US4306170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
AT-Cut quartz resonator, with w/t=2.0 to 2.8, l/t<25
Assignee: Seiko Instruments Inc
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Filing: 1979-08-27
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Granted: 1981-12-15
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Expires: 1999-08-27
Abstract
Abstract An AT-cut quartz resonator is disclosed, wherein the length l, the width w and the thickness t of the quartz crystal plate are respectively chosen in the directions of an electrical axis (X-axis), an optical axis (Z'-axis) and a mechanical axis (Y'-axis), the width-to-thickness ratio w/t is chosen in the range of 2.0 to 2.8 and the length-to-thickness ratio l/t is chosen less than 25. Consequently, an AT-cut quartz resonator of miniature size having high Q-values of the major mode and excellent frequency-temperature characteristics of the vibration frequency is realized.
Inventors
- 👤 Shunichi Motte
- 👤 Naoyuki Echigo
- 👤 Shiro Yamashita
- 👤 Tsuneo Kuwabara
- 👤 Kunihiro Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:56
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02007; H03H9/02015; H03H9/02023; G; G04; G04F; G04F5/00; G04F5/04; G04F5/06; G04F5/063; H03H9/02157
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A quartz resonator comprising: an AT-cut quartz crystal plate rotated counter-clockwise around the X-axis of the quartz crystal plate by a cut angle θ having a value from about 33°20' to about 36°20', having an overall length l, an overall width w and a maximum thickness t respectively extending along the X-axis, the Z'-axis and the Y'-axis of the quartz crystal plate, a width-to-thickness ratio w/t between about 2.0 to about 2.8 and a length-to-thickness ratio l/t less than about 25.
Claim 2
Dependent Claim
81 words
A quartz resonator comprising: an AT-cut quartz crystal plate rotated counter-clockwise around the X-axis of the quartz crystal plate by a cut angle θ having a value from about 33°20' to about 36°20', having an overall length l, an overall width w and a maximum thickness t respectively extending along the X-axis, the Z'-axis and the Y'-axis of the quartz crystal plate, a width-to-thickness ratio w/t between about 2.0 to about 2.8 and a length-to-thickness ratio l/t less than about 25.
Claim 3
Dependent Claim
23 words
An AT-cut quartz resonator as claimed in claim 1, wherein the X-Y' plane of the quartz crystal plate is almost rectangular in plan.
Claim 4
Dependent Claim
35 words
An AT-cut quartz resonator as claimed in claim 1, wherein major surfaces parallel to the X-Z' plane and side surfaces parallel to the X-Y' plane of the quartz crystal plate meet substantially at right angles.
Claim 5
Dependent Claim
44 words
An AT-cut quartz resonator as claimed in claim 1, wherein the thickness of the end portions along the length of a quartz crystal plate are thinner than the thickness of the major vibrating portion of the quartz crystal plate between the plate end portions.
Claim 6
Dependent Claim
39 words
An AT-cut quartz resonator as claimed in claim 1, wherein the side surface parallel to the X-Y' plane of the quartz crystal plate are rotated around the X-axis counter-clockwise by an angle α between about 0° to about 10°40'.
Claim 7
Dependent Claim
24 words
An AT-cut quartz resonator as claimed in claim 3, wherein the cut angle θ is within the range of about 33.20' to about 34°55'.
Claim 8
Dependent Claim
84 words
An AT-cut quartz resonator as claimed in claim 2, wherein the length l, the width w and the thickness t of the quartz crystal plate are respectively chosen in the directions of the X-axis, Z'-axis and the Y'-axis and the dimensional ratios w/t, l/t when indicated on a graph whose abscissa is w/t and whose ordinate is l/t are within a quadrangle defined by four points A, B, C, D having w/t and l/t coordinates A(2.41, 15.69), B(2.58, 15.56), C(2.66, 14.98) and D(2.41, 14.98).
Claim 9
Dependent Claim
50 words
An AT-cut quartz resonator as claimed in claim 7, wherein major surfaces parallel to the X-Z' plane and side surfaces parallel to the X-Y' plane of the quartz crystal plate meets substantially at right angles and the cut angle θ is within the range of about 34°35' to about 34°55'.
Claim 10
Dependent Claim
55 words
A rectangular AT-cut quartz resonator as claimed in claim 7, wherein the side surfaces of the quartz crystal plate parallel to the X-Y' planes are tilted counterclockwise by an angle α withing the range of about 0° to about 10°40' and the cut angle θ is within the range of about 34°35' to about 35°25'.
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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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |