JP3387539B2 - Speaker and electronic device using the speaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker having high directivity and an electronic device using the speaker.

[0002]

2. Description of the Related Art Conventionally, an electronic device has been known which outputs various instructions and messages by voice in addition to display on a display or the like. However, when such an electronic device is used in, for example, an office, its voice causes noise to surrounding people, and therefore the operator needs to use it by using headphones or earphones.

[0003]

However, when such headphones or earphones are worn, the operator cannot hear other sounds such as a telephone call.
Also, it is cumbersome to wear such headphones all the time, and the operability is extremely poor.

The present invention has been made in view of the above-mentioned conventional example, and is compact and ultra-sized to realize a man-machine interface using sound without wearing earphones and the like and without disturbing the surroundings. An object is to provide a speaker having directivity and an electronic device using the speaker.

Other advantages and objects of the present invention will be apparent from the description given below with reference to the accompanying drawings.

[0006]

In order to achieve the above object, the speaker of the present invention has the following structure. That is, a sound source unit that generates sound waves of at least two different frequencies, a sound wave generator that propagates sound waves from the sound source unit, and generates a sound wave of a frequency corresponding to the difference between the different frequencies; and the sound source unit. A sound wave absorbing portion provided on the sound wave output side of the sound wave generating portion to absorb the sound wave of
The sound source section in the propagation direction of the sound wave from the sound source section.
And the sound wave generating portion and the sound wave absorbing portion are layered in this order.
It is arranged in .

To achieve the above object, an electronic device using the speaker of the present invention has the following configuration. That is,
An electronic device in which a speaker is arranged on the upper surface of the display unit,
The speaker is composed of a substantially transparent member, propagates sound waves from the sound source unit that generates sound waves of at least two different frequencies, and generates sound waves of frequencies according to the difference between the different frequencies. And a substantially transparent sound wave absorber provided on the sound wave output side of the sound wave generator to absorb sound waves from the sound source unit, and outputs an acoustic signal to the speaker. And a display unit for displaying the display data on the display unit.

[0008]

[Operation] With the above configuration, how the sound wave propagates from the sound source section
In the order of the sound source section, the sound wave generation section, and the sound wave absorption section, respectively.
And arranged in layers, to generate acoustic waves of at least two different frequencies from the sound source unit, the propagating the sound wave by the sound wave generating unit generates a sound wave having a frequency corresponding to the difference of these different frequencies, the sound source by sound absorption unit Absorbs sound waves from parts. As a result, the speaker having superdirectivity can be made compact. In addition, it is possible to incorporate a speaker into a conventional small electronic device that was almost impossible, and by incorporating a super-directional speaker into the electronic device, an acoustic man-machine interface can be realized without disturbing others. it can. Moreover, the troublesomeness of wearing earphones or the like can be eliminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is an external perspective view of a speaker 100 of this embodiment.

In FIG. 1, reference numeral 1 denotes a sound source section for applying a pulse signal or the like to generate an acoustic signal corresponding to the frequency of the pulse signal. Reference numeral 2 is a propagation section, and the sound source section 1
A plurality of radiated sound waves of different frequencies are propagated while causing a non-linear interaction (described later with reference to FIG. 2). A sound absorbing unit 3 absorbs a primary sound (acoustic signal radiated from the sound source unit 1) that does not contribute to nonlinear interaction in the propagation unit 2 among the sound waves emitted from the sound source unit 1. The speaker 100 according to the present embodiment has such a three-layer structure.

The sound source section 1 is made of a transparent material having a piezoelectric characteristic, which is made of a PVDF (polyvinylidene fluoride) type copolymer or the like. Propagation part 2
Is a transparent material composed of wholly aromatic polyester,
In addition, it is composed of a material in which a nonlinear interaction of sound waves can occur. Further, in FIG. 1, the arrow direction indicates the propagation direction of the sound wave, and also indicates the extension direction of the propagation portion 2 made of wholly aromatic polyester or the like. Further, the sound absorbing portion 3 has a sound absorbing characteristic capable of sufficiently absorbing the primary sound and is made of a transparent material, for example, acrylic resin or the like.

Next, with reference to FIG. 2, the nonlinear interaction of sound waves in the propagation section 2 will be described.

