JP2011119867A - Video and audio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a video and audio device which can achieve a sense of units of a voice and a video using a small number of loudspeakers. <P>SOLUTION: The device includes: a display unit 60 displaying the video; loudspeakers 20 which generate the voice corresponding to the video; and a voice processing unit 15 which generates voice signals to be supplied to the loudspeakers 20 by a predetermined processing. The voice processing unit 15 is composed including a voice image localization processing unit 30 which generates voice signals so as to establish a localizing position of the image of the voice in an arbitrary position on the screen of the display unit 60. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an audiovisual apparatus that displays video and generates sound.

  Some audiovisual apparatuses such as home theater sets are provided with a surround speaker in addition to a left channel speaker and a right channel speaker. In such an audiovisual apparatus, by providing many speakers, the localization position of the sound image can be controlled, and the sense of reality is greatly improved. Here, the localization position of the sound image is the position of the virtual sound source that the viewer feels. For example, Patent Document 1 proposes an audiovisual apparatus that is provided with many speakers and controls the localization position of a sound image to improve the sense of reality.

Japanese Patent Laid-Open No. 02-59000

  By the way, when many speakers are provided in the room in order to improve the sense of reality of the audiovisual apparatus, the appearance of the room is often impaired. Further, for example, even when a plurality of speakers are built in a television set, it is difficult to arrange the speakers so as to obtain a sufficient effect in the recent trend of thin design and narrow frame design of the television set. Yes.

  On the other hand, even in an audiovisual apparatus having only two speakers, a left channel speaker and a right channel speaker, there is a restriction on the speaker arrangement. In general, in audiovisual equipment, it is desirable to place speakers at symmetrical positions across the screen in order to place the localization position of the sound image near the center of the screen. For example, a home theater system has restrictions on the size of the room and the arrangement in the room, and in any case, the degree of freedom of speaker arrangement becomes low. As a result, the speakers are often placed differently from the desired placement from the acoustic point of view, such as the lower part of the display. When viewing audio or video using such an audiovisual device, the localization position of the audio image output from the speaker and the position of the display on which the video is displayed do not match. Will be damaged, giving viewers a sense of incongruity.

  The present invention has been made in view of such problems, and its purpose is to ensure a sense of unity between audio and video while ensuring the degree of freedom in device design and speaker placement by minimizing the number of speakers. An object of the present invention is to provide an audiovisual apparatus capable of performing the above.

  The audiovisual apparatus of the present invention includes a display unit that displays video, a speaker that generates audio corresponding to the video, and an audio processing unit that generates an audio signal to be supplied to the speaker through predetermined processing. The audio processing unit includes a sound image localization processing unit that generates an audio signal that sets the localization position of the sound image of the audio to an arbitrary position on the screen of the display unit.

  In the audiovisual apparatus of the present invention, the video is displayed on the display unit, and sound corresponding to the video is generated from the speaker. At that time, the sound image localization processing unit sets the localization position of the sound image of the voice to an arbitrary position on the screen of the display unit. Thereby, the localization position of the sound image can be matched with the display position of the video.

  A plurality of speakers may be arranged above or below the display unit. At that time, the sound image localization processing unit localizes the sound image of the low frequency sound component on one of the upper part and the lower part of the display unit and the sound image of the high frequency sound component on the other side. Even in this case, the sound image localization processing unit can set the localization position of the sound image to an arbitrary position on the screen of the display unit, for example, the center.

  The audiovisual apparatus of the present invention further includes a positional relationship measuring unit that measures a relative positional relationship between the display unit and the viewer, and the sound image localization processing unit is configured to localize the sound image based on the measured positional relationship. The position may be controlled. The sound image localization processing unit may control the localization position of the sound image based on the content of the video.

  It is desirable that the sound image localization processing unit controls the localization position of a sound image of a voice component having a frequency higher than a predetermined frequency in the voice. In this case, the predetermined frequency may be set in advance based on the frequency band of the voice, or may be obtained based on the frequency band provided with a frequency band measuring unit that measures the frequency band of the voice. Further, a phase difference may be generated between the left and right audio signals of the audio component having a frequency higher than the predetermined frequency. Moreover, you may make it delay the audio | voice component of a frequency lower than the predetermined frequency.

