US3634684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron beam scanning apparatus
Assignee: Jeol Ltd
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Filing: 1970-03-17
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Granted: 1972-01-11
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Expires: 1990-03-17
Abstract
Abstract An electron beam scanning apparatus comprising a chamber defined, for example, by a cylindrical glass structure spaced about a mean electron beam path. Deflection coils are positioned outside the chamber. An electroconductive coating, for example, a layer of gold vapor deposited on the inside surface of the structure is grounded. The electron beam is deflected by magnetic fluxes at right angles to the path produced by deflection coils. Stray electrons are collected by the electroconductive coating.
Inventors
- 👤 Masayuki Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:23
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/09
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
In an electron beam scanning apparatus of a scanning electron microscope, in which an electron beam is deflected about a mean path, at least one deflection coil is provided, to which a highfrequency current is applied, for producing a magnetic field at right angles to the mean path, the improvement comprising an electrical insulating shield positioned between said coil and said mean path having a grounded electroconductive coating facing said beam path, the coating being so thin that little or no eddy currents appear in said coating.
Claim 2
Dependent Claim
87 words
In an electron beam scanning apparatus of a scanning electron microscope, in which an electron beam is deflected about a mean path, at least one deflection coil is provided, to which a highfrequency current is applied, for producing a magnetic field at right angles to the mean path, the improvement comprising an electrical insulating shield positioned between said coil and said mean path having a grounded electroconductive coating facing said beam path, the coating being so thin that little or no eddy currents appear in said coating.
Claim 3
Dependent Claim
19 words
An electron beam scanning apparatus according to claim 1 wherein the said electroconductive coating is a vapor-deposited gold layer.
Claim 4
Dependent Claim
16 words
An electron beam scanning apparatus according to claim 1 wherein the said shield is quartz glass.
Claim 5
Dependent Claim
16 words
An electron beam scanning apparatus according to claim 1 wherein the said shield is of plastic.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |