Piezoelectric transducer, piezoelectric actuator, and portable device

Abstract

The present invention provides a piezoelectric vibrating body, a piezoelectric driver, and a portable device. The piezoelectric vibrating body can greatly expand the amplitude, thereby greatly improving the driving efficiency. According to the investigation of the vibration energy density in the piezoelectric vibrating body (40A), through-holes (310) and hollow holes (411-414) are formed in the reinforcement plate main body (41). The part with the greatest deformation caused by longitudinal vibration or bending vibration. In this way, at the through hole and hollow hole formed at the position containing the largest deformation due to longitudinal vibration or bending vibration, the maximum vibration energy in the piezoelectric element (21) is exerted to realize the expansion of the amplitude, and at the same time, by strengthening The displacement of the piezoelectric element (21) toward the out-of-plane direction is restricted by the parts other than the through hole (310) and hollow holes (411-414) in the plate main body (41), so the amplitude of longitudinal vibration and bending vibration is reliable. to expand.

Description

technical field [0001] The present invention relates to a piezoelectric vibrating body, a piezoelectric driver, and a portable device. Background technique [0002] Conventionally, in small and portable electronic devices such as watches, miniaturization and thinning of components to be mounted have been desired, and reduction in power consumption has been desired in order to prolong battery life. Therefore, instead of stepping motors, piezoelectric actuators that are small and thin and have excellent conversion efficiency from electrical energy to mechanical energy have been used as driving devices incorporated in timepieces (for example, Patent Documents 1 to 5). [0003] Such a piezoelectric actuator incorporated in a portable device, as shown in Patent Document 1, has a piezoelectric vibrating body having a generally rectangular plate shape in which a reinforcing plate is laminated on a rectangular piezoelectric element. The piezoelectric transverse effect when an elect...

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Problems solved by technology

[0019] In addition, in Patent Documents 1 and 4, the reinforcement plate and the piezoelectric element are not in contact at the belly of the bending vibration, but there is no reinforcement plate portion extending approximately in the longitudinal direction at the approximately central portion of the rectangular piezoelectric element in the width direction. (In Patent Document 1, this part is referred to as the arm part) The shape is considered in particular, and since the width of this part is very narrow, it may not be possible to use the reinforcement plate to limit the direction and attachment to the piezoelectric element. Displacement in directions other than the direction of the plane (in-plane direction) perpendicular to the direction of the electric field

As a result, the effect of expanding the amplitude may not be obtained

That is, if the rigidity of the reinforcing plate is simply lowered, a displacement in a direction (out-of-plane direction) other than a direction (in-plane direction) along a plane perpendicular to the direction of the electric field applied to the piezoelectric element occurs, Therefore, the amplitude of the vibration along the direction (in-plane direction) perpendicular to the direction of the electric field is weakened

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