JPH0497698A - Microphone and digital audio equipment - Google Patents

Abstract

PURPOSE:To attain high sound quality by incorporating a microphone capsule, a microphone amplifier and an A/D converter to a microphone and amplifying a very minute signal quickly and digitizing the amplified signal. CONSTITUTION:A microphone amplifier 3, an A/D converter 4 and a conventional similar microphone capsule 2 are incorporated in a microphone 1. Since the microphone amplifier 3 and the A/D converter 4 are incorporated, a transmission signal sent to a microphone cable 6 is digitized and the microphone capsule 2 and the microphone amplifier 3 are connected by a shortest distance. Thus, the transmission loss of the microphone cable 6 is eliminated and the microphone with high sound quality is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a microphone and a digital audio device that have a built-in A/D converter and have a function of converting audio into digital signals.

BACKGROUND OF THE INVENTION In recent years, audio equipment has been digitized at a remarkable pace. However, the signal sent out from the microphone itself has not yet been digitized.

FIG. 6 is a block diagram showing the configuration of a conventional microphone and an audio device using the same.

In the figure, 1 is a conventional microphone, 16 is an analog audio device such as a cassette tape recorder,
These are connected by a balanced cable 17 for analog signals. Further, 2 is a microphone capsule for converting sound into an electric signal, 18 is an FET-stone source follower circuit, 19 is an unbalanced-to-balanced transformer, 20 is a balanced-to-unbalanced transformer, and 3 is a microphone amplifier.

The operation of the conventional microphone and audio device configured as described above will be explained below.

First, the microphone capsule 2 converts the sound into a minute electric signal, the current is amplified by the high input impedance source follower circuit 18, the unbalanced-balanced transformer 19 performs unbalanced-balanced conversion and impedance conversion, and then An analog audio signal is output to the cable 17. In the analog audio device 16, the input analog audio signal is first subjected to balanced-unbalanced conversion and impedance inverse conversion by a balanced-unbalanced transformer 20, and then amplified by a microphone amplifier 3 having a voltage amplification degree (gain) of about 40 dB. do.

Problems to be Solved by the Invention However, in the conventional configuration described above, the voltage gain is
B source follower circuit and voltage gain is approximately -20dB
Because the unbalanced-balanced transformer outputs the Akilog audio signal, the signal transmitted over a long balanced cable that exceeds 3 to 30 m will have a voltage level of -20 dB compared to the output signal of the microphone capsule. . Since this signal is a minute signal, there is a problem in that the transmission loss of information is large, resulting in deterioration of sound quality.

The present invention solves the above-mentioned conventional problems, and aims to provide an excellent microphone compatible with digital audio devices that can eliminate information transmission loss caused by connection cables between microphones and audio equipment, and can perform signal processing with high sound quality. purpose.

Means for Solving the Problems In order to achieve the above object, the present invention incorporates a microphone capsule, a microphone amplifier, and an A y"D':E inverter into a microphone, digitizes the signal in the microphone, and transmits the signal on the microphone cable. It is designed to send out digital signals.

Effects of the Invention With the above-described configuration, the present invention digitizes the audio signal transmitted over the microphone cable, thereby easily solving problems such as transmission distortion and S/N reduction due to transmission loss, which are unavoidable when transmitting analog signals. This can be avoided and the sound quality of the audio device can be improved.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

Embodiment 1 FIG. 1 is a block diagram of a microphone and a digital audio device using the same according to a first embodiment of the present invention. In the figure, 1 is the microphone of this embodiment,
In addition to the conventional microphone capsule 2, there is also a microphone amplifier 3.
It has a built-in A'D converter 4. 5 is a digital audio device that has functions equivalent to conventional analog audio devices. The microphone 1 and the digital audio device 5 are connected by a digitized microphone cable 6.

The operation of the microphone configured as above and the digital audio device using the same will be explained below.

