JPH0795697A - Surround signal processor and video/sound reproducing device - Google Patents

Abstract

PURPOSE:To provide a surround signal processor and a video/sound reproducing device capable of obtaining a surrounding effect by reproducing acoustic signals for front and rear by a pair of front speakers provided at both sides of a display. CONSTITUTION:A matrix differential signal (R-L signal) is generated from stereo signals L, R by a subtractor 9, and the matrix differential signal is processed by a filter 5. A processed signal, the inverse signal of it, and the stereo signals are added by an adder 6 and a differentiator 7, and they are outputted from a pair of speakers SP1, SP2. The transfer characteristic of the filter 5 is set at (F+K)/(S+A) or (F-K)/(S-A). Where, the transfer characteristic from a pair of transducers to the ear on the same side of a listener is shown as S, the transfer characteristic to the ear on the opposite side as A, the transfer characteristic from a position where the surround signal is desired to sound image normal-positioned to the ear on the same side of the listener as F, and the transfer characteristic to the ear on the opposite side as K.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surround signal processing apparatus which reproduces an acoustic signal from a pair of transducers and localizes a surround image to a sound image at a position different from the position of the pair of transducers. Surround signal reproduced from a pair of rear speakers by the pair of speakers, and a surround signal processing device capable of constructing a four-channel surround system with two speakers, and further this surround signal The present invention relates to a video / audio reproducing device including a processing device.

[0002]

(Technical Background) Conventionally, a front stereo signal (Lch, Rch stereo signal) is matrix-processed to, for example, an (LR) signal, (R-R) signal.
A signal of L) is generated and surround reproduction is performed using this as a rear stereo signal. Also,
In various sound image processing systems (for example, Dolby Surround system), in addition to the front stereo signal,
There are a center signal and a rear (stereo) signal, and the sound field is reproduced using a plurality of speakers.

However, such a sound field reproducing system requires a plurality of pairs of speakers (for example, 2 to 4 speakers and 5 speakers), and the installation positions of the speakers, such as a television receiver. It was difficult to use for those with restrictions. For this reason, there has been an attempt to perform sound image localization processing on the rear stereo signal and to reproduce the sound stereoscopically from a pair of front speakers. In this case, it is necessary to localize two different sound sources, ie, rear stereo signals, at different positions, ie, installation positions of a pair of rear speakers.

(Constitution of conventional surround signal processing device)
As described above, when the sound images of two different sound sources are localized at different positions, as shown in FIG. 6, the respective directions (LB and RB in the figure for the pair of rear speakers) to be localized are desired. It is necessary to perform localization processing on the rear stereo signals SL and SR by the two sound image localization processing filters 10 and 10 corresponding to the virtual installation position). Then, the stereo signals for rear and the stereo signals for front L and R, which have been subjected to the localization processing, are added to two adders AD and AD.
Mixing (i.e. overlapping) by
This was reproduced by a pair of existing transducers (the speakers SP1 and SP2 will be described below as an example).

As a sound image localization processing filter,
The general sound image localization processing filter 10 shown in FIG. 6 has been used. The sound image localization processing filter 10 includes a cancel filter unit that cancels left and right crosstalk components,
The localization filter section provides a transfer characteristic for localizing a sound image at a desired position. Note that R and L are front stereo signals, and SL and SR are rear stereo signals (surround signals) input to the sound image localization processing filter 10 (cancellation filter).

Reference numerals 11, 12, 13, and 14 denote convolvers (convolution operation means) for realizing a predetermined transfer characteristic, and 15, 1
Reference numeral 6 is an addition means, and AD is an adder, and these constitute a cancellation filter section. Note that S and A
Indicates a transfer characteristic from the pair of speakers SP1 and SP2 to both ears of the listener LM. S is a speaker SP1, SP2
To the same side of the ear, while A shows the opposite side of the transfer characteristic. The transfer characteristic is the impulse response from each speaker to both ears. Since the pair of speakers SP1 and SP2 are arranged substantially symmetrically with respect to the listener LM, the transfer characteristics from each speaker to both ears are symmetrical.

