US2914675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Element for correcting electron-optical systems
Assignee: US Philips Corp
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Filing: 1956-03-14
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Granted: 1959-11-24
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Expires: 1976-03-14
Abstract
No abstract record available.
Inventors
- 👤 Adrianus Cornelis Van Dorsten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:40
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/153
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
158 words
AN ELECTRON OPTICAL SYSTEM FOR AN ELECTRON MICROSCOPE HAVING A GIVEN OPTICAL AXIS COMPRISING ELECTRON BEAM PRODUCING MEANS, AN ELECTRON LENS SYSTEM FOR FOCUSSING THE ELECTION WHICH INTRODUCES ASTIGMATISM INTO THE FOCUSSED BEAM ALONG SAID AXIS, A PLURALITY OF PAIRS OF SPACED POLE MEMBERS EACH OF MAGNETIZABLE MATERIAL DISPOSED SYMMETRICALLY ABOUT SAID OPTICAL AXIS FOR COMPENSATING FOR THE ASTIGMATISM INTRODUCED INTO THE BEAN BY THE ELECTRON LENS SYSTEM, EACH OF SAID POLE MEMBERS HAVING A CYLINDRICAL POLE FACE THE GENERATRIX OF WHICH IS PARALLEL TO SAID AXIS, A MEMBER CONNECTING EACH OF SAID POLE MEMBERS TO ONE ANOTHER AND CONSISTING OF AN ELECTRICALLY-INSULATING FERROMAGNETIC MATERIAL HAVING A COMPOSITION MFE2O4 IN WHICH M IS A BIVALENT METAL, MEANS TO ALTERNATELY POLARIZE EACH OF SAID POLE MEMBERS IN AN OPPOSITE SENSE, MEANS TO APPLY EQUAL ELECTRICAL POTENTIAL DIFFERNECES BETWEEN ADJACENT POLE MEMBERS, AND MEANS FOR VARYING THE POTENTIAL DIFFERENCES BETWEEN AND THE FIELD STRENGTH OF SUCCESIVE PAIRS OF POLE MEMBERS.
Claim 2
Dependent Claim
158 words
AN ELECTRON OPTICAL SYSTEM FOR AN ELECTRON MICROSCOPE HAVING A GIVEN OPTICAL AXIS COMPRISING ELECTRON BEAM PRODUCING MEANS, AN ELECTRON LENS SYSTEM FOR FOCUSSING THE ELECTION WHICH INTRODUCES ASTIGMATISM INTO THE FOCUSSED BEAM ALONG SAID AXIS, A PLURALITY OF PAIRS OF SPACED POLE MEMBERS EACH OF MAGNETIZABLE MATERIAL DISPOSED SYMMETRICALLY ABOUT SAID OPTICAL AXIS FOR COMPENSATING FOR THE ASTIGMATISM INTRODUCED INTO THE BEAN BY THE ELECTRON LENS SYSTEM, EACH OF SAID POLE MEMBERS HAVING A CYLINDRICAL POLE FACE THE GENERATRIX OF WHICH IS PARALLEL TO SAID AXIS, A MEMBER CONNECTING EACH OF SAID POLE MEMBERS TO ONE ANOTHER AND CONSISTING OF AN ELECTRICALLY-INSULATING FERROMAGNETIC MATERIAL HAVING A COMPOSITION MFE2O4 IN WHICH M IS A BIVALENT METAL, MEANS TO ALTERNATELY POLARIZE EACH OF SAID POLE MEMBERS IN AN OPPOSITE SENSE, MEANS TO APPLY EQUAL ELECTRICAL POTENTIAL DIFFERNECES BETWEEN ADJACENT POLE MEMBERS, AND MEANS FOR VARYING THE POTENTIAL DIFFERENCES BETWEEN AND THE FIELD STRENGTH OF SUCCESIVE PAIRS OF POLE MEMBERS.
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) | 1962-11-23 | 1963-05-25 | 1963-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-23 | 1967-05-25 | 1967-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-23 | 1971-05-25 | 1971-11-24 | $7700.00 | Window Closed / Lapsed |