JPH03268700

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DESCRIPTION JPH03268700
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
vehicle interior sound field control apparatus for reproducing a desired sound field in a vehicle
interior of a car. 2. Description of the Related Art In recent years, development of a vehicle
interior sound field control device using a digital signal processor has been advanced in order to
obtain a sense of reality and a sense of spread in a vehicle interior. As a conventional vehicle
interior sound field control apparatus, it is shown by Unexamined-Japanese-Patent No. 1-220599
and the Japan Acoustics Society journal 45 volume 10 No. 786-793 pages, for example. Below,
the conventional vehicle interior sound field control apparatus is demonstrated. FIG. 6 shows the
configuration of this conventional vehicle interior sound field control device, FIG. 7 shows the
operation button arrangement of the operation unit, and FIG. 8 shows an example of the
reproduced signal to which the reflected sound is added. Indicates In FIG. 6, 601 is a
reproduction acoustic signal source, 602 is an A / D converter, 603 is a sound field control
means, and the sound field control means 603 is a left front reflection sound generation unit 651
and a right front reflection sound generation unit A left rear reflection sound generator 653 and
a right rear reflection sound generator 654 are provided. The internal configuration of each
reflected sound generation unit is shown in FIG. In FIG. 2, reference numerals 201, 202, 203 and
204 DEG 205 denote delay units, 208, 207, 208 and 209. 210 denote coefficient units, and 211
denotes an adder. 655.858 and 657 are adders. The control unit 604 is configured of a
microcomputer, and controls the delay coefficients of the delay units 201 to 205 in the sound
field control unit 603 and the multiplication coefficients of the coefficient units 206 to 210 in
accordance with the operation of the operation unit 606. Control to display information on
607.608 is a D / A converter, 609,610 61613.614 is an amplifier, 615 is a left front speaker
provided on the front left door, 616 is a right front speaker provided on the front right door, 619
is A left rear speaker provided on the left side of the rear tray, and a right rear speaker 620
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provided on the right side of the rear tray. In FIG. 7, 701, 702 and 703 ° 704 are operation
buttons for selecting a desired reproduction sound field. For example, 701 is a normal mode
without sound field reproduction, 702 is a jazz club, 703 is a live house, and 704 is a concert. It
will be a hole. Reference numeral 705 denotes a display element of the display unit θ05. The
operation of the vehicle interior sound field control apparatus configured as described above will
be described below. The acoustic signal output from the reproduction acoustic signal source 601
is converted to a digital signal by the A / D converter 602 and is input to the sound field control
means 603, and the left channel direct sound and the right channel direct sound are added by
the adder 655 It becomes synthetic direct sound.
The synthesized direct sound is delayed for a desired time by the delay units 201 to 205 inside
the left front reflection sound generation unit 651, and each delayed signal is adjusted to a
desired magnitude by the coefficient units 206 to 210, and the adder 211 The left front
reflection sound is generated to be synthesized. The left front reflection sound is added to the left
channel direct sound by the adder 656 to become the left front reproduction signal shown in FIG.
