JPH05227596A - Microphone - Google Patents

Abstract

PURPOSE:To obtain a microphone of low distortion, a broad band and a broad dynamic range. CONSTITUTION:A laser beam reflector 4 vibrating with a size in accordance with the size of input acoustic wave S at each time is provided. A laser beam Bi is irradiated to the laser beam reflector 4. The reflected laser beam Bo from the laser beam reflector 4 is made incident to a light emitting device 7, which detects the position of the reflected laser beam Bo at each time to detect the size of the acoustic wave at each corresponding time.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a microphone for capturing sound waves and converting them into optical or electrical signals.

[0002]

2. Description of the Related Art Microphones for converting sound waves into electric signals have a long history and have been gradually advanced in terms of characteristics.
Over the years, no innovative improvements have been seen. By the way, when classifying conventional microphones based on their operating principles, electromagnetic types such as magnetic type or dynamic type, electret condenser type, etc. that use electrostatic effect, and crystal type or ceramic type are used. It was limited to those utilizing the piezoelectric effect, which is called "etc."

[0003]

The above-mentioned conventional microphones have advantages and disadvantages depending on their operating principles, but the common drawback is that they can only take out an analog electric signal, and their size is typical. In general, it is a few mV. Therefore, it is difficult to obtain a good S / N (signal-to-noise) ratio, and if high conversion performance is to be obtained for the entire microphone circuit, a very low-noise amplifier is required for the subsequent amplifier. I had to pay a lot of attention to the wiring. In addition, non-linear distortion due to non-uniformity of electric field and magnetic field cannot be escaped, and even a material having considerably excellent characteristics cannot avoid occurrence of distortion of the order of several%. This is three or four orders of magnitude worse than the amplification distortion in the subsequent amplifier. Even a very simple amplifier can easily obtain a distortion of the order of a few percent of a comma, and a high-end amplifier can have a low noise and a low distortion such that the distortion must be measured in the ppm order instead of the% order. Given that, the distortion of the microphone at the input is a problem that must be greatly reduced. Furthermore, due to the influence of the stray capacitance and inductance, frequency characteristics not extend much in the exclusive electret condenser type, also there was the one with a frequency characteristic to clear with a margin of 20 kHz _Z being the audible range upper limit However, most were forced to accept narrow frequency bands. Therefore, as a matter of course, even if there is a request to detect only the audible band, which goes beyond the conventional concept of a microphone and that can detect the ultrasonic band, for example, there is almost no one that can respond to this. .. The present invention has been made in view of the above circumstances, and completely eliminates the above-mentioned drawbacks of the existing microphones and alleviates the above-mentioned drawbacks according to a new operation principle, and further, high precision digital recording technology of recent years and It aims to provide a microphone that is truly suitable for optical transmission systems and optical circuit technology.

[0004]

In order to achieve the above object, the present invention vibrates at a frequency corresponding to the frequency of an input sound wave and at a magnitude corresponding to the sound pressure of the sound wave, and irradiates the same. A laser beam reflecting means for reflecting the laser beam is provided, and a light receiving device for catching a position change or a shape change of the reflected laser beam from the laser beam reflecting means is provided. The laser light reflecting means is different from the vibrating plate means that directly receives sound waves.
It may be an independent means connected so as to be mechanically interlocked, or the vibrating means may also serve as this. Further, the laser light reflecting means is particularly in the shape of a diaphragm when catching a change in the shape of the reflected laser light rather than a change in the position of the laser light at that time. On the other hand, the light receiving device may be any device that can detect a change in the position or shape of the laser light reflected at that time.

[0005]

1 is a schematic block diagram of a first embodiment of a microphone constructed according to the present invention.
First, there is a vibrating means 1 that can receive a sound wave S to be detected. The vibrating means 1 may have a generally plate-like shape, and therefore will be referred to as the vibrating plate 1 below.
In this respect, the diaphragm 1 is placed at a predetermined stationary position in the absence of the input sound wave S, in accordance with the frequency of the input sound wave S, and its sound pressure ( It is held by a suitable elastic means 2 so that it vibrates at a moving distance according to its size. The type and material of the elastic means 2 are arbitrary, and springs, rubbers, and other materials and parts that are desirable for existing microphones may be used. By the way, if you consider only the vibration system of the diaphragm 1 without considering the distortion and nonlinearity due to the conversion system to electric signals, the existence of stray capacitance and inductance, the existing mechanism has extremely low distortion, wide band, wide dynamic range. The vibration system of is obtained. In other words, the present invention makes the most of this excellent characteristic of the vibration system without impairing it.

In this embodiment, a laser beam reflecting means 4 which vibrates at the same frequency as the diaphragm 1 and a proportional magnitude is provided to the diaphragm 1 via an appropriate mechanical connecting means 3. .. Generally, this laser light reflecting means 4 also
Since it may be in the form of a plate, it will be referred to as the laser beam reflector 4 or simply the reflector 4 in the following, but in the case of this laser beam reflector 4, one end thereof is supported by the support shaft 5 and the frequency of the input sound wave S is Vibration in the rotation direction is generated around the support shaft 5 according to the size.

On the other hand, the back surface of the laser light reflecting plate 4 is irradiated with the laser light B _i emitted from the laser light source 6, and the reflected laser light B _o reflected by the laser light reflecting plate 4 is Input to the light receiving device 7. The light-receiving device 7 may be of any type obtained by the existing technology as long as it can detect the change in the position of the reflected laser beam B _o input at that time with an appropriate resolution. Depending on the laser light incident position, the corresponding binary code may be output as an electrical digital signal, or an analog electrical signal or an optical signal may be output, or directly to a recording medium such as a photosensitive film. It may record the laser beam position from time to time.
Regarding the laser light, a laser beam emitted from the laser light source 6 so as to irradiate the laser light reflecting plate 4 is denoted by a symbol B _i.
Is used, and the symbol B _o is used for that after being reflected by the laser light reflection plate 4. However, when it is not necessary to distinguish between the two, the subscript i, o is omitted and the laser light B is simply used. To call.

According to the microphone structure of the present invention, the input sound wave S causes the diaphragm 1 to vibrate, and its movement is converted into proportional rotational vibration about the support shaft 5 of the laser light reflector 4. Then, the reflection direction of the laser beam B _i incident on the back surface of the laser beam reflector 4 changes correspondingly. Therefore, by capturing the change of the incident position of the reflected laser light B _o according to the frequency and the sound pressure of the input sound wave S by the light receiving device 7, the influence of the electrical stray capacitance and the inductance in the conversion system as in the conventional case is obtained. It is possible to obtain a microphone with a wide band, low distortion, and a high dynamic range without receiving it.

As described above, the light receiving device 7 is not essentially limited according to the present invention.
Some examples of desirable light receiving device configurations are given below.
First, when explained photodetection device 7 shown in FIG. 2, in this case, the laser beam B _o, as the elongated rectangular shape are denoted a schematic thin dot pattern, the irradiation direction (traveling Direction) and the above-mentioned position change direction (direction indicated by a double-headed arrow F in FIG. 2), both of which are suitable for forming a laterally long beam having a longitudinal dimension in a direction perpendicular to both directions. (Not shown) via (incident light B _i
It may have been molded at the stage of). On the other hand, the light receiving device 7
A one-dimensional photodiode array having a reflected laser beam B _o m-number of light detecting elements at a maximum along the positional change direction F (eg photodiode), along a horizontal direction of the reflected laser beam B _o n columns, They are arranged side by side. In the illustrated case, n is 4, and if the photodiode arrays 8 ¹ , 8 ² , 8 ⁴ , 8 ⁸ are assigned to each column, first, which photodiode array 8 ¹ , 8
² , 8 ⁴ and 8 ⁸ also have light incident on at least one of the maximum m photodetector elements in the row,
The output terminal is configured to emit an electric signal which can be electrically recognized as logic "1".

