JP2004112211A - Super-directive speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a super-directive speaker in which an optimal sound wave concentrating position can be set easily while facilitating design and manufacturing. <P>SOLUTION: The super-directive speaker comprises a sound generator 10 and a high frequency wave generator 50, an amplitude modulator 20 for converting the output signals from these generators into amplitude modulated signals, an amplifier 30 for amplifying the amplitude modulated signals from the amplitude modulator 20, and an electroacoustic converter 40 for radiating the amplified signals from the amplifier 30 as an acoustic vibration wherein the electroacoustic converter 40 comprises a plurality of substrates 43a-43f arranged independently and concentrically, and sound generating elements 41 mounted on these substrates 43a-43f, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a super-directional speaker that emits audible sound in a directional manner.
[0002]
[Prior art]
FIG. 4 is a block diagram showing a configuration of a conventional super-directional speaker disclosed in, for example, JP-A-11-239394, FIG. 5 is a front view showing an electroacoustic transducer in FIG. 4, and FIG. FIG.
In FIG. 4, reference numeral 10 denotes a sound generator for generating an electric sound signal corresponding to a sound that can be heard by a listener, and 20 denotes an amplitude modulation for inputting and modulating the sound signal generated by the sound generator 10. The amplitude modulator 20 receives and modulates the high-frequency signal generated by the high-frequency generator 50 as well. Here, the high-frequency generator 50 generates a high-frequency signal having a frequency in an ultrasonic band.
[0003]
That is, the amplitude modulator 20 modulates the audio signal from the audio generator 10 and the high-frequency signal from the high-frequency generator 50 into an amplitude-modulated wave signal and outputs the amplitude-modulated wave signal. Are amplified to, for example, 20 to 40 V or more. Reference numeral 40 denotes an electroacoustic transducer which receives an amplified signal from the amplifier 30, converts the signal into acoustic vibration and radiates the signal, and includes a bowl-shaped acoustic vibration radiating plate 42 as shown in FIG.
[0004]
The acoustic vibration radiating plate 42 has a circular shape as shown in FIG. 5 when viewed directly in the traveling direction of acoustic vibration, and has a large number of electroacoustic transducers (hereinafter referred to as sounding elements) 41 therein. They are arranged close to each other. These sound generating elements 41 are arranged along a bowl-shaped arc surface as shown in FIG. 6 as viewed from the lateral direction of the direction of the sound wave generated by the acoustic vibration. The arc-shaped surface of the acoustic vibration radiation plate 42 may have a free shape such as a parabola, and the sound generating element 41 is, for example, a ceramic piezoelectric element.
[0005]
Next, the operation will be described.
The propagation direction of the sound wave due to the acoustic vibration is indicated by a solid line in FIG. 6, and propagates while giving the largest acoustic energy in the vertical direction of the sound generating element 41. Thus, the acoustic vibrations converge at point A (see FIG. 6), giving the listener the maximum sound pressure at point A. This sound wave causes a non-linear interaction in the process of propagating through the air as an ultrasonic wave, is demodulated into a super-directional sound composed of low frequency components and the like, and is made audible to a listener.
[0006]
Here, the frequency band of the sound wave output by the sound generating element 41 may be any frequency band as long as it is an ultrasonic band of 20 kHz or more, and by using a relatively low ultrasonic band around 40 kHz, the listener can obtain a higher sound pressure. You can listen to audio. The conventional super-directional speaker configured as described above operates as a parametric sound source, and can create an area with high sound pressure in the sound field space.
[0007]
[Problems to be solved by the invention]
Since the conventional super-directional speaker is configured as described above, the acoustic vibration radiating plate 42 must be manufactured and equipped with a bowl-shaped curved surface in order to concentrate the sound emitted from the sound emitting element 41 toward the focal point. There was a problem. That is, the acoustic vibration radiating plate 42 having the bowl-shaped curved surface as described above requires processing accuracy at the time of molding or cutting, and accordingly requires a member having a high manufacturing cost. Must be arranged close to each other along the bowl-shaped curved surface in the inside of the device, and it takes time and effort to design and manufacture the entire electroacoustic transducer 40, which causes problems such as difficulty. there were. Further, once the final shape of the acoustic vibration radiating plate 42 is determined, there is a problem that the focal position is determined at one place and cannot be changed.
[0008]
Further, the acoustic vibration radiating plate 42 can have a variable focal length by changing the curved shape before the final shape is determined. In this case, the curved curvature of the entire acoustic vibration radiating plate 42 is changed. However, such curvature adjustment is very troublesome and difficult to focus, and there is a problem that it is difficult to set the distance of the sound wave concentration place.
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a super directional speaker which can be easily designed and manufactured and can easily set an optimum sound wave concentration place. .
[0010]
Another object of the present invention is to provide a super-directional speaker that can easily adjust the distance setting of an optimum sound wave concentration place during use.
[0011]
A further object of the present invention is to provide a super-directional speaker that can be easily assembled, thereby improving productivity and reducing costs.
[0012]
Another object of the present invention is to provide a super directional speaker capable of changing the maximum sound pressure position or controlling an optimal directivity pattern.
[0013]
[Means for Solving the Problems]
A super-directional speaker according to the present invention includes a voice generator and a high-frequency generator, an amplitude modulator that inputs these output signals and converts them into an amplitude-modulated wave signal, and an amplitude-modulated wave signal from the amplitude modulator. In a super-directional speaker including an amplifier to be amplified and an electro-acoustic transducer that radiates an amplified signal from the amplifier as acoustic vibration, a plurality of substrates that are individually and concentrically arranged adjacent to each other are provided. An electroacoustic transducer is configured by mounting an electroacoustic transducer.
[0014]
A super-directional speaker according to the present invention has a plurality of substrates on which electro-acoustic transducers are mounted, each of which is arranged so as to be slidable in an acoustic radiation direction.
[0015]
The super-directional speaker according to the present invention is obtained by forming a plurality of concentrically arranged substrates except for a substrate at a central portion thereof into a frame shape which can be concentrically arranged adjacently.
[0016]
In a super directional speaker according to the present invention, the electro-acoustic transducers arranged on each board are driven by different drive signals for each board.
[0017]
In a super directional speaker according to the present invention, the electro-acoustic transducers arranged on each board are driven by drive signals having different amplitudes or phases for each board.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described.
Embodiment 1 FIG.
FIG. 1A is a front view showing a superdirective speaker according to Embodiment 1 of the present invention, and FIG. 1B is a schematic sectional view taken along line II of FIG. 1A. 6 are denoted by the same reference numerals as in FIG.
In the figure, reference numeral 40 denotes an electroacoustic transducer which is a main part of a super-directional speaker, and includes a board group 43 including a plurality of boards 43a to 43f which are individually and concentrically arranged adjacently. . Reference numeral 41 denotes a sound emitting element mounted on each of the boards 43a to 43f and adjacent to each other.
[0019]
More specifically, in the substrate group 43, the central substrate 43a is formed in a size that can mount one sounding element 41, and the other substrates concentrically arranged adjacent to the substrate 43a. 43b to 43f are each formed in a frame shape. The frame-shaped substrates 43b to 43f according to the first embodiment are formed in a hexagonal frame shape as shown in FIG.
[0020]
As described above, one sounding element 41 is mounted on the central substrate 43a, and a plurality of sounding elements 41 are mounted adjacently on the other frame-shaped substrates 43b to 43f. Each of the substrates 43a to 43f has a through hole (not shown) for inserting an electric terminal (not shown) of the sounding element 41, and the electric terminal of the sounding element 41 is inserted into the through hole. The sound emitting element 41 is mounted by inserting and soldering.
[0021]
In this manner, each of the boards 43a to 43f on which the sounding elements 41 are mounted has the other frame-shaped boards 43b to 43f concentrically arranged adjacent to the board 43a on which one sounding element 41 is mounted. . Here, the sound emitting elements 41 are electrically connected in parallel or in series with the same polarity, and the respective circuits are electrically connected in parallel or in series even on each of the substrates 43a to 43f. Further, the respective substrates 43a to 43f are arranged so as to be reciprocally slidable in a parallel direction along the acoustic radiation direction, and by adjusting the slide, for example, as shown in FIG. Can be formed in a concave surface with respect to the acoustic radiation direction.
[0022]
The other configuration of the super-directional speaker including the electroacoustic transducer 40 configured as described above and the operation as a parametric speaker are the same as those of the conventional example shown in FIG.
[0023]
According to the first embodiment described above, a plurality of individually formed substrates 43a to 43f are concentrically arranged adjacent to each other, and among the substrates 43a to 43f, one substrate 43a to 43f is provided at the central portion. One sounding element 41 is mounted, and the other substrates 43b to 43f are formed in a frame shape, respectively. A plurality of sounding elements 41 are mounted on each of the frame-shaped substrates 43b to 43f. Since the other frame-shaped substrates 43b to 43f are arranged concentrically adjacent to each other with the substrate 43a on which is mounted as the center, there is an effect that the design and manufacture of the electroacoustic transducer 40 are facilitated.
[0024]
Here, all the sound emitting elements 41 of the electroacoustic transducer (superdirective speaker) 40 according to the first embodiment are parallel to their respective central axes (sound radiation direction axes), and are arranged in the conventional example shown in FIG. , All the sound emitting elements 41 are not directed to one point (focal point). However, since the directional radiation angles of the individual sound emitting elements 41 are as wide as, for example, a half-value width of about 120 degrees, the degree of concentration of both sound emitting elements 41 is There is almost no difference.
[0025]
That is, according to the first embodiment, like the conventional acoustic vibration radiating plate 42, a curved surface such as a parabola or an arc that requires processing accuracy is formed, and the curved surface has a through hole for mounting the sounding element 41. There is no need to make a hole, so that the design of the electro-acoustic transducer 40 can be facilitated as described above, and at the same time, another frame-shaped substrate centered on the substrate 43a on which one sounding element 41 is mounted. It is possible to easily assemble the electroacoustic transducer 40 simply by sequentially fitting the 43b to 43f, and the production thereof can be facilitated.
[0026]
Further, in the first embodiment, since the respective substrates 43a to 43f are arranged adjacent to each other so as to be slidable in the acoustic radiation direction, the slide adjustment is performed, so that the mounting surface of the sound generating element 41 is made concave. It can be changed or conversely changed to a convex surface. That is, by adjusting the slide amount of each of the substrates 43a to 43f, for example, when viewed in the cross section of FIG. It is possible to make the shape of a straight cone, change the curvature of the spherical surface and the inclination of the straight, and easily set the distance of the sound wave concentration place.
[0027]
Embodiment 2 FIG.
FIG. 2A is a front view showing a superdirective speaker according to Embodiment 2 of the present invention, and FIG. 2B is a schematic sectional view taken along line II-II of FIG. 2A. The same or corresponding parts as those described above are denoted by the same reference numerals, and redundant description is omitted.
In the first embodiment, in the board group 43, the other boards 43b to 43f other than the center board 43a on which one sounding element 41 is mounted are formed in a hexagonal frame shape, respectively, and the boards 43b to 43f are formed. Although a plurality of sound emitting elements 41 are arranged one by one on the circumference, in the second embodiment, the central substrate 43a is formed in a circular shape, and the other substrates 43b to 43f are formed in a circular frame shape. A plurality of sound emitting elements 41 are concentrically arranged on each of the substrates 43a to 43f. Therefore, the same operation and effect can be obtained in the case of the second embodiment. In the substrate group 43, the other substrates 43b to 43f except for the substrate 43a at the center thereof are not limited to a circular frame or a hexagonal frame, but may have other shapes such as an oval or polygonal frame. That is, any frame may be used as long as it can be arranged concentrically adjacently. Further, two or more sound emitting elements 41 on the circumference may be mounted adjacent to each of the substrates 43a to 43f.
[0028]
Embodiment 3 FIG.
FIG. 3 is a block diagram showing the configuration of the entire superdirective speaker according to Embodiment 3 of the present invention. The same parts as those in FIGS. 1, 2 and 4 are denoted by the same reference numerals.
In the figure, 10 is a voice generator, 20 is an amplitude modulator, and 50 is a high frequency generator, which are the same as the conventional example. However, the amplitude modulator 20 outputs an amplitude modulated wave signal divided according to the number of substrates of the substrate group 43. Numeral 60 denotes the same number of phase shifters as the number of boards of the board group 43. These phase shifters 60 receive output signals corresponding to the number of boards from the amplitude modulator 20, and each of the boards 43a to 43f The phase shift amount can be set every time. An amplifier 30 receives and amplifies an output signal from each of the phase shifters 60, and outputs the amplified signal to each of the boards 43a to 43f. (Not shown), the amplitude of the signal can also be set.
[0029]
According to the third embodiment described above, an output signal (amplitude modulated wave signal) from amplitude modulator 20 that outputs an amplitude modulated wave signal divided according to the number of substrates constituting substrate group 43 is input. The same number of the phase shifters 60 as the number of the boards are provided, and the output signals from the phase shifters 60 are configured to be amplified by the amplifiers 30 of the respective systems and output for each of the boards 43a to 43f. The phase and amplitude of the signal can be changed every time, and the sound emitting element 41 of each substrate can be driven by a signal having a different amplitude or phase shift. The setting of the spread of directivity can be arbitrarily controlled, and therefore, according to the configuration of the third embodiment, there is an effect that the optimum listening position and the directivity pattern can be adjusted.
[0030]
【The invention's effect】
As described above, according to the present invention, a plurality of electroacoustic conversions are performed by modulating a high-frequency signal from a high-frequency generator with an amplitude modulator using a voice signal from a voice generator and amplifying the signal with an amplifier. In a super-directional speaker that radiates as acoustic vibrations from the elements, a plurality of substrates that are individually and concentrically arranged adjacent to each other are formed, and the electro-acoustic transducer is mounted on each of these substrates. Unlike the conventional acoustic vibration radiation plate, there is no need to form a curved surface requiring processing accuracy such as a parabola or an arc, or to make a through hole for mounting a sound element on the curved surface. There is an effect that a super directional speaker that can be easily designed and manufactured can be obtained.
[0031]
According to the present invention, since the plurality of boards on which the electroacoustic transducers are mounted are arranged so as to be slidable in the acoustic radiation direction, the electroacoustic transducers of each board are adjusted by sliding each board. The mounting surface can be changed to a concave surface or a convex surface with respect to the sound radiation direction, so that the optimal sound pressure position during use can be easily adjusted, and the distance setting of the sound wave concentration place can be easily performed. There is an effect that a super directional speaker which can be provided at a low cost can be provided.
[0032]
According to the present invention, in the plurality of substrates arranged concentrically, other substrates except the substrate at the center are formed in a frame shape which can be concentrically arranged adjacently, so that each substrate is formed. It can be easily assembled concentrically, and this has the effect of increasing the productivity of the super-directional speaker.
[0033]
According to the present invention, since the electro-acoustic transducers arranged on each board are configured to be driven by different drive signals for each board, the drive signal of the electro-acoustic transducer mounted on each board is transmitted to each board. It is possible to provide a super-directional speaker that can be set for each time and can control the optimum listening position and the directivity pattern.
[0034]
According to the present invention, the electro-acoustic transducers arranged on each substrate are configured to be driven by drive signals having different amplitudes or phases for each substrate. There is an effect that it is possible to provide a super directional speaker capable of arbitrarily controlling the spread setting of sexual characteristics.
[Brief description of the drawings]
FIG. 1A is a front view showing a superdirective speaker according to a first embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view taken along line II of FIG. 1A. is there.
FIG. 2A is a front view showing a superdirective speaker according to a second embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view taken along line II-II of FIG. 2A. is there.
FIG. 3 is a block diagram showing a configuration of an entire superdirective speaker according to Embodiment 3 of the present invention.
FIG. 4 is a block diagram showing a configuration of a conventional super-directional speaker.
FIG. 5 is a front view showing the electroacoustic transducer in FIG.
FIG. 6 is a sectional view of FIG. 5;
[Explanation of symbols]
Reference Signs List 10 sound generator, 20 amplitude modulator, 30 amplifier, 40 electroacoustic transducer, 41 electroacoustic transducer (sounding element), 43 substrate group, 43a to 43f substrate, 50 high frequency generator, 60 phase shifter.

Claims (5)

A voice generator and a high-frequency generator, an amplitude modulator that inputs these output signals and converts them into an amplitude-modulated wave signal, an amplifier that amplifies the amplitude-modulated wave signal from the amplitude modulator, and an amplification from the amplifier In a super directional speaker including an electro-acoustic transducer that emits a signal as acoustic vibration, the electro-acoustic transducer includes a plurality of substrates arranged independently and concentrically adjacently, and these substrates A super-directional speaker comprising a configuration including an electro-acoustic transducer mounted on each of them. 2. The super-directional speaker according to claim 1, wherein each of the substrates is arranged so as to be slidable in a sound radiation direction. 3. A plurality of substrates arranged concentrically, except for a substrate at a central portion thereof, other substrates are formed in a frame shape which can be arranged concentrically adjacently. Super directional speaker as described. 4. The super-acoustic transducer according to claim 1, wherein the electro-acoustic transducers arranged on each substrate are driven by different drive signals for each substrate. Directional speaker. The super-directional speaker according to claim 4, wherein the electro-acoustic transducers arranged on each board are driven by drive signals having different amplitudes or phases for each board.

Images