Piezoelectric speaker based on piezoelectric cantilever beam

Abstract

The invention discloses a piezoelectric speaker based on a piezoelectric cantilever beam, belonging to the technical filed of piezoelectricity. The piezoelectric speaker is structured by bonding an upper layer piezoelectric ceramic piece and a lower layer piezoelectric ceramic piece of opposite polarization directions at both sides of a middle layer fiber sheet, thereby forming a piezoelectric cantilever beam; one end of the piezoelectric cantilever beam is fixed with an external frame so as to form a fixed end from which electrodes are led out; the movable end of the piezoelectric cantilever beam is connected with a vibration sheet by a link block with a damp function; and the vibration sheet is bonded to the external frame through a vibration film. The vibration sheet can serve as the main medium for driving air around the speaker and also the counter weight of the speaker, can reduce the first-order resonance frequency of the speaker effectively, and improve the effect of low pitch replay. The piezoelectric speaker provided by the invention has the characteristics of low resonance frequency, simple vibration mode and large vibration range and the like, and has the advantages of good low pitch performance, stable sound pressure output and high sound output and the like compared with a conventional surface mount type piezoelectric speaker.

Description

technical field [0001] The invention belongs to the application field of piezoelectric technology, in particular to a piezoelectric speaker based on a piezoelectric cantilever beam. Background technique [0002] Compared with traditional dynamic speakers, piezoelectric speakers have the characteristics of small, thin, light, no magnetic field interference, and low power consumption. Computers, portable multimedia players and other fields are widely used, and have extremely bright prospects and future. [0003] At present, the basic principle of the vibration and sound part of most piezoelectric speakers is: the piezoelectric ceramic sheet is bonded to the vibrating sheet, and the audio excitation voltage is applied to the ceramic sheet. Due to the inverse piezoelectric effect, the piezoelectric ceramic sheet drives the vibrating sheet to generate bending vibration. , so as to push the surrounding air to achieve the purpose of raising the voice. [0004] Compared with tradi...

AI Technical Summary

Problems solved by technology

[0004] Compared with traditional loudspeakers, it has certain advantages. At the same time, ordinary piezoelectric loudspeakers also have some shortcomings. The main performance is poor bass performance, unstable sound output frequency response, and low sound pressure.

This is because: ordinary speakers bond piezoelectric ceramic sheets with a Young's modulus as high as 500GPa with the vibrating sheet, making it difficult to deform the overall structure, resulting in high resonance frequency and poor bass performance; The role of the plate is the bending moment, which makes the structure of the speaker structure complex in the mid-frequency domain, the sound output frequency response is not stable, and the sound quality is poor; another disadvantage of the complex structural mode is that the vibration displacement of the vibration plate cannot be effectively accumulated, and the overall amplitude of the vibration plate Small, and the vibration phase of different positions on the vibrating plate is very different, even reversed, resulting in low sound pressure output

Images