US4087683A
Expired / Lapsed
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Image intensifying device
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1976-08-17
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Granted: 1978-05-02
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Expires: 1996-08-17
Abstract
Abstract An image intensifying device including a light transmissive photocathode layer, a cathode electrode composed of two annular parts, the smaller of which is electrically connected to the photocathode layer, and an annular insulating part between the two electrode parts, and an anode provided with a fluorescent screen receiving electrons from the photoconductive layer, with the electrode parts being connected together by a high value intermediate resistance and the smaller electrode part being connected to the negative pole of a d.c. voltage source via a cathode resistance whose value is selected such that upon incidence on the photocathode layer of long term, high intensity optical radiation which would exceed the capacity of the screen, a high voltage drop appears across the cathode resistance to prevent the energy of the electrons striking the screen from exceeding its capacity, while the capacitances existing between the anode and each annular part protect the screen from damage upon the occurrence of rapid optical radiation intensity increases.
Inventors
- 👤 Albert Lieb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:05
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J31/501
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
215 words
An image intensifying device having a photocathode layer applied to an inner surface of a light-transmissive photocathode carrier and having a cathode electrode, which has a first annular electrode part connected electrically to said photocathode layer and has a second annular electrode part and which is connected to the negative pole of a d.c. voltage source, the device further including an anode electrode provided with a fluorescent screen, characterized in that said second electrode part is connected to said first electrode part by an annular insulating part inserted therebetween, that said first electrode part has a smaller area than said second electrode part, that said first electrode part is connected to said second electrode part via a high value electrical intermediate resistance, and that said first annular electrode part is connected electrically to said negative pole of said voltage source via a high value cathode resistance, the resistance value of said cathode resistance being selected so that when there is an optical radiation, which would exceed the loading capacity of said fluorescent screen, acting intensely over a long period of time on said photocathode layer, a high voltage drop occurs across said cathode resistance so that the energy of the electrons meeting said fluorescent screen does not exceed the loading capacity of said fluorescent screen.
Claim 2
Dependent Claim
215 words
An image intensifying device having a photocathode layer applied to an inner surface of a light-transmissive photocathode carrier and having a cathode electrode, which has a first annular electrode part connected electrically to said photocathode layer and has a second annular electrode part and which is connected to the negative pole of a d.c. voltage source, the device further including an anode electrode provided with a fluorescent screen, characterized in that said second electrode part is connected to said first electrode part by an annular insulating part inserted therebetween, that said first electrode part has a smaller area than said second electrode part, that said first electrode part is connected to said second electrode part via a high value electrical intermediate resistance, and that said first annular electrode part is connected electrically to said negative pole of said voltage source via a high value cathode resistance, the resistance value of said cathode resistance being selected so that when there is an optical radiation, which would exceed the loading capacity of said fluorescent screen, acting intensely over a long period of time on said photocathode layer, a high voltage drop occurs across said cathode resistance so that the energy of the electrons meeting said fluorescent screen does not exceed the loading capacity of said fluorescent screen.
Claim 3
Dependent Claim
22 words
A device as defined in claim 1, wherein said intermediate resistance has approximately a value of 10 8 to 10 11 ohms.
Claim 4
Dependent Claim
21 words
A device as defined in claim 2, wherein said intermediate resistance has a value between 10 9 and 10 11 ohms.
Claim 5
Dependent Claim
32 words
A device as defined in claim 1 presenting a vacuum chamber enclosing the region between said photocathode layer and said screen, and wherein said intermediate resistance is arranged inside said vacuum chamber.
Claim 6
Dependent Claim
32 words
A device as defined in claim 1 presenting a vacuum chamber enclosing the region between said photocathode layer and said screen, and wherein said intermediate resistance is arranged outside said vacuum chamber.
Claim 7
Dependent Claim
20 words
A device as defined in claim 1, wherein said intermediate resistor comprises a semiconductive construction of said annular insulating part.
Claim 8
Dependent Claim
52 words
A device as defined in claim 1, wherein said first electrode part and said second electrode part are constructed so that the capacitance formed between said anode electrode and said first electrode part is at most half of the capacitance which is formed between said second electrode part and said anode electrode.
Claim 9
Dependent Claim
53 words
A device as defined in claim 1, wherein said first electrode part and said second electrode part are constructed so that the capacitance formed between said anode electrode and said first electrode part is less than one fourth of the capacitance which is formed between said second electrode part and said anode electrode.