8 (1). The left front reproduction signal is converted to an analog signal by the D / A converter
607, amplified by the amplifier 609, and drives the left front speaker 615. Similarly, the right
front reflection sound is generated by the right front reflection sound generator 652, and is
added to the right channel direct sound by the adder 657 to become a right front reproduction
signal, and drives the right front speaker 616. Also, the synthesized direct sound is delayed for a
desired time by the delay units 201 to 205 inside the left back reflection sound generator 653,
and each delayed signal is adjusted to a desired magnitude by the coefficient units 206 to 210,
and the adder 211 The left back reflection sound is generated. The left back reflection sound
directly becomes the left back reproduction signal shown in FIG. 8 (2). The left rear reproduction
signal is converted to an analog signal by the D / A converter 608, amplified by the amplifier
613, and drives the left rear speaker 619. Similarly, the right back reflection sound is generated
by the right back reflection sound generator 654 and becomes the right back reproduction signal
as it is, and drives the right back speaker 620. By selecting the operation buttons 701 to 704 of
the operation unit 606, the control unit 604 displays the selected sound field on the display unit
605, and the delay coefficients of the delay units 201 to 205 and the multiplication coefficients
of the coefficient units 206 to 210. For example, the sound field such as a jazz club or a concert
hall can be reproduced by changing the value to a preset value. SUMMARY OF THE INVENTION
However, in the above-described conventional configuration, (1) the size of the reflected sound
and the delay time are generally set so as to be a good sound field reproduction by listening at
the front seat The desired sound field can be reproduced in the seat, but in the rear seat, the
distance between the occupant's head and the rear speakers installed in the rear tray is very
short, the back reflection sound pressure is large, and the delay time is short, It is not possible to
hear proper back reflection sound, and good sound field reproduction can not be performed. (2)
The front signal for the rear seat passenger is the playback sound from the front left and right
door speakers, the distance from the speaker is far compared to the front seat passenger, and the
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sound is blocked by the front seat and the proper front playback sound is heard (3) In the car
room, the reflection time of the room itself is very fast compared to the ordinary room, and when
the reflection sound is added to the impulse-like music signal and reproduced, the reflection is
added When the number of sounds is limited, direct sound and each reflected sound may be
separated temporally and unnatural.
In such a case, the conventional sound field control apparatus selects another sound field in
which the delay time of the reflected sound is set to a short time, but this makes it possible to
reproduce in a sound field different from the desired sound field. The problem is that the original
function of the sound field control device can not be exhibited. The present invention solves the
above-mentioned conventional problems, and (1) the rear seat occupant can listen to the
appropriate back reflection sound like the front seat passenger with a simple operation, and (2)
depending on the presence or absence of the rear seat passenger There is no need for a seat
selection unit to be operated, (3) a passenger in the rear seat can listen to a proper forward
reproduction sound, and (4) an in-vehicle sound field control device that can easily adjust
reflected sound effects corresponding to various music sources. Intended to provide. Means for
Solving the Problem In order to achieve this object, the vehicle interior sound field control
apparatus of the invention of claim 1 receives an acoustic signal as an input, and delays this
input signal to obtain a front reflection sound. A sound generation unit has a back reflection
sound generation unit that delays the input signal to obtain back reflection sound as in the sound
generation unit, a delay unit connected to the output of the back reflection sound generation
unit, and a coefficient unit connected to the output of the delay unit A control unit which
simultaneously switches the delay coefficient of the delay unit and the multiplication coefficient
of the coefficient unit to a predetermined value by selecting the seat control button, the seat
selection button and the seat selection button provided on the operation unit. . In the vehicle
interior sound field control apparatus according to the second aspect of the present invention,
the infrared light emitting element provided on one door or the side wall of the rear seat of the
vehicle interior and the infrared light receiving element provided on the other door or the side
wall The configuration is such that the output of the rear seat occupant detection means is used
as a seat selection signal. In addition, the front reproduction signal is obtained by adding the
output of the front reflection sound generation unit which receives the sound signal of claim 3 of
the present application and delays the input signal to obtain front reflection sound, the input
signal and the front reflection sound generation unit. The sound field control means, which has
an adder to be obtained, and the first speaker for outputting the left channel signal of the front
reproduction signal are installed on the door on the left side of the rear seat or in the side wall
with the directivity axis aligned with the rear seat right passenger. A second speaker for
outputting the right channel signal of the front reproduction signal is installed on the door on the
right side of the rear seat or in the side wall with the directivity axis aligned with the passenger
on the rear left side. In addition, the sound signal of claim 4 of the present application is input,
and the input signal is subjected to delay processing to obtain the front reflection sound. The
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output from the front reflection sound generation part and the front reflection sound generation
part to obtain the rear reflection sound Sound field control means having a first coefficient unit
connected and a second coefficient unit connected to the output of the back reflection sound
generation unit and a reflection sound effect selection button and a reflection sound effect
selection button provided on the operation unit are selected Thus, the control unit
simultaneously switches the front reflection sound generation unit, the delay coefficient of the
rear reflection sound generation unit, the first coefficient unit, and the multiplication coefficient
of the second coefficient unit to predetermined values.