Numerals 17 and 18 are convolvers (convolution calculation means) for realizing a predetermined transfer characteristic, and a localization filter section for locating a sound image in each direction to be localized (virtual installation position of the rear speaker). Is. In addition,
F is the transfer characteristic from the position where the sound image is desired to be localized (the virtual installation position of the pair of rear speakers shown by LB and RB in the figure) to the ear on the same side of the listener LM, and K is the localization of the sound image. This is the transfer characteristic from the desired position to the ear on the opposite side of the listener LM. In the sound image localization processing filter 10 shown in FIG. 6, C is

[0008]

[Equation 1]

Is set. Therefore, the speaker SP
X'and Y'output from 1 and SP2 are

[0010]

[Equation 2]

[0011] When this signal reaches the ear of the listener LM, crosstalk is canceled and X is transmitted to the left ear and Y is transmitted to the right ear. Therefore, in order to perform sound localization, the signals x and Y to be transmitted to the inputs X and Y, respectively, are
process y,

[0012]

[Equation 3]

By inputting, the sound image is localized.
Note that F is the position where the sound image is to be localized (in the figure, LB, RB
From the virtual installation position of the pair of rear speakers) to the ear on the same side of the listener LM, and K is the transfer characteristic from the position where the sound image is desired to be localized to the ear on the opposite side of the listener LM. Is. In other words, for X'and Y '

[0014]

[Equation 4]

It suffices to perform the following signal processing. In surround processing, x = SL, y = SR,
It suffices to perform processing with two sets of sound image localization processing filters 10.

[0016]

By the way, in the above-mentioned conventional surround signal processing device, the sound image localization processing filter 10 (convolver 11, 12, 13, 14, 17, 17) is provided for each of the rear stereo signals. ) Is required, that is, a large number of convolvers are required, and the hardware scale becomes large. Therefore, there is a problem that it cannot be used for consumer products such as a television receiver.

However, the applicant of the present invention, like the pair of speakers for the rear of the surround reproduction system, has a listener L.
It has been found that the sound image localization processing device can be simplified when two different sound sources are localized at positions (left and right) symmetrical with respect to M. That is, according to the present invention, when the stereo image for the rear is localized in a position symmetrical to the listener LM (left and right) (the position where a pair of virtual rear speakers are installed), the coefficient of the filter is set. By optimizing, the present invention provides a new surround signal processing device in which a sound image localization processing device is composed of only two filters, an adder and a subtractor.

Further, from the front stereo signal to the matrix signal, that is, the (LR) signal, (R-
In the case of generating the signal L) and performing surround reproduction of this signal as a rear stereo signal, the sound image localization processing device is configured by only one filter and an adder to further simplify.

[0019]

In order to solve the above problems, the present invention provides a pair of transducers (a pair of existing front speakers SP1 as shown in FIG. 1).
, SP2) and reproduced by matrix processing at a position different from the position of the pair of transducers (for example, a virtual rear speaker installation position shown by LB and RB in the figure). A surround signal processing device for sound image localization of a surround signal, comprising matrix processing means (subtractor 9) for generating a difference signal (for example, RL signal) from an input stereo signal (L signal, R signal). A filter 5 for processing the difference signal,
The filter and the inverted signal thereof are added to the input stereo signal and reproduced by the pair of transducers (adder 6, subtracter 7). The characteristic is (F + K) /
(S + A) or (FK) / (S-A) (where S is the transfer characteristic from the pair of transducers to the same ear of the listener, A is the pair of transducers and the ear opposite to the listener) , F is the transfer characteristic from the position where you want to localize the surround signal to the same ear of the listener, K is the transfer characteristic from the position where you want to surround the surround signal to the opposite ear of the listener. ) Is provided, the surround signal processing device is provided.

