TWI818600B - Piezoelectric units for piezoelectric speakers - Google Patents

Abstract

A piezoelectric unit suitable for a piezoelectric speaker and includes: a substrate having a first rectangular block, a second rectangular block, and an intermediate area connected between the first and second rectangular blocks block; a first electrode disposed on a portion of a first surface of the first rectangular block; a second electrode disposed on a portion of a first surface of the second rectangular block, the The first and second electrodes form a positive electrode; a third electrode is disposed on a part of the second surface of the first rectangular block, and the first and second surfaces of the first rectangular block are opposite to each other. Corresponding; and a fourth electrode disposed on a part of a second surface of the second rectangular block, the third and fourth electrodes form a negative electrode, the first first electrodes of the second rectangular block Corresponds to the second surface.

Description

Piezoelectric units for piezoelectric speakers

The present invention relates to a unit, in particular to a piezoelectric unit for a piezoelectric speaker.

The sound pressure curve in the measured frequency response diagram of the sound emitted by the existing piezoelectric speaker is not flat in the low frequency range, that is, the low frequency characteristics of the piezoelectric speaker are poor, causing the piezoelectric speaker to have audio distortion problems, resulting in It is difficult for users to adjust the frequency response of the piezoelectric speaker during use. Therefore, how to improve the low-frequency sound quality of the piezoelectric speaker is a problem that relevant industries need to solve.

Therefore, an object of the present invention is to provide a piezoelectric unit for a piezoelectric speaker that can overcome the shortcomings of the prior art.

Therefore, the piezoelectric unit of the present invention is suitable for a piezoelectric speaker and includes a substrate and first to fourth electrodes.

The substrate has a first rectangular block, a second rectangular block, and a middle block connected between the first and second rectangular blocks.

The first electrode is disposed on a portion of a first surface of the first rectangular section.

The second electrode is disposed on a portion of a first surface of the second rectangular section, and the first and second electrodes form a positive electrode.

The third electrode is disposed on a portion of a second surface of the first rectangular block, and the first and second surfaces of the first rectangular block correspond to each other.

The fourth electrode is disposed on a part of a second surface of the second rectangular block. The third and fourth electrodes form a negative electrode. The first and second surfaces of the second rectangular block corresponding.

The effect of the present invention is to use the first to fourth electrodes of the present invention to effectively suppress the amplitude of non-main modes generated by the corresponding piezoelectric speaker. In this way, the piezoelectric unit using the piezoelectric unit of the present invention is effectively suppressed. The sound pressure curve measured by the speaker is flatter than the sound pressure curve of the existing piezoelectric speaker, and thus has more stable low-frequency characteristics.

Referring to FIGS. 1 to 3 , one embodiment of the piezoelectric unit of the present invention is suitable for a piezoelectric speaker (not shown). The piezoelectric unit is connected to a diaphragm of the piezoelectric speaker through a small-area pad (not shown). Since the technology of connecting the piezoelectric unit to the diaphragm is well known to those with ordinary knowledge and is not a feature of the present invention, its details are omitted and will not be described again. When the piezoelectric unit receives a voltage, a piezoelectric effect will be generated, so that the piezoelectric unit will vibrate, causing the diaphragm to bend and deform, thereby generating vibration to push the air to vibrate to generate sound waves, so that the diaphragm will vibrate. Piezoelectric speakers produce sound. The piezoelectric unit of the present invention includes a substrate 1 and first to fourth electrodes 2, 3, 4, 5.

The substrate 1 is composed of a first rectangular block 11, a second rectangular block 12, and an intermediate block 13 connected between the first and second rectangular blocks 11 and 12. In this embodiment, the spacer block (not shown) is disposed at the midpoint of each surface of a front surface and a back surface of the middle block 13 . The substrate 1 is a stainless steel substrate. Each of the first and second rectangular blocks 11 and 12 has a first surface (ie, front surface) and a second surface (ie, back surface) corresponding to the first surface.

The first surface of the first rectangular block 11 has first to fourth vertices 111 to 114. The second surface of the first rectangular block 11 has first to fourth vertices 111' to 114'. The first surface of the second rectangular block 12 has first to fourth vertices 121 to 124. The second surface of the second rectangular block 12 has first to fourth vertices 121' to 124'. In the first surface of the first rectangular block 11, the first vertex 111 is adjacent to the second and fourth vertices 112, 114, and the second vertex 112 is adjacent to the first and third vertices 111, 113 , the third vertex 113 is adjacent to the second and fourth vertices 112 and 114. The order of the vertex positions of the second surface of the first rectangular block 11 and the first and second surfaces of the second rectangular block 12 is the same as that of the first surface of the first rectangular block 11, so No more details. A first side of the middle block 13 connects the second and third vertices 112, 113, 112', 113' of the first and second surfaces of the first rectangular block 11. A second side of the middle block 13 connects the first and fourth vertices 121, 124, 121', 124' of the first and second surfaces of the second rectangular block 12. The first and second side surfaces of the middle block 13 correspond to each other.

The first electrode 2 is disposed on a part of the first surface of the first rectangular area 11 . The second electrode 3 is disposed on a portion of the first surface of the second rectangular region 12 . The first and second electrodes 2 and 3 form a positive electrode. The third electrode 4 is disposed on a part of the second surface of the first rectangular block 11 , and the fourth electrode 5 is disposed on a part of the second surface of the second rectangular block 12 . The third and fourth electrodes 4 and 5 form a negative electrode. In this embodiment, each of the first to fourth electrodes 2 to 5 has a trigonal structure. The first electrode 2 has first to third vertices 21 to 23. The second electrode 3 has first to third vertices 31 to 33. The third electrode 4 has first to third vertices 41 to 43. The fourth electrode 5 has first to third vertices 51 to 53. In the first rectangular block 11, a midpoint of a line connecting the second and third vertices 112 and 113 of the first surface serves as a first midpoint, and the third vertices 112 and 113 of the second surface A midpoint of a line connecting the second and third vertices 112' and 113' serves as a second midpoint. In the second rectangular block 12, a midpoint of a line connecting the first and fourth vertices 121, 124 of the first surface serves as a third midpoint, and the third midpoint of the second surface A midpoint of a line connecting the first and fourth vertices 121' and 124' serves as a fourth midpoint.

The first vertices 21 and 41 of the first and third electrodes 2 and 4 are respectively located at the first vertices 111 and 111' of the first and second surfaces of the first rectangular block 11. The second vertices 22 and 42 of the first and third electrodes 2 and 4 are respectively located at the first and second midpoints of the first rectangular block 11 . The third vertices 23 and 43 of the first and third electrodes 2 and 4 are respectively located at the fourth vertices 114 and 114' of the first and second surfaces of the first rectangular block 11. In this embodiment, in each of the first and third electrodes 2, 4, between the first and second vertices 21, 22 (41, 42) and between the second and third vertices Each edge between 22 and 23 (42, 43) is an arc-shaped edge, and the edge between the first and third vertices 21 and 23 (41, 43) is a straight edge.

The first vertices 31 and 51 of the second and fourth electrodes 3 and 5 are respectively located at the second vertices 122 and 122' of the first and second surfaces of the second rectangular block 12. The second vertices 32 and 52 of the second and fourth electrodes 3 and 5 are respectively located at the third vertices 123 and 123' of the first and second surfaces of the second rectangular block 12. The third vertices 33 and 53 of the second and fourth electrodes 3 and 5 are respectively located at the third and fourth midpoints of the second rectangular block 12 . In this embodiment, in each of the second and fourth electrodes 3, 5, between the first and third vertices 31, 33 (51, 53) and between the second and third vertices The edges between 32 and 33 (52, 53) are each arc-shaped edges, and the edges between the first and second vertices 31 and 32 (51, 52) are straight edges.

Referring to Figures 4 and 5, there is shown a piezoelectric unit according to another embodiment of the present invention, which is similar to this embodiment. The difference between the two is that the first to fourth electrodes 6, 7, 8, and 9 are used instead of the first to fourth electrodes 6, 7, 8, and 9 respectively. The first to fourth electrodes 2~5 (see Figure 3). In this another embodiment, each of the first to fourth electrodes 6 to 9 has a quadrilateral structure. The first electrode 6 has first to fourth vertices 61 to 64. The second electrode 7 has first to fourth vertices 71 to 74. The third electrode 8 has first to fourth vertices 81 to 84. The fourth electrode 9 has first to fourth vertices 91 to 94.

In this another embodiment, the first vertices 61 and 71 of the first and third electrodes 6 and 8 are respectively located on the first and second surfaces of the first rectangular block 11 . A vertex 111, 111'. The second and third vertices 62 and 63 of the first electrode 6 are respectively spaced from the second and third vertices 112 and 113 of the first surface of the first rectangular block 11 by the same distance. The second and third vertices 82 and 83 of the third electrode 8 are respectively spaced from the second and third vertices 112' and 113' of the second surface of the first rectangular block 11 by the same distance. The fourth vertices 64 and 74 of the first and third electrodes 6 and 8 are respectively located at the fourth vertices 114 and 114' of the first and second surfaces of the first rectangular block 11. The distance between the second and third vertices 62 and 63 of the first electrode 6 is greater than the same distance. The distance between the second and third vertices 82 and 83 of the third electrode 8 is greater than the same distance.

In another embodiment, the first and fourth vertices 71 and 74 of the second electrode 7 are respectively connected with the first and fourth vertices 121 and 121 of the first surface of the second rectangular block 12 . 124 spaced by that same distance. The first and fourth vertices 91 and 94 of the fourth electrode 9 are respectively spaced from the first and fourth vertices 121' and 124' of the second surface of the second rectangular block 12 by the same distance. The second vertices 72 and 92 of the second and fourth electrodes 7 and 9 are respectively located at the second vertices 122 and 122' of the first and second surfaces of the second rectangular block 12. The third vertices 73 and 93 of the second and fourth electrodes 7 and 9 are respectively located at the third vertices 123 and 123' of the first and second surfaces of the second rectangular block 12. The distance between the first and fourth vertices 71 and 74 of the second electrode 7 is greater than the same distance. The distance between the first and fourth vertices 91 and 94 of the fourth electrode 9 is greater than the same distance.

In this another embodiment, in each of the first to fourth electrodes 6~9, the first and second vertices 61, 62 (71, 72), (81, 82), ( 91, 92) and the edges between the third and fourth vertices 63, 64 (73, 74), (83, 84), (93, 94) are each an arc-shaped edge. Between the first and fourth vertices 61, 64 (71, 74), (81, 84), (91, 94) and between the second and third vertices 62, 63 (72, 73), (82, The sides between 83) and (92, 93) are each straight line sides.

Referring to FIG. 6 , the change of the sound pressure level (Sound pressure level) of the piezoelectric speaker using the piezoelectric unit of this embodiment and the other embodiment and the existing piezoelectric speaker in a free sound field versus a frequency is shown. A simulation diagram of. In FIG. 6 , symbol P1 represents the sound pressure simulation curve of the existing piezoelectric speaker, symbol P2 represents the sound pressure simulation curve of the piezoelectric speaker using the piezoelectric unit of this embodiment, and symbol P3 represents the sound pressure simulation curve of the piezoelectric speaker using the piezoelectric unit of this embodiment. The sound pressure simulation curve of the piezoelectric speaker of this piezoelectric unit. The distance between the sound pressure measurement point and the diaphragm of each piezoelectric speaker is 10 centimeters. The positive electrode and the negative electrode of each piezoelectric speaker cooperate to receive an AC signal with a driving voltage of 15V. It can be seen from Figure 6 that the sound pressure simulation curves P2 and P3 measured using the piezoelectric speaker of the present invention are flatter than the sound pressure simulation curve P1 of the existing piezoelectric speaker, and the sound pressure in the frequency range of 600Hz to 2000Hz is The voltage level is maintained at about 55dB. In this way, the piezoelectric speaker using the piezoelectric unit of the present invention does have stable sound pressure at low frequencies compared with the existing piezoelectric speakers. That is, the piezoelectric speaker using the piezoelectric unit of the present invention has better low frequency. characteristic.

