Patent US3829691A successfully refreshed from Google Patents.
US3829691A
Expired / Lapsed
US
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Image signal enhancement system for a scanning electron microscope
Assignee: Etec Systems Inc
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Filing: 1969-09-22
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Granted: 1974-08-13
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Expires: 1989-09-22
Abstract
Abstract The invention pertains to a method and apparatus for reducing the effect of aberrations in an optical or electron-optical system. This is done by varying the focal point over a range and altering the reproduced images to produce a composite image substantially free of the said aberrations.
Inventors
- 👤 R Hufnagel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:46
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/26; H01J37/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
In a scanning electron microscope having a source of electrons, means for focusing the electrons at a sample object, means for scanning the electrons in mutually perpendicular directions across said object, and means for providing an electrical output signal representative of the object, means to reproduce an image of said object, said microscope exhibiting a symmetrical aberration, the improvement for increasing the conformity between a reproduced image and the object comprising means for varying the location of the focal point during a scanning interval at each of a plurality of information element locations and means for altering the output signal in accordance with a predetermined electrical signal.
Claim 2
Dependent Claim
107 words
In a scanning electron microscope having a source of electrons, means for focusing the electrons at a sample object, means for scanning the electrons in mutually perpendicular directions across said object, and means for providing an electrical output signal representative of the object, means to reproduce an image of said object, said microscope exhibiting a symmetrical aberration, the improvement for increasing the conformity between a reproduced image and the object comprising means for varying the location of the focal point during a scanning interval at each of a plurality of information element locations and means for altering the output signal in accordance with a predetermined electrical signal.
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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |