JPS62120200A - Sounding element - Google Patents

Abstract

PURPOSE:To vibrate a thin piece, generate a sound wave and widen an using range of an element by providing a sounding part forming a capacitor by the vibrating thin piece and an element base stand having the thin piece on the element and changing a charge stored in the capacitor according to an input signal. CONSTITUTION:The sounding part 20 forming the capacitor by the vibrating thin piece 12 and the element base stand having the thin piece 12 is provided on the element. Then, an electrode 15 of a supporting substrate 2 side, namely the thin piece 12 and an electrode 16 of a floating plate 7 side have a capacitor structure and the charge stored in the electrodes 15, 16 is changed with a time according to an audio signal. A Coulomb force operating on the electrodes 15, 16 according to the quantity of the charge is changed and as a result, the electrodes 15, 16 namely, the thin pieces vibrate correspondingly to the audio signal. The vibration vibrates air and generates the sound wave.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a sounding element using an electromechanical transducer having fine oscillating flakes. [Prior Art] Speakers have conventionally been used as sound generating devices, and electrodynamic speakers, electrostatic speakers, and the like have been used. FIG. 5 is a schematic diagram showing an example of an electrostatic speaker,
(,) is a perspective view, and (b) is an A-A'l analysis drawing thereof. In the figure, 100 is a fixed electrode made of a curved perforated metal plate, 101 is a vibrating membrane made of thin polyester with aluminum vapor-deposited, and 102 is a spring for tensioning the vibrating membrane 101 without loosening. The vibrating membrane 101 and the fixed electrode 100 constitute a capacitor with an air gap of approximately 0.3 mm, so when an audio signal is applied to both ends, the vibrating membrane 10
1 vibrates according to the applied voltage and emits sound. Such an electrostatic speaker has a simple structure because the vibrating membrane 101 is made of a single piece of polymer film, etc., and is used in high-temperature speakers and microphones that operate with small amplitude. [Problems to be Solved by the Invention] However, due to the structure of the above-mentioned speaker, there is a limit to miniaturization, and if an attempt is made to forcibly miniaturize the speaker, there is a problem in that the sound production characteristics deteriorate. [Means for Solving the Problems] An object of the present invention is to provide a sounding element that can be extremely miniaturized. The sweating element of the present invention has at least one sounding section on the element that constitutes a capacitor with a thin piece and an element base having the thin piece, and changes the electric charge stored in the capacitor according to an input signal. Accordingly, the thin piece is vibrated to generate sound. [Example] Hereinafter, the sound generating element according to the present invention will be specifically explained based on the drawings. FIG. 1(,) shows an enlarged sectional view of a sounding element according to the present invention, and numeral 1 indicates a surface layer that vibrates and emits sound. A substrate 2 supporting the surface layer 1 is made of Au or the like. 3 and 4 are surface layers 1. In the support member of the support substrate 2, reference numeral 3 is a contact part for receiving a hinge part which performs an electromechanical operation in particular, and reference number 4 is an insulating material of polyoxide Sl. 5 is a polysilicon gate, 6 is an air gap and 0
．． The cavity is about 6 μm to several 100 μm. Further, 7 is a floating field plate, 8 is an N70-ting source, 9 is a gate oxide, and 10 is a supporting substrate such as silicon. Figure 1(b) is the front view from direction A of 1st 1(a) [2
], 11 is the air gap, Niko 1.1;, Kiki (vibrating thin piece that vibrates when the contract is completed, 1.3Pi hinge 11 parts are fully shown.) 4 is the vibrating thin piece on the surface of the sound generating element. Indicates the surface other than 12. 4: The sound generating element in the double-page spread is an IC or LS1.

