New piezoelectric speaker

Abstract

The embodiment of the present invention discloses a novel piezoelectric speaker, which is applied in the field of electroacoustic technology. The novel piezoelectric speaker comprises a first piezoelectric sheet, a second piezoelectric sheet, a bass diaphragm and a sound cavity. The first piezoelectric sheet and the second piezoelectric sheet are respectively pasted on two sides of the bass diaphragm to form a piezoelectric sheet bass diaphragm structure, and the first piezoelectric sheet and the second piezoelectric sheet are connected in parallel. The piezoelectric sheet bass diaphragm structure is pasted and installed at the opening of the sound cavity, which can make the bass function of the piezoelectric speaker more obvious and increase the volume of its sound.

Description

Technical Field

[0001] The invention belongs to the field of electronic technology, and in particular relates to a novel piezoelectric speaker. Background Art

[0002] Speakers are widely used in various audio and communication equipment. Piezoelectric speakers (hereinafter referred to as piezoelectric speakers) have the advantages of low energy consumption and light weight, but piezoelectric speakers have two fatal flaws: one is that they cannot be used for low-frequency playback and are limited to high-frequency applications; the other is that the sound pressure level is relatively low, that is, the sound is relatively small. Existing technologies have not made any breakthroughs in the bass sound problem of piezoelectric speakers for many years. Piezoelectric speakers are limited to the sound of certain high-frequency prompt sounds and warning sounds, which greatly limits the applicable scenarios. Summary of the invention

[0003] The invention provides a novel piezoelectric speaker, aiming to solve the problem that the piezoelectric speaker cannot produce bass and has low sound.

[0004] The embodiment of the present invention provides a novel piezoelectric speaker, comprising:

[0005] A first piezoelectric sheet, a second piezoelectric sheet, a bass diaphragm, and a sound cavity;

[0006] The first piezoelectric sheet and the second piezoelectric sheet are respectively adhered to two sides of the bass diaphragm to form a piezoelectric sheet bass diaphragm structure;

[0007] The first pressing plate and the second pressing plate are connected in parallel;

[0008] The piezoelectric bass diaphragm structure is glued and installed at the opening of the sound cavity.

[0009] Furthermore, the bass diaphragm is a circular diaphragm having a rubber edge with a hardness of 55 degrees, and the rubber edge has a plurality of protrusions to form a rubber wavy edge.

[0010] Furthermore, the bass diaphragm is made of paper fiber mixed with wool fiber.

[0011] Further, it also includes: a sound vibration plate;

[0012] The sound vibration plate is adhered to the bass diaphragm.

[0013] Furthermore, the sound vibration plate is a honeycomb resonance plate, and the honeycomb resonance plate includes a plurality of honeycombs, and each of the honeycombs constitutes a bass resonance cavity.

[0014] Furthermore, a boost inductor is provided at the input end of the novel piezoelectric speaker, the output end of the boost inductor is connected to the first piezoelectric sheet and the second piezoelectric sheet connected in parallel, and the input end of the boost inductor is electrically connected to the output end of the amplifier of the novel piezoelectric speaker.

[0015] Furthermore, the boost inductor is an eight-fold voltage boost inductor.

[0016] Furthermore, the first piezoelectric sheet and the second piezoelectric sheet are both rectangular piezoelectric ceramic sheets.

[0017] It can be seen from the above embodiments of the present invention that the first piezoelectric sheet and the second piezoelectric sheet are respectively pasted on the two sides of the bass diaphragm, and the bass diaphragm can produce bass. Two piezoelectric sheets are pasted on the two sides of the bass diaphragm to form a push-pull piezoelectric drive, so that the bass diaphragm obtains twice the maximum amplitude value, and the mid- and low-frequency sound pressure output by the speaker is improved. The new piezoelectric speaker in this embodiment can produce bass, and the sound is loud enough, so that the piezoelectric speaker can be used as widely as the dynamic speaker, and the application range of the piezoelectric speaker is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0019] Figure 1 is a cross-sectional view of a novel piezoelectric speaker provided by an embodiment of the present invention;

[0020] Figure 2 is a top view of a novel piezoelectric speaker provided by an embodiment of the present invention;

[0021] Figure 3 This is a boost circuit diagram of a novel piezoelectric speaker provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0023] This embodiment provides a new type of piezoelectric speaker. Figure 1 and Figure 2 , Figure 1 A cross-sectional view of a novel piezoelectric speaker provided by an embodiment of the present invention; Figure 2 A top view of a novel piezoelectric speaker provided in an embodiment of the present invention.