However, in this embodiment, in each of the photodiode arrays 8 ¹ , 8 ² , 8 ⁴ , and 8 ⁸ , only the photo-detecting elements shown by squares with a dark dot pattern in the drawing are shown. However, it is configured to show sensitivity to the incidence of light (in other words, the photo-detecting element shown by the white squares exhibits sensitivity by masking the light-incident surface or cutting the conversion electric output line. Or the photodetector is provided only at the positions of the squares with a dark dot pattern, and when viewed from the relationship between the columns, the same from time to time. Horizontal laser beam B _o
It is different whether or not the photo-detecting element exhibiting sensitivity when illuminated by is located at that position. That is, in the light receiving device 7 shown in FIG. 2, in the matrix arrangement of the maximum of m × n photodetecting elements, the outputs of the four parallel photodiode arrays are arranged according to the so-called programmable logic array. In combination, as a digital electrical signal according to the current position of the laser light,
It is designed to output binary code directly.
Therefore, in the case of the arrangement shown in the figure, the output of the ^first photodiode array 8 ¹ located at the right end in the figure is the L of weight 2 ¹
The SB bit output D1, the output of the second photodiode array 8 ² is the second bit output D2 having a weight of 2 ² , and the output of the third photodiode array 8 ⁴ is the third bit output D4 having a weight of 2 ⁴ , The output of the photodiode array 8 ⁸ located at the left end is a so-called MSB, which is the most significant bit output D8 having a weight of 2 ⁸ . For example, when the laser beam B _o is at the position shown in FIG. 2, a photodetector element that receives the laser beam B _o is provided, or a photodetector element that has sensitivity at the irradiation position is provided. Since the diode array is the leftmost array 8 ⁸ only, 1
The output logic of the -2-4-8 code is "1000" from the MSB side.

As is apparent, in the case of the configuration example of the light receiving device shown in FIG. 2, the combinational relations from the combination of the photodetecting elements located at the bottom to the combination at the topmost in order. As can be seen from the above, the smallest binary value "0000" is sequentially read by the ordinary binary system to "000".
1 ”,“ 0010 ”, ... Increment by 1, and an example of reaching the maximum logical value“ 1111 ”is shown, but the method of setting the logical value is arbitrary, and in the first place. The number of bits (the number of arrays) can be arbitrarily changed according to the required resolution or dynamic range.

Similarly, in FIG. 3, a digital binary code is output according to the position change of the reflected laser light B _o , and eventually the instantaneous magnitude of the input sound wave.
A light receiving device 7 having a configuration different from that shown in FIG. That is, even in the light receiving device 7, the photodiode array 8 is used as in the previous case, but the number of the photodiode array 8 may be one, and m photo detecting elements are provided in the moving direction F of the reflected laser light B _o. All (indicated by squares) have photosensitivity. In this case, the reflected laser light B _o does not have to be particularly long in the horizontal direction, and may have an ordinary narrow beam shape. Depending on the position of the laser light reflecting plate 4 at that time, any one of the light detection beams may be detected. Illuminate the element. The photodiode array 8 is configured to input the output of each photodetection element to the combinational logic circuit 9,
The combinational logic circuit 9 emits a logic value signal of an individual magnitude to each photodetecting element according to a predetermined relationship. The resolution of this output is also arbitrary, and in the case of the figure, the output D1, D2, D4, D8 1-2-4-
It is planned that a logical value according to 8 codes (from the LSB side) will be generated, but it is not limited to this.

[0013] receiving device 7 shown in FIG. 4 is inserted on the way of the light path of the reflected laser beam B _o, slits S ₁₀ at a predetermined pitch along the positional change direction F of the reflected laser beam B _o, ·
.. has a blind-shaped slit means 10 in which .. Therefore, the reflected laser beam B _o is choppered by the slit group according to the magnitude of the sound wave at that time, and therefore the output beam B _S of the blind slit means 10.
Is an optical signal B whose pulse width is modulated according to the magnitude of the sound wave.
It becomes _S. Therefore, this can be processed as it is by the optical circuit, but in order to convert it into an electric signal, the remaining configuration shown in FIG. 4 can be incorporated. That is, the output light B _S of the blind-shaped slit means 10 is input to the photo-detecting element 12, which may be generally a photodiode, by an appropriate lens system 11, and the converted electric signal is constructed by a normal counter technique. Pulse processing circuit 1
If it is input to 3, the digital code output can be obtained at the output.

