Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
An expansion mode piezoelectric vibrator, comprising: a ceramic piezoelectric plate having first and second opposed major surfaces; first electrode means disposed on said first major surface; second electrode means disposed on said second major surface, the position and geometry of said first and second electrode means causing said piezoelectric vibrator to vibrate primarily in an expansion mode; and said ceramic piezoelectric plate having the shape of a quadrilateral, the four corner angles of said quadrilateral having values which cause said corner angles to cooperate to suppress at least one predetermined spurious mode of vibration of said vibrator, said at least one spurious mode of vibration being at least one of an edge mode and a bending mode vibration, at least one said corner angle being an acute angle.
Claim 2
Dependent Claim
128 words
An expansion mode piezoelectric vibrator, comprising: a ceramic piezoelectric plate having first and second opposed major surfaces; first electrode means disposed on said first major surface; second electrode means disposed on said second major surface, the position and geometry of said first and second electrode means causing said piezoelectric vibrator to vibrate primarily in an expansion mode; and said ceramic piezoelectric plate having the shape of a quadrilateral, the four corner angles of said quadrilateral having values which cause said corner angles to cooperate to suppress at least one predetermined spurious mode of vibration of said vibrator, said at least one spurious mode of vibration being at least one of an edge mode and a bending mode vibration, at least one said corner angle being an acute angle.
Claim 3
Dependent Claim
17 words
An expansion mode piezoelectric vibrator in accordance with claim 1, in which said quadrilateral is a parallelogram.
Claim 4
Dependent Claim
67 words
A piezoelectric vibrator in accordance with claim 2, wherein two opposite said sides of said parallelogram have a first length and the remaining two opposite said sides of said parallelogram have a second length shorter than said first length; and the ratio of said second length to said first length being within an optimum range of ratios for suppressing said at least one spurious mode of vibration.
Claim 5
Dependent Claim
66 words
A piezoelectric vibrator in accordance with claim 3, 1 or 2, wherein two opposite angles of said four corner angles are selected to be equal obtuse angles and the remaining two opposite angles are selected to be equal acute angles, and wherein the value of said acute angles lies within an optimum range of angle values for suppressing said at least one spurious mode of vibration.
Claim 6
Dependent Claim
18 words
A piezoelectric vibrator in accordance with claim 4, wherein said optimum range of angle values 75° to 89°.
Claim 7
Dependent Claim
17 words
A piezoelectric vibrator in accordance with claim 5, wherein said piezoelectric plate is configured as a rhombus.
Claim 8
Dependent Claim
19 words
A piezoelectric vibrator in accordance with claim 3, wherein said second optimum range of ratios is 0.7 to 0.98.