Piezoelectric electroacoustic transducing device

Abstract

In order to improve the sound pressure level and the sound quality of a piezoelectric electroacoustic transducing device without impairing the size, the productivity, the cost, and the like of the device, the piezoelectric electroacoustic transducing device 1 has: a frame 20; a piezoelectric vibrator 10 in which piezoelectric elements 12, 13 are bonded to a metal plate 11; and a support member 30which supports a peripheral portion of the piezoelectric vibrator 10 on the frame 20, and which is made of a resin film such as a ring-like PET resin, and a mesh or embossed concave and convex structure is formed on the surface of the support member 30. While maintaining the external shape of the support member 30, the support member 30 is provided with a flexibility at which a large displacementof the piezoelectric vibrator 10 is not impeded.

Description

technical field [0001] The present invention relates to a piezoelectric electroacoustic transducer built in electronic equipment such as mobile phones, PDAs, PCs, and digital cameras and used as a sound source. Background technique [0002] Patent Document 1 (JP Unexamined Publication No. 9-271096 ) and Patent Document 2 (JP Unexamined Publication No. 2001-339793 ) describe the invention of piezoelectric electroacoustic transducers that include a frame, a piezoelectric A vibrator and a supporting member, the piezoelectric vibrator is formed by joining a piezoelectric element to a metal plate, and the supporting member supports the peripheral portion of the piezoelectric vibrator on the above-mentioned frame; In addition, in paragraph [0020] of Patent Document 1 It is recorded in the patent document 2 that the supporting member is constituted by thin plates of resins such as polyesters such as PET and PBT, polyimide, vinyl chloride or other plastics; , and is ring-shaped, fo...

AI Technical Summary

Problems solved by technology

[0003] In the inventions described in Patent Documents 1 and 2, since a relatively hard material is used for the supporting member, there is a problem that a large displacement of the piezoelectric vibrator is hindered, but this problem cannot be applied by applying the technology described in Patent Document 3. to the inventions described in Patent Documents 1 and 2 to solve

[0004] The problem to be solved by the present invention is: in Patent Document 3, a bending portion bent in the thickness direction is provided on the support member so as not to hinder the large displacement of the piezoelectric vibrator, but it is not suitable for the following cases: in terms of size , there is no room for a large bending portion between the piezoelectric vibrator and the frame

And, fundamentally speaking, piezoelectric electroacoustic transducers are smaller and thinner than dynamic electroacoustic transducers, so they can be used as sound sources for small electronic devices. There is no room for forming a large bending portion between the electric vibrator and the frame, and the technology described in Patent Document 3 cannot be applied to the inventions described in Patent Documents 1 and 2. Therefore, in the following piezoelectric In the electroacoustic transducer of the piezoelectric type, a large displacement of the piezoelectric vibrator is hindered, resulting in a decrease in sound pressure level and sound quality. This piezoelectric electroacoustic transducer has a frame, a piezoelectric vibrator, and a supporting member. The piezoelectric vibrator is composed The piezoelectric element is bonded to a metal plate, and the support member supports the peripheral portion of the piezoelectric vibrator on the frame.

In addition, even if a large bending portion can be formed between the piezoelectric vibrator and the frame, there will be restrictions on the increase in the size of the piezoelectric element in the future, resulting in the following disadvantages: it is impossible to increase the size of the piezoelectric element to improve the low-frequency sound. The sound quality is improved due to the pressure level, the bending part is easy to collapse (recessed, etc.) during assembly or vibration, and it is difficult to maintain the function, and the forming is troublesome and it is difficult to reduce the cost, etc.

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