Further, as shown in FIG. 2, for example, a sound signal is reproduced from a pair of transducers (a pair of existing front speakers SP1 and SP2), and a position different from the position of the pair of transducers (for example, A surround signal processing device for sound-localizing a surround signal (SL signal, SR signal which is a stereo signal for rear) to a virtual rear speaker installation position shown by LB and RB in the figure, Means (adder 2, differencer 3) for generating a sum signal and a difference signal from a surround signal (SL signal, SR signal which is a surround signal for rear) to be sound image localized, and a first for processing the sum signal Filter 4 (transfer characteristic P), a second filter 5 (transfer characteristic N) that processes the difference signal, and signals processed by the first and second filters And a means for generating the sum signal and the difference signal (adder 6, difference device 7) and means for reproducing the generated sum signal and the difference signal from the pair of transducers. The transfer characteristics P and N of the filter are: P = (F + K) / (S + A) N = (FK) / (S-A) (where S is from the pair of transducers to the ear on the same side of the listener) A transfer characteristic, A is a transfer characteristic from a pair of transducers to the opposite ear of the listener, F is a transfer characteristic from a position where the surround signal is desired to be sound image localized to the same ear of the listener, and K is a sound image of the surround signal. The present invention provides a surround signal processing device characterized in that a transfer characteristic from a position to be localized to an ear on the opposite side of a listener is set).

Further, it comprises a display means for reproducing a picture, a pair of speakers arranged on both sides of the display means for reproducing a sound, and a surround signal processing device for sound-localizing a surround signal as described above. A video / audio reproduction device is provided.

[0022]

According to the sound image localization processor constructed as described above, the difference signal between the input stereo signals (L signal, R signal) is processed by the filter, and the processed signal and its inverted signal are processed. And a stereo signal are output and reproduced by a pair of front transducers (a pair of front speakers SP1 and SP2). In this way
By using the input signal to the filter of the difference signal of the stereo signal, and the output signal from the filter and its inverted signal, only one filter is used, and the virtual rear signal position different from the position of the pair of front transducers is used. The sound image localization of the rear-matrix processed signals (RL and LR signals) is performed at the speaker installation positions (however, at two positions that are substantially symmetrical with respect to the listener LM).

Further, according to the sound image localization processing apparatus configured as described above, the sum signal and the difference signal of the input surround signals (rear SL signal and SR signal for rear) are the first and second signals. The signals are processed by the filters 4 and 5, and a sum signal and a difference signal of the processed signals are output to output a pair of front transducers (a pair of front speakers SP).
1, SP2). In this way, by using the input of the sum signal and the difference signal to the filter, and the sum signal and the difference signal from the filter output, only the first and second two filters are used, and the pair of front filters is used. The sound signals of the rear SL signal and the SR signal are localized at virtual virtual rear speaker installation positions different from the transducer positions (however, at two positions that are substantially symmetrical with respect to the listener LM).

Further, by combining such a surround signal processing device and a video / audio reproducing device, it is possible to reproduce a video without being limited to the installation position of the display means and the pair of existing transducers (speakers). You can set a suitable sound image fixed position for surround sound.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a surround signal processing device and a video / audio reproducing device according to the present invention will be described in detail below with reference to the drawings. (Embodiment 1) FIG. 2 is a block diagram of a surround signal processing device. As shown in the figure, the surround signal processing device is
The surround processing unit 1, the adder 2, the difference unit 3, the first filter 4, the second filter 5, the adder 6, and the difference unit 7 are roughly configured. The surround processor 1 is means for generating rear stereo signals (surround signals) SL, SR from the input front stereo signals L, R, and is a known amplitude adjusting circuit, reverberation adding circuit, reflected sound. It is composed of additional circuits. The first filter 4 and the second filter 5 are convolution operation means such as a convolver, which have P and N transfer characteristics described later, respectively.

The rear stereo signals SL and SR from the surround processor 1 are added by an adder 2 and a subtractor 3 to generate a sum signal and a difference signal of the two signals. The generated sum signal is processed by the first filter 4, and the generated difference signal is processed by the second filter 5. The signals processed by the first and second filters 4 and 5 are added by an adder 6 and a differencer 7
Thus, a sum signal and a difference signal of both signals are generated and used as a processed output signal. Further, in the adder 6 and the differencer 7,
The processed output signal and the front stereo signals L and R are added, reproduced by a pair of transducers (hereinafter, a pair of speakers SP1 and SP2 is taken as an example), and heard by a listener LM. In addition, a pair of speakers SP
Reference numerals 1 and SP2 are front speakers arranged and used at positions substantially symmetrical to the listener.

Further, in the above configuration, the transfer characteristics P and N of the first and second filters are P = (F + K) / (S + A) N = (FK) / (S-A) where S Is the transfer characteristic from the pair of existing speakers SP1 and SP2 to the same ear of the listener LM, A is the transfer characteristic from the pair of speakers SP1 and SP2 to the opposite ear of the listener LM, and F is the surround. The position where the sound image is to be localized (the position is substantially symmetrical with respect to the listener LM.
In the middle, the transfer characteristics from the position indicated by LB and RB, that is, the installation position of the virtual rear speaker) to the ear on the same side of the listener LM, K is the position of the listener LM from the position where the surround signal is desired to be localized. It is the transfer characteristic to the opposite ear.

The same side means, for example, the right ear for the right speaker, and the opposite side means, for example, the left ear for the right speaker. In addition, a pair of speakers SP1 and S
Since the position of P2 and the localization position for locating different sound images are substantially symmetrical with respect to the listener LM, the left and right transfer characteristics have symmetrical values.

In the surround signal processing device thus configured, the rear stereo signals SL and SR (surround signals) from the surround processor 1 are processed and reproduced from the pair of speakers SP1 and SP2. SP
From 1 to the right ear of the listener LM, right speaker SP2
To the left ear of the listener LM, that is, crosstalk is canceled. Left speaker S for listener LM
The signal from P1 is only for the left ear of the listener and the right speaker SP
The signal from 2 will be heard only in the right ear of the listener. Further, processing according to the transfer characteristics of F and K is performed, and the sound image is localized at the desired sound image localization positions LB and RB. Next, this point will be described in detail in comparison with the conventional example.

In the configuration of the surround signal processing device shown in FIG. 2, the transfer characteristics P and N of the first and second filters 4 and 5 are P = (F + K) / (S + A) N = (F−K) / (S-A). Therefore, when the outputs X'and Y'from the pair of speakers SP1 and SP2 are calculated, when the inputs are x and y,
Output X'is

[0031]

[Equation 5]

When the numerator is calculated here,

[0033]

[Equation 6]

Therefore, X'is

[0035]

[Equation 7]

It is Similarly, when Y'is obtained,

[0037]

[Equation 8]

Therefore, if inputs such as x = SL and y = 0 are added,

[0039]

[Equation 9]

Thus, the same result as the above-mentioned expressions (1a) and (1b) can be obtained. That is, if only the x side is input, the sound image of SL is localized at the localization position LB by the convolution process, as is clear from the equations (2a) and (2b). Furthermore, x =
If you add 0, y = SR,

[0041]

[Equation 10]

When compared with the above equations (2a) and (2b), the result is that the coefficients (transmission characteristics) that are opposite to the left and right with respect to the input y are convoluted. That is, the signal input to the y side is localized in a position symmetrical with respect to the signal input to the x side. That is, the sound image of SR is localized at the localization position RB by the convolution processing.

Therefore, when rear stereo signals SL and SR are given as inputs of x = SL and y = SR,
Since the superposition principle holds, the sound image of the rear stereo signal (surround signal) SL is on the left side LB, and the sound image of the rear stereo signal (surround signal) SR is on the right side RB.
Will be localized to. As a result, conventionally, a large number of convolvers were required to localize the sound image of the rear stereo signal (surround signal) to different places, but as described in detail in the above embodiment, the first filter 4 is used. , The second filter 5 can be used for the configuration, and the hardware scale can be small.

Therefore, as shown in FIG. 3A, a pair of speakers SP1 and SP1 are provided on both sides of the television receiver TV.
By only providing SP2, the surround signals SL and SR are reproduced from the position as shown in FIG. 3 (B), and the stereo signals L and R from the front are localized to the rear without installing a rear speaker. Rear surround signal SL,
With SR, stereoscopic surround sound can be reproduced.

The front stereo signals L and R
And the rear surround signal subjected to the sound image localization processing may be reproduced from a pair of speakers provided separately in front. For example, as shown in FIG. 3C, the rear speakers SP11 and SP12 may be provided on the front side, for example, both outsides of the television receiver TV. In this case, the front stereo signals L and R and the rear surround signal subjected to the sound image localization processing are not added by the adder 6 and the difference unit 7 which also functions as the adder in FIG. The stereo signals L and R for reproduction are reproduced from the front speakers SP1 and SP2, and the rear surround signals subjected to the sound image localization processing are rear speakers SP11 and S2.
Play from P12. According to this structure, the front speakers SP1 and SP2 and the rear speaker SP
The characteristics and installation direction of 11 and SP12 can be set individually, and a higher surround effect can be obtained.