Of course, the digital code output by the above-described three light receiving device configuration examples can be converted into an analog electric signal by digital-analog converting it.
Rather, according to the light-receiving device having the above-described configuration, the conventional microphone cannot generate a digital output directly in response to the input of a sound wave, but is characterized in that it can generate the digital output. If an analog electric output can be obtained, the following light receiving device configuration example is also available.

The light receiving device 7 shown in FIG. 5 has a variable density filter 14 whose density changes along the direction F of the position change of the reflected laser light B _o . In the illustrated state, results equivalent direction cross-sectional dimension of the reflected laser beam B _o has a structure that changes along the moving direction F of the reflected laser beam, the variable density filter 14 which forms a triangular shape when viewed from the side shown However, the density distribution of the light absorbing medium inside the filter may be changed along the direction F to obtain the variable density characteristic. In any case, according to the light receiving device having such a configuration, the occasional magnitude of the input sound wave and the occasional light amount or attenuation amount of the laser light B _o passing through the variable density filter can be associated with each other. Therefore, the sound wave can be detected by such an amount of light. When it is necessary to convert this into an electric signal, as shown in FIG.
The output light B _o 'of _No. 4 may be input to the photodetecting element 12 such as a photodiode through an appropriate lens system 11 and then the analog electric output may be taken out.

Similarly, there is a method for extracting the analog electric output as shown in FIG. That is, the laser beam B is irradiated in the irradiation direction (traveling direction) like a slender rectangular shape schematically shown with a thin dot pattern in FIG.
And a horizontal beam having a longitudinal dimension in a direction perpendicular to both the above-mentioned position change direction F,
While shaping is performed via an appropriate optical system (not shown) (in this respect, it is similar to the embodiment shown in FIG. 2 described above), on the way of the optical path of the reflected laser light B _o having such a horizontally long shape. Is an opening 1 through which the reflected laser light B _o passes.
The width of 6 is inserted through the variable slit 15 which changes along the position change direction F of the laser beam. In FIG. 6, a view of the variable slit 15 seen from the front is also shown, which is easy to understand, but in this case, the slit or opening 16 is concerned.
Has a triangular shape when seen in a plan view, the output light B _o ′ passing therethrough is proportional to the input sound wave in its light intensity. Therefore, if it is desired to convert this into an electric signal, as in the embodiment shown in FIG. 5, if the output light B _o 'is converged by the appropriate lens system 11 to the appropriate photodetection element 12, this photodetection is performed. An analog electrical output corresponding to the output of element 12 can be obtained.

FIG. 7 shows a further modified example. First of all, the diaphragm 1 and the laser light reflection plate 4 have been separate members until now, but the rear surface of the vibration plate 1 can also be used as the laser light reflection plate 4 by mirror-finishing. That is the point. This point can be similarly applied to other embodiments. On the contrary, when the vibration plate 1 and the laser light reflection plate 4 are separate members and are connected so as to be interlocked with each other by mechanical means, the degree of positional change of the reflected laser light B _o is small. When it passes, a mechanical lever can be used for the mechanical connecting means to achieve mechanical amplification. However, for the purposes of the present invention, there are as few mechanical moving parts as possible. From that meaning, as shown in FIG.
The configuration example in which the vibration plate 1 also serves as the laser light reflection plate 4 is extremely advantageous.

The second modification shown in FIG. 7 is that a so-called laser range finder 17 is used. Of course,
In this case, both the laser light source and the light receiving device 7 are included in the components of this laser range finder. Inside the laser rangefinder,
A typical and highly accurate one utilizes the principle of interference of laser light. Therefore, when this is adopted, if one of the plurality of reflecting mirrors constituting the laser interferometer is the laser light reflecting plate 4 in the present invention, the movement amount (displacement) of the laser light reflecting plate 4 is changed. As long as (amount) is larger than the laser wavelength, it is possible to obtain a laser light output that is pulse-width modulated according to the occasional magnitude of the input sound wave based on the light and darkness of light generated by the interference principle.

