US3471740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling cathode ray tube brightness and contrast
Assignee: Photo Electronics Corp
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Filing: 1966-02-18
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Granted: 1969-10-07
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Expires: 1986-02-18
Abstract
No abstract record available.
Inventors
- 👤 Alex W Dreyfoos Jr
- 👤 George W Mergens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:43
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72; G03B27/73; G03B27/735; H; H04; H04N; H04N17/00; H04N17/04; H04N3/00; H04N3/02; H04N3/04; H04N5/00; H04N5/44; H04N5/57; H04N5/58; H04N5/66; H04N5/68
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A METHOD FOR CONTROLLING THE BRIGHTNESS OF A PICTURE DISPLAYED BY A CATHODE RAY PICTURE TUBE WHILE MAINTAINING SUBSTANTIALLY CONSTANT PICTURE TUBE CONTRAST RESPONSE TO VIDEO SIGNALS COMPRISING THE STEPS OF VARYING THE D.C. LEVEL OF THE VOLTAGE BETWEEN THE CATHODE AND A FIRST GRID TO MAINTAIN THE DESIRED BRIGHTNESS LEVEL WHILE INVERSELY VARYING THE D.C. LEVEL OF THE VOLTAGE BETWEEN THE CATHODE AND A SECOND GRID TO THEREBY MAINTAIN A SUBSTANTIALLY CONSTANT PICTURE TUBE CONTRAST RESPONSE TO VIDEO SIGNALS.
Claim 2
Independent Claim
80 words
A METHOD FOR CONTROLLING THE BRIGHTNESS OF A PICTURE DISPLAYED BY A CATHODE RAY PICTURE TUBE WHILE MAINTAINING SUBSTANTIALLY CONSTANT PICTURE TUBE CONTRAST RESPONSE TO VIDEO SIGNALS COMPRISING THE STEPS OF VARYING THE D.C. LEVEL OF THE VOLTAGE BETWEEN THE CATHODE AND A FIRST GRID TO MAINTAIN THE DESIRED BRIGHTNESS LEVEL WHILE INVERSELY VARYING THE D.C. LEVEL OF THE VOLTAGE BETWEEN THE CATHODE AND A SECOND GRID TO THEREBY MAINTAIN A SUBSTANTIALLY CONSTANT PICTURE TUBE CONTRAST RESPONSE TO VIDEO SIGNALS.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-06 | 1973-04-07 | 1973-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-06 | 1977-04-07 | 1977-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-06 | 1981-04-07 | 1981-10-07 | $7700.00 | Window Closed / Lapsed |