(Embodiment 2) In Embodiment 2, as a surround signal, a front stereo signal and a rear stereo signal are switched to enable sound image localization diagonally forward or diagonally rearward, respectively. Is a configuration diagram thereof.

As shown in FIG. 4, in this embodiment, in addition to the basic configuration of FIG. 3, the first switches S1L, S1R, as the means for switching the surround signal for sound image localization,
Second switches S2L and S2R are added, and a CPU (control computer) 20 and a ROM (memory) 21 are added as means for setting transfer characteristics according to the sound image localization position of the switched surround signal in the filters 4 and 5. Has been done. A ROM (memory) 21 records a filter coefficient group for localizing a sound image at each sound image localization position. For example, virtual rear speaker installation positions LB, RB
The filter coefficient for placing the sound image at a fixed position and the filter coefficient for placing the sound image at a wider opening angle position LV, RV than the installation positions SP1, SP2 of the existing front speakers are stored.

The first switches S1L and S1R are
The input stereo signal for the front and the stereo signal for the rear from the surround processor 1 are switched to form a sound image localization means composed of an adder 2, a differencer 3, a first and a second filter 4, 5 and the like in the subsequent stage. , Surround signals for sound image localization are selectively supplied. The second switches S2L and S2R are switching means for selectively reproducing the front stereo signal together with the surround signal. The first switches S1L and S1R and the second switches
The switches S2L and S2R are also controlled by the CPU (control computer) 20 described above.

The surround signal processing device is configured as described above, and as shown in FIG.
A pair of speakers SP1 and SP2 are provided on both sides of the speaker. Then, a mode switching signal is sent to the CPU 20. For example, in the case of mode 1, the CPU 20 uses the first switch S1L,
S1R and the second switches S2L and S2R are on the a side,
The first and second filters 4 and 5 are set with filter coefficients that cause the sound image to be fixed at the installation positions LB and RB of the virtual rear speaker. Then, as in the case of FIG. 8B, the rear surround signals SL and SR are reproduced from the position as shown in FIG. 5B, and the stereo from the front is installed without installing a rear speaker. Signals L and R, rear surround signals SL and SR localized rearward,
Three-dimensional surround sound is played (mode 1).

Further, for example, in the case of mode 2a, the CPU
Reference numeral 20 designates the first switches S1L, S1R and the second switches S2L, S2R on the b side, and at the same time, rather than the installation positions SP1, SP2 of the front speakers existing in the first and second filters 4, 5. A filter coefficient that sets the sound image at a fixed position in the wide opening angle position LV, RV is set. Then,
As shown in FIG. 5 (C), front stereo signals L and R are localized on both sides of the television receiver TV (display means). In this way, even in a television receiver having a narrow width, the stereo feeling of the front sound is not deteriorated due to the restriction of the installation intervals of the speakers.

Further, the ROM (memory) 21 stores the filter coefficient for positioning the sound image at the opening angle positions LN and RN, which are narrower than the installation positions SP1 and SP2 of the existing front speakers, and stores the first and second filter coefficients. Second filter 4, 5
It may be set to. In this case, FIG.
Contrary to (C), as shown in FIG. 5 (D), the stereo images L and R for the front are localized inward, that is, on the display means (on the display). For a video / audio reproduction device having a horizontally long display means, such as a horizontally long screen television receiver, a large-sized projector, or a movie theater screen, in this way, the position of the obtained sound image matches the image, The sound image becomes clearer (mode 2b).

Furthermore, in mode 2a and mode 2b,
The second switches S2L and S2R are set to the a side, and FIG.
As shown in (E), the front voice may be localized and reproduced at the installation positions SP1 and SP2 of the existing front speakers and the positions LN and RN on the display means (on the display) (mode). 3).

(Third Embodiment) In the third embodiment, the front stereo signals (Lch and Rch stereo signals) are subjected to a difference matrix process to obtain (LR) signals and (R-R) signals.
This can be realized with a more simplified configuration in the example of performing the surround reproduction by generating the signal L) and using this as a rear stereo signal. FIG. 1 is a block diagram of a surround signal processing device that performs surround processing using a difference matrix.

In this case, since the (LR) signal and (RL) are used as the rear stereo signal, the signal to the filter 4 shown in FIG. 2 becomes 0, and the signal processing for this system is performed. There is no need to do it. That is, in the adder 2 shown in FIG. 2, SL + SR = (LR) + (RL) = 0. Further, in the differentiator 3 shown in FIG. 2, SR-SL = (RL)-(LR) = 2 (RL), and the difference matrix signal (R-
L) should be doubled and input.

Therefore, as shown in FIG. 1, only the signal processing consisting of the filter 5, the adder 6, the differencer 7 and the amplitude adjuster 8 is sufficient, and the number of filters is one, and the hardware scale is further reduced. can do. Therefore, a pair of speakers SP1 and SP2 are provided on both sides of the display DP.
If a television receiver is constructed by integrally installing
4 channel surround sound can be easily reproduced with only one speaker. Moreover, as described above, since the surround signal processing device has an extremely simple configuration as shown in FIG. 1, the surround signal processing device can be applied to a television receiver which is an inexpensive consumer product.

In the first to third embodiments described above, the transfer characteristics F and K from the position where the sound image is desired to be localized to the listener.
, That is, the first and second filters 4, 5
The sound image localization may be performed at any desired position by varying the transfer characteristics P and N. Specifically, transfer characteristics P and N (coefficients of filters) corresponding to a plurality of sound image localization positions are stored in a memory such as RAM and ROM, and the transfer characteristics corresponding to a desired sound image localization position are stored in the CPU. And read it from the memory (for example, the CPU shown in FIG.
20, ROM 21) and the first and second filters 4 and 5 described above.
According to this structure, the left and right sound images can be rotated around the listener LM and the surround sound can be reproduced at the best position.

Although a pair of speakers SP1 and SP2 are used as a pair of transducers in this embodiment,
A headrest type speaker or headphones may be used.
In this case, the crosstalk transfer characteristic A basically does not exist, and in the above example, approximately A = 0 and can be omitted. In this case, a frequency characteristic relating to headphones may be further added, and a more realistic sound field can be reproduced.

Further, in any of the embodiments, a video / audio reproducing apparatus such as a television receiver generally has
A pair of (stereo) speakers (SP1, SP2) are arranged on both sides of a display means (display) for reproducing an image. Since the viewer (listener LM) views the display substantially in front of the viewer, the pair of speakers (SP1, SP2) are installed at positions substantially symmetrical with respect to the listener (LM). Also, when two different surround signals are sound image localized at the two rear positions, there is no problem if the two rear image positions are limited to positions substantially symmetrical with respect to the listener LM, and rather the surround effect is achieved. From the viewpoint of, it is a desirable position.

Therefore, a video / audio reproducing device such as a television receiver and the above-mentioned sound image localization processing means 1 which is an essential part of the present invention (a pair of speakers are installed at positions substantially symmetrical to the listener. 2 which is almost symmetrical to the listener
It is extremely useful to add a surround function in combination with a simplified one) on the assumption that the sound image is localized at a location.

(Embodiment 4) In these embodiments, the surround effect is further improved by making a difference between the front and rear surround signals for surround reproduction. The basic configuration shown in FIGS. 1 and 2 will be described as an example.

(A) Example of a structure in which the sense of distance is made different by giving a relative level (strength) difference In the basic structure shown in FIG. 1, a plurality of level adjusting means 8 (or 2 and 4
In the basic configuration shown in (1), the surround processor 1 causes the reproduced front signal and the rear surround signal to have a level difference. For example, if you increase the level of the rear surround signal relative to the front signal,
The surround effect is emphasized.

Then, a plurality of level differences (for example, standard and before and after it) are set in advance so that they can be selected according to the preference of the listener, the content of the music (sound) to be reproduced, and the state of the reproducing apparatus. It is good to leave. If there is a level difference between the front and rear surround signals to be reproduced, the distance (feeling) from both signals will be different, so the surround effect that depends on the listener's position, that is, the speaker installation position The obtained position range becomes wider, which is also desirable. The level (strength) difference may be continuously variable.

(B) Example of structure with relative time difference In the basic structure shown in FIGS. 1, 2 and 4, a plurality of delay means are provided to reproduce front signal and rear signal. Give a time difference to the surround signal. For example, one rear surround signal for front
When delayed by about 2 to 120 ms, the rear surround signal becomes clear and the rearward localization becomes clear. Even in this case, the delay time of the rear surround signal may be variable so that it can be selected according to the listener's preference, the content of the music (sound) to be reproduced, and the state of the reproducing device. In addition,
Even if the time difference is implemented by the surround processor 1 (FIG. 2),
Separate delay devices may be provided before and after the filters 4 and 5, respectively.

(C) Example of structure in which reflected sound is added to rear surround signal In the basic structure shown in FIGS. 2 and 4, the surround processor 1 adds reflected sound to the rear surround signal. The reflected sound is obtained by delaying the rear surround signal by several tens of ms as the initial reflected sound and by several hundred ms as the higher-order reflected sound, and adding it so that the level is gradually attenuated.
Adding reflected sound to the rear surround signal improves the out-of-head feeling of the sound in the rear and eliminates the sickness of the sound.
In this case, it is advisable to variably adjust the level of the reflected sound to be added.

Further, the reflected sounds added to the left and right surround signals are made different, for example, delay time, level,
If the frequency characteristic and the attenuation characteristic are different for the left and right, the out-of-head feeling of the sound in the rear is further improved, and the sound moves away from the head.

[0066]

As described above in detail, according to the surround signal processing device of the present invention, the signal processing is performed with an extremely simple structure, so that the acoustic signal from the pair of transducers is placed at a position different from its installation position. The surround image can be localized. Therefore, even when the surround signal reproduced from the pair of rear speakers is simulated by the pair of front speakers to construct a four-channel surround system with two speakers, the hardware scale is small. It can be made inexpensive and can be used for consumer equipment such as a television receiver.

By combining such a surround signal processing device and a video / audio reproducing device, it is possible to reproduce a video without being limited to the installation position of the display means and the pair of existing transducers (speakers). A suitable surround effect can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a surround signal processing device according to the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the surround signal processing device.

FIG. 3 is an explanatory diagram of a video / audio reproduction device including a surround signal processing device.

FIG. 4 is a configuration diagram showing another embodiment of the surround signal processing device.

FIG. 5 is an explanatory diagram of a video / audio reproduction device including a surround signal processing device.

FIG. 6 is a configuration diagram of a conventional general surround signal processing device.

[Explanation of symbols]

1 Surround Processor 2 Adder 3 Differencer 4 First Filter (Transfer Characteristic P) 5 Second Filter (Transfer Characteristic N) 6 Adder 7 Differencer 8 Amplitude Adjuster 9 Differencer 20 CPU 21 ROM S1L, S1R First switch S2L, S2R Second switch DP display TV television receiver LM listener SP1, SP2 pair of speakers (transducer)
And its installation position LB, RB Installation position of a virtual rear speaker (position where a sound image is to be localized) S Transfer characteristics from a pair of speakers SP1 and SP2 to the same ear of the listener LM A A pair of speakers SP1 , SP2 to the opposite ear of the listener LM F Transfer characteristics from the virtual rear speaker installation positions LB, RB to the same ear of the listener LM K Virtual rear speaker From the installation positions LB, RB of the listener to the opposite ear of the listener LM LN, RN Opening angle position narrower than the speaker installation positions (SP1, SP2) LV, RV Speaker installation positions (SP1, SP2) Wide opening position L, R Front stereo signal SL, SR Rear stereo signal (surround signal) X ', Y'Output from a pair of speakers

Claims (9)

[Claims] 1. A surround signal processing device which reproduces an acoustic signal from a pair of transducers and localizes a sound image of a matrix-processed surround signal at a position different from the positions of the pair of transducers, wherein the input stereo signal is input. Matrix processing means for generating a difference signal from a signal, a filter for processing the difference signal, a signal processed by the filter and its inverted signal, and an input stereo signal are added, and the pair of transducers are added. And a transfer characteristic of the filter is (F + K) / (S + A) or (F−K) / (S−
A) (However, S is the transfer characteristic from the pair of transducers to the same ear of the listener, A is the transfer characteristic from the pair of transducers to the opposite ear of the listener, and F is the sound signal localization of the surround signal. A surround signal processing device, wherein K is the transfer characteristic from the position to the ear on the same side of the listener, and K is the transfer characteristic from the position where the surround signal is desired to be sound image localized to the ear on the opposite side of the listener). 2. Display means for reproducing video, and a pair of speakers arranged on both sides of the display means for reproducing audio.
A video / audio reproduction device comprising a surround signal processing device for sound localization of a matrix-processed surround signal, the matrix processing means for generating a difference signal from an input front stereo signal, and the difference signal. The surround signal processing device is configured from a filter and a unit that adds a signal processed by the filter and an inverted signal thereof and an input front stereo signal, and reproduces the sound from the pair of speakers. The transfer characteristic of the filter is (F + K) / (S + A) or (F−K) / (S−
A) (However, S is the transfer characteristic from the pair of speakers to the ear on the same side of the listener, A is the transfer characteristic from the pair of speakers to the ear on the opposite side of the listener, and F is the sound signal localization of the surround signal. Transfer characteristics from position to ear on the same side of the listener,
K is a transmission characteristic of the surround signal from the position where the sound image is to be localized to the ear on the opposite side of the listener). 3. A surround signal processing device which reproduces an acoustic signal from a pair of transducers and localizes a surround image to a sound image at a position different from the positions of the pair of transducers. Means for generating a sum signal and a difference signal, a first filter for processing the sum signal, a second filter for processing the difference signal, and a signal processed by the first and second filters And a means for generating a sum signal and a difference signal, and a means for reproducing the generated sum signal and the difference signal from the pair of transducers, wherein the transfer characteristics P and N of the first and second filters are represented by P = (F + K) / (S + A) N = (FK) / (S-A) (where S is the transfer characteristic from a pair of transducers to the ear on the same side of the listener) A is the transfer characteristic from the pair of transducers to the ear on the opposite side of the listener, F is the transfer characteristic from the position where the surround signal is desired to be sound image localized to the ear on the same side of the listener, K is the sound signal where the surround signal is localized Surround signal processing device, characterized in that the transfer characteristic from the position to the ear on the opposite side of the listener) is set. 4. Display means for reproducing video, and a pair of speakers arranged on both sides of the display means for reproducing audio.
A video / audio reproducing device comprising a surround signal processing device for localizing a surround image to a sound image, comprising: means for generating a sum signal and a difference signal from a surround signal desired to be sound image localized; and a first filter for processing the sum signal. A second filter for processing the difference signal; a means for generating a sum signal and a difference signal from the signals processed by the first and second filters; and a means for generating the sum signal and the difference signal. The surround signal processing device is composed of the means for reproducing from the pair of speakers, and the transfer characteristics P and N of the first and second filters are P = (F + K) / (S + A) N = (F -K) / (S-A) (where S is the transfer characteristic from the pair of speakers to the ear on the same side of the listener, A is the transfer characteristic from the pair of speakers to the ear on the opposite side of the listener, F Transfer characteristic of the surround signal from the position desired to be sound image localization to the same side of the ear of the listener,
K is a transmission characteristic of the surround signal from the position where the sound image is to be localized to the ear on the opposite side of the listener). 5. The video / audio reproducing apparatus according to claim 4, wherein the front stereo signal is reproduced and the rear stereo signal is rearranged as a surround signal for sound image localization rearward. 6. A video / audio reproducing apparatus according to claim 5, further comprising a varying means for varying a relative level between the front stereo signal to be reproduced and the surround signal. 7. A video / audio reproducing apparatus according to claim 4, wherein the front stereo signal is used as a surround signal and sound is localized on both sides of the display means or on the display means for reproduction. 8. A sound image localization position is made variable by having a means for storing a transmission characteristic corresponding to a plurality of sound image localization positions and a means for setting a transfer characteristic according to a desired sound image localization position in a filter. A surround signal processing device according to claim 1, a video / audio reproduction device according to claim 2,
The surround signal processing device according to claim 3, or the video / audio reproduction device according to claim 4. 9. The surround according to claim 1, further comprising means for switching a surround signal for sound image localization, and means for setting a transfer characteristic according to a sound image localization position of the switched surround signal in a filter. Signal processor,
The video / audio reproduction device according to claim 2, the surround signal processing device according to claim 3, or the video / audio reproduction device according to claim 4.