Patent ID: 6666091
Filing Date: 2003-12-23
Classification: G01C

Abstract:
An angular velocity sensor comprising:a tuning fork vibrator having: a first vibrator including at least two arms formed of a single crystalline piezoelectric material and at least one base for connecting said arms; and a second vibrator having an approximate shape to that of said first vibrator and formed of a single crystalline piezoelectric material; wherein said first vibrator and said second vibrator are directly bonded in their thickness directions so that their crystal axis directions which generate piezoelectric phenomena have inverse polarities relative to each other in their width directions to form said tuning fork vibrator having at least two tuning fork arms and at least one tuning fork base; a first electrode disposed on a surface of one of said two tuning fork arms, and a second electrode disposed on a surface of an other of said two tuning fork arms; a third electrode disposed on a rear face of said one of said two tuning fork arms at a position opposing said first electrode, and a fourth electrode disposed on a rear face of said other of said two tuning fork arms at a position opposing said second electrode; and fifth, sixth, seventh, and eighth electrodes disposed as detection electrodes on said two tuning fork arms, wherein said tuning fork vibrator for connecting a drive power such that: when said first electrode acts as a drive electrode, a drive signal having a phase different from that of said first electrode is provided to said second electrode; or a drive signal having an identical phase with that of said first electrode is provided to said fourth electrode; when said third electrode acts as said drive electrode, a drive signal having an identical phase with that of said third electrode is provided to said second electrode; or a drive signal having a phase different from that of said third electrode is provided to said fourth electrode, and said fifth electrode and said eighth electrode respectively disposed on an outer side face of said two tuning fork arms and are commonly connected, and said sixth electrode and said seventh electrode respectively disposed on an inner side face of said two tuning fork arms and are commonly connected, so that a detection signal is output at the commonly connected parts.