Refer to FIG. 7 , which is a simulation diagram of the change of sound pressure level versus frequency in a closed sound field of a piezoelectric speaker using the piezoelectric unit of this embodiment and another embodiment and an existing piezoelectric speaker. The relevant measurement settings and definitions of symbols P1~P3 in Figure 7 are the same as those in Figure 6, so they will not be described again. It can be seen from Figure 7 that during the low frequency period, such as the frequency of 600Hz to 2000Hz, the sound pressure simulation curves P2 and P3 measured for the piezoelectric speaker using the piezoelectric unit of the present invention are compared with the sound pressure simulation of the existing piezoelectric speaker. Curve P1 is relatively flat and does have better low-frequency characteristics.

To sum up, the first to fourth electrodes 2 to 5 and the first to fourth electrodes 6 to 9 of the present invention can effectively suppress the vibration of the corresponding piezoelectric speaker in non-main modes ( The main mode is a first mode, the first mode is that the middle block 13 has a higher vibration, and the first and second rectangular blocks 11, 12 have a lower vibration) , as a result, the sound pressure curve measured for the piezoelectric speaker using the piezoelectric unit of the present invention is flatter than the sound pressure curve of the existing piezoelectric speaker, and thus has more stable low-frequency characteristics, which can improve the existing piezoelectric speaker. Piezoelectric speakers have the problem of audio distortion, and it is easier to adjust the frequency response of the piezoelectric speakers in use.

However, the above are only examples of the present invention and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made based on the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. within the scope covered by the patent of this invention.

1:Substrate 11: First rectangular block 111~114: first to fourth vertices 111’~114’: first to fourth vertices 12: The second rectangular block 121~124: first to fourth vertices 121’~124’: first to fourth vertices 13:Middle block 2, 3, 4, 5: first to fourth electrodes 21~23: first to third vertices 31~33: first to third vertices 41~43: first to third vertex 51~53: first to third vertex 6, 7, 8, 9: first to fourth electrodes 61~64: first to fourth vertices 71~74: first to fourth vertices 81~84: first to fourth vertices 91~94: first to fourth vertices P1~P3: Sound pressure simulation curve

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a front view of an embodiment of the piezoelectric unit of the present invention; Figure 2 is a rear view of this embodiment; Figure 3 is a side view of this embodiment; Figure 4 is a front view of another embodiment of the piezoelectric unit of the present invention; Figure 5 is a rear view of the other embodiment; Figure 6 is a simulation diagram illustrating the change of sound pressure level versus frequency in a free sound field of a piezoelectric speaker using the piezoelectric unit of this embodiment and another embodiment and an existing piezoelectric speaker; and 7 is a simulation diagram illustrating the change of sound pressure level versus frequency in a closed sound field of a piezoelectric speaker using the piezoelectric unit of this embodiment and another embodiment and a conventional piezoelectric speaker.

1:Substrate

11: First rectangular block

111~114: first to fourth vertices

12: The second rectangular block

121~124: first to fourth vertices

13:Middle block

2, 3: First and second electrodes

21~23: first to third vertices

31~33: first to third vertices

Claims (9)