[7
Can be manufactured using process similar to/C process. FIG. 1(C) &D: This is an electrical equivalent diagram of the Kinoi IF element. This electrical equivalent diagram and Figure 1(a),
The principle of the present sound generating element/harper 11 will be explained with reference to (b). In FIG. 1(C), 15 is an electrode on the support substrate 2 side;
6 is an electrode on the floating plate 7 side, 17 is an electrode on both sides.
18 is a bias power supply, 19 is an audio signal applied to
is resistance.゛Pole 15 and electrode 1i16 form a capacitor structure, and depending on the audio signal, both poles 1 and 16 form a capacitor structure.
5.16 The charge stored in the cell changes with time. The Coulomb force acting on both poles 15 and 16 changes according to the amount of charge, and as a result, the electrode 15 (that is, the vibrating thin piece 12 in FIG. 1(b)) vibrates in accordance with the audio signal.
The vibrations vibrate the air and generate sound waves. At this time, the sound wave generation efficiency (intensity) and the sound wave characteristics are greatly influenced by the material and shape of the vibrating thin piece 12, and are particularly influenced by the material and shape of the surface layer 1 which is in direct contact with the air. FIGS. 2(a) and 2(b) each show a vibration layer 21 on the surface layer 1 having a shape that facilitates generation of a predetermined sound wave.
This figure shows an example of a configuration in which (a) is a cross-sectional view, and (b) is a cross-sectional view.
) is a front view from direction A. In the same figure, (a)-
(I) and (b)-(1) are examples in which a mushroom-shaped vibrating layer 21 parallel to the vibrating thin piece 12 is provided, and (a)-(
II) and (b)-Ql) show an example in which a vibrating layer 21 having an upright shape is provided on a thin piece 12. The vibration layer 21 responds to the vibration of the thin piece 12, (,) −(1)
, the vibration (t
(or resonance), so the efficiency of sound generation is improved. The vibration layer 21 may be formed of the same material as the surface layer 1, but
Due to the structure of the capacitor, it is preferable to use another insulating material. Further, the shape of the vibration layer 21 is limited to that shown in FIG. 2, and it goes without saying that various shapes are possible. FIG. 3 is an enlarged view of a part of a sounding element in which a large number of sounding sections 20 are provided on a 5-square chip 30. As described above, the sound generating element of the present invention can be integrated, and can be used for applications that could not be used conventionally due to the size. Further, in order to improve the sound generation characteristics of the chip 30 as a whole, it is also possible to provide sound generation sections 20 having different sound generation characteristics on the chip 30. As a method, the vibrating layer 2 shown in FIG.
] In addition to the method of providing . FIGS. 4(a) and 4(b) are diagrams showing a method of changing the amplitude width (in other words, the deflection angle θ of the flake). Generally, the deflection angle θ shown in FIG. 4 (,) is determined by the following relational expression. θ= K (1/b) (V/h)2t”/13・
...... (1) Here, b is the width of the bow, t is the width of the vibrating thin piece 12, t is the thickness of the vibrating thin piece 12, h is the height of the air gap, and ■ is the vibrating thin piece 12. is the value of the applied voltage applied to . From the above equation (1), it can be seen that the deflection angle θ changes depending on the configuration conditions of the vibrating thin plate 12 (z, t, h) and the voltage υ1]. The applied voltage V varies according to the audio voltage unless an external control circuit such as an amplifier circuit is incorporated, but even if the voltage is the same, the sound generating section with different configuration conditions such as z, t, h, etc. If a number of sound generating elements are provided, the possibilities of using the present sound generating element will increase, since there will be many types of sound generating sections with different sound generating characteristics. Specifically, it becomes possible to widen the sound range and reduce distortion. [Effects of the Invention] As described above, according to the present invention, there is an effect that extremely small and widely applicable sound generating elements can be provided in large quantities and at low cost through an IC or LSI process.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the sound generating element according to the present invention, in which (a) is an enlarged sectional view, (b) is an enlarged front view, and (C) is an enlarged front view.
is an electrical equivalent diagram. FIG. 2 is a diagram showing another embodiment of the present sound generating element in which a vibration layer is formed. FIG. 3 is a schematic diagram of the integrated sound generating element. FIG. 4 is a diagram showing the configuration conditions of a sounding element that changes the amplitude of the vibrating thin plate. FIG. 5 is a schematic diagram showing an example of a conventional electrostatic speaker. 1: Surface layer, 12: Vibrating thin piece, 20: Sounding part.

Claims (2)

[Claims] (1) The element has at least one sounding section that constitutes a capacitor with a thin piece and an element base having the thin piece, and the thin piece is A sounding element characterized by vibration. (2) The sound generating element according to claim 1, characterized in that a vibration layer is formed on the thin piece.