Vibration type angular velocity sensor

A vibration type angular velocity sensor comprising:

• first and second sensor units having respective vibrators oscillating in a predetermined standard vibrating direction and sensing waveform generating sections that detect an angular velocity oscillatory component generating in an angular velocity sensing direction differentiated from said standard vibrating direction when an angular velocity is applied to said vibrator, and the sensing waveform generating sections also generate an angular velocity sensing waveform based on said angular velocity oscillatory component, said first and second sensor units causing the vibrators thereof to oscillate with mutually opposite phases in said standard vibrating direction so as to cause the respective sensing waveform generating sections to generate first and second angular velocity sensing waveforms having mutually inverted phases,
• a differential waveform detector for obtaining a differential waveform between said first angular velocity sensing waveform and said second angular velocity waveform so as to cancel in-phase components acting to respective vibrators of said first and second sensor units in said angular velocity sensing direction, and
• an input gain adjuster for adjusting at least one of an input gain of said first angular velocity sensing waveform and an input gain of said second angular velocity sensing waveform entered into said differential waveform detector so as to reduce a residual in-phase component of said differential waveform,
• wherein
• said differential waveform detector includes a differential amplification circuit that inputs analog data of said first and second angular velocity sensing waveforms, and said input gain adjuster includes an analog input gain adjusting circuit that adjusts an analog input gain of said angular velocity sensing waveform,
• said sensing waveform generating sections include a vibration detecting capacitor for changing a distance between electrodes in accordance with said angular velocity oscillatory component a bias power source for applying a constant bias voltage to said vibration detecting capacitor, and a charge amplifier for detecting a charge amount change of said vibration detecting capacitor in accordance with a change of said distance between the electrodes when said bias voltage is applied and for converting the detected charge amount change into a voltage to output an angular velocity sensing voltage waveform, and
• said analog input gain adjusting circuit is disposed between said charge amplifier and said differential amplification circuit for adjusting an input gain of said angular velocity sensing voltage waveform produced from said charge amplifier and entered into said differential amplification circuit.

A vibration type angular velocity sensor comprising:

• first and second sensor units respectively having vibrators oscillating in a predetermined standard vibrating direction and sensing waveform generating sections that detects an angular velocity oscillatory component generating in an angular velocity sensing direction differentiated from said standard vibrating direction when an angular velocity is applied to said vibrators, and the sensing waveform generating sections also generate an angular velocity sensing waveform based on said angular velocity oscillatory component, said first and second sensor units causing the vibrators thereof to oscillate with mutually opposite phases in said standard vibrating direction so as to cause respective sensing waveform generating sections to generate first and second angular velocity sensing waveforms having mutually inverted phases,
• a differential waveform detector for obtaining a differential waveform between said first angular velocity sensing waveform and said second angular velocity waveform so as to cancel in-phase components acting to respective vibrators of said first and second sensor units in said angular velocity sensing direction, and
• an input gain adjuster for adjusting at least one of an input gain of said first angular velocity sensing waveform and an input gain of said second angular velocity sensing waveform entered into said differential waveform detector so as to reduce a residual in-phase component of said differential waveform,
• wherein
• said differential waveform detector includes a differential amplification circuit that inputs analog data of said first and second angular velocity sensing waveforms, and said input gain adjuster includes an analog input gain adjusting circuit that adjusts an analog input gain of said angular velocity sensing waveform,
• said analog input gain adjusting circuit has a buffer amplifier provided at an input stage of said differential amplification circuit that inputs said angular velocity sensing waveform,
• at least part of a gain determining resistor of said buffer amplifier is constituted by a variable resistor, and
• an output of said buffer amplifier being gain adjusted based on resistance value adjustment of said variable resistor is entered into said differential amplification circuit as the angular velocity sensing waveform having been subjected to analog input gain adjustment.