Claim 10
Dependent Claim
53 words
A device as defined in claim 1, wherein said first electrode part and said second electrode part are constructed so that the capacitance formed between said anode electrode and said first electrode part is less than one eighth of the capacitance which is formed between said second electrode part and said anode electrode.
Claim 11
Dependent Claim
25 words
A device as defined in claim 1, wherein said cathode resistor has a resistance value of approximately 10 7 to 5 · 10 9 ohms.
Claim 12
Dependent Claim
56 words
A device as defined in claim 1, wherein said second electrode part has a rotationally symmetrical annular diaphragm, with an electron passage opening dimensioned so that it closely surrounds an electron beam emitted by said effective photocathode layer and with the edge forming the electron passage opening arranged to be located closely adjacent said photocathode layer.
Claim 13
Dependent Claim
28 words
A device as defined in claim 11, wherein said annular diaphragm is frusto-conical and is arranged with its end with the smaller diameter closely adjacent said photocathode layer.
Claim 14
Dependent Claim
32 words
A device as defined in claim 1, and comprising a capacitance of approximately 1 up to 2000 pF, connected between said negative pole of said voltage source and said second electrode part.
Claim 15
Dependent Claim
18 words
A device as defined in claim 13, wherein said capacitance has a value between 2 and 200 pF.
Claim 16
Dependent Claim
59 words
A device as defined in claim 1, wherein at least one of said two electrode parts is constructed to be rotationally a symmetrical so that when there is a voltage difference between these said two electrode parts and a deflection in the electrons emitted by said photocathode layer occurs which is transverse to the longitudinal axis of the tube.
Claim 17
Dependent Claim
28 words
A device as defined in claim 15, wherein the construction of said electrode part or parts, which is rotationally a symmetrical is located close to said photocathode layer.
Claim 18
Dependent Claim
36 words
A device as defined in claim 15, wherein the construction of said electrode part or parts which is rotationally a symmetrical is carried out by means of sheet parts placed on said electrode part or parts.
Claim 19
Dependent Claim
52 words
A device as defined in claim 15, wherein said two electrode parts of said cathode electrode closely adjacent said photocathode layer define an annular clearance which is rotationally a symmetrical so that when there are varying potentials at said two electrode parts an electrical lens is formed which is rotationally a symmetrical.
Claim 20
Dependent Claim
60 words
A device as defined in claim 15, wherein the construction of said electrode part of parts which is rotationally a symmetrical is carried out so that when there is a voltage difference between said two electrode parts there is a deflection of all electrons emitted by said photocathode layer substantially in one direction transverse to the axis of the tube.
Claim 21
Dependent Claim
42 words
A device as defined in claim 15, wherein the construction of said electrode parts which is rotationally a symmetrical is carried out by means of extensions, the extents of which in the longitudinal direction vary axially of the tube along the circumference.
Claim 22
Dependent Claim
42 words
A device as defined in claim 15, wherein the construction of said electrode parts, which is rotationally a symmetrical is carried out by providing its inner edge(s) with a different spacing along the circumference with respect to the axis of the tube.
Claim 23
Dependent Claim
29 words
A device as defined in claim 15, wherein the construction of said electrode parts, which is rotationally a symmetrical is produced by frusto-conical parts which are rotationally a symmetrical.
Claim 24
Dependent Claim
111 words
An image intensifying device comprising a light transmissive photo cathode layer, a cathode electrode including a first annular electrode part electrically connected to said photocathode layer, a second annular electrode part of a larger area than said first annular electrode part, an annular insulating part disposed between said first annular electrode part and said second annular electrode part and electrically insulating said first and second electrode parts from one another, a high value electrical intermediate resistance connecting said first annular electrode to said second annular electrode, a d.c. voltage source, and a high value cathode resistance connecting said first annular electrode part to the negative pole of said d.c. voltage source.
Claim 25
Dependent Claim
111 words
An image intensifying device comprising a light transmissive photo cathode layer, a cathode electrode including a first annular electrode part electrically connected to said photocathode layer, a second annular electrode part of a larger area than said first annular electrode part, an annular insulating part disposed between said first annular electrode part and said second annular electrode part and electrically insulating said first and second electrode parts from one another, a high value electrical intermediate resistance connecting said first annular electrode to said second annular electrode, a d.c. voltage source, and a high value cathode resistance connecting said first annular electrode part to the negative pole of said d.c. voltage source.
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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |