US4191906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tuning fork type quartz crystal resonator with notched tines
Assignee: Suwa Seikosha KK
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Filing: 1978-08-25
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Granted: 1980-03-04
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Expires: 1998-08-25
Abstract
Abstract A conventional tuning fork type quartz crystal resonator has mainly two vibration modes. They are fundamental vibration mode and overtone having the resonance frequency six times as much as the frequency of fundamental vibration. These two vibration modes have similar high quality factors. When this resonator is put to practical use, there are instances where it oscillates in undesirable mode of vibration. Accordingly, in this invention, concave portions are provided at the tops of resonator in order to prevent it. It is the most effective in case that concave portions are provided in the region of 0.65 to 0.85 from roots of arms.
Inventors
- 👤 Shigeru Kogure
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:05
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/21; H03H9/215; H03H3/00; H03H3/007; H03H3/02; H03H3/04; H03H2003/0414; H03H2003/0492
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
A tuning fork type quartz crystal resonator having the flexure mode of vibration and a mechanically supporting portion disposed below the roots of arms, and comprising the arms of said tuning fork type quartz crystal resonator provided with concave portions in the region of 0.65 through 0.85 from the roots of arms in the case where said roots of arms are 0 and top edges of arms are 1, said concave portions suppressing the generation of overtone by making the effective length of overtone longer to said supporting portion.
Claim 2
Dependent Claim
89 words
A tuning fork type quartz crystal resonator having the flexure mode of vibration and a mechanically supporting portion disposed below the roots of arms, and comprising the arms of said tuning fork type quartz crystal resonator provided with concave portions in the region of 0.65 through 0.85 from the roots of arms in the case where said roots of arms are 0 and top edges of arms are 1, said concave portions suppressing the generation of overtone by making the effective length of overtone longer to said supporting portion.
Claim 3
Dependent Claim
20 words
A tuning fork type resonator as claimed in claim 1, wherein said concave portion is in the form of rectangle.
Claim 4
Dependent Claim
20 words
A tuning fork type resonator as claimed in claim 1, wherein said concave portion is in the form of semicircle.
Claim 5
Dependent Claim
18 words
A tuning fork type resonator as claimed in claim 1, wherein said resonator is made by photo-chemical-etching techniques.
Claim 6
Dependent Claim
21 words
A tuning fork type resonator as claimed in claim 1, wherein said concave portion is provided at the position of 0.75.
Claim 7
Dependent Claim
46 words
A tuning fork type resonator as claimed in claim 1, wherein the length X of the electrode is longer than the length at the time when said concave portion is not provided and moreover said concave portion is provided in the region of 0.65 through 0.85.
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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |