US3868536A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image intensifier tube employing a microchannel electron multiplier
Assignee: DKP A Corp OF
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Filing: 1971-10-18
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Granted: 1975-02-25
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Expires: 1991-10-18
Abstract
Abstract In an image intensifier tube, photon images received by a photocathode are converted into electron images which are accelerated by an accelerating anode and focused upon the input face of a microchannel electron multiplier. The multiplier multiplies the current of the electron images and the output electron images are directed onto the output flourescent screen. The operating voltages for the photocathode, and anode are referenced to the potential applied to the electron multiplier such that variations in the potential applied across or to the electron multiplier do not produce changes in magnification. The anode is biased positive with respect to the microchannel plate to form an ion trap to inhibit flow of ions from the electron multiplier to the photocathode, thereby avoiding bright spots in the output image. Voltage divider resistors are provided in the anode bias and photocathode bias circuits for dropping the anode potential generally in proportion to the drop in the photocathode potential experienced at high input light levels to prevent cut off of the image.
Inventors
- 👤 Jr Richard S Enck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:57
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/50; H01J31/506; H01J31/507
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
209 words
In an image intensifier tube, a photocathode means disposed to receive a photon image for emitting into the tube an electron image corresponding to the received photon image, microchannel electron multiplier means having an input face disposed to receive the emitted electron image for multiplying the electron current of said image, an anode electrode means disposed intermediate said photocathode means and said microchannel multiplier means along the path of flow of the electron image for accelerating the electron image and for focusing same upon said electron receiving the face of said microchannel electron multiplier means, and power supply means for biasing said anode electrode means at a potential positive with respect to the operating potential of said input face of said microchannel electron multiplier means to inhibit the flow of positive ions from said microchannel multiplier means to said photocathode means, said biasing means for biasing said anode means relative to said microchannel electron multiplier means include, a series connection of a voltage regulating means and a resistor to form a source of regulated anode bias potential connected in parallel with the potential applied across said microchannel electron multiplier means, and means for applying the regulated anode bias potential derived across said voltage regulator means to said anode means.
Claim 2
Dependent Claim
209 words
In an image intensifier tube, a photocathode means disposed to receive a photon image for emitting into the tube an electron image corresponding to the received photon image, microchannel electron multiplier means having an input face disposed to receive the emitted electron image for multiplying the electron current of said image, an anode electrode means disposed intermediate said photocathode means and said microchannel multiplier means along the path of flow of the electron image for accelerating the electron image and for focusing same upon said electron receiving the face of said microchannel electron multiplier means, and power supply means for biasing said anode electrode means at a potential positive with respect to the operating potential of said input face of said microchannel electron multiplier means to inhibit the flow of positive ions from said microchannel multiplier means to said photocathode means, said biasing means for biasing said anode means relative to said microchannel electron multiplier means include, a series connection of a voltage regulating means and a resistor to form a source of regulated anode bias potential connected in parallel with the potential applied across said microchannel electron multiplier means, and means for applying the regulated anode bias potential derived across said voltage regulator means to said anode means.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein said voltage regulating means includes a Zener diode.
Claim 4
Dependent Claim
41 words
The apparatus of claim 1 wherein said means for applying the voltage derived across said voltage Regulator means to said anode means includes, anode resistive means connected in series beteen said anode means and said source of regulated anode bias potential.
Claim 5
Dependent Claim
55 words
The apparatus of claim 3 including, cathode bias means for biasing said photocathode means at a potential negative with respect to the potential of the input face of said microchannel electron multiplier means, and cathode resistive means connected in series with said cathode bias means between said photocathode means and said microchannel electron multiplier means.
Claim 6
Dependent Claim
46 words
The apparatus of claim 4 wherein said anode resistive means and said cathode resistive means form a voltage divider when said anode intercepts substantial electron image current emitted from said photocathode means, and said cathode resistive means being substantially more resistive than said anopde resistive means.
Claim 7
Dependent Claim
57 words
The apparatus of claim 5 wherein the resistances of said cathode resistive means and said anode resistive means are proportioned such that the ratio of the anode resistance Ra to the cathode resistance Rc is approximately equal to or within 50% greater than the ratio of the anode source potential Va to the cathode source potential Vc.
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) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |