Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS5633883 BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a and 1b are side views showing the operation of a piezoelectric ceramic, FIG. 2 is a perspective view of a piezoelectric ceramic direct emission type speaker of this invention, and FIG. 3 is a sectional view of the same. 22 is a piezoelectric ceramic. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of a direct emission type speaker using piezoelectric ceramic. As is well known in the art, piezoelectric on ceramic acts as a piezoelectric body by performing a polarization operation to align the polarization of each domain by applying a DC voltage in the thickness direction of the ceramic. Then, by applying an electric field in the thickness direction, the shape is changed to perform electro-mechanical or: [e. In order to use such a piezoelectric ceramic as a diaphragm of a speaker, as shown in FIG. ? Bimorph-type piezoelectric ceramic / plate in which two plates of the piezoelectric ceramic element plate 1.1 are pasted with the same poles facing each other, or the piezoelectric ceramic element plate 1 is attached to the metal plate 2 as shown in FIG. The thing of the composition which wore is appropriate. This is because the piezoelectric ceramic having such a configuration vibrates so that its central portion is curved by applying an AC signal (audio signal) to both electrodes, and as a result, it emits an acoustic wave. Therefore, in the following description, the piezoelectric ceramic refers to the two configurations. When adopting such a piezoelectric ceramic for a direct radiation type speaker, the following drawbacks must be solved. First of all, the piezoelectric ceramic has an extremely sharp Q at its resonance frequency, so the reproduction bandwidth is extremely narrow, and it is used for a speaker that reproduces a very limited frequency band like a tweeter-1 or spear eater. It is also difficult to do. This invention supports the piezoelectric ceramic at at least two points, and the positions of the supporting points are different in each of the three piezoelectric ceramics. The second 2- ° C. penetration will be described in detail below. Tsukanaka No. 2-Hit to λ, 21 is a support, and the support (the support 21 has at least two or more pieces per piezoelectric ceramic to support the 01-05-2019 1 piezoelectric ceramic 22) The piezoelectric ceramic 22 is attached to the upper end surface of the protrusion 21a with a rubber adhesive or the like. The bonding positions of the piezoelectric ceramic 22 and the protrusion 21 a are different in each piezoelectric ceramic 22. For example, in the figure, the first mold type ceramic (left side in the figure) is diagonally 02 points, the second piezoelectric ceramic is 2 points on the vertical axis, and the third piezoelectric ceramic is 2 points on the left and right axis Are supported respectively. It is well known that the vibration body changes the vibration collection depending on the position of its support. Therefore, as in the present invention, each of the four piezoelectric ceramics has a different resonance frequency by changing the supporting position of each one of the n electric ceramics. In such a configuration, when an audio signal is manually applied to a lead wire connected to each piezoelectric ceramic, each lower-type ceramic exhibits a vibration corresponding to the audio signal, but as described above, the inter-resonance wave number of each piezoelectric ceramic is different. Therefore, the respective resonance peaks are coupled in a static manner, and the overall frequency characteristic is broadened. Furthermore, the frequency characteristics increase the number of piezoelectric ceramic and change the support position variously so that the resonance frequency is continuously generated, make the shape and size of the piezoelectric ceramic different, and change the material of the piezoelectric ceramic, Furthermore, by using a material having an appropriate internal loss for the projections 21 a of the support 21 or by interposing an elastic material between the support 21 and the piezoelectric ceramic 22, the frequency characteristic between resonance frequencies can be made more flat. It is possible. As described above, the present invention supports a plurality of piezoelectric ceramics at two or more points respectively, and by making the supporting positions of the respective piezoelectric ceramics different, the resonance frequencies of the respective ones are made different, thus a wide band It is suitable for high-quality sound speakers, and can be used to enhance playback. 01-05-2019 2
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