Operation According to the present invention, the rear reproduction signal size is reduced at the
time of rear seat selection of the seat selection means by the above-described configuration, and
the initial delay time of the rear reproduction signal is increased in advance. You can listen to the
proper back reflection sound in the seat as well as in the front seat. (2) When the rear seat
occupant shields the infrared rays, the infrared rays are not input to the light receiving portion,
the output state of the light receiving portion changes, and this enables the automatic detection
of the rear seat passenger. (3) On the left side of the rear seat, the distance from the right
speaker is long but the directivity matches, and the distance from the left speaker is short but the
directivity does not match. As a result, the left and right sound pressures almost match. Similarly,
the right and left sound pressures of the rear seat and the right side of the rear seat will be
substantially the same, so that the right front playback sound can be heard in the rear seat. (4) At
the time of large selection of the effect of the reflection sound effect selection means, the sound
field reproduction assuming a large room is set in advance by enlarging the size of each
reflection sound and increasing the delay time of each reflection sound. When the effect of the
reflected sound effect selection means is large, the sound of a small room can be estimated by
setting in advance to reduce the size of each reflected sound and reduce the delay time of each
reflected sound. The field reproduction can be performed, and the adjustment of the effect of the
reflected sound becomes easy. Embodiment An embodiment of the present invention will be
described with reference to the drawings. FIG. 1 shows the configuration of the vehicle interior
sound field control apparatus in the embodiment of the present invention, FIG. 2 shows the
configuration of the reflected sound generation unit, and FIG. 3 shows the operation button
arrangement of the operation unit FIG. 4 shows the speaker arrangement of the rear seat of the
vehicle interior and the arrangement of the rear seat occupant detection means, and FIG. 5 shows
an example of the reproduction signal to which the reflected sound is added. In FIG. 1, 101 is a
reproduction acoustic signal source, and 102 is an A / D converter. The sound field control unit
103 includes a front reflection sound generation unit 151, a right front reflection sound
generation unit 152, a left back reflection sound generation unit 153, and a right back reflection
sound generation unit 154, which are inside the sound field control unit 103. The internal
configuration of each reflected sound generation unit is shown in FIG. In FIG. 2, reference
numerals 201, 202, 203, 204, 205 denote delay units, 206, 207, 208 ° 209. 210, coefficient
units, and 211, an adder. 155.156 and 157 are adders, 158.159 is a coefficient unit, and 160 is a
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delay unit. A microcomputer 104 controls the delay coefficients of the delay units 201 to 205 in
the sound field control unit 103 and the multiplication coefficients of the coefficient units 206 to
210 by the operation of the operation unit 106, and information is displayed on the display unit
105. Control to display.
107. 108 is a D / A converter, 109. 110. 111. 112 ° 113. 114 is an amplifier, 115
is a left front speaker provided at the front left door, 116 is a right front speaker provided at the
front right door, and 117 is a left center speaker provided at the rear left door The distance
between the left center speaker 117 and the listening position at the rear left seat is set equal to
the distance between the left front speaker 115 and the listening position at the front left seat.
Reference numeral 118 denotes a right center speaker provided on the rear right side door,
which is arranged symmetrically with the left center speaker 117. A left rear speaker 119 is
provided on the left side of the rear tray, and a right rear speaker 120 is provided on the right
side of the rear tray. In FIG. 3, 301, 302, 303, 304 are operation buttons for selecting a desired
reproduction sound field. For example, 301 is a normal mode in which the sound field
reproduction is not performed, 302 is a jazz club, 303 is a live house, 304 is a concert. It will be
a hole. 305 is a seat selection button, 306 is a reflected sound effect selection button, and 307 is
a display element of the display unit 105. In FIG. 4, the left center speaker 117 is driven by the
amplifier 111 for the left front reproduction signal. The right center speaker 118 is driven by the
amplifier 112 for the right front reproduction signal. 401 is an infrared light emitting element of
the rear seat occupant detection means provided on the rear left side door located on the rear
seat left side, 402 is an infrared light receiving element provided on the rear right side door
located on the rear seat right side, 403 is a rear seat Reference numeral 104 denotes a control
unit of the sound field control unit 103. About the vehicle interior sound field control apparatus
of the present Example comprised as mentioned above, the following FIG. 1, FIG. 2, FIG. 3 is
shown. The operation will be described with reference to FIGS. 4 and 5. The acoustic signal
output from the reproduction acoustic signal source 101 is converted to a digital signal by the A
/ D converter 102 and input to the sound field control means 103, and the left channel direct
sound and the right channel direct sound are added by the adder 155 It becomes synthetic direct
sound. The synthesized direct sound is delayed for a desired time by the delay units 201 to 205
inside the left front reflection sound generation unit 151, and each delayed signal is adjusted to a
desired size by the coefficient units 206 to 210, and is added by the adder 211. The left front
reflection sound is generated to be synthesized. The left front reflection sound is changed in
magnitude by the coefficient unit 158 and added to the left channel direct sound by the adder
156 to become the left front reproduction signal shown in FIG. 5 (1). The left front reproduction
signal is converted to an analog signal by the D / A converter 107, amplified by the amplifier
109, and driven by the left front speaker 115 and amplified by the amplifier 111 to drive the left
center speaker 117.
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Similarly, the right front reflection sound is generated by the right front reflection sound
generator 152, the magnitude is changed by the coefficient unit 158, and is added to the right
channel direct sound by the adder 157 to become the right front reproduction signal, and the
right front speaker 116 While driving, the right center speaker 118 is driven. Further, the
synthesized direct sound is delayed for a desired time by the delay units 201 to 205 inside the
left back reflection sound generator 153, and each delayed signal is adjusted to a desired
magnitude by the coefficient units 206 to 210, and the adder 211 The left back reflection sound
is generated. The left back reflection sound is delayed for a fixed time by the delay unit 160, and
the magnitude is changed by the coefficient unit 159 to become the left back reproduction signal
shown in FIG. 5 (2). The left rear reproduction signal is converted to an analog signal by the D /
A converter 108, amplified by the amplifier 113, and driving the left rear speaker 119. Similarly,
the right back reflection sound is generated by the right back reflection sound generator 154,
delayed for a fixed time by the delay unit 160, changed in magnitude by the coefficient unit 159
to become a right back reproduction signal, and drive the right back speaker 120. . By selecting
any of the operation buttons 301 to 304 of the operation unit 106, the control unit 104 displays
the selected sound field on the display unit 105, and at the same time, the delay coefficients of
the delay units 201 to 205 and the coefficient units 206 to 210. The multiplication factor can be
changed to a preset value to reproduce, for example, a sound field such as a jazz club or a
concert hall. In this embodiment, although the number of the reflected sound of each reflected
sound generation unit is five, it is needless to say that any number may be used. Next, the
operation of the seat selection button will be described. When the seat selection button 305 is set
to the front seat mode, the control unit 104 sets the delay factor of the delay unit 160 to zero
and makes the multiplication factor of the coefficient unit 158.159 the same. In this case, the
operation is the same as that of the conventional example. FIG. 5 (2) shows a left rear
reproduction signal in the front seat mode. When the seat selection button 305 is set to the rear
seat mode, the control unit 104 sets the delay coefficient of the delay unit 160 to 11 seconds,
and sets the multiplication coefficient of the coefficient unit 159 AdB lower than the
multiplication coefficient of the coefficient unit 158. Note that 11 seconds is the delay time of the
sound wave corresponding to the distance between the front seat and the rear seat, and AdB is
the sound pressure at the front seat and the sound pressure at the rear seat when the rear
speaker 119.120 is the sound source. Difference. The left rear reproduction signal when the seat
selection button 305 is set to the rear seat mode is shown in FIG. 5 (3). With the above
configuration, when the seat selection button 305 is set to the front seat mode, if the sound
pressure of the back reflection sound at the front seat is R dB and the delay time from the rear
speaker is Tr seconds, the seat selection When the button 305 is set to the rear seat mode, the
level of the back reflection sound is lowered by AdB (and the delay time is increased by 11
seconds, but the distance to the rear speaker decreases, so the sound pressure of the back
reflection sound at the rear seat The delay time is Tr + T 1-T 1 = Tr seconds, and the sound
pressure of the back reflection sound heard in the front seat in the front seat mode and the back
reflection sound heard in the rear seat in the rear seat mode The delay time for direct sound is
almost the same.
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As described above, according to the present embodiment, the seat selection button is provided
in the operation unit, and when the user listens in the rear seat, the seat selection button is set to
the rear seat mode, and the rear reflection sound similar to the front seat in the rear seat is
obtained. It will be possible to listen. Next, the operation of the rear seat occupant detection
means will be described. When the rear left or right door is closed, the control unit 403 causes
the infrared light emitting element 401 to emit light, and when there is no occupant in the rear
seat, the light reaches the infrared light receiving element 402 and its output is input to the
control unit 403. No rear passenger is detected. Conversely, when there is a rear seat passenger,
the light does not reach the infrared light receiving element 402, and the output is input to the
control unit 403, the presence of the rear seat passenger is detected, and automatic detection of
the rear seat passenger becomes possible. . By inputting the output of the rear seat occupant
detection means as a seat selection signal to the control unit 104 of the sound field control
means, the operation of the seat selection button 305 can be made unnecessary. As described
above, according to the present embodiment, by providing the rear seat occupant detection
means using the infrared light emitting element, the rear seat mode can be automatically set
when the rear seat is taken without operating the rear seat selection button of the operation unit.
Is selected, making the operation complicated and erroneous. Next, the operation of the rear door
speaker will be described. As shown in FIG. 4, the left center speaker 117 which outputs the left
front reproduction signal aligns its directivity axis to the rear right passenger and the sound
pressure directivity characteristics are the sound pressure at the rear right side and the rear left
Set the sound pressure at the seat to be almost equal. Similarly, the right center speaker 118 that
outputs the right front reproduction signal aligns its directivity axis to the rear passenger on the
rear seat, and the sound pressure directivity characteristics are the sound pressure in the rear
seat right seat and the sound pressure in the rear seat left seat Set to be approximately equal.
When an in-phase signal is supplied to the left center speaker 117 and the right center speaker
118 configured in this way, the sound pressure output by the left center speaker 117 and the
sound pressure output by the right center speaker 118 are substantially equal in the rear seat
right seat The noise image will be localized in front of the rear right side of the seat. Similarly,
even in the rear seat left seat, the sound pressure output by the left center speaker 117 and the
sound pressure output by the right center speaker 118 are substantially equal, and the sound
image is localized in front of the front seat left seat. In addition, the front playback sound listens
to the sound from the left front speaker 115 and the right front speaker 116 in the front seat,
and the sound from the left center speaker 117 and the right center speaker 118 in the rear seat.
Will hear almost the same forward playback sound. As described above, according to the present
embodiment, by providing a speaker having directivity specific to the rear door, the sound image
is localized at the front center of each listener for both the rear left and right seats, similar to the
front seat. We can hear forward reproduction sound.
