KR920001796Y1 - Stereo wireless radio transmitter and receiver for head phone - Google Patents

Abstract

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Description

Stereo wireless headphone transmitter and receiver

1 is a perspective view of an acoustic device, a transmitter, and a receiver according to the present invention.

2 is a detailed circuit diagram of a transmission circuit provided in the transmitter in the stereo wireless headphone transmission and reception apparatus of the present invention.

3 is a block diagram of a transmission circuit provided in the transmitter of the present invention.

Figure 4 is a detailed circuit diagram of the receiving circuit provided in the receiver in the stereo wireless headphone transmitter and receiver of the present invention.

* Explanation of symbols for main parts of the drawings

A: Sound device 1: Transmitter body

1B: Wireless headphone unit 4, 4, 8, 8 ': Antenna

15, 15 ': Speaker 18, 18': Low frequency amplifier stage

19, 19 ': High range emphasis 20, 20': FM modulation / local oscillation

21, 21 ': Multiplier 24, 24': RF amplifier

25, 25 ': mixed / local oscillation stage 26, 26': intermediate frequency amplification stage

27, 27 ': detector 28, 28': audio amplifier

The present invention relates to a stereo wireless headphone transmission and reception apparatus for receiving sound of an acoustic device wirelessly at a long distance. In particular, the stereo audio signal of the left and right channels output from the audio device can be FM at different frequencies from the transmitter side. Stereo radio headphone transmission and reception device that modulates and transmits each channel, and the receiver embedded in the headphone outputs the received audio signal to the speaker through the signal processing (detection and amplification) path for each channel. It is about.

In the conventional sound equipment, the headphone and the sound equipment are connected by wires, which causes inconvenience in the range of activity, and in order to solve such inconvenience, the infrared transmitter is connected to the main body of the sound apparatus as a headphone device using wireless communication. In addition, the infrared receiver is provided on the headphone side so that the audio signal can be wirelessly modulated by infrared modulation, which is inconvenient due to the limitation of reception due to the reception direction and angle of the headphones and the intervention of obstacles in the center.

In another case of the conventional wireless headphone device, an FM signal is modulated and transmitted on the transmitter side, and a receiver is demodulated to listen to the sound. However, this is a single transmission frequency for the audio signal of the left and right channels on the transmitter side. It is difficult to exclude the noise effect of 19KHZ generated by the stereo separator, and it is inevitable that the sound quality is inevitable because the receiver side separates and amplifies the audio signal of the left and right channels using the stereo separator. .

According to the present invention, the left channel audio signal and the right channel audio signal output from the audio stage of the audio device are FM-modulated and transmitted at different transmission frequencies, respectively. By demodulating through the signal processing path to listen to the audio signal to the left and right speakers, it eliminates the limitations of the conventional wired headphone and the infrared headphone, as well as the simultaneous separation of the left and right channels and stereo separation at the receiving side. The purpose and object of the present invention is to provide a stereo wireless headphone transmitting and receiving device that can eliminate the disadvantages and facilitate the audio listening and improve the reception sound quality. The effect will be described in detail as follows.

First, referring to FIG. 1, a configuration of an acoustic apparatus, a transmitter, and a receiver to which the present invention is applied will be described. In the conventional stereo audio apparatus A, the transmitter body (A ') of the stereo jack hole A' of the acoustic apparatus A is described. 1) Insert and connect the stereo plug 17 of the transmission control device section 1A installed in the inside of the transmitter body 1 in a pair of boards that constitute the transmission circuit which is the electrical device circuit shown in Figs. To the left and right headphones to transmit stereo sound of different audio channels for each audio channel, and the power switch (2), the variable resistance handle (10) (10 '), and the charge indicator lamp (3) on the upper surface of the transmitter body (1). 3 ', the radio wave transmitting antenna 4, 4' is formed, and the ordinary adapter charging jack hole 5, 5 'is formed on the side of the transmitter body 1, and the wireless headphone device 1B The headband 6 is connected between the left and right support 7 and the right head support 7 Receiving antennas (8) (8 ') are inserted into the hanging holes (7' ') perforated in the formed clamping portion (7') and receiving variable resistance handles (13) (13 ') in the head caps (9) and (9'). ), The adapter charging jack 11, the adapter charging indicator (12) is installed, the switch variable resistance handle 13, 13 'is equipped with a switch (2') inside the left and right head cap (9) (9 ') Is provided with a circuit board 14 composed of the receiving circuits shown in FIGS. 4 and 5, and speaker 15 and 15 'are formed at the center thereof, and shield wires 16 are connected to the left and right circuit boards 14, respectively. Configuration.