In FIG. 2, reference numeral 4 denotes a sound source corresponding to the sound source unit 1 of FIG.
Sound waves of ₁ and f ₂ shall be emitted. At this time, these two sound waves interfere with each other in the medium 5 to generate a beat. Here, the frequency of the carrier wave in which the two sound waves are combined is (f ₁ + f ₂ ) / 2, and the frequency of amplitude modulation corresponding to the beat is (f ₁ −f ₂ ) / 2. Here again, if both of these frequency component waveforms are sound waves of sufficiently large amplitude, this synthesized sound wave will gradually distort and eventually (f ₁ −f ₂ ) as shown in the waveform of FIG. Produces a difference sound and disappears.

Due to such a phenomenon, two large amplitude sound waves (frequency f ₁ and f ₂ ) emitted from the sound source 4 are
A non-linear interaction is caused while propagating in the medium 5, and a virtual sound source corresponding to the frequency difference (f ₁ −f ₂ ) is formed in the medium 5. Here, sound waves having frequencies f ₁ and f ₂ are called primary waves, and sound waves having a frequency (f ₁ −f ₂ ) are called secondary waves. In this way medium 5
The sound source of the secondary wave formed in is defined as a virtual sound source. The sound wave 6 from the virtual sound source is output as long as the non-linear interaction between the primary waves continues, and is output until the primary wave is attenuated to a linear wave with an infinitely small amplitude. That is, a virtual sound source is formed over a very long distance. In other words, since a very long vertical array is formed in the medium 5, the sound wave 6 output from the virtual sound source shows a very sharp directivity even if the frequency of the difference sound is low.

Next, the propagation characteristics in the propagation section 2 (medium 5) of the speaker 100 of this embodiment will be described.

In the propagating section 2, a wholly aromatic polyester is used as a material for facilitating generation of a non-linear interaction between primary waves. This wholly aromatic polyester uses monomers such as aromatic diols, aromatic dicarboxylic acids, and hydroxycarboxylic acids as mesogenic groups. Further, it is known that the anisotropy of the elastic constant of the wholly aromatic polyester increases in the stretching direction by stretching. This means that the speed of sound propagation in the stretching direction is dramatically increased. Further, since the propagation speed of the sound wave in the propagation section 2 is increased, the waveform of the sound wave itself is easily distorted, and as a result, a non-linear interaction is likely to occur. In addition to this wholly aromatic polyester, for example, PE (polyethylene), P
Even if a material such as VDF (polyvinylidene fluoride) is adopted for the propagation part 2, the same effect can be obtained.

Based on the principle described above, the speaker 100 (FIG. 1) of this embodiment will be described in more detail.

The sound source section 1 has frequencies f ₁ and f ₂ shown in FIG.
2 primary waves are generated, and these frequencies f ₁ and f
The difference of ₂ is set to be in the audible range. For example,
If the frequency f ₁ is set to 50 KHz and the frequency f ₂ is set to 45 KHz, the frequency (f ₁ −f ₂ ) of the secondary wave is 5 KHz.
The propagation unit 2 corresponds to the medium 5 that causes a nonlinear interaction as shown in FIG. 2, and generates a sound wave 6 (secondary wave) generated by a virtual sound source. Here, the primary waves of the frequencies f ₁ and f ₂ generated from the sound source unit 1 are basically 36
It is transported in the propagation section 2 with a spread of 0 ^° . At that time, the sound wave that remains as a primary wave in the propagating portion 2 without contributing to the generation of the sound wave 6 from the virtual sound source is absorbed by the sound absorbing portion 3 and is radiated as an extra sound into the air. Never.

FIG. 3 is a block diagram showing the structure of the parametric speaker 100 of this embodiment and the structure of its drive unit. The parts common to those in FIG. 1 are designated by the same reference numerals, and their description will be omitted.

In FIG. 3, reference numeral 7 is a power supply section for supplying electric power for driving the speaker 100, and 8 is a pulse signal having frequencies f ₁ and f ₂ for determining the frequency of the sound wave emitted from the sound source section 1. It is an oscillator. Reference numeral 9 denotes a drive circuit, which receives power supply from the power supply unit 7 and inputs a pulse signal from the oscillator 8 to drive the sound source unit 1 according to the frequency thereof. As a result, the sound source unit 1 radiates sound waves (primary waves) having frequencies f ₁ and f ₂ . In this way, the sound wave 6 having a very sharp directivity is output from the speaker 100 of the present embodiment.

