JPS58182999A - Piezoelectric speaker - Google Patents

Abstract

PURPOSE:To attain small sized and light weight piezoelectric speaker without decreasing the area of the diaphragm, by containing a square diaphragm having folded section in a square frame and connecting a piezoelectric element to the folded section of the diaphragm. CONSTITUTION:A shallow groove is formed at the center of the square frame 10 having an extended bottom 11 and an extended rising piece 12 made of a plastic material, and a soft and flexible substance 20 having a circular or a semi-circular notch 21 is bonded to the groove. Plural piezoelectric element 30 are arranged on the substance 20, and the folded sectioin 41 of the square diaphragm 40 is bonded to a projection 31 of the elements 30 arranged on a line. Both opposing sides of the square diaphragm 40 are linked to the piece 12 of the square frame 10. Then, the piezoelectric speaker is made small in size and light in weight without reducing the area of the diaphragm 40.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric speaker 4 incorporating a piezoelectric element vqA that undergoes flexural vibration.

As shown in Fig. 1, the conventional soil 4C type speaker has a circular bottom part 6 of a frame (1) having a flexible material +2
A piezoelectric element (3) is placed through the piezoelectric element (
Center 6 of 3): The top st- of a conical diaphragm (4) is connected, and the 14 circumferences of this diaphragm (4) are connected to the opening side of the frame il+.

Such piezoelectric speakers have a simpler structure than electrodynamic speakers that use magnetic apposition, and have advantages such as no magnetic influence, but due to the miniaturization of audio equipment in recent years. Due to the demand, it is desired to produce a piezoelectric speaker that is smaller, lighter, and has an easier t*.

The present invention has been made in view of this problem, and provides a piezoelectric speaker that is small in size and has a large diaphragm area. be.

Figures ta+ and (b) show a perspective view and a view from I11 of one embodiment 11 of the pressure 4 type speaker of the present invention, and the same figure (0)
In these figures, which show perspective views of l'knee pressure' soldering elements, 0I is (to) the bottom al of the square frame fl (l'
l Center C: A flexible material in the form of a plate that is adhesively arranged, and has a large number of circular or semicircular cutouts Qυ... formed therein. cn is a disc-shaped pressure-enhancing element placed on the flexible material Ql, and a protrusion C is placed in the center of the upper part.
(11 is formed. (II is a rectangular diaphragm that is bent and formed along the center line, and the center m+ of the bent part I is the protrusion c11 of the upper pressure element (7). ) upper part 62 is joined by adhesive, and both opposing sides of the diaphragm 4tG parallel to the bent part (40) are connected to the compatible upper piece (
13!13 g”: adhesive ζ; thus connected.

6G is an external connection terminal fixed to the bottom 1υ of the square frame G (1), and this terminal 1 and the upper piezoelectric element are connected by a lead wire (51) In.

In the pressure/value type speaker with a rejection configuration, if an acoustic signal is input to the terminal ■, this signal is applied to the piezoelectric element cp+=, and iI
The f'a element CI is a concentric nodal circle! It forms and bends and vibrates. Therefore, this vibration force is transmitted from the central protrusion C(11) to the bent portion of the diaphragm +I(l), thereby driving the entire diaphragm +Il.

Figure 5 (: Speaker according to the above-mentioned embodiment of the present invention (diaphragm: 5c
mX7clI) is shown by the solid line, #I1
Figure 1 shows that of Zuso's conventional speaker (diaphragm: φ51)!
As is clear from the figure, indicated by the broken line, the speaker of the present invention has a slightly lower back pressure on the low-frequency side compared to the conventional product 4-, but has a more reflat H4a number characteristic in the high-frequency range (-). There is.

In the second embodiment of the present invention described above, a single piezomagnetic element was used as the drive source, but the flexible material (7)
A plurality of elements ...... are arranged in - rows (two devices) on top, and projections s ((υ...
If the configuration is such that the top (: diaphragm (bent part of @ + 41) t pressure (element c1 was used; longitudinal direction 1: if a rectangular piezoelectric element that bends and vibrates is used, its center (: there is no need to provide a protrusion); The parts ζ can be directly combined.

For reference, the following will be explained with reference to Figures 44 and 5. Frame material (II' is longitudinal direction C; Longitudinal direction C: Parallel pairs of tuned sides C: are respectively extended rising pieces ++
jt+4 is formed. The frame member O6 is made of, for example, an insulating plastic material, and a large number of terminals (1) are arranged and fixed in advance to the extension 1 (a) of the frame member (O6). The flexible material j has a strip shape extending in the longitudinal direction, and has many circular or semicircular cutouts Qυ.
... is formed and the above frame material G (1' extension bottom #G
Shallow groove 1 formed in the center of ll'; fitted with adhesive. As this flexible material, for example, foamed bream foam is used.

Then, the adhesive on the lower surface of the double-sided tape (60) (therefore, the plurality of connected piezoelectric elements C(1)...) are adhered onto the flexible material using an adhesive. Ru.

Note that this equal-pressure can element C(1)... is a thin metal plate 6 and two piezoelectric material plates bonded together. A protrusion (wings are formed), but a separate protrusion member may be adhesively bonded to the center of the piezoelectric element C1. Cut IfIv shape 4: It is bent and formed, and this central extended bent part (46) is a plurality of the above-mentioned pressure '@ elements (pigeon... each protrusion (31)...upper part; both life tape ( 60), and both opposing sides thereof are connected using an adhesive. For example, Nomex (trade name) manufactured by DuPont is used.

Thus, 1g5 Figure 4: As shown, integral C: assembled frame material qi, flexible material i and a plurality of piezoelectric elements C (1
)... and the diaphragm material 11d.
By cutting in a direction perpendicular to the longitudinal direction as shown by the broken line u't', a plurality of pressure 4-type speakers as shown in FIG. Selecting the cut of the continuum appropriately (: therefore,
A piezoelectric type Subi 1I (8) equipped with a desired number of piezoelectric elements can be obtained.

As is clear from the above description, the piezoelectric speaker of the present invention has a rectangular frame C; a rectangular diaphragm having a bent portion is housed therein, and a piezoelectric element is coupled to the bent portion of the diaphragm. Therefore, compared to a conventional circular piezoelectric speaker, the size and weight can be reduced without reducing the diaphragm area χ. Furthermore, compared to the conventional speaker 62, it can have a simpler structure and can be continuously molded, so manufacturing costs can be significantly reduced.

[Brief explanation of drawings]

Figure Is1 is a cross-sectional view of a conventional piezoelectric speaker, Figure 112 (
1), (1)), and (0) are a perspective view of a piezoelectric speaker of the present invention, a side view thereof, and a perspective view of a piezoelectric can element. Figure 5 shows the pressure '4 of the present invention.
An exploded perspective view of the tM speaker and a perspective view of the speaker continuum! It shows. ill...Square frame, ■--Flexible material, (to)...Piezoelectric 2' Heiko, +41...Square diaphragm. Figure 214 Figure 3 Figure 5

Claims (1)

[Claims] 1) A square frame, a flexible material bonded to the frame, and an appropriate number of plate-shaped piezoelectric elements placed on the flexible material, and driven by the piezoelectric elements. The diaphragm is formed by bending, and the bent portions are connected to an appropriate number of the piezoelectric elements C; and the opposite sides thereof are connected to the opposite sides of the frame, respectively. A pressure 1i type speaker characterized by being connected to.