JPS5916499A - Microphone - Google Patents

Abstract

PURPOSE:To attain optionally the control of directivity and sound adsorption of multi-mixing, by coupling the other end of plural optical fibers coupled with a microphone unit to be opposite to an output plane of a semiconductor laser having a strong self-coupling effect. CONSTITUTION:Plural microphone units 40-1, 40-2, 40-3 are coupled to one laser output plane of the semiconductor laser 44 having a strong self-coupling effect with optical fibers 42-1, 42-2 and 42-3. An optical fiber 43 is coupled to the other output plane of the laser 44. Then, the laser light from the one laser output plane of the laser 44 is irradiated to internal diaphragms 41-1, 41-2, 41-3 in the unit 40-1, 40-2, 40-3 and the reflecting light is fed back. Thus, the feedback light is synthesized and interferred with a Fabry-Perot resonator constituted in the laser 44 to produce the change in the intensity of the laser light.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention provides a microphone that can arbitrarily perform directivity control and multi-mixing sound collection using an external microphone array, and also enables optical fiber transmission of the microphone output. It is related to.

Conventional configuration and its problems In general, when controlling the directivity of a microphone, a waveform interference type directivity control force method is employed.

FIG. 1 shows an example of waveform interference type directivity control using a microphone array. In Figure 1, 20-1.20
-2...20-5 is used as an acoustic/electrical converter.
These are heavy-duty microphone units that are arranged at a predetermined distance so that their directivity axes face in the front direction. 21 is F microphone Unison) 20-1 to 20-5
It is a synthesizer of the output from . Microphones like this
In an array configuration, when the distance between the microphone unit and the synthesizer is long, the influence of induced noise 5i- is injected into the microphone unit to reduce it. An impedance converter such as an effect transistor is built in, and the output is transmitted after converting it to a low impedance. -Multi-mixing When collecting sound, a method is adopted that combines the outputs of microphone units directed toward multiple speakers. Figure 2 shows the two sides of the multi-mixing sound collection. For example, this corresponds to a case where a microbong is placed for each speaker to amplify or record sound at a roundtable discussion. In Fig. 2, 32-1.32-2...32-5 are speakers, 30-1.30-2...30-6 are microphone units, Ishibeguns converters, output circuits, A microbon with a built-in power supply and the like, 31 is a synthesizer.

By the way, when transmitting the microphone output through an optical fiber, the output of the microbon unit color is converted to an electrical-to-optical converter (hereinafter referred to as r-1, 10 converter) optical signal 5'' by an electrical signal converter, and this The optical signal 3 from the E10 converter is transmitted by optical fiber, but as mentioned above, the microphone output with directional splitting by the microphone array and the multi-mixing sound collection/hi-microphone output are transmitted by optical fiber. If you try to do this, you will need a new E10 converter to obtain optical signals, and this new E10 converter must be installed for each microphone unit, which makes the configuration complicated and increases the cost. I got it.

OBJECTS OF THE INVENTION An object of the present invention is to enable directivity control and multi-mixing by a microphone array without using a new converter for optical fiber transmission. The goal is to provide a microbot that can perform the following tasks.

Structure of the Invention The microphone of the present invention has a 1-A microphone unit coupled to a single-power laser output surface of a single semiconductor radar with a strong self-coupling effect by an optical fiber, and the other side of the conductor laser. An optical fiber 7' is coupled to the laser output surface of the laser. With this configuration, hi+: 1' Laser light from one laser output surface of the conductor laser is irradiated onto the vibrating membrane as an external mirror configured inside the plurality of microphone units via each of the optical fibers. Since the reflected light from these diaphragms can be fed back to the semiconductor laser via each of the optical fibers, the feedback light from the plurality of microphone units can be fed back to the Fabry-based laser configured in the semiconductor laser. They can be combined in a Perot resonator and interfered to produce changes in the intensity of laser light. With that, a new E
10 Even without a converter, the output from the microphone unit can be converted and synthesized into an optical signal, and the optical fiber coupled to the output surface of the other laser of the conductor laser It has the advantage of being able to detect and transmit changes in light intensity.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described. FIG. 3 shows an embodiment of the present invention, in which 40-1.
4o-2, 40-3 are microphone units, and vibration membranes 41-1.41-2.41-3 serve as external mirrors.
have.

42-1, 42-2, and 42-3 are optical fibers, one end of which is connected to the microphone output port 40-1.
The vibrating membranes 41-1, 41-2, and 41-3 as external mirrors constituting 40-2, 4o-3 are coupled to face each other. Reference numeral 44 denotes a semiconductor laser with a strong self-coupling effect, and the other ends of the optical fibers 42-1, 42-2, and 42-3 are coupled to one laser output surface of the semiconductor laser so as to face each other. Reference numeral 43 denotes an optical fiber, one end of which is coupled so as to face the other laser output surface of the semiconductor laser.

The principle of acoustic-to-optical conversion in a microphone with such a configuration is that a laser beam from a semiconductor radar is irradiated onto a diaphragm, and the reflected light, which is phase-modulated by the change in the diaphragm, is converted into a semiconductor laser fabric.・It detects the intensity change of the laser beam caused by feedbanking and interference in the bellows resonator as a microphone output, and the microphone output appears as a change in light intensity, so it is a new E10.
No converter is required. However, in this case, in order to add directivity to the microphone, the microphone unit must be made up of a microphone array stone 10 to provide directivity. Therefore, the plurality of microphone units 40-1, 40-2, and 40-3 are arranged on the same axis so that their directivity axes face forward. Therefore, the outputs of a plurality of microphone units can be combined with one semiconductor laser.

In addition, in the case of multi-mixing sweat absorption, one ゛1'-
A plurality of microphone units coupled to one laser output surface of a conductor laser via a plurality of optical fibers may be arranged in a multi-way arrangement so as to face the speaker.

Effects of the Invention As described above, according to the present invention, one laser output surface of one semiconductor laser with a strong self-coupling effect,
Since the other ends of the plurality of optical fibers connected to the microphone outputs are connected so as to face each other, the outputs of the plurality of microphone units can be synthesized by the Fabry-Perot device in the semicircular body. I can do it. Therefore,
Since the combined microphone output is obtained as an optical signal on the other laser output surface of the semiconductor laser, optical fiber transmission is effective and there is no effect of induced noise even on long distance transmission. Moreover, since the half +
Fiber transmission is possible without using 10 transducers.

In addition, since one semiconductor laser can be used for multiple microponses, only one semiconductor laser drive circuit, output circuit, power supply, etc. are required. , it is also advantageous for power saving. In fact, since the microphone units can be arranged freely using the optical fiber, it has the advantage of allowing for free design such as multi-mixing and directivity control.

[Brief explanation of drawings]

Figures 1 and 2 are the configuration diagram of a conventional microphone.
The figure is a configuration diagram showing an embodiment of the microphone of the present invention. 40-1, 40-2, 40-3...microphone unit, 41-1. 41-2.41-3...
... Vibration membrane, 42-1.42-2.42-3.43.
...Optical fiber, 44...Semiconductor laser. Name of agent: Patent attorney Kazuo Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] Each of a plurality of microphone outputs is connected to the laser output surface of one semiconductor laser with a strong self-coupling effect by an optical fiber, and the laser light from one laser output surface of the semiconductor laser is connected. irradiating the vibrating membranes as external mirrors configured inside each of the microphone units through each of the above optical fibers, and feeding back the reflected light from these vibrating membranes to the semiconductor laser through each of the above optical fibers;
2) The feedback lights from each microphone unit are combined and interfered within the Fabry-Perot resonator of the semiconductor laser to cause a change in the intensity of the radar'-light, and the resulting change in the intensity of the Loew'-light is A microphone configured to be detected by an optical fiber coupled to the output face of the other semiconductor laser.