FIG. 4 is a block diagram showing an example in which the parametric speaker 100 of this embodiment is used in an electronic device in combination with a display 101 of the electronic device.

In FIG. 4, reference numeral 101 is a display section (display) such as a CRT or liquid crystal, and 100 is a parametric speaker of this embodiment. Reference numeral 201 denotes an information processing unit for controlling the entire electronic device, which includes the speaker 10
The audio signal output to 0 is output to the audio signal processing unit 203, and the display data for the display unit 101 is output to the video signal processing unit 202. The audio signal processing unit 203 drives the speaker 100 according to an instruction from the information processing unit 201 to generate sound. In addition, the video signal processing unit 202 displays various data on the display unit 101 according to the signal from the information processing unit 201.

With such a configuration, the sound or voice (acoustic signal) generated from the parametric speaker 100 has extremely high directivity as described above, and therefore the operator operating this electronic device. No one else can hear you. As a result, it will not bother other people. Further, it is possible to provide the operator with a new interface using sound or voice, and it is possible to provide an electronic device with a more improved man-machine interface. The distance at which this acoustic signal can be heard is determined by the audio signal processing unit 2
Although it can be adjusted by a volume or the like (not shown) provided on the display unit 03, it is appropriate that the distance is about twice the distance at which the characters and the like displayed on the display unit 101 can be read.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, according to this embodiment, it is possible to provide a speaker having extremely high directivity.

Also, by combining this speaker with an electronic device, it is possible to provide an interface that can be heard only by the operator without causing noise to people other than the operator of the device.

Moreover, since the speaker of this embodiment can be made extremely thin, it can be compactly incorporated into an electronic device.

Further, the operator can be freed from the trouble of using an earphone or the like as in the conventional case, and a more friendly man-machine interface can be realized.

[0030]

As described above, according to the present invention, there is an effect that a man-machine interface using sound can be realized without wearing earphones and the like and without disturbing the surroundings.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the configuration of a speaker of this embodiment.

FIG. 2 is a diagram for explaining the principle of the speaker of this embodiment.

FIG. 3 is a block diagram showing a configuration of a speaker and a drive unit thereof according to the present embodiment.

FIG. 4 is a block diagram showing an example in which the speaker of this embodiment is incorporated in an electronic device.

[Explanation of symbols]

1 sound source section 2 propagation section 3 sound absorption part 5 medium (virtual secondary wave source region) 6 Sound waves from a virtual sound source 7 power supply 8 oscillators 9 drive circuit 100 parametric speakers 101 display

Claims (4)

(57) [Claims] 1. A sound source section for generating sound waves of at least two different frequencies; a sound wave generating section for propagating sound waves from the sound source section and for generating sound waves of frequencies according to the difference between the different frequencies; and a said sound wave generating unit sound absorption portion provided on acoustic output side in order to absorb the sound waves from the sound source portion, the propagation direction of the sound wave from the sound source portion, the said tone generator
The sound wave generator and the sound wave absorber are arranged in layers in this order.
A speaker characterized by being used . 2. The loudspeaker according to claim 1, wherein the sound wave generator is a stretched body of a polymer material having structural anisotropy, and the stretching direction and the sound wave propagation direction are substantially the same. And speaker. 3. The speaker according to claim 1 or 2, wherein the sound source section is transparent. 4. An electronic device in which a speaker is arranged on the upper surface of a display unit, wherein the speaker is composed of a substantially transparent member, and a sound source unit for generating sound waves of at least two different frequencies; Is provided on the sound wave output side of the sound wave generation unit for absorbing the sound wave from the sound source unit, and a substantially transparent sound wave generation unit that propagates the sound wave and that generates a sound wave having a frequency corresponding to the difference between the different frequencies. An electronic device, comprising: a substantially transparent sound wave absorbing section, which is provided, and an acoustic signal generating section that outputs an acoustic signal to the speaker; and a display section that displays display data on the display section.