close

Вход

Забыли?

вход по аккаунту

?

JPH06315198

код для вставкиСкачать
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 JPH06315198
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
audio output circuit suitable for use in audio equipment and video equipment which perform
stereo reproduction.
[0002]
2. Description of the Related Art Heretofore, as audio equipment for stereo reproduction, there
have been system components and CD radio cassettes (radio-equipped tape recorders with a
built-in compact disc player), etc. In the case of a system component in which a car, an amplifier,
a tape deck, etc. are respectively separated, the left and right speakers are arranged separately in
front of the listener (ideally, an optimum stereo effect can be obtained) In the front of the
listener, the stereo reproduction is performed by arranging them at an angle of 60.degree. Which
is extended by 30.degree. To the left and right respectively in front of the listener.
[0003]
However, the left and right channel speakers are used on both sides of the rack where the
amplifier, tape deck, etc. are incorporated, in view of the fact that the indoor space is narrow and
wiring to the left and right channel speakers is troublesome. It is a reality that it is used in the
same arrangement form as a speaker integrated CD radio cassette, so that the sense of sound
spread etc. is impaired and a sufficient stereo effect can be obtained. It was not.
08-05-2019
1
For example, as shown in FIG. 9, when the listener P is listening at a distance L1 from the
acoustic device 1 having the left and right channel speaker 1L, 1R arranged on both sides, the
left and right channel speaker 1L 1R is located at an angle which is respectively θ1 extended to
the front left and right as viewed from the listener P, but when the distance from the acoustic
device 1 becomes L2, the left and right spread angles become smaller as θ2 (θ1> θ2) As the
distance gets farther, the sense of sound spreading disappears, and the stereo effect will fade.
[0004]
In order to obtain a sufficient stereo effect even in the case of listening in such a speaker
arrangement, therefore, there is one in which the audio output circuit is devised. For example, as
shown in FIG. 10, the left and right channel system audio signals are extracted as additional
signals to each other and the signal levels are controlled by the left and right channel system
attenuators 2L and 2R respectively, and then the left channel system attenuator 2L is produced.
The phase-controlled signal is phase-inverted and added to the right channel audio signal by
adder 3R, and the phase-controlled signal by right channel attenuator 2R is phase inverted and
left by adder 3L. Derivation to the left and right channel speaker 1L and 1R, respectively, in
addition to the channel sound signal, makes it possible to give a sense of sound spread and to not
significantly impair the stereo effect.
[0005]
In this way, for example, as shown in FIG. 11, when the listener P is listening at a distance L3
from the audio device 1, the audio signal at the listener P position (for the sake of explanation,
the right channel Considering the vector of the system audio signal only, the right channel
system audio signal from the right channel system speaker 1R is represented by a plus vector F1
from the listener P toward the right channel system speaker 1R, and the left channel By
representing the inverted right channel voice signal from the speaker 1L as a minus vector F2, a
composite vector F3 of these vectors F1 and F2 indicates the direction of sound. Therefore, in
this case, it is felt that the right channel speaker 1R is present at the dotted line position (a
spread angle is θ3 ') on the front right side with respect to the listener P. The same applies to
the left channel speaker 1L.
[0006]
08-05-2019
2
Then, when the distance of the listener P from the audio device 1 becomes L2, the vector F4 of
the right channel audio signal from the right channel speaker 1R and the inverted right channel
system from the left channel speaker 1L A composite vector F6 with the vector F5 of the audio
signal indicates the direction of the sound. That is, although the actual right channel speaker 1R
is located at the spread angle θ2, the right channel spi is located at the front right two-dot chain
line position (spread angle θ2 ') with respect to the listener P -There will be a feeling that there
is a car 1R, and the spread of the diversion will be obtained.
[0007]
Here, 4L and 4R are left and right channel system input terminals to which left and right channel
system audio signals are respectively input, and 5L and 5R are left and right channel system
volume volumes for adjusting the levels of left and right channel system audio signals to which
additional signals are added. , 6L and 6R are left and right channel system output amplifiers.
There is also a system in which such additional signals to the left and right channel system audio
signals are respectively delayed and added to give a feeling of sound field (surround feeling) to
be further included in the sound.