[0024] The novel piezoelectric loudspeaker comprises: a first piezoelectric sheet 10, a second piezoelectric sheet 20, a bass diaphragm 30 and a sound cavity 40;

[0025] The first piezoelectric sheet 10 and the second piezoelectric sheet 20 are respectively adhered to two surfaces of the bass diaphragm 30 to form a piezoelectric sheet bass diaphragm structure.

[0026] The first pressing plate 10 and the second pressing plate 20 are connected in parallel;

[0027] Specifically, the first pressing plate 10 and the second pressing plate 20 are both rectangular piezoelectric ceramic plates, wherein two ends of the first pressing plate 10 are connected to two ends of the second pressing plate 20 through a first parallel lead 11 and a second parallel lead 12 , respectively.

[0028] The piezoelectric bass diaphragm structure is glued and installed at the opening of the sound cavity 40 .

[0029] Furthermore, a first lead 21 and a second lead 22 are respectively led out from two ends of the second piezoelectric sheet 20 ; the acoustic cavity has a first lead pin 41 and a second lead pin 42 , wherein the first lead pin 41 is connected to the first lead 21 , and the second lead pin 42 is connected to the second lead 22 .

[0030] In this embodiment, the first piezoelectric sheet and the second piezoelectric sheet are respectively pasted on the two sides of the bass diaphragm. The bass diaphragm can produce bass. Two piezoelectric sheets are pasted on the two sides of the bass diaphragm to form a push-pull piezoelectric drive. That is, when the electrical signal is added, the vibration force generated by the first piezoelectric sheet and the second piezoelectric sheet forms a push and a pull with the same force direction on the bass diaphragm, so that the bass diaphragm obtains twice the maximum amplitude value, thereby improving the sound pressure output by the speaker. The new piezoelectric speaker in this embodiment can produce bass, and the sound is loud enough, so that the piezoelectric speaker can be used as widely as the dynamic speaker, thereby improving the application scope of the piezoelectric speaker.

[0031] Furthermore, the bass diaphragm 30 is a circular diaphragm having a rubber edge with a hardness of 55 degrees, and the rubber edge has 1 to 3 protrusions to form a rubber wave edge. Figure 1 Two protrusions are shown, which are respectively close to the two ends of the bass diaphragm 30 , that is, the two protrusions are closer to the two ends of the bass diaphragm 30 relative to the center position of the bass diaphragm 30 .

[0032] Furthermore, the bass diaphragm 30 is made of a paper fiber mixed with wool fiber material. Such a shape and material combination has better low-frequency vibration characteristics and can produce lower-frequency sounds.

[0033] Furthermore, the novel piezoelectric speaker also includes a sound vibration plate 50, which is attached to the bass diaphragm 30. The sound vibration plate 50 is specifically a honeycomb resonance plate, which includes a plurality of honeycombs, each of which constitutes a bass resonance cavity. The plurality of bass resonance cavities in the honeycomb vibration plate can significantly improve the bass of the novel piezoelectric speaker, reducing the original minimum 400 Hz (hertz) to 250 Hz.

[0034] The honeycomb resonance plate is attached to the bass diaphragm 30. When the first piezoelectric sheet 10 and the second piezoelectric sheet 20 receive electrical signals and generate electrical vibrations, the bass diaphragm 30 vibrates and drives the honeycomb resonance plate to generate resonant vibrations and emit the same sound waves synchronously. After adding the honeycomb resonance plate, the volume can be increased by 3dB, and the effect of increasing the volume is obvious.

[0035] Furthermore, the driving voltage of the piezoelectric sheet is increased. The piezoelectric sheet is a voltage-driven element. The output of a common power amplifier circuit, especially a low-power amplifier circuit, is only about 1-3V, which cannot effectively drive the piezoelectric sheet to reach the maximum amplitude. Therefore, in this embodiment, by adding a boost inductor, the signal voltage applied to both ends of the piezoelectric sheet is increased by 7 volts, thereby driving the piezoelectric sheet to reach the maximum amplitude, so that the output sound of the new piezoelectric speaker can reach the maximum.