First, the microphone capsule 2 converts the sound into an electrical signal, and the microphone amplifier 3, which has a high input impedance and a voltage gain of about 20 dB, amplifies the sound to a voltage level that can be converted into A and 'D. It is converted into a digital signal and output. This digitized audio signal is transmitted through the microphone cable 6 and
The signal is input to a digital audio device 5 such as an AT or a digital compatible amplifier.

As described above, according to this embodiment, the microphone amplifiers 3, !
By incorporating the Ay'D converter 4, the transmission signal sent to the microphone cable 6 is digitized, and by connecting the microphone capsule 2 and microphone amplifier 3 at the shortest distance, the microphone cable 6 can be transmission loss is eliminated, and a high-quality microphone can be provided.

Embodiment 2 A second embodiment of the present invention will be described below with reference to FIG.

FIG. 2 is a block diagram of a microphone and a digital audio device using the same, showing a second embodiment of the present invention.

In the figure, 2 is a microphone capsule, 3 is a microphone amplifier, 4 is an A/D converter, and 5 is a digital audio device, which is the same as the configuration shown in FIG. 1.

The difference from the configuration shown in FIG. 1 is that the microphone 1 has a built-in wireless transmitter 7 and a wireless receiver 8 is provided on the input side of the digital audio device 5, thereby making the microphone 1 wireless.

The microphone configured as described above and the digital audio device using the same will be described below, focusing on the operations specific to the second embodiment.

First, an audio signal digitized by the A/D converter 4 built into the microphone 1 is modulated into a wireless digital audio signal 9 by the wireless transmitter 7 and transmitted. This signal is received by the wireless receiver 8 and demodulated into a digital audio signal, which is input to the digital audio device 5.

As described above, by making the microphone 1 wireless, the microphone cable 6 shown in FIG. 1 becomes unnecessary, and the installation and connection of the digital microphone becomes extremely flexible. Furthermore, since the audio signal is converted into a wireless signal after being digitized, there is no loss of sound quality due to transmission loss or modulation distortion. This allows for high sound quality,
Moreover, a microphone that can be installed freely and a digital audio device using the microphone can be realized.

Embodiment 3 A third embodiment of the present invention will be described below with reference to FIG.

In the figure, 2 is a microphone capsule, 4 is an A/D converter, and 5 is a digital audio device, which has the same configuration as that shown in FIG. What is different from the configuration shown in FIG. 1 is that the microphone 1 has a built-in amplification control circuit 10 for controlling the amplification degree of the built-in microphone amplifier 3, and a control logic circuit 11 is provided on the digital audio equipment side. This is where the signal line 12 is connected.

The microphone configured as described above and the digital audio device using the same will be described below, focusing on the operations specific to the third embodiment.

A control signal (digital signal) is transmitted from the control logic circuit 11 provided in the digital audio device 5 (E) through the control signal 112, and is converted into an analog amplification control signal by the amplification control circuit 10. Control the amplification degree of 3.

As described above, by controlling the amplification degree of the microphone amplifier 3 by remote control using the control logic circuit 11, the level meter etc. on the digital audio device 5 side can
It becomes possible to control the input signal level of the A/D converter 4 while monitoring the characteristics of the A/D converter 4 so that the characteristics of the A/D converter 4 can be used effectively.As a result, quantization distortion is reduced and sound quality deterioration caused by this is eliminated. .

Embodiment 4 A fourth embodiment of the present invention will be described below with reference to FIG.

FIG. 4 is a block diagram of a fourth embodiment of the present invention. In the figure, 2 is a microphone capsule, 4 is an A/D converter, and 5 is a digital audio device, which is the same as the configuration shown in FIG. Also, 3 is a microphone amplifier, which is the same as the one in Fig. 3. The configuration unique to FIG. 4 is that the microphone 1 has a built-in digital signal processor (hereinafter referred to as DSP) 13.

The microphone configured as described above will be described below, focusing on operations specific to the fourth embodiment.

When the conversion data of the A/D converter 4 is input to the DSP 13, the DSP 13 detects the voltage level of the output signal of the microphone amplifier 3 from this data, and calculates the full scale of the A/D converter 4 based on the data for a certain period of time. A signal is output to the microphone amplifier 3 to control the voltage amplification degree of the microphone amplifier 3 to be optimal.

With the above configuration, the DS built into microphone 1
P13 makes it possible to optimally and automatically control the voltage amplification degree of the microphone amplifier 3, and as a result, it is possible to provide a high-quality microphone with little quantization distortion.

Embodiment 5 A fifth embodiment of the present invention will be described below with reference to FIG.

FIG. 5 is a block diagram of a microphone and a digital audio device using the same, showing a fifth embodiment of the present invention. In the figure, 2 is a microphone capsule, 3 is a microphone amplifier with adjustable amplification, 4 is an A/D converter, S is a digital audio device, 10 is an amplification control circuit, and l is a control logic circuit, the configuration of which is shown in FIG. is the same as

Moreover, the wireless transmitter 7 and the wireless receiver 8
It is similar to the one shown in the figure. The configuration unique to FIG. 5 is that the microphone 1 includes a control signal wireless receiver 14 for the amplification control signal of the microphone amplifier 3, and the digital audio device 5gI is provided with a control signal wireless transmitter 15.

With the above configuration, control signals are also made wireless, and the third
In addition to the high sound quality shown in the embodiment, it is possible to provide a microphone that can be installed extremely freely, and a digital audio device using the same.

Effects of the Invention As described above, the present invention has a microphone with a built-in microphone capsule, microphone amplifier, and A/D converter, and has a configuration that quickly amplifies and digitizes minute signals. (with no transmission loss of information), it can provide a microphone with high sound quality.

Furthermore, since the configuration is such that the connection between the microphone and the audio equipment is digitized and then wireless, it is possible to provide a digital audio device using a microphone that can be installed extremely freely while maintaining high sound quality.

Furthermore, the configuration that allows the amplification degree control of the microphone amplifier built into the microphone makes it possible to effectively utilize the performance of the A/D converter, and as a result, it is possible to provide a high-quality microphone with little quantization distortion.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a microphone according to a first embodiment of the present invention and a digital audio device using the same, and FIGS.
A block diagram showing the configuration of a microphone in a fifth embodiment and a digital audio device using the same;
The figure is a block diagram showing the configuration of a conventional microphone and an audio device using the same. 1...Microphone, 2...Mic capsule, 3...Mic amplifier, 4...
A/D converter, 5...Digital audio equipment, 6...Microphone cable, 7...White...Wireless transmitter, 8...Wireless receiver, 9... ...Wireless digital audio signal, 1o...Amplification degree control circuit, 11...
Control logic circuit, 12... Music/digital control signal line, 13... Digital signal processor, 14... Wireless receiver for control signal, 15
...Wireless transmitter for control signals. Name of agent: Patent attorney Shigetaka Awano

Claims (5)

[Claims] (1) A microphone that has a built-in microphone capsule, microphone amplifier, and A/D converter, and has the function of converting audio into digital signals. (2) A digital audio device in which a wireless transmitter is added to the microphone according to claim 1, a wireless receiver is provided on the digital audio device side, and the connection between the microphone and the digital audio device is made wireless and digital. (3) A digital audio device in which a microphone amplifier amplification degree control circuit is added to the microphone according to claim 1, and the amplification degree of the microphone amplifier is remotely controlled by a control logic circuit provided on the digital audio device side. (4) The microphone according to claim 1, further comprising a digital signal processor to automatically control the amplification degree of the microphone amplifier by digitally processing the output of the A/D converter. (5) A microphone amplifier amplification control circuit, a wireless transmitter for digital audio signals, and a wireless receiver for control signals are added to the microphone according to claim 1, and wireless reception for digital audio signals is provided on the digital audio device side. A digital audio device that remotely controls the amplification level of a microphone amplifier by installing a wireless transmitter and a wireless transmitter for control signals.