[0008]
However, such a conventional audio output circuit can provide a sense of sound spread and
sound field that is enveloped by sound, but a vague sound image in terms of sound image
localization Furthermore, the sound image moved and became unstable depending on the
listening position of the listener. Therefore, it was very tired when listening for a long time, and it
could not be said that a sufficient stereo effect could be obtained. For example, as can be seen
from FIG. 11, when the distance from the acoustic device 1 to the listener P is L2 and L3, the
magnitudes of the composite vectors F6 and F3 and the angles θ2 ′ and θ3 ′ also change
significantly. Depending on the position of the stereo effect and the sound pressure level will be
greatly changed. The present invention has been made in view of these points, and it is an object
of the present invention to provide an audio output circuit which can always obtain an optimum
stereo effect without being influenced by a listening position or the like. It is.
[0009]
08-05-2019
3
In order to achieve the above object, according to the present invention, the left channel audio
signal is extracted as an additional signal and the phase inversion is performed on the right
channel audio signal and the right channel audio signal is added as an additional signal. Control
the level and phase of the additional signal to the left and right channel based audio signals
based on the listening position information for the left and right channel based loudspeakers in
the audio output circuit for extracting and inverting the phase and adding each to the left
channel based audio signal Control means is provided. For example, the control means controls
the level of the additional signal to be 0.52 times the original signal level and to shift its phase by
75 °.
[0010]
Specifically, the control means takes out left and right channel system audio signals as additional
signals to each other and controls the signal levels of the left and right channel system
attenuators, and the level-controlled signals by the both attenuators. Control of left and right
channel system phase control circuit for controlling the phase respectively, level attenuation
amount at both attenuators and phase shift amount at both phase control circuits based on
listening position information for the left and right channel system speakers Control signal
phase-controlled by the left channel system phase control circuit to be inverted into a right
channel system audio signal, and phase controlled signal by the right channel system phase
control circuit. Phase inversion is performed to be added to the left channel system audio signal.
[0011]
Furthermore, a left channel system delay circuit for delaying the left channel system audio signal
and a right channel system delay circuit for delaying the right channel system audio signal are
provided, and the delayed left channel system audio signal is provided with the phase for the
right channel system. The signal phase-controlled by the control circuit is phase-inverted and
added, and the signal phase-controlled by the left channel system phase control circuit is phaseinverted and added to the delayed right channel audio signal It is a thing.
[0012]
Further, the control means takes out each of left and right channel system audio signals as an
additional signal of each other as an adder for inverting and adding one phase, and a level of a
difference signal of the left and right channel system audio signals outputted from the adder.
Attenuator for controlling the phase, phase control circuit for controlling the phase of the signal
level-controlled by this attenuator, level attenuation amount in the attenuator, and phase shift
amount in the phase control circuit And a control circuit that controls each based on the listening
position information for the speaker, and phase-inverts the signal phase-controlled by the phase
control circuit to the channel-system audio signal that is phase-inverted at the time of addition. A
08-05-2019
4
signal whose phase is controlled by the phase control circuit is added to the channel-based audio
signal which is not subjected to phase inversion at the time of addition, without phase inversion.
[0013]
Further, left and right channel system delay circuits and attenuators for delaying and level
controlling the left and right channel system audio signals to which signals from the phase
control circuit are respectively added are provided in advance, and the left and right channel
system attenuators are provided. The amount of level attenuation is controlled in accordance
with the amount of level attenuation in the attenuator.
[0014]
In this manner, the level and phase of the additional signal to the left and right channel audio
signals are controlled using the attenuator, the phase control circuit, etc. based on the listening
position information for the left and right channel speakers. Therefore, it is possible to provide a
stable sound image and a sufficient sense of sound spread without being influenced by the
listening position and the like, and always obtain an optimum stereo effect.
Also, by delaying the left and right channel-based audio signals to which the additional signal is
added instead of the additional signal, a sound-like feeling with a wide spread of sound can be
obtained with a high degree of freedom in design It will be.
Furthermore, by using the difference signal of the left and right channel audio signals as the
additional signal, the signal processing time becomes short and the circuit configuration becomes
simple.
[0015]
An embodiment of the present invention will be described below with reference to the drawings.
The same reference numerals are given to the same parts as the conventional ones and the
explanation thereof is omitted.
08-05-2019
5
In this embodiment, the level and phase of the additional signal to the left and right channel
system audio signal are obtained from the listening position information (the left and right
channel system speaker arrangement plane (in this case, audio equipment) with respect to the
left and right channel system speaker). Control based on the distance information to the listener
and the distance information between the left and right channel speaker so that the optimum
stereo effect can be obtained even if the listener listens to any position before and after the audio
device. It is
[0016]
Specifically, the left and right channel audio signals converted into digital by the A / D converter
and input to the left and right channel input terminals 4L and 4R as shown in FIG. And the left
and right channel system attenuators 7L and 7R, and the left and right channel system phase
control circuits 8L and 8R for controlling the phase of the signal level-controlled by both
attenuators 7L and 7R, and both attenuations. A control circuit 9 (for example, a control circuit
9) which controls the level attenuation amount in the inverters 7L and 7R and the phase shift
amount in both phase control circuits 8L and 8R based on listening position information for the
left and right channel speaker 1L and 1R. A microcomputer), and a left channel system delay
circuit 10L for delaying the left channel system audio signal converted into digital form from the
left channel system input terminal 4L; A right channel system delay circuit 10R for delaying the
right channel system audio signal converted into digital signal from the channel system input
terminal 4R, and phase control for the delayed left channel system audio signal by the right
channel system phase control circuit 8R The left channel system adder 11L which inverts the
phase of the received signal and adds it, and the phase controlled signal in the left channel
system phase control circuit 8L is phase inverted and added to the delayed right channel system
voice signal A right channel system adder 11R and left and right channel system D / A converters
12L and 12R for converting left and right channel system audio signals, to which addition signals
are respectively added by these two adders 11L and 11R, are converted into original analog are
provided. It is
[0017]
Here, 13 is a distance measuring circuit for measuring the distance from the audio device 1 to
the listener P. For example, the listener P receives a distance information signal sent by operating
the remote control transmitter. Thus, the distance to the listener P is measured and input to the
microcomputer 9.
08-05-2019
6
The listener can manually input the distance between the left and right channel speaker 1L and
1R. In this case, the left and right channel speaker 1L and 1R are disposed adjacent to both sides
of the rack portion. This is known because it has the same arrangement form as a speaker
integrated type CD radio cassette, and is assumed to be stored in advance in a data ROM or the
like.
[0018]
Therefore, the microcomputer 9 uses such a distance from the audio device 1 to the listener P
and the distance between the left and right channel speaker 1L and 1R as listening position
information, and an optimal stereo effect is obtained at each listening position. The level and
phase of the obtained additional signal are calculated, and the level attenuation amount in both
attenuators 7L and 7R and the phase shift amount in both phase control circuits 8L and 8R are
controlled.
[0019]
For example, as shown in FIG. 2, when the listener P is listening at a distance L3 from the
acoustic device 1, the spread angle θ3 of the left and right channel speaker 1L, 1R is 30 ° or
more. It is assumed that the magnitude of the vector F2 of the additional signal is zero, assuming
that sufficient stereo effect can be obtained even with only the vector F1 of the right channel
speech signal.
When the distance from the audio device 1 becomes L4 and the vector angle of the right channel
audio signal (the spread angle θ of the right channel speaker 1R) becomes 30 ° or less, the
vector F7 of the right channel audio signal And the phase and angle of the vector F8 of the
additional signal so that the resultant vector F9 of the vector F8 of the additional signal and the
vector F8 of the additional signal has the same size as the vector F7 of the right channel voice
signal at an angle of 30 ° Set Similarly, even if the distance of the listener P becomes L2, the
composite vector F6 of the vector F4 of the right channel speech signal and the vector F5 of the
additional signal thereof is the same as the vector F4 of the right channel speech signal at an
angle of 30 °. The angle and the magnitude of the vector F5 of the additional signal are set so as
to be the magnitude. In this way, even if the listener P listens to the acoustic device 1 at any
position before and after, it can be felt that the left and right channel system speakers 1L and 1R
are always located at the front right and left 30 °. An ideal stereo effect will be obtained.
[0020]
08-05-2019
7
Specifically, assuming that the distance to the listener P is L and the distance between the left
and right channel speaker 1L, 1R is W, the left and right channel speaker 1L, 1R viewed from the
listener P to the front left and right The spread angle θ of is determined by θ = tan−1 {L / (W /
2)}, from which the phase and level of the additional signal, ie, the angle and magnitude of the
additional signal vector from the antiphase can be calculated. For example, as shown in FIG. 3,
the vector Fm of the right channel sound signal from the right channel speaker 1R, the inverted
right channel sound signal from the left channel speaker 1L, ie, the vector Fs of the additional
signal When considering only the case of the right channel sound signal, the angle Φ and the
size | Fs | are Φ = 180 ° −90 ° −2θ− (30 ° −θ) / 2 = 75 ° −3θ / 2 | Fs It can be
determined by | = | Fm | × 2 × sin {(30 ° −θ) / 2} (where θ ≦ 30 °).
[0021]
In this way, the composite vector of the vector of the right channel speech signal and the vector
of the additional signal has the same magnitude as the vector of the right channel speech signal
regardless of where the listener P listens before and after The angle is such that the sound can be
heard from the direction of the spread angle of 30 °. For example, as shown in FIG. 4, when the
vector angle of the right channel audio signal is 30 ° (the spread angle θ of the right channel
speaker), the additional signal vector F11 is Φ = 30 °, | F11 | = 0. The resultant vector F12 has
the same angle and the same size as the vector F10 of the right channel speech signal. Further, as
shown in FIG. 5, when the vector angle of the right channel audio signal is 0 °, the additional
signal vector F14 has ° = 75 ° and | F14 | = | F13 | × 0.52 and the synthesis thereof The
vector F15 has the same magnitude as the vector F13 of the right channel voice signal and has
an angle at which the sound can be heard from the direction of the spread angle of 30 °. The
same applies to the case of the left channel audio signal.
[0022]
FIG. 6 shows a flowchart of the control operation of the microcomputer 9. The microcomputer 9
starts its control operation based on the control program stored in the program ROM etc. In this
case, the distance W between the channel speakers 1L and 1R is read from the data ROM, and
the distance L to the listener P is read from the distance measurement circuit 13 in the next step
# 10. Then, it is determined whether or not the distances W and L read in the next step # 15 are
the same as the values used in the previous control, and if it is the same, the previous control
state may be maintained. It will end. If they are not equal, the process proceeds to step # 20 to
08-05-2019
8
obtain the spread angle θ of the left and right channel speaker.
[0023]
Then, in step # 25, it is determined whether or not θ is 30 ° or more. If it is determined that
the value is large, the process proceeds to step # 30 and angle Φ of the additional signal vector
is determined. Then, the process proceeds to step # 35 where the size | Fs | is determined, and in
the next step # 40, the level attenuation amount in left and right channel attenuators 7L and 7R
and the phase control circuit 8L and 8R for left and right channels After performing control with
the amount of phase shift, the control operation is ended. If it is determined in step # 25 that θ
is 30 ° or more, the process proceeds to step # 45 where the magnitude | Fs | of the additional
signal vector is made zero, and then the process proceeds to step # 40.
[0024]
Next, FIG. 7 shows another embodiment in which a sense of depth is given by performing
reverberation processing on such additional signals to the left and right channel based audio
signals, and 14L and 14R indicate left and right channel based systems. Reverberation circuits
for left and right channels reverberant circuits 15L and 15R respectively add signals from feed
backup tuners described later to signals phase-controlled by left and right channel system phase
control circuits 8L and 8R, 16L and 16R are left and right channel reverberation delay circuits
that respectively delay the signals from the reverberation adders 15L and 15R, and 17L and 17R
feed back the signals from the reverberation delay circuits 16L and 16R, that is, predetermined
levels Are fed back to the reverberation adders 15L and 15R, and 18L and 18R are phase control
circuits 8L for the left and right channel systems. Signal to the left and right channel system for
reverberation circuit 14L from 8R, a left and right channel system for adder for signal
respectively adds from 14R.
[0025]
Next, FIG. 8 shows a specific configuration of the digital processing unit 19 from the left and
right channel system input terminals 4L and 4R to the D / A converters 12L and 12R in order to
shorten the processing time of the additional signal generation. Is an adder which takes out left
and right channel system audio signals as addition signals to each other and inverts one of the
phases, and in this case, inverts and adds the phase of the left channel system audio signal, 21 is
outputted from this adder 20 A band-pass filter for band-limiting the difference signal of the left
and right channel system audio signals to the 200 to 9 KHz band (the band where the stereo
effect is felt most in terms of hearing), 22 is a difference signal (200 Attenuator for controlling
the level of ~ 9 KHz band; 23 is a phase control circuit for controlling the phase of the signal
08-05-2019
9
level-controlled by this attenuator 22 For example, the coefficient is changed using a first-order
IIR filter), and the level attenuation amount in the attenuator 22 and the phase shift amount in
the phase control circuit 23 correspond to the left and right channel speaker 1L and 1R. The
microcomputer 9 is controlled based on the listening position information.
