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Piezoelectric speaker, piezoelectric audio device employing piezoelectric speaker, and sensor with alert device attached

一种压电扬声器、传感器元件的技术，应用在传感器、压电/电致伸缩换能器谐振换能器、传感器类型等方向，能够解决声压低、无法获得充分声压等问题，达到提高声压的效果

Inactive Publication Date: 2014-04-23
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, in such a piezoelectric speaker, the sound pressure in the low range is still low, and sufficient sound pressure cannot be obtained

Method used

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  • Piezoelectric speaker, piezoelectric audio device employing piezoelectric speaker, and sensor with alert device attached
  • Piezoelectric speaker, piezoelectric audio device employing piezoelectric speaker, and sensor with alert device attached
  • Piezoelectric speaker, piezoelectric audio device employing piezoelectric speaker, and sensor with alert device attached

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0084] refer to Figure 1 to Figure 4 The piezoelectric speaker according to Embodiment 1 of the present invention will be described. The piezoelectric speaker 1 of the present embodiment is characterized in that it includes a piezoelectric vibrator 2 , a membranous body 3 provided around the piezoelectric vibrator 2 to hold the piezoelectric vibrator 2 , and a frame 4 supporting the outer peripheral portion of the membranous body 3 , The membranous body 3 constitutes a bellows structure having peaks and valleys in the outer peripheral direction corresponding to the natural frequency of the in-phase mode in which the abdomen and nodes are concentrically formed, and the piezoelectric vibrator and the membranous body form a sounding body. The piezoelectric vibrator 2 has a piezoelectric body 21 composed of piezoelectric elements, and a metal plate as a plate-like body 22 having a diameter larger than that of the piezoelectric body 21 and concentrically attached to the surface of...

Embodiment approach 2

[0109] Next, Embodiment 2 of the present invention will be described.

[0110] In this embodiment, if Figure 13 As shown in (a) to (c), the bellows structure of the membranous body 3 is characterized in that the bellows correspond to the bellies of the vibration mode in a one-to-one manner, and there is no bellows at the nodes of the vibration mode ( peaks and valleys). Here, the configuration of the piezoelectric speaker is the same as that of the first embodiment described above except for the bellows shape.

[0111] refer to Figure 13 The operation of emitting radiated sound by the piezoelectric speaker 1 of the present embodiment configured as described above will be described. Figure 13 (a) to (c) show the vibration mode ( Figure 13 (a)), the displacement of the vibrating part of the piezoelectric speaker ( Figure 13 (b)) and the composition of the membranous body ( Figure 13 (c)). Here, when the signal voltage of the radiated sound is applied to the piezoele...

Embodiment approach 3

[0115] Next, Embodiment 3 of the present invention will be described.

[0116] Next, the results of measurements regarding the third resonance will be described.

[0117] exist Figure 14 Indicates that for will be with Figures 1 to 4 The same piezoelectric vibrator 2 as in the first embodiment described above is formed in the size of 35Φ, and only the piezoelectric vibrator 2 of 35Φ is shown (curve a), and the case where the 50Φ membranous body 3 is connected to the piezoelectric vibrator 2 of 35Φ is shown. The case (curve b) and the case (curve c) where a 50Φ membranous body 3 with bellows is connected to a 35Φ piezoelectric vibrator 2 are the results of measuring the relationship between sound pressure and resonance frequency.

[0118] in addition, Figure 15 is an enlarged view of the vicinity of the third resonance point.

[0119] As can be seen from the figure, the curve b indicates the sound pressure increase in the low range, and the curve c indicates the sound pr...

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Abstract

A piezoelectric speaker having a high sound pressure level in a low-frequency domain and a high-frequency domain, a piezoelectric audio device, and a sensor with an alert device attached employing the piezoelectric speaker are provided. A piezoelectric speaker 1 of the invention includes a piezoelectric vibrator 2 including a piezoelectric body 21 formed of a piezoelectric element and a plate-shaped body (plate) which has a larger diameter than the piezoelectric body 21 and which is attached to a surface of the piezoelectric body 21 in a concentric form, and a film-shaped body 3 that is provided around the piezoelectric vibrator 2 so as to elastically hold the piezoelectric vibrator. The film-shaped body 3 has a coarse and dense portion in a circumferential direction thereof, which has a physically coarse portion, and which can become a mountain portion 3M or a valley portion 3V or both, and is disposed so as to correspond to a natural frequency of an in-phase mode wherein antinodes and nodes are formed in a concentric form. The piezoelectric vibrator 2 and the film-shaped body 3 form a sound producing body.

Description

technical field [0001] The present invention relates to a piezoelectric speaker, a piezoelectric acoustic device using the same, and a sensor with an alarm, and particularly relates to improvement of the sound pressure of a piezoelectric speaker using a piezoelectric element. Background technique [0002] Conventionally, a piezoelectric speaker using a piezoelectric vibrator in which a piezoelectric element is bonded to a metal plate is known. Compared with dynamic speakers, the piezoelectric speaker has a thinner and simpler structure, so it can be reduced in size and is also inexpensive. However, such a piezoelectric speaker has a problem that the sound pressure is high near the resonance frequency, but the sound pressure is low at other frequencies, especially low frequency regions. In this specification, the low frequency region (hereinafter referred to as low region) refers to below about 1kHz, the high frequency region (hereinafter referred to as high region) refers t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04R17/00H04R1/28H04R1/34
CPCH04R17/00H04R2307/207H04R7/20H04R2231/003H04R1/345H04R17/10H04R7/04
Inventor 福岛实北田耕作赤坂修西川哲广
Owner PANASONIC CORP