JPS58201500A - Stereophonic sound reproducer - Google Patents

Abstract

PURPOSE:To attain a single reproducing circuit and to simplify the constitution, by switching and reproducing sound signals of plural channels sequentially with a pulse generating circuit and two switching circuits. CONSTITUTION:A stereo pickup 22 detects sound signals of two channels recorded on a disc and introduces the left and right channel sound signals to the 1st switching circuit 23 respectively. A pulse generating circuit 28 introduces a pulse signal in a predetermined period T with almost 50% of duty ratio. This pulse signal is given to the 1st switching circuit 23 and the 2nd switching circuit 25. The circuit 23 has a switch 29 switching the switching mode at the rise and the fall of the pulse signal from the pulse generating circuit 28. Further, the circuit 25 has a switch 37 switching the switching mode at the rise and the fall of the pulse signal from the circuit 28. The switch 37 has individual contacts 38, 39. The individual contacts 28, 29 are connected to balancing circuits 41, 42 arranged corresponding to the left and right channels, the power is amplified to drive speakers 26, 27 of the left and right channels.

Description

[Detailed description of the invention] The present invention relates to a stereophonic sound reproduction device.

Referring to FIG. 1, in the prior art, a stereo pickup 1 detects an acoustic signal which is an electrical signal such as a two-channel human voice or music recorded on a disk. From this stereo pickup 1, a left channel audio signal and a right channel sound l1l (No. 11) are derived.The audio signal of each channel from the stereo pickup 1 corresponds to the left and right channels individually. Two regeneration circuits 2.3 are provided for regeneration.

The reproduction circuit 2 includes an equalizer circuit 4, a voltage amplification circuit 5, and a tone control circuit 6. The left channel audio signal from the tone control circuit 6 of the reproduction circuit 2 is provided to the next speaker 8 via the power amplification circuit 7, which is arranged in correspondence with the left channel. The speaker 8 outputs sound corresponding to the left channel sound signal. The reproducing circuit 3 has the same structure as the reproducing circuit 2, and includes an equalizer circuit 9, a voltage amplification circuit IO, and a tone control circuit wA11. The sound signal of the right channel from the tone control circuit 11 of the reproduction circuit 3 is given to nine speakers 13 arranged corresponding to the right channel via a power amplification circuit 12t.
3 outputs sound. With this configuration, stereophonic sound is reproduced.

However, since two sets of reproducing circuits are required, the configuration becomes complicated, the configuration space becomes large, the power consumption becomes large, and the cost becomes high. Furthermore, in the case of a plurality of channels, for example, four channels, four sets of reproducing circuits having the same configuration as d1 are required.

An object of the present invention is to solve the above-mentioned technical problems and provide a three-dimensional sound reproduction device that requires only a single reproduction circuit, has a simplified configuration, and can adjust the mutual level balance between channels. It is to be.

Hereinafter, the present invention will be explained in detail with reference to FIG.

FIG. 2 is a block circuit diagram of an instant embodiment of the present invention.

The two-channel sound No. 48 recorded on a medium 9, for example, a disk, is reproduced three-dimensionally by the three-dimensional sound reproduction device 21. The stereophonic sound reproducing device 21 includes a stereo pickup 22 as an acoustic @ signal detector, a %l switching circuit 23, a single reproducing circuit 24, a second switching circuit 25, and two balance circuits 41 and 42. , two power amplifier circuits 43, 44, and two speakers 26°2
7 and a pulse generation circuit 28, the stereo pickup 22 detects the 92-channel sound recorded on the disk (M'1',
The left and right channel audio signals shown in FIG. 2 are respectively led out to the first switching circuit 23.

Note that the waveforms of the left and right channel audio signals shown in FIGS. 3(1) and 3(2) are shown as equalized waveforms for convenience.

As shown in FIG. 3(3), the pulse generating circuit 28 derives a pulse signal at a predetermined constant period T and at a duty ratio of approximately 50 inches. This noise signal is transmitted to the first switching circuit 23 and the second switching circuit 2.
given to 5. The same wave number 1/T of the pulse signal is 40k, assuming that the upper limit of each acoustic signal @ii& is 20k)lz
Selected above Hz.

The first switching circuit 23 is composed of a semiconductor element such as a transistor, a relay, etc., and a switch 29f that changes the switching mode 'Jk at the rise and fall of the pulse signal from the pulse generation circuit 28:
have The switch 29 comprises individual contacts 30.31 and a common contact 32.

The individual contact 30 has the stereo pickup 22 on the left side.
The audio signal of the channel is applied, and the individual contact 31 is applied with the audio signal of the right channel.

Common contact 32 is connected to an input of regeneration circuit 24 .

At time [1] at the rising edge of pulse No. M, the switch 29 switches to the state shown in the second diagram, and the individual contact 30
and the common contact 32 are electrically connected. At time t2 when the pulse signal falls, the switch 29 is switched and the individual contacts 31 and the common contact 32 are made conductive. At the next rising edge of the pulse signal, at time t3, the switch 29 is switched again and the individual contacts 30 and the common contact are made conductive. In this way, the switching mode 1 of the switch 29 is changed over.

During the high level period of the pulse signal, the left channel audio signal is given to the reproduction circuit 24 as shown in FIG.
As shown in 6+, the sound signal of the right channel is transmitted to the reproduction circuit 2.
given to 4. Therefore, as shown in FIG. 3 (6), the reproduction circuit 24 is a 1° reproduction circuit in which the left channel acoustic signal and the right channel acoustic signal are alternately and sequentially switched at the T/2 period. 24 is an equalizer circuit 33 for making the same wave number characteristic of each acoustic signal from the first switching circuit 23 7 lat; and an equalizer circuit 3;
a voltage amplification circuit Ij1134 for voltage amplifying each acoustic signal passing through the voltage amplification circuit 34; and a tone control circuit 35 for changing the same wave number characteristic of the acoustic signal passing through the voltage amplification circuit 34.
and has. Tone control stage II of the reproduction circuit 24
! Each sound (g) shown in FIG. 3(6) from +35 is applied to the second switching circuit 25.

The second switching circuit 25ii, like the switching circuit l@23 in %l, is composed of semiconductor elements such as transistors or relays, and is a switch that changes the switching mode at the rise and fall of the pulse signal from the pulse generation circuit 28. It has 37. switch 3
7 is provided for the individual contacts 38, 39 and the common contact 401. The common contact 40 has a tone control circuit l@35.
Each acoustic signal S is given via . The individual contact point 38 is
It is connected to a balance circuit 41 arranged corresponding to the left channel. The individual contacts 39 are connected to a balance circuit 42 arranged corresponding to the right channel.

At time t1 when the pulse signal rises, the switch 37
This changes to the state shown in the second figure, and the common contact 40 and the individual contacts 38 are electrically connected. When the pulse signal falls at the 9 o'clock time [2, the switch 37 Vi is replaced and the common contact 40 and the individual contact 39 are brought into conduction 1, and at the next rise of the pulse signal at the 9 time t3, the switch 37 Switching occurs again, and the common contact 40 and the individual contacts 38 are electrically connected. In this way, the switching mode of the switch 37 is changed.

During the high level period of the pulse signal, as shown in Fig. 3 (4), the left channel sound (i!
1 is given. During the period when the pulse signal is at one level,
As shown in FIG. 3 (51), the right channel audio signal is applied to the balance circuit 42.

By operating knobs (not shown), the balance circuits 41 and 42 adjust the mutual level balance between the acoustic signals from the switching circuit 25 of the WJ2 to #, i! be done. The left channel sound signal whose level has been adjusted by the balance circuit 41 is given via the power amplification circuit 43 to the speaker 26 arranged corresponding to the left channel and outputting sound. The right channel audio signal whose level has been adjusted by the balance circuit 42 is sent to the power amplifier circuit 4.
4 to a speaker 27 arranged opposite to the right channel and outputting sound. In addition, balance circuit 4
Since the mutual level balancing between the left and right channels according to 1.42 is performed before the power amplifier circuits 43 and 44, there is no power loss.

During the high level period of the pulse signal, the left channel sound signal is applied to the speaker 26, as shown in FIG. 3(4), and the left channel sound is output from the speaker 26. During the low level period of the pulse signal, as shown in Fig. 3 (5)
As shown in the figure, the right channel sound signal is given to the speaker 27, and the right channel sound is output from the speaker 27. Although the sound of each channel output from the speaker 26 and the speaker 27 is individually discontinuous, there is no problem due to the sampling theorem, and the sound is three-dimensional and has high fidelity.

In the above embodiment, the medium is a disk, but the present invention can be applied to magnetic tape, radio waves, etc.
It can be implemented in accordance with the above. In this case, the acoustic signal detector may be a magnetic head, a magnetic tape player, a tuner, or the like. Furthermore, although the explanation has been made in the case where the acoustic signal recorded on the medium has two channels, the sound '11 signal may have multiple channels, for example four channels, and in the case of four channels, the first and second switching The circuit may include a switch having a switching function that sequentially switches four channels of audio signals. Furthermore, the reproducing circuit 24 may have other configurations.

As described above, according to the present invention, the audio signals of the *& channels are sequentially switched and reproduced by the panel generation circuit and the first and second switching circuits, so that only a single reproduction circuit is required. The configuration is simplified. Furthermore, since there is a single reproducing circuit, the configuration space is small, the power consumption is small, the cost is low, and the difference in sensitivity between multiple channels can be reduced to zero. Furthermore, each balance circuit is placed after the second switching circuit, and each power amplifier circuit is placed after each balance circuit, so the mutual level balance between each channel can be adjusted. Moreover, there is no power loss.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram of the prior art, Fig. 42 is a block circuit diagram of an embodiment of the present invention, and Fig. W2B is a ninth waveform diagram explaining the previous work. 21... Three-dimensional sound reproduction device, 22... Stereo pickup, 23... First switching circuit, 24...
... Regeneration circuit, 25 ... Second switching circuit, 2
6.27...Speaker, 28...Rigulus generation circuit,
29.37...Switch, 41.42...Balance IgIW11.43.44...Power amplifier circuit ~, 〆 ζ-/
N, No -1
No o 0

Claims (1)

[Claims] An audio system which outputs a plurality of channels of audio signals recorded on a recording medium, and derives a sound VId number for each channel.
No. 8 detector, a pulse generation circuit that derives a pulse signal at a predetermined constant period, and in response to pulse No. 1d from the dfJri pulse generation circuit, The sound of the valley channel < the l-th switching l which is derived r-orderly by switching g! l! a reproducing circuit for reproducing and outputting the signal S from the first switching circuit, and a pulse signal from the pulse generating circuit; In response, a second switching circuit that sequentially switches the f-sound signal from the reproduction circuit No. 011 to derive an audio signal for each channel; the plurality of balance circuits for adjusting the mutual level balance between the respective sound signals from the switching circuit; the plurality of power amplification circuits for amplifying the power of each sound signal via the respective balance circuits; and each channel. A stereophonic sound reproducing apparatus comprising: a plurality of speakers arranged correspondingly to each other, and outputting sound in response to each acoustic signal from each of the power amplifying circuits.