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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
sound reproducing apparatus using headphones.
2. Description of the Related Art When music is played back using headphones, the sound
emitted from the driver of the headphones reaches the ear directly. Therefore, when the
reproduction sound localized to the L or R channel is localized immediately to the side of a
human, and the sound to be localized to the center of the L and R channels is localized to the
head, the music is reproduced by the speaker. There is a disadvantage that only unnatural
reproduced sound can be obtained by comparison.
Therefore, with the development of digital signal processing technology in recent years, the
reproduction signal of 5 channels of front L channel, front R channel, front center channel, rear L
channel and rear R channel makes any position around the listener. For example, a headphone
system has been proposed that can reproduce a multi-channel reproduction system such as
Dolby Digital by using headphones, which can localize sound images.
By using this headphone system, it is possible, for example, to localize the sound image at a
predetermined position around the listener wearing the headphones, regardless of where the
listener is located with respect to the screen. It becomes.
Therefore, in the multi-channel reproduction system using the conventional speaker, when the
listener is positioned at the left end with respect to the screen, for example, the reproduction
sound reproduced from the L-channel speaker is emphasized while the headphone system is
used. In this case, even if the listener is positioned at a position other than the front of the screen,
the sound image is localized at the optimum position if the viewer faces the screen.
In order to obtain higher-fidelity playback sound, it is necessary to use expensive headphones. In
particular, when it is desired to reproduce even a deep bass, it is necessary to use headphones
having a driver with a large aperture, which is disadvantageous in cost, and the weight of the
headphones is increased. It becomes difficult to use.
SUMMARY OF THE INVENTION In order to solve the above problems, the present invention
listens to a subwoofer that reproduces low frequency signals and a low frequency signal that is
reproduced by the subwoofer even when the listener wears It consists of possible headphones.
described in detail based on the embodiments shown in the drawings.
FIG. 1 shows a circuit block diagram of the device of the present invention. A digital stream
signal output from a DVD player or the like is input to an input terminal 11 provided in the signal
processing unit 10. This digital signal is demodulated by the decoder 12 into so-called 5.1
channel signals, that is, 6 channels of front L channel, front R channel, front center channel, rear
L channel, rear R channel and subwoofer channel.
Signals other than the subwoofer channel are input to the signal processing circuit 13 to perform
virtual surround processing. The virtual sarland processing is signal processing for localizing a
virtual sound source around the listener only by the reproduced sound from the two drivers 41
and 42 of the headphone 40, and controls the transfer function of the reproduced sound.
However, the detailed description is omitted.
The 2-channel output from the signal processing circuit 13 is input to the modulation circuit 14
to perform modulation necessary for the infrared light emission unit 15 to emit infrared light.
Further, the signals of the six channels output from the decoder 12 are added by the adding
circuit 16 and then pass through a low pass filter (hereinafter referred to as LPF) 17 whose
cutoff frequency is about 200 Hz. By this processing, not only the subwoofer channel but also
low frequency components of all channels are output to the subwoofer output terminal 18.
The subwoofer output terminal 18 is connected to the subwoofer 20 by a connecting cable 19.
An amplifier 21 is built in the box of the subwoofer 20, and the amplifier 21 drives the
subwoofer unit 22.
Infrared light from the infrared light emitting unit 15 is received by the infrared light receiving
unit 31 provided in the headphone circuit unit 30, and after being demodulated into an L
channel signal and an R channel signal by the demodulation circuit 32, they are respectively
amplified by the amplifiers 33 and 34. The drivers 41 and 42 of the headphones 40 are driven.
Here, although the headphone circuit unit 30 is integrally incorporated in the headphone 40, it is
illustrated separately from the headphone 40 in FIG. 1 for the sake of explanation.
The headphone 40 adopts an open air system in which external sounds can be heard. As a result,
the listener wearing the headphone 40 can listen to the low frequency sound reproduced by the
subwoofer 20 together with the reproduced sound reproduced by the drivers 41 and 42 of the
headphone 40. Therefore, the low frequency band hears the reproduced sound from the
subwoofer 20, and the reproduced sound in the middle to high frequency band hears the
reproduced sound reproduced from the drivers 41 and 42 of the headphone 40. As a result,
since the headphone 40 is not required to have a bass reproduction capability, it is possible to
use a lightweight and inexpensive headphone equipped with a driver with a small diameter.
FIG. 2 shows a listener wearing such headphones 40 in a room 50. As shown in FIG. The
headphones 40 are wireless systems based on the infrared system, so they can freely take up a
listening position in the room 50 without being disturbed by the cable. In addition, the listener
52 located in front of the display 51 as well as the listeners 53 and 54 not located in front of the
screen wear the headphones 40 and face the display 51, for example, playback from the center
channel The reproduced sound to be played is localized on the display 51 in front of the listeners
53, 54. Therefore, the correct sound field space can be reproduced regardless of the position of
the listener who wears the headphone 40 on the screen.
Although the headphones 40 in the above-described embodiment are of the cordless type of
infrared transmission, the present invention is not limited to this, and it is also possible to use
ordinary headphones of the wire type.
Further, as this headphone 40, it is possible to adopt one that can listen to the bass reproduced
by the subwoofer 20 even though the headphone 40 is attached.
Therefore, the present invention is not limited to the open air system as in the embodiment, and
various modes can be taken without departing from the scope of the present invention, such as
that headphones of other systems can be adopted.
As described above, according to the present invention, since the bass is reproduced by the
subwoofer, the headphones do not have to have the ability to reproduce bass. Therefore,
inexpensive and lightweight headphones having a driver with a small diameter can be used,
which is advantageous in cost, and has the effect of wearing the headphones for a long time
without fatigue.
Brief description of the drawings
Fig. 1 Circuit block diagram of the headphone system.
2 is a diagram showing a listener wearing the headphones 40 in the room 50.
Explanation of sign
10 signal processing unit 20 subwoofer 30 headphone circuit unit 40 headphone 51 display