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Next, the operation of the reflected sound effect selection button will be described. When the
reflection sound effect selection button 30B is selected to be large, each reflection sound
generation unit generates the same reflection sound as that of the conventional example. When
the reflection sound effect selection button 306 is selected to be small, the control unit 104
controls the left front reflection sound generation unit 151, the right front reflection sound
generation unit 152, the left back reflection sound generation unit 153, and the right back
reflection in the sound field control means 103. The delay coefficients of the delay units 201 to
205 in each of the sound generation units 154 are reduced to, for example, 1/2, and the
multiplication coefficients of the coefficient multipliers 15B and 159 are reduced to, for example,
1/2. The left rear reproduction signal when the reflected sound effect selection button 306 is set
to the small effect mode is shown in FIG. 5 (4). By configuring as described above, when the large
effect of the reflected sound effect selection button 30B is selected, the size of each reflected
sound is thick and the pitch of the delay time is set large to give a sufficient sense of spread. A
sound field assuming a large room can be reproduced. However, when a music signal containing
an impulse-like component is reproduced in this state, the reflection time of the room itself is
hardly added because the reflection time of the single room is short, and only the output from
the sound field control device is heard When the number of reflections added by the sound field
control device is limited, the direct sound and the reflections are separated temporally and there
is a sense of unnaturalness. In such a case, by selecting the small effect of the reflected sound
effect selection button 306, the size of each reflected sound is reduced, and at the same time the
pitch of the delay time is also reduced. The direct sound and the reflected sound can be
reproduced well without being temporally separated. As described above, according to the
present embodiment, a reflection sound effect selection button is provided in the operation unit,
and the large effect mode is usually selected to set the sound field reproduction state assuming a
large room with a sufficient sense of expansion, impulse shape When playing back the music
signal, select the effect small mode of the reflection sound effect selection button and set the
sound field reproduction state assuming a small room where direct sound and each reflection
sound are not separated in time and can not be heard. It is possible to easily adjust the reflection
sound effect suitable for reproduction of various music sources. As described above, according to
the present invention, the control unit simultaneously switches the delay coefficient of the delay
unit and the multiplication coefficient of the coefficient unit to a predetermined value by
selecting the seat selection button. In the same manner as above, proper back reflection sound
can be heard, and good sound field reproduction can be performed. Further, the output of the
rear seat occupant detection means constituted by an infrared light emitting element provided on
one door or side wall of the rear seat of the vehicle and an infrared light receiving element
provided on the other door or side wall is used as a seat selection signal By doing this, automatic
detection of the rear seat occupant becomes possible, and the rear seat mode is automatically
selected at the time of getting in the rear seat, and the manual operation is not complicated and
there is no erroneous operation.
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In addition, the first speaker that outputs the left channel signal of the front playback signal is
installed on the door on the left side of the rear seat or in the side wall with the directivity axis
aligned with the passenger on the rear seat right side. By placing the second speaker to output
the right axis of the rear seat on the right side door or the side wall of the rear seat with the
directivity axis aligned with the left rear passenger, the sound image is localized at the front
center of each listener Proper forward playback sound can be heard, and good sound field
playback can be performed. Furthermore, control to simultaneously switch the multiplication
coefficient of the front reflection sound generation unit, the delay coefficient of the back
reflection sound generation unit and the first coefficient unit and the second coefficient unit to a
predetermined value by selecting the reflection sound effect selection button By providing a
section, the effect large mode is selected to set the sound field reproduction state assuming a
large room with a sufficient sense of expansion, and when reproducing an impulse-like music
signal, the effect small mode of the reflected sound effect selection button By selecting a small
room where direct sound and each reflected sound can not be heard separately in time, it is
possible to adjust the reflected sound effect suitable for reproduction of various music sources by
setting it as a sound field reproduction state assuming a small room. The sound field can be
enjoyed according to the conditions inside the vehicle, which can be done with extremely easy
selection operation, and its practical effect is great.
[0002]
Brief description of the drawings
[0003]
FIG. 1 is a block diagram of a vehicle interior sound field control apparatus according to an
embodiment of the present invention, FIG. 2 is an internal block diagram of a reflected sound
generation unit, and FIG. 3 is a layout diagram of operation buttons of the operation unit of the
embodiment. Fig. 4 is a speaker arrangement of the rear seat of the vehicle interior of the same
embodiment and a layout diagram of the rear seat occupant detecting means, Fig. 5 is a
characteristic diagram showing an example of reproduction signals of the same embodiment, and
Fig. 6 is a conventional vehicle interior FIG. 7 is a block diagram of the sound field control device,
FIG. 7 is a layout diagram of operation buttons of the operation unit, and FIG. 8 is a characteristic
diagram showing an example of a conventional reproduction signal.
103 ... sound field control means, 151 ... left front reflection sound generation unit, 152 ... right
front reflection sound generation unit, 153 ... left back reflection sound generation unit, 154 ...
right back reflection sound Generation unit 155, 156. 157 ··· Adder, 158, 159 · · · Coefficient unit
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160 · · · Delay unit 104 · · · Control unit 105 · · · Display unit 106 · · · Operation unit 305: seat
selection button 306: reflected sound effect selection button 401: infrared light emitting element
402: infrared light receiving element 403: control unit of rear seat occupant detecting means.
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