Patent US4459508A successfully refreshed from Google Patents.
US4459508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image tube having a conductive film for preventing spurious discharge from taking place
Assignee: NEC Corp
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Filing: 1981-08-10
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Granted: 1984-07-10
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Expires: 2001-08-10
Abstract
Abstract An image tube comprises a conductive film along the inside surface of an insulating tube extending axially of the image tube between a photoelectric cathode and a fluorescent anode. The conductive film should be electrically connected to the photoelectric cathode and have an axial length between 1/2 and 3/4 of that of the insulating tube. The conductive film may be formed along the outside surface of the insulating tube and either together with or without a conventional semi-insulating layer formed along the inside surface of the insulating tube.
Inventors
- 👤 Kozo Ichikawa
- 👤 Tadao Shima
- 👤 Tadafumi Hoshiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:24
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J29/00; H01J29/86; H01J29/88; H01J2229/00; H01J2229/88; H01J2229/882
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
132 words
An image tube comprising an axially extending insulating tube having first and second open ends; a photoelectric cathode and a fluorescent anode sealed to said insulating tube to hermetically close said first and said second open ends, respectively; an intermediate electrode in a hollow space enclosed with said insulating tube, said photoelectric cathode, and said fluorescent anode; a conductive film formed along said insulating tube in electrical contact with said photoelectric cathode and having an axial length which is between about 1/2 and 3/4 of the distance between said first and said second open ends; said insulating tube having an inside surface, wherein said conductive film is formed along said inside surface; and a semi-insulating layer formed on said conductive film and along a remaining inside surface portion of said insulating tube.
Claim 2
Dependent Claim
132 words
An image tube comprising an axially extending insulating tube having first and second open ends; a photoelectric cathode and a fluorescent anode sealed to said insulating tube to hermetically close said first and said second open ends, respectively; an intermediate electrode in a hollow space enclosed with said insulating tube, said photoelectric cathode, and said fluorescent anode; a conductive film formed along said insulating tube in electrical contact with said photoelectric cathode and having an axial length which is between about 1/2 and 3/4 of the distance between said first and said second open ends; said insulating tube having an inside surface, wherein said conductive film is formed along said inside surface; and a semi-insulating layer formed on said conductive film and along a remaining inside surface portion of said insulating tube.
Claim 3
Dependent Claim
112 words
An image tube comprising an axially extending insulating tube having first and second open ends; photoelectric cathode and a fluorescent anode sealed to said insulating tube to hermetically close said first and said second open ends, respectively; an intermediate electrode in a hollow space enclosed with said insulating tube, said photoelectric cathode, and said fluorescent anode; and a conductive film formed along said insulating tube in electrical contact with said photoelectric cathode and having an axial length which is between about 1/2 and 3/4 of the distance between said first and said second open ends; said insulating tube having an outside surface, wherein said conductive film is formed along said outside surface.
Claim 4
Dependent Claim
112 words
An image tube comprising an axially extending insulating tube having first and second open ends; photoelectric cathode and a fluorescent anode sealed to said insulating tube to hermetically close said first and said second open ends, respectively; an intermediate electrode in a hollow space enclosed with said insulating tube, said photoelectric cathode, and said fluorescent anode; and a conductive film formed along said insulating tube in electrical contact with said photoelectric cathode and having an axial length which is between about 1/2 and 3/4 of the distance between said first and said second open ends; said insulating tube having an outside surface, wherein said conductive film is formed along said outside surface.
Claim 5
Dependent Claim
26 words
An image tube as claimed in claim 2, said insulating tube further having an inside surface, wherein a semi-insulating layer is formed along said inside surface.
References Cited (Backward Citations)
US4001618A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-10 | 1988-01-09 | 1988-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-10 | 1992-01-09 | 1992-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-10 | 1996-01-09 | 1996-07-10 | $7700.00 | Window Closed / Lapsed |