The method of using the wireless headphone song and receiver according to the present invention configured as described above will be briefly described. First, the jack hole A 'of the conventional stereo sound apparatus A is drawn out from the transmitter 1A of the present invention. Insert the stereo plug (17) When the pole is inserted into the adapter jack hole (5) (5 ') installed on the side of the body (1), the charging indicator lamp (3) turns on, and after a certain period of time, the charging completion indicator lamp (3') displays the charging completion. Becomes

At this time, when the ON switch 2 is operated, the transmission circuit device part, which is the transmission control device part 1A circuit, operates inside the body 1 to transmit the output audio signal of the acoustic device A for each channel. ') Is emitted through.

At this time, in order to eliminate the interference, the paired antennas 4 and 4 'connected to the radio wave generator of the substrate are " "If you adjust the shape, the transmission antenna (4) (4 ') separates the left and right channel audio signals into two transmission frequencies with different frequencies, so that the transmission antenna (4) (4') has more effective propagation. Can be sent.

At this time, if you adjust the variable resistance handle (10) (10 ') according to the distance of the wireless headphone device (1B), the intensity of the outgoing radio wave is adjusted to listen to the stereo sound received from the headphone speaker (15) (15') You can do it.

On the other hand, the radio headphone unit 1B also has an antenna 8 (8) addressed to the headband 6 in the radio receiver headphone unit 1B as the reception circuit operates by the power charged in the same manner as described above. The audio signal of the left channel and the audio signal of the right channel received at ') are input to the receiving circuit of the circuit board 14 inside the head caps 9 and 9' as the connection of the shield wire 16, thereby receiving the receiving circuit. According to the signal processing for each channel, the sound is output from the speaker 15 (15 '), so that the stereo sound can be heard very clear, that is, no noise at all.

In particular, the present invention is equipped with a variable resistance adjusting handle (3) (3 ') that can adjust the sound to be strong or weak, so that the volume can be adjusted to hear very clear stereo sound.

As described above, the transmission circuit of the present invention, which is provided in pairs in the transmitter body 1 for wirelessly transmitting the output audio signal of the acoustic device A for each of the left and right channels, has a plug 17 as shown in FIG. The audio signal of the left channel LEFT CHANNEL is adjusted from the audio signal (output of the audio device A) input through the control unit 10 of the variable resistor VR to adjust its input level and the variable resistor VR The audio signal of the predetermined level adjusted by the < RTI ID = 0.0 >

The amplified audio signal is subjected to the FM modulation / local oscillation stage of the rear stage after the high-frequency emphasis for improving the signal-to-noise ratio according to the time constants of the resistor (R) and the capacitor (C) in the pre-emphasis (19). Local oscillation and FM modulation by the transistors Q13 and 15 of the transistor 20 are delayed. At this time, the local oscillation frequency and the FM modulation frequency (transmission frequency for the audio signal of the left channel) are set appropriately. The frequency is different from the right channel transmission frequency by the right channel transmission circuit, which will be described later.

The audio signal of the FM-modulated left channel is multiplied and amplified by the multiplier 21 composed of the transistor Q14 and the transformer L6 and then output through the antenna 4.

Such a transmission operation is performed by supplying power to the entire circuit from the power supply unit 22 by turning on the power switch 2 and the power supply unit 22 can be charged at any time by the quick charging unit 23, and the state of charge is Represented by lamps 3 and 3 ', the transistor Q17 is for comparison with a reference voltage, and when charging is complete, the charging stop signal is supplied from the transistor Q20 to the transistors Q15 and Q16 to cut off the charging power. This is the same as a normal battery charging circuit.

The transmitting circuit of FIG. 2 is for transmitting the audio signal of the left channel among the audio signals output from the acoustic apparatus A. In the transmitter body 1 of FIG. The same configuration is provided for the RIGHT CHANNEL, and a pair of left and right channel transmission circuits is provided.

3 is a block diagram of a transmission circuit according to the present invention, which shows a low frequency amplifier stage 18, a high frequency emphasis unit 19, and an FM modulation / local oscillation stage 20 for a left channel audio signal as shown in FIG. , A multiplier 21, a low frequency amplifier stage 18 'for the right channel audio signal with a transmit antenna 4, a high-frequency amplification section 19', an FM modulator / local oscillator 20 ', a multiplier 21' , The transmission antenna 4 'is configured and its operation is the same as the audio signal processing operation of the left channel, but the transmission frequency of the right channel (the transmission frequency of the FM modulator / local oscillator 20' and the multiplier 21 '). Is different from the transmission frequency of the left channel.

In other words, the present invention separates the left and right channels of the audio signal output from the acoustic device A, and transmits the signals at separate transmission frequencies after signal processing.

FIG. 4 shows a receiving circuit of the audio signal transmitted as described above. The left channel receiving circuit is constituted by the circuit board 14 of the wireless headphone unit 1B in FIG.

That is, only the audio signal of the left channel is tuned and amplified in the RF amplifier stage 24 including the coils L1 and L2 and the transistor Q1 among the audio signals received by the antenna 8 in FIG. Subsequently, in the mixed / local oscillation stage 25 including the subsequent coils L3 and L4 and the transistor Q2, an intermediate frequency signal of 10,7MHZ, which is a difference from the local oscillation signal generated by the coil L4, is converted into a transistor ( Q2) It is output from the collector stage and supplied to the intermediate frequency amplifier stage 26.

The intermediate frequency signal supplied to the intermediate frequency amplifier stage 26 is amplified by three stages by three transistors Q2, Q4 and Q5 and the intermediate frequency transformers T1, T2 and T3, and the amplified intermediate frequency signal is detected by a detector ( 27, the audio signal (low frequency signal) of the left channel is detected and output from the detection transformer T4 by the detection circuit including the transformers T4 and T5, and the low frequency signal is handled by the handle 13 of the variable resistor VR. After adjusting the pressure level (volume) is supplied to the audio amplifier stage 28.

In the audio amplifier stage 28, the audio signal of the input left channel is amplified by the amplification IC IC1 and output to the speaker 15 of the left channel.

Such a reception operation is performed by supplying power to the entire circuit from the power supply unit 29 by turning on the power switch 2 'and the power supply unit 29 can be frequently charged by the rapid charging unit 30 and is in a charged state. Is indicated by the lamps 12 and 12 ', and its configuration and operation are the same as those of the rapid charging circuit 23 of the transmitting circuit in FIG.

That is, the transistor Q8 is for comparison with a reference voltage, and when charging is completed, the charging power supply is cut off by supplying the charging battery signal from the transistor Q11 to the transistors Q6 and Q7, which is the same as a conventional battery charging circuit.

The receiving circuit of FIG. 4 is for receiving the audio signal of the left channel transmitted from the transmitter body 1 side. In the wireless headphone device 1B according to the present invention, such a receiving circuit is the same for the right channel. A pair of left and right channel pairs receiving circuits is provided.

5 is a block diagram of the receiver circuit of the present invention showing the antenna 8, the RF amplifier stage 24, the mixed / local oscillation stage 25, the intermediate frequency amplifier stage 26, the detection for the left channel audio signal The unit 27, the audio amplifier stage 28, the speaker 15 is configured, the operation is the same as the audio signal processing operation of the left channel, but the RF amplifier stage 24 'that the tuning for the transmission frequency of the right channel, the RF Mixed / local oscillation stage 25 'for the intermediate frequency output from the amplifying stage 24' output signal, intermediate frequency amplifier stage 26 'of the mixed / local oscillation stage 25' output signal, and the intermediate frequency amplifier stage 26 A detector 27 'for detecting an output signal of'), an audio amplifier stage 28 'of the right channel which is an output of the detector 27', and an output speaker 15 '.

That is, in the present invention, the audio signal transmitted from the transmitter side to the left and right channels, respectively, is separated from the conventional receiving circuit using a separate stereo splitter (MPX). , 15 ').

As described above, according to the present invention, the audio signal output from the audio device is connected to the headphone jack hole (A ') by plug 17 and modulates the left and right channel audio signals in the transmitter body 1 and then transmits them. The receiver on the headphone side processes audio signals transmitted for each of the left and right channels for each channel and listens through the speakers 15 and 15 '. It is possible to improve the sound quality accompanying the sound effect can be realized with the convenience of using the audio device according to the audio sound listening by wireless.

In addition, the present device may be employed as a training aid in a language lab or as an auxiliary means for interpreting a conference hall.

Claims (1)

The audio signal output from the acoustic device A is amplified at the transmitter side, multiplied after FM modulation, and transmitted to the antennas 4 and 4 '. The receiver is provided at the headphone side to receive the receiver antennas 8 and 8'. In the wireless headphone device which amplifies an FM RF signal, converts it into an intermediate frequency, detects an audio, and separates a channel through a stereo separator, and then outputs the audio to a speaker (15, 15 '), the audio output from the acoustic device (A). Among the signals, a low frequency amplifier stage 18, a high frequency emphasis section 19, and an FM modulation / local oscillation stage forming a left channel dedicated signal processing path to separately transmit audio signals of a left channel and an audio signal of a right channel at different transmission frequencies, respectively. (20), a low frequency amplifier stage 18 'that includes a multiplier 21 and forms a right channel dedicated signal processing path, a high frequency emphasis unit 19', an FM modulator / local oscillator 20 ', and a multiplier 21 ') To the left and right channel pair An RF amplifier stage 24, a mixed / local oscillation stage 25, and an intermediate frequency amplifier stage 26, which form a transmission circuit, and extracts only the left channel FM signal from the received FM signal to form a left channel dedicated signal processing path. And an RF amplifier stage 24 ', a mixed / local oscillation stage 25, an intermediate portion having a detector 27 and an audio amplifier stage 28 and extracting only the right channel FM signal to form a right channel dedicated signal processing path. Stereo wireless headphones characterized by comprising a frequency amplifier stage 26 ', a detector 27' and an audio amplifier stage 28 'as a pair of left and right channels to form a receiving circuit of the wireless headphone device 1B. Send and receive device.