JPH08271627A - Distance measuring device between loudspeaker and microphone - Google Patents

Abstract

PURPOSE: To provide a simplified device by which the distance between a loudspeaker and a microphone is measured by means of ultrasonic waves. CONSTITUTION: A sing-along apparatus is composed of a music player 4, an audio amplifier 6, loudspeakers 8, 9, 10 and a microphone 11. A time-sharing ultrasonic pulse signal which is generated by an ultrasonic oscillator 1, an ultrasonic-generation-timing creation circuit 2 and an analog switch 3 is superposed on the output of the audio amplifier 6 via a mixer 7, and a superposed signal is transmitted sequentially to the respective loudspeakers 8, 9, 10. Sounds by the respective loudspeakers 8, 9, 10 are received by the microphone 11, a received signal is passed through a high-pass filter 12, and an inaudible-band ultrasonic signal is taken out so as to be output to a distance-between- loudspeaker-and-microphone measuring circuit 14. A pulse signal by the ultrasonic-generation-timing creation circuit is input simultaneously to the circuit 14, their timings are compared, the ultrasonic arrival time between the respective loudspeakers 8, 9, 10 and the microphone 11 is found, and the distance between them is measured on the basis of the spatial propagation speed of ultrasonic waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker and microphone distance measuring device, and more particularly to a device for outputting the sound of a microphone to a large number of speakers for measuring the distance between each speaker and the microphone.

[0002]

2. Description of the Related Art In a karaoke apparatus or the like, it is often desired that the volume of a singing voice unrelated to oneself be lowered. To solve this, many speakers are installed and the volume of the speaker near the microphone of the singer is increased. However, the speaker volume is controlled by humans. ing. To automatically perform this speaker volume control,
It is necessary to measure the distance between the mosquito and the microphone.

Conventionally, as a method of generally detecting the distance between the speaker and the microphone, there is a method of utilizing the ultrasonic wave in the inaudible band and calculating the distance from the arrival time of the ultrasonic wave, for example, Japanese Patent Laid-Open No. 6-138224. The one described in Japanese Patent Publication is known.

This is because the time required for an ultrasonic pulse transmitted from an ultrasonic transducer to hit an object and be reflected, and for the reflected wave to return to the ultrasonic transducer again is determined via a comparator circuit. Then, the distance to the object is measured.

[0005]

However, in the above-mentioned prior art, it is necessary to newly install ultrasonic wave distance measuring means at the positions of the respective speakers and microphones, and control these measuring means and measure information. There is a drawback in that the entire device is complicated and the price is expensive, such as the need for a means for collecting.

An object of the present invention is to make the above-mentioned ultrasonic wave distance measuring means as simple as possible so that the speaker and microphone of the object to be measured for distance measurement are part of the ultrasonic wave distance measuring means. The purpose is to simplify the distance measuring device using ultrasonic waves as much as possible.

[0007]

The above object is to use a speaker capable of generating an inaudible band ultrasonic wave and a microphone capable of receiving the same in an acoustic device, and to use this as a part of an ultrasonic distance measuring device. To do.

Further, the ultrasonic distance measuring apparatus superimposes the ultrasonic signal from the ultrasonic pulse generating means on the output of the audio amplifier and generates it from the speaker.
It is not necessary to have a separate signal line for controlling the ultrasonic wave generation means.

Further, in receiving the ultrasonic pulse, since the ultrasonic wave is superposed on the audible band audio signal sent from the microphone side to the mixer, the ultrasonic pulse signal is separated by using a high pass filter. This eliminates the need to use a separate line for collecting information.

Next, as a method for distinguishing which ultrasonic pulse is emitted from the speaker, a means for superimposing the ultrasonic pulse on the signal sent from the audio amplifier to each speaker in a time-division manner is taken. Achieve by

[0011]

[Operation] The inaudible band ultrasonic pulse sent from each speaker in time division is received by the microphone, the ultrasonic pulse signal is separated using the high pass filter, and the arrival time of each ultrasonic wave is detected. Calculate the distance between each speaker and the microphone.

[0012]

The present invention will be described below with reference to examples. FIG.
Is an embodiment of the present invention and is applied to a karaoke apparatus including a music player 4, an audio amplifier 6, speakers 8, 9, 10 and a microphone 11.

In the figure, an inaudible band ultrasonic wave generated by the ultrasonic oscillator 1 is an ultrasonic wave generation timing generation circuit 2
Analog switch 3 by controlling the pulse signal created in
Are separated and become time-division ultrasonic pulse signals.

This ultrasonic pulse signal is superimposed on the output of the audio amplifier 6 via the mixer 7, and the speaker 8 and
9 and 10 are sequentially transmitted as inaudible band ultrasonic pulses. This transmitted ultrasonic pulse is received by the microphone 11 side through each space, converted into an electric signal, and then converted into an inaudible band signal (ultrasonic wave) by the high pass filter 12 and an audible band signal (voice signal) by the low pass filter 13. ) Is separated into
The inaudible band signal is measured by the speaker / microphone distance measuring circuit 14
Is input to

The speaker / microphone distance measuring circuit 14 also receives the pulse signal generated by the ultrasonic wave generation timing generating circuit 2 at the same time, and the microphone 11 is used as a reference.
The signals received by are compared with each other to calculate the arrival time of the ultrasonic pulse from each of the speakers 8, 9 and 10 to the microphone 11, and from this and the spatial propagation velocity of the ultrasonic wave, each of the speakers 8,
The distance between 9 and 10 and the microphone 11 is calculated. The speaker volume control can be automatically performed based on the measurement result of the distance between each of the speakers 8, 9, 10 and the microphone 11.

That is, in order to control the audio amplifier 6 by the amplifier gain control circuit 15 using each distance measurement signal of the measurement circuit 14 to increase the volume of the speaker 8 close to the microphone 11 or to output a stereo sound. Is microphone 11
The volume of the speaker 10 far from is increased.

The audible band signal separated by the low pass filter 13 is fed back and superposed on the output signal of the player 4 by the mixer 5.

The speaker and microphone distance measuring device of the present invention can be applied to various audio devices other than the karaoke device.

[0019]

As described above, according to the invention, it is not necessary to have an independent ultrasonic distance measuring device for measuring the distance between the speaker and the microphone, and the ultrasonic wave electric signal generating means and the microphone side receive. An inexpensive device can be achieved with a simplified circuit configuration in which a means for calculating the distance between the speaker and the microphone is detected on the audio amplifier side by detecting the arrival time of the ultrasonic wave from the ultrasonic electric signal. can do.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

[Explanation of symbols]

1 ... Ultrasonic oscillator, 2 ... Ultrasonic wave generation timing creation circuit, 3 ... Analog switch, 4 ... Music player, 5,7
... mixer, 6 ... audio amplifier, 8, 9, 10 ... speaker, 11 ... microphone, 12 ... high-pass filter, 13 ...
Low-pass filter, 14 ... Speaker-microphone distance measuring circuit, 15 ... Amplifier gain control circuit.

Claims (1)

[Claims] 1. In a speaker-microphone distance measuring device in an audio device in which a plurality of speakers are installed for a microphone, a time division pulse signal of an inaudible band ultrasonic wave is superimposed on an audible band signal circuit of the audio device. The distance between each speaker and the microphone is measured from the timing of the means for transmitting to the speaker, the inaudible band ultrasonic signal separated from the signal received by the microphone and the time-division pulse signal of the transmitted inaudible band ultrasonic wave. And a distance measuring device between a speaker and a microphone.