[0036] Specifically, see Figure 3 , Figure 3 This is a boost circuit diagram of the new piezoelectric speaker in this embodiment. A boost inductor 60 is set at the input end of the new piezoelectric speaker. The output end of the boost inductor 60 is connected to the first piezoelectric sheet 10 and the second piezoelectric sheet 20 connected in parallel. The input end of the boost inductor 60 is electrically connected to the output end of the amplifier (not shown in the figure) of the new piezoelectric speaker.

[0037] Specifically, the boost inductor 60 is an eight-fold voltage boost inductor.

[0038] The working principle of the above circuit is: the signal output by the amplifier is sent from the input end to the primary winding of the boost inductor 60, and the signal is increased by 7 times through the boost winding of the boost inductor 60, that is, the input weak signal is increased to more than 7V, and then applied to the first piezoelectric sheet and the second piezoelectric sheet connected in parallel, so that the voltage requirement of the maximum vibration amplitude can be achieved and a louder sound can be obtained.

[0039] The sound-generating principle of the above-mentioned speaker is as follows: the electrical signal of the sound passes through the above-mentioned boost circuit, and is output to the first piezoelectric sheet and the second piezoelectric sheet after the inductor sound pressure is boosted. The first piezoelectric sheet and the second piezoelectric sheet obtain the high-voltage electrical signal, generate electrical vibration, and the bass diaphragm vibrates. At the same time, the honeycomb resonance plate pasted together with the bass diaphragm generates resonant vibration and also synchronously emits sound waves of the same frequency.

[0040] The new piezoelectric speaker provided in this embodiment has extremely low power consumption. Compared with a dynamic speaker with the same sound power, its power consumption is only 1 / 20, which greatly reduces power consumption, saves electric energy, and makes the standby time of the whole machine long enough; it is extremely light: compared with a dynamic speaker with the same sound pressure level, its weight is only 1 / 4 of that of a dynamic speaker; it has a wide range of uses: it can be widely used in audio and various sound-generating devices, has low power consumption and light weight, and is particularly suitable for current portable sound-generating devices, which can greatly extend the battery life and service life. Since the piezoelectric speaker is not a power component, the power amplifier configured for this purpose does not need to be equipped with a heat sink. It reduces material consumption and reduces material costs.

[0041] The above is a description of the new piezoelectric speaker provided by the present invention. For those skilled in the art, according to the concept of the embodiments of the present invention, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A piezoelectric speaker, characterized in that: include: A first piezoelectric sheet, a second piezoelectric sheet, a bass diaphragm, and a sound cavity; The first piezoelectric sheet and the second piezoelectric sheet are respectively attached to two sides of the bass diaphragm to form a piezoelectric sheet bass diaphragm structure, wherein when an electrical signal is added, the vibration force generated by the first piezoelectric sheet and the second piezoelectric sheet forms a push and a pull in the same direction on the bass diaphragm; The first piezoelectric sheet and the second piezoelectric sheet are connected in parallel, and the second piezoelectric sheet is connected in parallel with the acoustic cavity; The piezoelectric bass diaphragm structure is glued and installed at the opening of the sound cavity; The bass diaphragm is made of paper fiber mixed with wool fiber; The piezoelectric speaker further comprises: a sound vibration plate; The sound vibration plate is connected to the first piezoelectric sheet, and the sound vibration plate is specifically a honeycomb resonance plate.

2. The piezoelectric speaker according to claim 1, wherein: The bass diaphragm is a circular diaphragm having a rubber edge with a hardness of 55 degrees. The rubber edge has two protrusions to form a rubber wave edge. The two protrusions are respectively close to the two ends of the bass diaphragm, and the first piezoelectric sheet and the second piezoelectric sheet are located between the two protrusions.

3. The piezoelectric speaker according to claim 2, wherein: The sound vibration plate is adhered to the bass diaphragm.

4. The piezoelectric speaker according to claim 3, characterized in that The honeycomb resonance panel includes a plurality of honeycombs, and each of the honeycombs constitutes a bass resonance chamber.

5. The piezoelectric speaker according to claim 4, characterized in that A boost inductor is arranged at the input end of the piezoelectric speaker, an output end of the boost inductor is connected to the first piezoelectric sheet and the second piezoelectric sheet connected in parallel, and an input end of the boost inductor is electrically connected to an output end of an amplifier of the piezoelectric speaker.

6. The piezoelectric speaker according to claim 5, characterized in that The boost inductor is an eight-fold voltage boost inductor.

7. The piezoelectric speaker according to claim 6, wherein: The first piezoelectric sheet and the second piezoelectric sheet are both rectangular piezoelectric ceramic sheets.

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