[0026]
Further, 24 is a reverberation circuit, 25 is a reverberation adder for adding a signal from a feed
backup tuner to be described later to the signal phase-controlled by the phase control circuit 23,
and 26 is a signal from the reverberation adder 25 Delay circuit 27 for delaying the signal, 27
feeds back the signal from the delay circuit 26 for reverberation, that is, a feed backup tuner for
supplying to the reverberation adder 25 after being attenuated to a predetermined level, 28 is
phase control Adders 29L, 29R and 30L, 30R add the signals from the reverberation circuit 24 to
the signals from the circuit 23, respectively delay the left and right channel audio signals
converted into digital from the left and right channel input terminals 4L, 4R and The gain of both
attenuators 30L and 30R is the level attenuation amount at the attenuator 22 by the left and
right channel system delay circuits and level adjusters that perform level control. It is controlled
depending on.
Reference numerals 31L and 31R denote left and right channel system adders which respectively
add the signal from the adder 28 to the delayed and level controlled left and right channel
system audio signals, and the left channel system of the phase inverted one at the time of the
addition by the adder 20. The signal from the adder 28 is phase-inverted and added to the audio
signal, and the signal from the adder 28 is not phase-inverted to the right-channel voice signal
which is not phase-inverted at the time of addition in the adder 20 It is supposed to be added.
Reference numerals 32L and 32R denote left and right channel system output terminals for
outputting signals from the left and right channel system adders 31L and 31R to the left and
right channel system D / A converters 12L and 12R.
[0027]
In this case, the left and right channel audio signals output from both output terminals 32L and
32R are the left channel system, assuming that the gain of the attenuator 22 is A and the gains of
the left and right channel attenuators 30L and 30R are B. Audio signal = BL-A (R-L) = (A + B) L-AR
08-05-2019
10
Right channel system audio signal = BR + A (R-L) = (A + B) R-AL, so that A + B in this equation
becomes 1 The gains A and B are controlled by the microcomputer 9, and as a result, the same
signals as in FIG. 7 are sent to the left and right channel system D / A converters 12L and 12R.
Here, A is controlled to be 2 × sin {(30 ° −θ) / 2}. Although the phase of the left channel
system audio signal is inverted to obtain the difference signal of the left and right channel system
audio signals, the phase of the right channel system audio signal may be reversed, or the band
filter You may omit the reverberation circuit for giving a sense of depth.
[0028]
As described above, in the present embodiment, the distance from the audio device to the listener
is measured by using the remote control transmitter, but even if the listener can arbitrarily input
the distance by using a key, etc. good. Further, although the system component type audio
equipment has been described in this embodiment, the present invention is not limited to this,
and may be, for example, a speaker integrated CD radio cassette or stereo type video equipment,
May be any one that performs stereo reproduction. In particular, in a small radio cassette player
or the like in which the distance between the left and right channel speaker is extremely narrow,
the level of the additional signal is the original signal level without measuring the distance to the
listener or the distance between the speakers one by one. By setting (or switching by switch
operation) the phase to be shifted by 75.degree. By 0.52 times of (1), a sufficient stereo effect
can be obtained.
[0029]
As described above, according to the audio output circuit of the present invention, the level and
phase of the additional signal to the left and right channel audio signals are controlled based on
the listening position information for the left and right channel speakers. As a result, it is possible
to obtain an optimal stereo effect even if the listener listens at any position before and after the
audio device. Also, by delaying the left and right channel-based audio signals to which the
additional signal is added, respectively, it is possible to obtain a sound field feeling that is wide
and wrapped. Further, by using the difference signal of the left and right channel audio signals as
the additional signal, it is possible to shorten the signal processing time and simplify the circuit
configuration.
08-05-2019
11
Документ
Категория
Без категории
Просмотров
0
Размер файла
23 Кб
Теги
jph06315198
1/--страниц
Пожаловаться на содержимое документа