US3944829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for processing a video signal from a scanning electron microscope
Assignee: Jeol Ltd
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Filing: 1974-03-26
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Granted: 1976-03-16
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Expires: 1994-03-26
Abstract
Abstract A scanning electron microscope for displaying a scanning image utilizing a time distributed pulsed video signal. The low frequency noises in the pulsed signal are deleted according to the occurrence of sudden pulse intensity variation between adjacent video pulse signals.
Inventors
- 👤 Masayuki Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:14
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/26; H01J37/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
A scanning electron microscope incorporating a means for irradiating a specimen with an electron beam, a deflecting means for scanning the electron beam over the surface of said specimen, a detecting means for detecting the secondary electrons or the like emitted from the specimen as a result of electron beam impingement and producing a pulsed video signal indicative thereof, and a display means for displaying a scanning image of said specimen by using the pulsed output signal from said detecting means which is synchronized with said deflecting means, the improvement comprising a signal processing circuit located between said detecting means and display means for extracting noise pulses from the pulsed video signal comprising means for detecting the absolute value of the pulse height difference between successive pulses of said pulsed video signal and means for rejecting video pulse signals when the absolute value of the pulse height difference exceeds a selected value twice in succession.
Claim 2
Dependent Claim
155 words
A scanning electron microscope incorporating a means for irradiating a specimen with an electron beam, a deflecting means for scanning the electron beam over the surface of said specimen, a detecting means for detecting the secondary electrons or the like emitted from the specimen as a result of electron beam impingement and producing a pulsed video signal indicative thereof, and a display means for displaying a scanning image of said specimen by using the pulsed output signal from said detecting means which is synchronized with said deflecting means, the improvement comprising a signal processing circuit located between said detecting means and display means for extracting noise pulses from the pulsed video signal comprising means for detecting the absolute value of the pulse height difference between successive pulses of said pulsed video signal and means for rejecting video pulse signals when the absolute value of the pulse height difference exceeds a selected value twice in succession.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |