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US5438231A Expired / Lapsed US ⏱️ 0.0 years remaining

Thin film micromechanical resonator gyro

Assignee: Boeing North American Inc
•
Filing: 1993-08-23
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Granted: 1995-08-01
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Expires: 2013-08-23
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Abstract

Abstract A method to fabricate a tuning fork resonator gyro which uses non-piezoelectric substrate structure is proposed. The tuning fork structure can be effectively rendered piezoelectric for activation and sensing by thin film deposition of a piezoelectric material. Electrical excitation of the piezo film excites vibrations in the structure of the drive tuning fork, and the gyro signal generated due to rotation can be picked up from the piezo film on the signal tuning fork. Most piezoelectric films have a much higher piezoelectric coupling than crystalline quartz, the material used in the prior art. The piezoelectric films on mechanically hard non-piezoelectric substrates are simpler for fabrication, electroding, and have a number of other advantages over the prior art. Fabrication of the tuning fork structures can be done more simply than the prior art, and deposition of the piezo films can be accomplished by sol-gel, or other thin film techniques. The proposed methods thus provide considerable flexibility to separately optimize the resonator structure in terms of the physical and mechanical properties of the structure, the required piezoelectric properties, and methods for fabrication, processing and low cost manufacturing of resonator gyros.

Inventors

  • 👤 Mohsen Khoshnevisan
  • 👤 Manouchehr E. Motamedi
  • 👤 Ratnakar R. Neurgaonkar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:35
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/21; G; G01; G01C; G01C19/00; G01C19/56; G01C19/5607; G01C19/5621

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 82 words
A thin film micromechanical resonator, comprising: (a) a non-piezoelectric tuning fork having two tines; (b) a piezoelectric thin film disposed on each tine of the fork; and (c) at least three electrodes connected to each thin film, a first electrode being connected to a first side of each piezoelectric thin film and second and third electrodes being connected to a second side of each thin film; such that the application of an alternating voltage to the electrodes causes the fork to resonate.
Claim 2
Dependent Claim 82 words
A thin film micromechanical resonator, comprising: (a) a non-piezoelectric tuning fork having two tines; (b) a piezoelectric thin film disposed on each tine of the fork; and (c) at least three electrodes connected to each thin film, a first electrode being connected to a first side of each piezoelectric thin film and second and third electrodes being connected to a second side of each thin film; such that the application of an alternating voltage to the electrodes causes the fork to resonate.
Claim 3
Dependent Claim 23 words
The resonator of claim 1, wherein the tuning fork is made of fused quartz, silicon, CVD diamond, or Al 2 O 3 .
Claim 4
Dependent Claim 15 words
The resonator of claim 1, wherein the piezoelectric film comprises piezoceramics such as PZT, PLZT.
Claim 5
Dependent Claim 19 words
The resonator of claim 1, wherein the piezoelectric film comprises solid solution ferroelectric oxides such as SBN, or PBN.
Claim 6
Dependent Claim 16 words
The resonator of claim 1, wherein the piezoelectric film is ZnO, AlN, or PVF 2 .
Claim 7
Dependent Claim 87 words
A thin film micromechanical resonator, comprising: (a) a non-piezoelectric tuning fork having two tines; (b) a piezoelectric thin film disposed only on an upper surface of each tine of the fork; and (c) at least three electrodes connected to each thin film, a first electrode being connected to a first side of each piezoelectric thin film and second and third electrodes being connected to a second side of each thin film; such that the application of an alternating voltage to the electrodes causes the fork to resonate.
Claim 8
Dependent Claim 87 words
A thin film micromechanical resonator, comprising: (a) a non-piezoelectric tuning fork having two tines; (b) a piezoelectric thin film disposed only on an upper surface of each tine of the fork; and (c) at least three electrodes connected to each thin film, a first electrode being connected to a first side of each piezoelectric thin film and second and third electrodes being connected to a second side of each thin film; such that the application of an alternating voltage to the electrodes causes the fork to resonate.
Claim 9
Dependent Claim 22 words
The resonator claim 6, wherein the tuning fork is made of fused quartz, silicon, CVD diamond, or Al 2 O 3 .
Claim 10
Dependent Claim 15 words
The resonator of claim 6, wherein the piezoelectric film comprises piezoceramics such as PZT, PLZT.
Claim 11
Dependent Claim 19 words
The resonator of claim 6, wherein the piezoelectric film comprises solid solution ferroelectric oxides such as SBN, or PBN.
Claim 12
Dependent Claim 16 words
The resonator of claim 6, wherein the piezoelectric film is ZnO, AlN, or PVF 2 .

References Cited (Backward Citations)

US3634787A Cited
JPS5549020A Cited
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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) 1998-07-31 1999-01-30 1999-08-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-07-31 2003-01-30 2003-08-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-07-31 2007-01-30 2007-08-01 $7700.00 Window Closed / Lapsed

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