US4508967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic optical apparatus comprising pyrolytic graphite elements
Assignee: Cameca SAS
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Filing: 1983-01-11
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Granted: 1985-04-02
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Expires: 2003-01-11
Abstract
Abstract The electronic optical apparatus provided is such that the parts situated in the immediate vicinity of the beam, anode, screen placed inside the condenser block, screen formed from a tube and limiter diaphragms inside the deflection block, screen placed between the final focussing lens and the sample to be observed and the secondary electron collector electrode have their faces exposed to the electron beam formed from pyrolytic graphite.
Inventors
- 👤 Pierre Boissel
- 👤 Mathias Tong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:13
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/26; H01J37/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
69 words
In an electronic optical apparatus comprising an electron gun, a condenser block for the electron beam coming from the gun, a deflection and focussing block for the beam coming from the condenser block and a useful signal detection device, the tubular screen surrounding the beam inside the condenser block and the deflection block are formed from a vacuum tight outer part and an inner part formed from pyrolytic graphite.
Claim 2
Dependent Claim
69 words
In an electronic optical apparatus comprising an electron gun, a condenser block for the electron beam coming from the gun, a deflection and focussing block for the beam coming from the condenser block and a useful signal detection device, the tubular screen surrounding the beam inside the condenser block and the deflection block are formed from a vacuum tight outer part and an inner part formed from pyrolytic graphite.
Claim 3
Dependent Claim
34 words
The apparatus as claimed in claim 1, wherein the anode of the electron gun is a part of revolution formed from pyrolytic graphite pierced with a hole for the passage of the beam therethrough.
Claim 4
Dependent Claim
30 words
The apparatus as claimed in claim 2, wherein the internal face of the side wall of the electron gun is coated at least partially with a layer of pyrolytic graphite.
Claim 5
Dependent Claim
29 words
The apparatus as claimed in claim 3, wherein the focussing lens for the electron beam is separated from the object stand by an anticontamination screen formed from pyrolytic graphite.
Claim 6
Dependent Claim
34 words
The apparatus as claimed in claim 4, wherein the condenser tube comprises at least one limiter diaphragm in the form of a disk, pierced with a hole of selected size, formed from pyrolytic graphite.
Claim 7
Dependent Claim
23 words
The apparatus as claimed in claim 5, wherein the useful signal detection device comprises a secondary electron collector electrode formed from pyrolytic graphite.
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) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |