US3636346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron beam generator for electron microscope or the like apparatus
Assignee: Hitachi Ltd
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Filing: 1970-03-16
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Granted: 1972-01-18
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Expires: 1990-03-16
Abstract
Abstract An electron beam generator for electron microscopes or the like apparatus comprising an electron gun, an anode placed in a position opposite to the electron gun, and an electron gun chamber containing therein the electron gun and the anode, wherein either an electrical insulation layer is formed on the inner surface of the electron gun chamber or a cylinder of an electrically insulating material is provided to enclose the electron gun and the anode.
Inventors
- 👤 Hiroshi Akahori
- 👤 Yoshiro Ohnuma
- 👤 Morioki Kubozoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:05
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/06; H01J37/067; H01J37/07
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
169 words
An electron beam generator for electron microscopes or the like apparatus comprising an electron gun consisting of a cathode for emitting thermions and a control electrode for controlling said thermions, said electrode being biased negatively with respect to said cathode; high-vOltage feed means electrically insulated from said apparatus for applying a high voltage to said electron gun; an anode disposed at a position opposite to and spaced away from said electron gun by a predetermined distance, said anode being connected to ground potential; and a gun chamber provided with a vacuum seal for housing said electron gun, highvoltage feed means and anode, said gun chamber being composed of a metallic wall which is at an equipotential with said anode, wherein said gun chamber is provided with means formed of a solid smooth-surfaced hydrophobic electrical insulation for preventing electrical discharges between the wall of said gun chamber and said two electrodes, said insulation means surrounding said two electrodes and being spaced away from said two electrodes by a predetermined distance.
Claim 2
Dependent Claim
169 words
An electron beam generator for electron microscopes or the like apparatus comprising an electron gun consisting of a cathode for emitting thermions and a control electrode for controlling said thermions, said electrode being biased negatively with respect to said cathode; high-vOltage feed means electrically insulated from said apparatus for applying a high voltage to said electron gun; an anode disposed at a position opposite to and spaced away from said electron gun by a predetermined distance, said anode being connected to ground potential; and a gun chamber provided with a vacuum seal for housing said electron gun, highvoltage feed means and anode, said gun chamber being composed of a metallic wall which is at an equipotential with said anode, wherein said gun chamber is provided with means formed of a solid smooth-surfaced hydrophobic electrical insulation for preventing electrical discharges between the wall of said gun chamber and said two electrodes, said insulation means surrounding said two electrodes and being spaced away from said two electrodes by a predetermined distance.
Claim 3
Dependent Claim
57 words
An electron beam generator for electron microscopes or the like apparatus according to claim 1, characterized in that said means for preventing electrical discharges consists of a smooth-surfaced hydrophobic electrical insulation layer having good electrically insulating and heat-resisting properties formed on the inner surface of said metallic wall, and said layer is substantially free from volatile substances.
Claim 4
Dependent Claim
49 words
An electron beam generator for electron microscopes or the like apparatus according to claim 2 characterized in that the electrical insulation layer formed on the inner wall surface of said gun chamber consists of a material selected from polyester and epoxy resins having good electrically insulating and heat-resisting properties.
Claim 5
Dependent Claim
45 words
An electron beam generator for electron microscopes or the like apparatus according to claim 2 characterized in that the electrical insulation layer formed on the inner wall surface of said gun chamber consists of a material selected from sintered alumina and magnesia materials and glass.
Claim 6
Dependent Claim
48 words
An electron beam generator for electron microscopes or the like apparatus according to claim 1 wherein said means formed of a solid electrical insulation for preventing electrical discharges is an element of cylindrical shape disposed between said electron gun and said chamber wall and surrounding said two electrodes.
Claim 7
Dependent Claim
40 words
An electron beam generator for electron microscopes or the like apparatus according to claim 5 wherein said cylindrical insulation element consists of a material selected from a group consisting of sintered alumina and magnesia materials, glass and highly polymerized material.
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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |