Inertia Force Sensor

• US 20090007663A1
• Filed: 03/26/2007
• Published: 01/08/2009
• Est. Priority Date: 03/27/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uemura, Takeshi
• Granted Patent: US 8,015,874 B2
• Time in Patent Office: Days
• US Class Current: 73/504.150
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Abstract

An inertial force sensor is provided in which each of switches is connected in parallel with each of resistors of low-pass filter and high-pass filter, respectively, and capacitor of high-pass filter can be boost charged by making switches on without mediate resistors.

Claims

1. An inertial force sensor comprising:

an oscillator and a sensory circuit for outputting an angular velocity signal after smoothing a detected signal outputted by the oscillator;

wherein

the sensory circuit has a low-pass filter and a high-pass filter formed by connecting a resistor and a capacitor;

one end of the capacitor of the high-pass filter is connected to between the resistor and the capacitor of the low-pass filter;

an angular velocity signal is outputted after smoothing the detected signal through the low-pass filter and the high-pass filer; and

a switch is connected in parallel with the resistor of either one of the low-pass filter and the high-pass filter, and the capacitor is charged by making the switch on.

2. The inertial force sensor of claim 1 wherein:

the switch is connected in parallel with both of the resistors of the low-pass filter and the high-pass filter, and the capacitor is charged by making the switch on.

3. The inertial force sensor of claim 1 wherein:

the sensory circuit further comprises a noise filter;

the angular velocity signal to be outputted by the high-pass filter is outputted through the noise filter;

the noise filter has an amplifier;

the angular velocity signal is inputted to a non-inverted input terminal of the amplifier;

a voltage is applied to an inverted input terminal of the amplifier through an input resistor;

the angular velocity signal is outputted from an output terminal of the amplifier after being amplified; and

a voltage equivalent to the voltage applied to the inverted input terminal of the amplifier is applied to one end of the capacitor of the high-pass filter.

4. The inertial force sensor of claim 1 wherein:

the switch is provided at both ends of the capacitor of the high-pass filter; and

a front stage circuit and a rear stage circuit are connected through the switch.

5. The inertial force sensor of claim 4 further having a function of suspending supply of power to the front stage circuit or the rear stage circuit.