Nihon Dempa Kogyo Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Minoru Ishihara

Kozo Ono

Shingo Kawanishi

Jiro Terada

Junichi Yukawa

Akio Chiba

Tamotsu Kurosawa

Kuniharu Nakamaru

A tuning fork type piezoelectric vibrator is provided with vibrating arms which can improve shock resistance while suppressing a CI value to a small value. A first groove (base end side) and a second groove (tip side) extend along a longitudinal direction from a base end of the vibrating arm and are formed on at least one of a front surface or a back surface of the vibrating arms. Then, a ratio L/Lwhich is the ratio of a length Lof the first groove to a length Lfrom the base end of the vibrating arm to the tip of the second groove, is set between 0.35 and 0.65, and a ratio d/Lwhich is the ratio of a space d between the first groove and the second groove to the length Lfrom the base end of the vibrating arm to the tip of the second groove, is set between 0.010 and 0.016.

Piezoelectric vibrator

A tuning fork-type crystal vibrator is provided that has improved CI and shock resistance. The tuning fork-type crystal vibrator includes a tuning fork-shaped crystal element made of a pair of tuning fork arms having grooves in their principal surfaces, and a tuning fork base portion from which the pair of tuning fork arms extends, an outer shape of the tuning fork-shaped crystal element being processed by etching. The tuning fork-type crystal vibrator has a protrusion, formed due to anisotropy of said etching, on a +X surface of the lateral faces of the tuning fork-shaped crystal element, and a first slanted portion rising from a &#x2212;X direction in a +X direction formed in a tuning fork slit. A tip of the tuning fork slit on a principal surface side is shifted in +X direction from a center line bisecting the tuning fork-shaped crystal element in a width direction to a position at which tuning fork vibrations of the pair of tuning fork arms are balanced.

Tuning fork-type crystal vibrator

A tuning fork type quartz crystal unit has a base and a pair of arms extending from respective ends of the base in a crystallographic Y direction of quartz crystal. Each of the arms comprises a first crystal member and a second crystal member which extend in the Y direction. The first crystal member and the second crystal member are joined to each other in a crystallographic YZ plane by a direct bonding such that the first crystal member and the second crystal member have respective crystallographic X directions oriented away from each other and extending parallel to each other. Each of the arms has excitation electrodes disposed respectively on a pair of exposed surfaces thereof which lie in the YZ plane. The direct bonding comprises, for example, a siloxane bond by which the first crystal member and the second crystal member are joined to each other.

Tuning fork type crystal unit and bar type crystal unit

An integral bimorph angular rate sensor is formed by directly bonding two tuning fork members in the thickness direction to enhance the detecting sensitivity of the angular velocity sensor. The individual tuning fork members are formed from a single crystalline piezoelectric material such as quartz and are bonded in the crystal axis direction as to establish a piezoelectric phenomenon wherein the piezoelectric materials of the bonded tuning fork members have inverse polarities in their width or thickness directions.

Growing community of inventors

Kawagoe, Japan

Minoru Ishihara