Piezoelectric actuator, acoustic element, and electronic device

A piezoelectric actuator, piezoelectric element technology, applied to piezoelectric/electrostrictive/magnetostrictive devices, piezoelectric/electrostrictive transducers, piezoelectric effect/electrostrictive or magnetostrictive Motors and other directions can solve the problems of poor performance of acoustic components, large average amplitude, and inability to provide

Inactive Publication Date: 2008-09-10
NEC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] Although piezoelectric actuators can be advantageously reduced in size and thickness, they are inferior to electromagnetic actuators in terms of acoustic component performance
This is due to the rigidity of the piezoelectric element itself and the fact that piezoelectric actuators do not provide a sufficiently large average amplitude compared to electromagnetic actuators

Method used

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  • Piezoelectric actuator, acoustic element, and electronic device
  • Piezoelectric actuator, acoustic element, and electronic device
  • Piezoelectric actuator, acoustic element, and electronic device

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0148] Manufactured according to Invention Example 1 as Figure 15A The piezoelectric actuator having the piezoelectric element 10 placed on the lower surface of the bottom plate 24 is shown in and 15B.

[0149] The specific structure is as follows:

[0150] Piezoelectric element: Upper and lower electrode layers (piezoelectric material layer, see figure 1 ), each of which has a thickness of 8 μm.

[0151] Elastomer: The elastomer with a thickness of 0.05 is made of phosphor bronze. By "elastomeric body" is meant an integrated structure comprising a base plate, extensions and uprights.

[0152] Beam: upright portion height = 1.0 mm, extension portion length = 2.0 mm, beam width: 4.0 mm, and beam bending angle = 90°.

[0153] Support member: Shape = circular with a diameter of 17mm, thickness = 1.55mm, gap L 1 = 1.0 m, and material = SUS304.

[0154] The piezoelectric plate is made of zirconate lead titanate ceramics, and the electrode layer is made of silver / palladium a...

example 2

[0174] Manufactured according to Invention Example 2 as Figure 17A and 17B The piezoelectric actuator shown. This piezoelectric actuator differs from the piezoelectric actuator according to Inventive Example 1 in that the structure of the beam 30 is different. Beams have such Figure 8 The curved portion 37 is shown. Other structural details are the same as the piezoelectric actuator according to Inventive Example 1.

[0175] The specific structure is as follows:

[0176] Piezoelectric element: Same as Inventive Example 1.

[0177] Elastomer: Same as Inventive Example 1.

[0178] Beam: upright portion height = 1.0 mm, extension portion length (including curved portion) = 2.0 mm, beam width: 4.0 mm, and curvature radius of curved portion = R2.0.

[0179] Support member: the same as Invention Example 1.

[0180] 【result】

[0181] Resonant frequency = 472Hz

[0182] Maximum vibration velocity amplitude = 345mm / s

[0183] Vibration velocity ratio = 0.91

[0184] Vibra...

example 3

[0187] Manufactured according to Invention Example 3 as Figure 18 The piezoelectric actuator shown. This piezoelectric actuator differs from the piezoelectric actuator according to Inventive Example 1 in that piezoelectric elements are provided on both surfaces of the base plate, having a bimorph structure. Other structural details are the same as the piezoelectric actuator according to Inventive Example 1.

[0188] The specific structure is as follows:

[0189] Piezoelectric element: shape = square with a side length of 10 mm, thickness = 0.4 mm. The upper and lower electrode layers of each piezoelectric element were the same as Inventive Example 1 and had a thickness of 8 μm.

[0190] Elastomer: Same as Inventive Example 1.

[0191] Beam: same as Invention Example 1.

[0192] Support member: Shape = circular with a diameter of 17mm, thickness = 1.95mm, gap L 1 = 1.0 m.

[0193] 【result】

[0194] Resonant frequency = 662Hz

[0195] Maximum vibration velocity amplitude...

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PUM

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Abstract

A piezoelectric actuator capable of providing high sound pressure and excellent frequency characteristics when it is used as an acoustic element and advantageous for a reduction in size. The piezoelectric actuator (50) comprises a piezoelectric element (10) performing such an expansion / contraction motion that its principal plane is expanded or contracted according to the state of a filed, a pedestal (24) on which the piezoelectric element is stamped, and four beam parts (30) connected to the outer peripheral parts of the pedestal (24). The pedestal (vibrating part) is vertically vibrated according to the expansion / contraction motion of the piezoelectric element (10). Each of the beam parts (30) comprises an extension part (35) extending from the outer peripheral part of the pedestal (24) to the outside and a rise part (36) continuously extended from the extension part (35) in a direction perpendicular to the extended direction of the extension part (35).

Description

technical field [0001] The present invention relates to a piezoelectric actuator for generating vibration using a piezoelectric element, and an acoustic component and an electronic device using the piezoelectric actuator. Background technique [0002] Currently, electromagnetic actuators are used as drive sources for acoustic components such as speakers. The electromagnetic actuator includes a permanent magnet and a voice coil, and generates vibration by the action of a magnetic circuit of a stator including the magnet. The electromagnetic speaker emits sound by vibrating a low-rigidity vibration plate, such as an organic thin film, etc., fixed to the vibrating body of the electromagnetic actuator. [0003] In recent years, the demand for portable phones and personal computers has gradually increased, and accordingly the corresponding demand for small and energy-saving actuators has also increased. The electromagnetic actuator is required to provide a large current to the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B06B1/06H02N2/00H04R17/00
CPCH01L41/0973B06B1/0603H04R17/00G10K9/122H01L41/0833H10N30/2041
Inventor 大西康晴佐佐木康弘土岐望
Owner NEC CORP
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