Piezoelectric loudspeaker adopting interdigital electrodes or spiral electrodes

Abstract

The invention belongs to the technical field of a loudspeaker, in particular relates to a piezoelectric loudspeaker adopting interdigital electrodes or spiral electrodes, which comprises a vibrating membrane, a piezoelectric ceramic wafer, electrodes and a frame, wherein the piezoelectric ceramic wafer is bonded on the vibrating membrane; the electrodes are arranged on the surface of the piezoelectric ceramic wafer; the frame is used for restricting the vibrating membrane; the electrodes are divided into positive electrodes and negative electrodes; and the electrodes are arranged in an interdigital structure, an interdigital spiral structure or a circular or polygonal concentric staggered structure or in other staggered arrangement modes. The interdigital or spiral electrode structure enables the direction of polarization to be parallel with the plane of the vibrating membrane and enables the electric field between spiral electrodes to be consistent with the direction of polarization, i.e. the ceramic deformation utilizes the piezoelectric strain coefficient d33 rather than the piezoelectric strain coefficient d31 generally used in the traditional piezoelectric loudspeaker. Under the condition that the size, the material and the electric field intensity are consistent, the strain of the piezoelectric ceramic wafer of the invention in the plane of the vibrating membrane is more than two times of the corresponding strain of the traditional piezoelectric loudspeaker, and the vibration of the plane of the vibrating membrane is large, thereby generating larger sound pressure level.

Description

technical field [0001] The invention belongs to the technical field of loudspeakers, and particularly relates to a piezoelectric loudspeaker using interdigitated or spiral electrodes. Background technique [0002] A loudspeaker is an electro-mechanical-sound transducer, which is an important element in audio equipment. Speakers are widely used in people's daily life, bringing a lot of convenience. In the fields of electronic products such as automobiles, radio, TV, speakers, mobile phones, MP4, and computers, the application of speakers can be seen almost everywhere. There are many types of speakers, which can be divided into electric type (ie moving coil type), electrostatic type (ie capacitive type), electromagnetic type (ie reed type), piezoelectric type and so on according to their energy conversion principle; Divided into woofers, mid-range speakers, and tweeters, among which moving coil speakers are the most widely used. Because of its small, thin and light character...

AI Technical Summary

Problems solved by technology

[0011] In the case of constant total thickness, the use of multilayer piezoelectric ceramics will reduce the driving voltage accordingly. This is a current mainstream solution, but it will also bring the disadvantages of complex processing technology and increased cost.

In particular, once the piezoelectric speaker adopts a multilayer ceramic structure, the production process must consider the use of Ag-Pb silver-palladium noble metal inner electrodes and low-temperature sintering technology for piezoelectric ceramics. These most advanced ceramic firing technologies are bound to increase piezoelectricity. The production cost of the loudspeaker and the subsequent research and development cost of the product

In addition, due to factors such as thermal matching between the ceramic dielectric layer and the inner electrode layer, electrical fatigue and physical fatigue, and complex preparation processes, the multilayer piezoelectric speaker has formed discrete electrical parameters of the ceramic and speaker prepared in production. larger

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