A piezoelectric unit suitable for a piezoelectric loudspeaker, comprising: A substrate having a first rectangular block, a second rectangular block, and an intermediate block connected between the first and second rectangular blocks; a first electrode disposed on a portion of a first surface of the first rectangular block; a second electrode disposed on a portion of a first surface of the second rectangular section, the first and second electrodes forming a positive electrode; a third electrode disposed on a portion of a second surface of the first rectangular block, the first and second surfaces of the first rectangular block corresponding to each other; and A fourth electrode is provided on a part of the second surface of the second rectangular block. The third and fourth electrodes form a negative electrode. The first and second electrodes of the second rectangular block corresponding to the surface. The piezoelectric unit as claimed in claim 1, wherein, The first and second surfaces of the first and second rectangular blocks each have first to fourth vertices, the first vertex is adjacent to the second and fourth vertices, and the second vertex is adjacent to the third vertices. a and a third vertex, the third vertex being adjacent to the second and fourth vertices, A first side of the middle block connects the second and third vertices of the first and second surfaces of the first rectangular block, and a second side of the middle block connects the second rectangular area the first and fourth vertices of the first and second surfaces of the block correspond to the first and second sides of the intermediate block, and Each of the first to fourth electrodes has a trigonal structure. The piezoelectric unit as claimed in claim 2, wherein, Each of the first to fourth electrodes has first to third vertices, In the first rectangular block, a midpoint of a line connecting the second and third vertices of the first surface serves as a first midpoint, and the second and third vertices of the second surface A midpoint of a line connecting the vertices serves as a second midpoint. In the second rectangular block, a midpoint of a line connecting the first and fourth vertices of the first surface serves as a second midpoint. The third midpoint is a midpoint of a line connecting the first and fourth vertices of the second surface as a fourth midpoint, The first vertices of the first and third electrodes are respectively located at the first vertices of the first and second surfaces of the first rectangular block, and the third vertices of the first and third electrodes The two vertices are respectively located at the first and second midpoints of the first rectangular block, and the third vertices of the first and third electrodes are respectively located at the first and second midpoints of the first rectangular block. the fourth vertices of the two surfaces, and The first vertices of the second and fourth electrodes are respectively located at the second vertices of the first and second surfaces of the second rectangular region, and the third vertices of the second and fourth electrodes The two vertices are respectively located at the third vertices of the first and second surfaces of the second rectangular block, and the third vertices of the second and fourth electrodes are respectively located at the second rectangular block. Wait for the midpoint between the third and fourth points. The piezoelectric unit as claimed in claim 3, wherein, In each of the first and third electrodes, the edges between the first and second vertices and between the second and third vertices are each an arc-shaped edge, and the first and third The edge between vertices is a straight line edge, and In each of the second and fourth electrodes, the edges between the first and third vertices and between the second and third vertices are each arc-shaped edges, and the first and second The edge between vertices is the straight edge. The piezoelectric unit as claimed in claim 1, wherein, The first and second surfaces of the first and second rectangular blocks each have first to fourth vertices, the first vertex is adjacent to the second and fourth vertices, and the second vertex is adjacent to the third vertices. a and a third vertex, the third vertex being adjacent to the second and fourth vertices, A first side of the middle block connects the second and third vertices of the first and second surfaces of the first rectangular block, and a second side of the middle block connects the second rectangular area the first and fourth vertices of the first and second surfaces of the block correspond to the first and second sides of the intermediate block, and Each of the first to fourth electrodes has a quadrilateral structure. The piezoelectric unit of claim 5, wherein each of the first to fourth electrodes has first to fourth vertices, The first vertices of the first and third electrodes are respectively located at the first vertices of the first and second surfaces of the first rectangular region, and the second and third vertices of the first electrode The vertices are respectively spaced from the second and third vertices of the first surface of the first rectangular block by an equal distance, and the second and third vertices of the third electrode are respectively separated from the second and third vertices of the first rectangular block. The second and third vertices of the second surface are spaced apart by the same distance, and the fourth vertices of the first and third electrodes are respectively located on the first and second surfaces of the first rectangular region. the fourth vertices, and The first and fourth vertices of the second electrode are respectively spaced from the first and fourth vertices of the first surface of the second rectangular block by the same distance. The first and fourth vertices of the fourth electrode The fourth vertices are respectively spaced from the first and fourth vertices of the second surface of the second rectangular block by the same distance, and the second vertices of the second and fourth electrodes are respectively located in the second rectangle. The second vertices of the first and second surfaces of the block, and the third vertices of the second and fourth electrodes are respectively located at the first and second surfaces of the second rectangular block. The third vertex. The piezoelectric unit of claim 6, wherein the distance between the second and third vertices of the first and third electrodes is greater than the same distance, and the distance between the second and third vertices of each of the second and fourth electrodes is The distance between the first and fourth vertices is greater than the same distance. The piezoelectric unit of claim 6, wherein in each of the first to fourth electrodes, the edges between the first and second vertices and between the third and fourth vertices are respectively is an arc-shaped edge, and the edges between the first and fourth vertices and between the second and third vertices are each a straight edge. The piezoelectric unit according to claim 1, wherein the substrate is a stainless steel substrate.

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