Angular velocity sensor

An angular velocity sensor comprising:

• a vibrator including an arm and a weight on an XY plane composed of an X axis and a Y axis perpendicular to each other;
• a driving circuit for driving the vibrator;
• and
• a sensing circuit for sensing angular velocity given to the vibrator,
• wherein the vibrator includes a first sensing electrode on the arm, a second sensing electrode on the arm, a third sensing electrode on the arm and a fourth sensing electrode on the arm;
• wherein a monitor signal from a monior electrode on the vibrator is input into the driving circuit, and the driving circuit outputs a driving signal to a driving electrode on the vibrator,
• wherein the sensing circuit includes:
• a first sensing terminal connected to the first sensing electrode by a first signal line and connected to the second sensing electrode by a second signal line;
• a second sensing terminal connected to the third sensing electrode by a third signal line and connected to the fourth sensing electrode by a fourth signal line;
• a first disconnection sensing circuit;
• and
• second disconnection sensing circuit,
• wherein the first sensing electrode outputs a first signal containing a first sense component and a first monitor component,
• wherein the second sensing electrode outputs a second signal containing a second sense component with a phase substantially the same as a phase of the first sense component and a second monitor component with a phase substantially opposite to a phase of the first monitor component,
• wherein the third sensing electrode outputs a third signal containing a third sense component with a phase substantially opposite to a phase of the first sense component and a third monitor component with a phase substantially the same as a phase of the first monitor component,
• wherein the fourth sensing electrode outputs a third signal containing a fourth sense component with a phase substantially opposite to a phase of the first sense component and a fourth monitor component with a phase substantially opposite to a phase of the first monitor component,
• wherein a signal output from the first sensing terminal is input into the sensing circuit, and the sensing circuit senses an angular velocity around a Z axis substantially perpendicular to the X axis and the Y axis,
• wherein a signal output from the first sensing terminal is input into the first disconnection sensing circuit, and the first disconnection sensing circuit outputs a first disconnection sense signal showing that the first signal line or the second signal line is disconnected, and
• wherein a signal output from the second sensing terminal is input into the second disconnection sensing circuit, and the second disconnection sensing circuit outputs a disconnection sense signal showing that the third signal line or the fourth signal line is disconnected.