. Ruedy
- 👤 George A. Morton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:45
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J29/385
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
53 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, the lateral resistivity of said resistive layer varying along the surface thereof.
Claim 2
Dependent Claim
53 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, the lateral resistivity of said resistive layer varying along the surface thereof.
Claim 3
Dependent Claim
76 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said conductive, insulating and resistive layers being transparent.
Claim 4
Dependent Claim
76 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said conductive, insulating and resistive layers being transparent.
Claim 5
Dependent Claim
58 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, the lateral resistivity of said resistive layer varying along the surface thereof, said resistive layer being transparent.
Claim 6
Dependent Claim
58 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, the lateral resistivity of said resistive layer varying along the surface thereof, said resistive layer being transparent.
Claim 7
Dependent Claim
53 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said spaced portions comprising a pair of concentric rings of conductive material.
Claim 8
Dependent Claim
53 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said spaced portions comprising a pair of concentric rings of conductive material.
Claim 9
Dependent Claim
52 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said terminal means comprising wires extending through bores in said substrate.
Claim 10
Dependent Claim
52 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said terminal means comprising wires extending through bores in said substrate.
Claim 11
Dependent Claim
57 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said terminal means comprising wires extending through bores in said substrate, said resistive layer being transparent.
Claim 12
Dependent Claim
57 words
A photocathode comprising a substrate having thereon, a photoemissive layer, an electrically resistive layer underlying the photoemissive layer, and terminal means electrically connected to spaced portions of said resistive layer, whereby a voltage differential may be applied between said spaced portions, said terminal means comprising wires extending through bores in said substrate, said resistive layer being transparent.
Claim 13
Dependent Claim
139 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said insulating layer leaving uncovered spaced portions of said conductive layer, said resistive layer extending through said insulating layer into contact with one of said spaced portions of said conductive layer, and said electrical contacting means including a first terminal means connected to the other of said spaced portions of said conductive layer and a second terminal means connected to said resistive layer, said conductive, insulating, and resistive layers being transparent.
Claim 14
Dependent Claim
139 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said insulating layer leaving uncovered spaced portions of said conductive layer, said resistive layer extending through said insulating layer into contact with one of said spaced portions of said conductive layer, and said electrical contacting means including a first terminal means connected to the other of said spaced portions of said conductive layer and a second terminal means connected to said resistive layer, said conductive, insulating, and resistive layers being transparent.
Claim 15
Dependent Claim
151 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said insulating layer leaving uncovered spaced portions of said conductive layer, said resistive layer extending through said insulating layer into contact with one of said spaced portions of said conductive layer, and said electrical contacting means including a first terminal means connected to the other of said spaced portions of said conductive layer and a second terminal means connected to said resistive layer, said conductive, insulating, and resistive layers being transparent, the lateral resistivity of said resistive layer varying along the surface thereof.
Claim 16
Dependent Claim
151 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said insulating layer leaving uncovered spaced portions of said conductive layer, said resistive layer extending through said insulating layer into contact with one of said spaced portions of said conductive layer, and said electrical contacting means including a first terminal means connected to the other of said spaced portions of said conductive layer and a second terminal means connected to said resistive layer, said conductive, insulating, and resistive layers being transparent, the lateral resistivity of said resistive layer varying along the surface thereof.
Claim 17
Dependent Claim
155 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said substrate being flat, said insulating layer leaving uncovered central and edge portions of said conductive layer, said resistive layer extending through said insulating layer into contact with said central portion, the lateral resistivity of said resistive layer varying radially symmetrically along the surface of said resistive layer, said conductive, insulating, and resistive layers being transparent, and said electrical connecting means including a first terminal means connected to an edge of said conductive layer and a second terminal means connected to an edge of said resistive layer.
Claim 18
Dependent Claim
155 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said substrate being flat, said insulating layer leaving uncovered central and edge portions of said conductive layer, said resistive layer extending through said insulating layer into contact with said central portion, the lateral resistivity of said resistive layer varying radially symmetrically along the surface of said resistive layer, said conductive, insulating, and resistive layers being transparent, and said electrical connecting means including a first terminal means connected to an edge of said conductive layer and a second terminal means connected to an edge of said resistive layer.
Claim 19
Dependent Claim
86 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said conductive layer being made of a highly reflective material, and said insulating and resistive layers being transparent.
Claim 20
Dependent Claim
86 words
A photocathode comprising a substrate, a conductive layer on said substrate, an insulating layer overlying said conductive layer, a resistive layer overlying said insulating layer, means for electrically connecting said conductive layer to said resistive layer, a photoemissive layer overlying said resistive layer, and means for making electrical contact with said conductive layer and said resistive layer, whereby a voltage differential may be applied across said resistive layer, said conductive layer being made of a highly reflective material, and said insulating and resistive layers being transparent.
References Cited (Backward Citations)
US2883543A
Cited
US3121648A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |