JPS6376700

Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPS6376700
[0001]
Industrial Application Field 2 The present invention relates to a wireless speaker system in sound
field reproduction having a sense of reality, with speakers arranged at the front and back. 2.
Description of the Related Art In recent years, with the spread of high fidelity video tape
recorders and video disks, sound field reproduction having a sense of reality has attracted
attention. As a prior art, for example, Noriko Ogura et al. "Consideration of oscillation and
modulation circuit", (Sho, 55.6. 10). There are space propagation techniques and sound field
regeneration techniques as shown in Ohm, P1o4o and [Technics SH-AV22 Technical Guide].
Hereinafter, an example of the wireless speaker system described above will be described with
reference to the drawings. FIG. 2 is a block diagram of sound field reproduction, and FIG. 3 is a
block diagram of a reproduction system of a rear speaker. In FIG. 2, reference numeral 23
denotes a differential amplifier for obtaining a difference signal between the stereo L channel
and R channel. A phase shifter 24 generates a time delay to the differential signal obtained by the
differential amplifier. An inverting amplifier 25 inverts the polarity of the time-delayed difference
signal. 26.27 is an amplifier for amplifying the obtained signal, 28.29 is a front speaker
(hereinafter referred to as a front speaker), and 30 ° 31 is a rear speaker (hereinafter referred
to as a rear speaker). The signal m for the rear speaker obtained by the wireless speaker system
configured as described above is frequency-modulated by the oscillator 32 generating the carrier
shown in FIG. 3 and the modulator 34. The modulated signal is spatially propagated as radio
waves. In FIG. 3, 10.17 is a high frequency amplifier for high frequency amplification of the
spatially propagated modulation signal, 11 ° 19 is an intermediate frequency amplifier, 12 and
20 are demodulators, and the spatially propagated signal is processed in order. 13.21 is an
amplifier for amplifying a signal, 30.31 is a rear speaker, and 9 and 18 are batteries for power
supply. The operation of the wireless speaker system configured as described above will be
described below. First, in FIG. 2, the stereo original signal and R are converted to a (R−L) signal
10-05-2019
1
by the differential amplifier 23, and are converted to a ψ (R−L) signal by the phase shifter 24 to
be an original signal and added. (L + ψ (R−L)) and is led to the front speaker 28 via the
amplifier 26. On the other hand, the stereo original sound R passes through the phase shifter 24
and is then inverted by an inverting amplifier to form a signal of -ψ (R−L), which is then added
to the original signal R and R−ψ (I (−L) ) And is led to the front speaker 29 via the amplifier 27.
By the way, the signal m of the rear speaker 30.31 is represented by the difference between the
above-mentioned R-(I (-L) and L + (R-L). That is, the signal of the rear speaker 30.31 is R−L−2ψ
(Ft−L), and the signal to the front speaker 28.29 is added with a phase shift difference. By doing
this, the sense of direction of the sound source in a program source such as a tape or a record is
preserved, and an acoustic effect accompanied by a sense of expansion and a sense of expansion
can be obtained. This is defined as a surround effect, and the above-mentioned sound effect is
hereinafter simply referred to as a surround 6 to -1 effect. In FIG. 2, the rear speaker 30 ° 31 is
inconvenient because it is connected by a cord, which is not preferable in practical use.
Therefore, it is conceivable to use wireless radio waves as seen in FIG. In this method, first, the
signal m for the rear speakers 30 and 31 passes through the oscillator 32 and the modulator 34
and is emitted to space as a radio wave. After the signal emitted to the space is received, it is
amplified by the high frequency amplifiers 10 and 17 and converted to the original rear speaker
signal m by the demodulators 12 and 20 through the intermediate frequency amplifier 11.19, It
is amplified by an amplifier 13.21 and amplified by a rear speaker 30 ° 31. Problems to be
solved by the invention However, in the configuration as described above, not only the resistance
to electromagnetic induction is poor and high quality acoustic signals can not be obtained, but
also the risk of generating radio interference or secrecy is maintained. There is a problem that
there is no problem, and development of a high-performance wireless speaker system has been
desired. Also, providing a two-channel signal transmitter for rear speakers and 6 to 6 on the
transmission side has a disadvantage of high cost. SUMMARY OF THE INVENTION In view of the
above problems, the present invention provides a high-performance wireless speaker system
capable of obtaining high-quality audio signals. Means for Solving the Problem In order to solve
the above-mentioned problems, the wireless speaker system of the present invention is arranged
so as to preserve the sense of direction of the sound source and to realize an acoustic effect
accompanied by a sense of expansion and a sense of expansion. A plurality of front and rear
speakers, at least one or more light emitting diodes for converting an output electric signal to the
plurality of rear speakers into an optical signal and propagating the space, receiving the optical
signal and forming an input electric signal And a transmission system comprising a combination
of at least one or more photodiodes to be converted, wherein all of the optical signals to the
plurality of rear speakers are signal light modulated at the same modulation frequency . The
present invention is a high performance wireless speaker system in which all optical signals to
rear squisker 71 \ 5 ° can be propagated in space with the same modulation signal light by the
above-mentioned configuration, and high quality acoustic signals using light can be obtained. Is
10-05-2019
2
obtained.
Embodiment A wireless speaker system according to an embodiment of the present invention will
be described with reference to the drawings. FIG. 1 is a block diagram of a wireless speaker
system in an embodiment of the present invention. In FIG. 1, the rear speaker signal m is the
same as the signal obtained in the conventional example shown in FIG. This signal m is
frequency-modulated by the modulator 2. The carrier wave at this time is about 500 KHz, which
is generated by the oscillator 1. The modulated rear speaker signal m is propagated to space as
an optical signal as an FM modulated signal light by the light emitting diode drive circuit 6 and
the light emitting diode 7. The light signal is received as the same signal by the photodiodes 8
and 16 and converted into an electrical signal. Thereafter, the signal converted into the electric
signal is tuned and amplified by the high frequency amplifier 10.17, and thereafter amplified by
the intermediate frequency amplifier 11.19 as in the conventional example, and the
demodulators 12, 20. The signal demodulated and amplified by the amplifier 13.21 is
transmitted to the rear speaker 30.31. Power supply batteries 9 and 18 are respective speaker
system power supplies. Although 600 KHz is used as the modulation frequency in the present
embodiment, it may be anywhere within the range of response of the light emitting diode.
Further, instead of the power supply battery, a DC power supply may be obtained from an AC
commercial power supply by a DC converter. Effect of the Invention As described above,
according to the present invention, not only the high-quality acoustic signal excellent in the
electromagnetic induction resistance can be obtained by the propagation of the light space, but
also the occurrence of the radio wave interference does not occur. Also, since the rear speaker
signal channel on the transmission side is one channel, no extra cost is incurred, and a high
quality acoustic signal resistant to disturbance noise can be obtained wirelessly by the optical
signal obtained by FM modulation. .
[0002]
Brief description of the drawings
[0003]
FIG. 1 is a block diagram of a wireless 9-Heo speaker system according to an embodiment of the
present invention, FIG. 2 is a block diagram of a speaker system for realizing a reproduction
sound field of a surround effect, and FIG. It is a block diagram of a speaker system.
6 ······ Drive circuit, 7 · · · · · · Light emitting diode, 8 ° 16 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·・・
10-05-2019
3
Rear speaker.
10-05-2019
4

Download Report