US4249077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion charge neutralization for electron beam devices
Assignee: Individual
•
Filing: 1978-08-04
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Granted: 1981-02-03
•
Expires: 1998-08-04
Abstract
Abstract An electron beam device in which an electron beam swept over a target causes the buildup of negative charges on the surface of said targets. The negative charges are neutralized by low-kinetic-energy positive ions emitted by an ion source whose output exceeds the number of ions necessary to neutralize the negative charges.
Inventors
- 👤 Charles K. Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:16
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/026
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
51 words
In an electron beam device of the type in which a narrowly defined electron beam is swept over a target, the improvement comprising a positive ion source arranged to supply positive ions to said target and thereby neutralize negative charges on said target resulting from impingement of said electron beam thereon.
Claim 2
Dependent Claim
51 words
In an electron beam device of the type in which a narrowly defined electron beam is swept over a target, the improvement comprising a positive ion source arranged to supply positive ions to said target and thereby neutralize negative charges on said target resulting from impingement of said electron beam thereon.
Claim 3
Dependent Claim
22 words
The device defined in claim 1 in which said source emits ions having a kinetic energy less than about 100 electron volts.
Claim 4
Dependent Claim
34 words
The device defined in claim 1 in which said source emits said ions at a rate substantially in excess of the rate at which negative charges are generated on said target by said beam.
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) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |