Electrical audio signal processing systems and devices – Binaural and stereophonic
Reexamination Certificate
1999-03-23
2001-06-12
Mei, Xu (Department: 2644)
Electrical audio signal processing systems and devices
Binaural and stereophonic
C381S309000, C381S311000, C381S097000
Reexamination Certificate
active
06246772
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a wireless headphone/ speakers sound field control circuit, which improves stereo, sound-surround sound effect, and allows the user to adjust left/right, front/back sound field contrast.
FIGS. 1 and 2
show two different wireless headphone/speakers sound field control circuits according to the prior art. In
FIG. 1
, wireless signal receiver
1
is connected to a signal amplifier AMP through a variable resistor VR
1
, and left and right speakers L SP and R SP are respectively connected to the left channel output terminal and right channel output terminal of the signal amplifier AMP. Signal from the wireless signal receiver
1
is regulated through the variable resistor VR
1
, then amplified through the signal amplifier AMP, and then outputted through the speakers L SP and R SP. The variable resistor VR
1
is for regulating the volume. This design has drawbacks. One drawback is that it has the functions of “receiving” and “amplification”, however it is not capable of processing sound field. Another drawback of this design is that the stereo effect is determined subject to the signal source, and the stereo effect of received signal well be reduced after amplification. In
FIG. 2
, two differential amplifiers A
1
and A
2
are respectively connected between the wireless signal receiver
1
and the speakers L SP and R SP, and two variable resistors VRA
1
and VRA
2
are respectively connected between the wireless signal receiver
1
and the differential amplifiers A
1
and A
2
for volume control. This design also has numerous drawbacks. One drawback of this design is that the differential amplifiers A
1
and A
2
simply amplify stereo signals from the wireless signal receiver
1
, however they cannot reprocess received signals, i.e., the differential amplifiers A
1
and A
2
cannot shift the phase of main sound, background sound, and sound-surround sound of main sound and background sound. The shifting of “phase” affects the stereo effect of sound field. Further, the variable resistors VRA
1
and VRA
2
can only adjust volume, they cannot adjust the direction of sound field, i.e., the stereo effect, as shown in
FIG. 5
, is shifted between left and right, but not between multiple directions of left and right/front and back.
SUMMARY OF THE INVENTION
The present invention has been accomplished to provide a wireless headphone/speakers sound field control circuit which eliminates the aforesaid drawbacks. The present invention achieves a multi-direction sound field effect. According to one aspect of the present invention, a phase-shifting circuit is connected between the left differential amplifier and the right differential amplifier, having two sub-circuits each formed of a first capacitor, a variable resistor, a second capacitor and a resistor, each sub-circuit being connected in series between the right or left variable resistor and the left or right differential amplifier. The phase-shifting circuit enables the differential amplifiers to have a dual signal input, so that left sound channel signal is inputted into the right differential amplifier and right sound channel signal is inputted into the left differential amplifier to achieve a stereo effect. Therefore, left main sound and right main sound are neutralized by phase shifting, and the sound-surround sound effect is improved. According to another aspect of the present invention, variable resistors are provided for enabling the user to adjust contrast conveniently. According to still another aspect of the present invention, received sound signal is reprocessed, so that output signals from the differential amplifiers provide better sound field contrast. According to still another aspect of the present invention, phase shifting control is stepless, and the adjustment can be made at the speakers by the user without through the main nit (signal source). Therefore, the invention enables the speakers to provide a stereo sound field effect, and allows the user to adjust sound field contrast directly at the speakers.
REFERENCES:
patent: 4087629 (1978-05-01), Atoji et al.
patent: 4118599 (1978-10-01), Iwahara et al.
patent: 4139728 (1979-02-01), Haramoto et al.
patent: 4349698 (1982-09-01), Iwahara
patent: 4817162 (1989-03-01), Kihara
patent: 4980914 (1990-12-01), Kunugi et al.
patent: 5119420 (1992-06-01), Kato et al.
patent: 5121433 (1992-06-01), Kendall et al.
patent: 5677957 (1997-10-01), Hulsebus
patent: 5717763 (1998-02-01), Choi et al.
patent: 5784474 (1998-07-01), Kohut et al.
patent: 61-187500 (1986-08-01), None
Mei Xu
Rosenberg , Klein & Lee
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