On the other hand, when the moving distance of the laser light reflecting plate 4 is insufficient, the laser light reflecting plate 4 is used as the first reflecting mirror as shown in FIG. Therefore, a fixed reflecting mirror 18 is provided as the second reflecting mirror, and the laser beam B may be reflected and reciprocated between the first reflecting mirror 4 and the second reflecting mirror 18 a proper number of times. Even in the case of constructing a microphone for the ultrasonic region, the speed of light is so high that it does not cause a problem compared with the speed of sound, so that there is no problem even if such a repeated reflection method is adopted. Of course, this can be applied to other embodiments and can replace the use of the mechanical "lever" described above.

On the other hand, in all of the embodiments described so far, the entrance of the irradiation laser light B _i to the laser light reflecting plate 4 and the exit of the outgoing laser light B _o from the laser light reflecting plate 4 to the light receiving device 7 are carried out. Are spatially different from each other, but if the optical switching mechanism shown in FIG. 9 is adopted and the input and output laser beams B _i and B _o are temporally separated, the inlet and the outlet are Can be in the same position. That is, in FIG. 9, irradiation of the laser light B _i from the laser light source 6 to the laser light reflecting means 4 is allowed in the first time width, and the laser light reflecting plate 4 is transferred to the light receiving device 7 in the second time width. An optical switch 19 is provided to permit the irradiation of the reflected laser light B _o . Further, in this embodiment, as described above, the sound wave S
When the mechanical quantity of the laser light reflecting plate 4 is insufficient due to the input of, the function of amplifying this is also incorporated.

The operation will be described below. The laser light B _i emitted from the laser light source 6 is initially emitted for a first time width which is a short time, as indicated by an imaginary line arrow a. After passing through the switch 19, the laser light reflector 4
Is irradiated. When the first time width has elapsed, the optical switch 19 closes and functions to reflect the reflected laser light reflected by the laser light reflecting plate 4 and indicated by the arrow c to the laser light reflecting plate 4 again. Therefore, while the optical switch 19 is closed, the laser light reciprocates between the optical switch 19 and the laser light reflection plate 4, and the displacement amount of the laser light reflection plate 4 due to the input sound wave S is as described above. If it is small, it has the function of amplifying it. At this time, if the attenuation of the reciprocating laser light becomes a problem, an appropriate optical amplifier 20 may be inserted in the laser light path as shown in FIG. Next, the optical switch 19, which is also applicable only to short the second time width, switching the optical path as indicated by arrow b in phantom lines, the photodetector reflected laser beam B _o from the laser light reflecting plate 4 21 To enter. On the other hand, since the original laser light B _i emitted from the laser light source 6 is also guided to the photodetector 21 by the semitransparent mirror 22, the laser light reflector 4 at that time is caused by the phase information difference between them. You can know the position of. Therefore, if the above operation is repeated at a speed sufficiently higher than the frequency of the sound wave S to be detected,
The sound wave S can be detected substantially in real time.

As is apparent, in the operation of FIG. 9, if it is not necessary to amplify the displacement amount of the laser light reflecting plate 4, the above-mentioned first time width and second time width are calculated as It may be repeated without a gap, and in order to make the laser beam reciprocate between the laser beam reflector 4 and the optical switch 19, the optical switch 19 interrupted between the first and second time widths is used.
The third time span closing is unnecessary. Further, the optical switch 19 for switching the optical path can be extremely easily assembled by a person skilled in the art by existing technology, for example, by combining a deflection element and an electro-optical effect. Of course, the method of temporally separating laser light input / output according to the embodiment shown in FIG. 9 can be combined with the other embodiments described above.

The embodiment shown in FIG. 10, instead of the method of detecting the current position of the laser light reflecting plate 4 according to the current sound pressure of the input sound wave S as in the previous embodiments, An example is shown in which the sound pressure of the sound wave S is captured by changing the shape of the laser light at that time. That is, the diaphragm 1 that receives the input sound wave S is made of, for example, an elastic thin film, and the back surface of the diaphragm 1 is subjected to a process such as metal deposition or plating to be mirror-finished so as to serve also as the laser light reflecting plate 4. Further, as shown by the cross-sectional shape in the figure, since the diaphragm 1 or the laser light reflecting plate 4 in this embodiment has a diaphragm shape, the curvature of the input sound wave S varies depending on the magnitude of the input sound wave S. A changing convex mirror (which may be a concave mirror in the opposite direction to the illustrated cross section) is obtained.
Therefore, the laser light B _i emitted from the laser light source 6 through the semi-transparent mirror 23 to the laser light reflecting plate 4 is converged or diffused by the reflecting mirror whose shape changes depending on the sound pressure of the input sound wave S at that time. Since the beam diameter thereof changes correspondingly, when the beam diameter is passed through the semi-transparent mirror 23 again to illuminate the aperture 24 having an appropriate aperture diameter, the amount of light transmitted therethrough changes. Therefore, while the amount of transmitted light of the aperture 24 is detected by the photodetector 25, when compared with the original amount of light by another photodetector 26, the amount of deformation of the laser light reflecting plate 4, that is, the input at that time is detected. The magnitude of the sound wave S can be detected.

Of course, also in this embodiment, the configuration disclosed in the other embodiments described above can be appropriately adopted as the modified structure. For example, the vibrating plate 1 and the laser light reflecting plate 4 may have a separate structure in which they are mechanically connected, and in this case, the laser light reflecting plate 4 has a diaphragm shape. However, in the case of adopting the mechanical coupling means including the above-described embodiments, the linear vibration of the diaphragm 1 is directly changed to the linear vibration without conversion to the rotary vibration system as shown in FIG. It may be a system that transmits to the laser light reflection plate 4 in any form. Furthermore, in the examples so far,
In both cases, the surface that receives the input sound wave S and the surface that receives the irradiation of the laser light are on the opposite sides. However, depending on the spatial positional relationship of each component, the vibrating plate 1 or the laser light reflecting plate 4 may be used. It is obvious that both the sound wave incident surface and the laser light incident surface can be on the same side.

[0025]

The present invention is a microphone for detecting the position or shape of a laser light reflecting plate, which changes according to the sound pressure of a sound wave at that time, by using the laser light. The distortion in the conversion system can be greatly reduced (in principle, zero). further,
Since there is no influence of the surrounding electric field and magnetic field and no influence of stray capacitance or inductance, it is possible to provide a microphone having an extremely wide frequency characteristic, a sufficiently wide dynamic range, and a high degree of design freedom. Also,
It is possible to transmit the light as it is or directly encode the sound pressure information into a digital code, which is truly suitable for future digital transmission and digital recording technologies.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a microphone according to a first embodiment configured according to the present invention.

FIG. 2 is a schematic configuration diagram of an example of a light receiving device having a matrix arrangement of photodetection elements, which is suitable for the microphone of the present invention.

FIG. 3 is a schematic configuration diagram of an example of a light receiving device having a photodetector array, which is suitable for the microphone of the present invention.

FIG. 4 is a schematic configuration diagram of an example of a light receiving device having a blind slit means, which is suitable for the microphone of the present invention.

FIG. 5 is a schematic configuration diagram of an example of a light receiving device having a variable density filter, which is suitable for the microphone of the present invention.

FIG. 6 is a schematic configuration diagram of an example of a light receiving device having a variable slit, which is suitable for the microphone of the present invention.

FIG. 7 is a schematic configuration diagram of an embodiment configured according to the present invention and utilizing the principle of a laser distance system.

FIG. 8 is an explanatory diagram of an example for optically amplifying the mechanical displacement amount of the vibration plate or the laser light reflection plate.

FIG. 9 is an explanatory diagram of a configuration example in which the laser light emitted to the laser light reflector and the reflected laser light from the laser light reflector are temporally separated.

FIG. 10 is a schematic configuration diagram of another embodiment of the present invention for detecting the change in shape of the laser light reflector according to the sound pressure of the input sound wave.

[Explanation of reference numerals] 1 vibrating plate, 4 laser light reflecting plate, 6 laser light source, 7 light receiving device, 8 photodetector array, 8 ¹ photodetector array, 8 ² photodetector array, 8 ⁴ photodetector array, 8 ⁸ photodetector array, 9 combinational logic circuit, 10 blind-slit means, 12 photodetector, 14 variable density filter, 15 variable slit, 17 laser interferometer, 18 fixed mirror, 19 optical switch, 21 photodetector , 22 semi-transparent mirror, 23 semi-transparent mirror, 24 aperture, 25 photodetector, 26 photodetector, S input sound wave, laser light to B _i laser light reflection plate, reflected laser light from B _o laser light reflection plate.

