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US3878408A Expired / Lapsed US ⏱️ 0.0 years remaining

Quartz crystal timepiece having tuning capacitor device

Assignee: Suwa Seikosha KK
•
Filing: 1973-04-06
•
Granted: 1975-04-15
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Expires: 1993-04-06
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Abstract

Abstract The oscillator circuit of a quartz crystal timepiece is provided with a tuning capacitor device consisting of a stepped variable capacitor and a continuously variable capacitor connected in parallel with each other and in series with said quartz crystal.

Inventors

  • 👤 Isao Nemoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 15:36
CPC Classifications
G; G04; G04F; G04F5/00; G04F5/04; G04F5/06; H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03L; H03L1/00; H03L1/02; H03L1/028; H03B5/323; H03B5/362

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 200 words
In a circuit particularly suited for producing oscillating signals and including a parallel coupled continuous variable capacitor and a step variable capacitor, the improvement comprising said step variable capacitor, and continuously variable capacitor being mounted to a base plate, first and second lower electrodes mounted on said base plate, and means mounted on said base plate electrically connecting said lower electrodes, said step variable capacitor being defined by a fixed dielectric mounted on said first lower electrode, and a plurality of upper electrodes mounted on said fixed dielectric, each of said electrodes having a different area overlapping said lower electrodes, a rotatable electrically conductive first switch contact member selectively positionable in electrical engagement with one of said upper electrodes, and said continuously variable capacitor being defined by an electrically conductive shaft rotatably mounted on said base plate out of electrical engagement with said first and second lower electrodes; a rotatable dielectric mounted for rotation with said shaft partly overlapping said second lower electrodes; a rotatable upper electrode supported by said rotatable dielectric in variable overlapping relation to said second lower electrode and electrically connected to shaft; said switch contact being supported by and electrically connected to said electrically conductive shaft.
Claim 2
Dependent Claim 200 words
In a circuit particularly suited for producing oscillating signals and including a parallel coupled continuous variable capacitor and a step variable capacitor, the improvement comprising said step variable capacitor, and continuously variable capacitor being mounted to a base plate, first and second lower electrodes mounted on said base plate, and means mounted on said base plate electrically connecting said lower electrodes, said step variable capacitor being defined by a fixed dielectric mounted on said first lower electrode, and a plurality of upper electrodes mounted on said fixed dielectric, each of said electrodes having a different area overlapping said lower electrodes, a rotatable electrically conductive first switch contact member selectively positionable in electrical engagement with one of said upper electrodes, and said continuously variable capacitor being defined by an electrically conductive shaft rotatably mounted on said base plate out of electrical engagement with said first and second lower electrodes; a rotatable dielectric mounted for rotation with said shaft partly overlapping said second lower electrodes; a rotatable upper electrode supported by said rotatable dielectric in variable overlapping relation to said second lower electrode and electrically connected to shaft; said switch contact being supported by and electrically connected to said electrically conductive shaft.
Claim 3
Dependent Claim 32 words
A circuit as claimed in claim 1, wherein said oscillating circuit includes a quartz crystal vibrator connected in series with the parallel connection of said step variable capacitor and continuously variable capacitor.
Claim 4
Dependent Claim 35 words
A circuit as claimed in claim 2, wherein each capacitance difference between respective steps of said step variable capacitor is of a value not more than the maximum variable capacitance of the continuously variable capacitor.

References Cited (Backward Citations)

US1396030A Cited
US1616832A Cited
US2858490A Cited
US3404298A Cited
US3737805A Cited
US3754152A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-04-14 1978-10-14 1979-04-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-04-14 1982-10-14 1983-04-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-04-14 1986-10-14 1987-04-15 $7700.00 Window Closed / Lapsed

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