Claims (12)

[Claims] 1. A laser beam reflecting means that vibrates at a frequency according to the frequency of an input sound wave and at a magnitude according to the sound pressure of the input sound wave, and that reflects the emitted laser light; A light-receiving device that captures a position change of the reflected laser light from the laser-light reflecting means; 2. The microphone according to claim 1, wherein the laser light reflecting means is connected to the vibrating means that directly receives the sound wave so as to mechanically interlock with each other. microphone. 3. The microphone according to claim 1, wherein the laser light reflecting means is a vibrating means that directly receives the sound wave. 4. The microphone according to claim 1, 2, or 3, wherein the laser beam has a laterally long shape having a longitudinal dimension in a direction perpendicular to an irradiation direction of the laser beam and a direction of the position change. The light-receiving device is in the form of a matrix in which a plurality of photo-detecting elements are arranged in the direction of position change of the laser light and the lateral direction of the laser light; and the position of the laser light at that time. According to
The number of photo-detecting elements which are in a side-by-side relation in the lateral direction of the laser light and the combination of the photo-detecting elements to which the reflected laser light is input at the same time sometimes form binary codes corresponding to the respective positions. The arrangement of the matrix has been determined. 5. The microphone according to claim 1, wherein the light-receiving device is a light-receiving array including a plurality of photo-detecting element groups arranged in parallel in the direction of position change of the reflected laser light. A microphone including a circuit for transmitting a binary code corresponding to each of the photodetection elements to which the reflected laser light is input at any time. 6. The microphone according to claim 1, wherein the light-receiving device is inserted in the optical path of the reflected laser light and has a predetermined pitch along the direction in which the position of the laser light changes. A plurality of slits are continuously formed, and a slit-like slit means is formed; an optical signal pulse-width-modulated according to the magnitude of the sound wave is obtained as a laser light output passing through the above-mentioned slit-like slit means. And a microphone. 7. The microphone according to claim 1, wherein the laser beam has a laterally long shape having a longitudinal dimension in a direction perpendicular to an irradiation direction of the laser beam and a direction of the position change. The light-receiving device has a variable slit whose opening width for passing a part of the oblong laser beam changes along the direction of position change of the laser beam; and the occasional magnitude of the input sound wave. And the amount of laser light passing through the variable slit at any given time have a correspondence relationship. 8. The microphone according to claim 1, wherein the light-receiving device has a variable density filter whose density changes along a direction of position change of the laser beam; A microphone having a correspondence relationship between a size at that time and a light amount or attenuation amount of the laser light passing through the variable density filter at that time. 9. The microphone according to claim 1, wherein the laser light reflecting means is a reflecting mirror means forming a part of a laser interferometer, and the light receiving device is generated by the interferometer. Generating a pulse-width modulated laser light output according to the occasional magnitude of the input sound wave, based on the light and shade of light. 10. The microphone according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the laser light reflecting means is a first reflecting means which is first irradiated with laser light,
The laser light reflected by the first reflecting means is again
Second reflecting means for reflecting toward the first reflecting means; after reflecting and reciprocating the laser light a plurality of times between the first and second reflecting means, the laser light is transmitted to the light receiving device. A microphone characterized by inputting; 11. The microphone according to claim 1, wherein the laser light reflection means has a diaphragm structure, and the light receiving device reflects the reflection of the input sound wave according to the size of the input sound wave at that time. A microphone for capturing the change in the shape of the reflected laser light according to the occasional magnitude of the input sound wave, instead of the change in the position of the laser light. 12. Claims 1, 2, 3, 4, 5, 6, 7,
8. The microphone according to 8, 9, 10 or 11, wherein irradiation of the laser light reflecting means from a laser light source is allowed in a first time width, and the laser light reflecting means is irradiated to the light receiving device in a second time width. A microphone further comprising: an optical switch that allows the input of the reflected laser light; the first time width and the second time width are alternately repeated at a predetermined cycle.