  According to the audiovisual apparatus of the present invention, since the localization position of the sound image of the sound can be set to an arbitrary position on the screen of the display unit, the sense of unity between the sound and the video can be improved, and the viewer feels uncomfortable. You can avoid giving.

It is a conceptual diagram showing an example of the concept of the sound image localization which concerns on this invention. It is a block diagram showing the example of 1 structure of the audiovisual apparatus which concerns on the 1st Embodiment of this invention. FIG. 3 is a block diagram illustrating a configuration example of a sound image localization processing unit illustrated in FIG. 2. FIG. 4 is a block diagram illustrating a configuration example of a phase shift unit illustrated in FIG. 3 and a characteristic diagram illustrating a characteristic example thereof. FIG. 4 is a block diagram illustrating a configuration example of a virtual sound image processing unit illustrated in FIG. 3. FIG. 3 is a schematic diagram for explaining an acoustic transfer function in the audiovisual apparatus shown in FIG. 2. FIG. 3 is a schematic diagram illustrating a positional relationship between a viewer and a display unit in the audiovisual apparatus illustrated in FIG. 2. FIG. 3 is a schematic diagram showing a localization position of a sound image in the audiovisual apparatus shown in FIG. 2. FIG. 3 is a schematic diagram illustrating a change in the localization position of a sound image in the audiovisual apparatus illustrated in FIG. 2. FIG. 3 is a diagram illustrating an example of a user interface in the audiovisual apparatus illustrated in FIG. 2. It is a block diagram showing the example of 1 structure of the sound image localization process part which concerns on the 1st modification of the 1st Embodiment of this invention. It is a block diagram showing the example of 1 structure of the sound image localization process part which concerns on the 2nd modification of the 1st Embodiment of this invention. It is a block diagram showing the example of 1 structure of the sound image localization process part which concerns on the 3rd modification of the 1st Embodiment of this invention. It is a block diagram showing the example of 1 structure of the audiovisual apparatus which concerns on the 2nd Embodiment of this invention. 15 is a flowchart illustrating an operation example of a viewer detection unit illustrated in FIG. 14. FIG. 15 is a schematic diagram illustrating an operation example of the viewer detection unit illustrated in FIG. 14. It is a block diagram showing the example of 1 structure of the audiovisual apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram showing the example of 1 structure of the audiovisual apparatus which concerns on the 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description will be given in the following order.
1. 1. Concept of sound image localization First Embodiment 3. FIG. Second embodiment 4. Third embodiment 5. Fourth embodiment

<1. Concept of sound image localization>
FIG. 1 shows the concept of sound image localization according to the present invention. This example shows how the sound output from the speakers 20L and 20R arranged below the display unit 60 can be heard by the viewer.

  Usually, the sound generated from the speakers 20L and 20R is heard from the direction of the speakers 20L and 20R. In this example, the sound can be heard from below the display unit 60. That is, for the viewer, the direction of the display unit 60 where the video is displayed is different from the direction of the speakers 20L and 20R where the sound is generated. Therefore, for example, when the voice of the speaker displayed as a video on the display unit 60 is heard from below the display unit 60 where no speaker can exist, the viewer feels uncomfortable.

  As will be described later, the audiovisual apparatus of the present invention outputs low frequency component audio from the speakers 20L and 20R, and for high frequency component audio, the tweeters (virtual tweeters 21L and 21R) appear on the screen. By performing the audio signal processing as arranged above, the position of the sound source (sound images 7L and 7R) that the viewer feels (the position of the sound image) is set on the screen of the display unit 60. In the following, the speaker 20 is appropriately used as a general term for the speakers 20L and 20R, the virtual tweeter 21 is appropriately used as a general term for the virtual tweeters 21L and 21R, and the sound image 7 is appropriately used as a general term for the sound images 7L and 7R.

<2. First Embodiment>
[Configuration example]
(Overall configuration example)
FIG. 2 shows a configuration example of the audiovisual apparatus according to the first embodiment of the present invention. The audiovisual apparatus 1 includes an audio processing unit 15, a speaker 20, a video processing unit 17, and a display unit 60.

  The audio processing unit 15 is a circuit that performs predetermined audio signal processing, and includes a sound image localization processing unit 30 that sets a localization position of a sound image, which will be described later, and is configured by an audio DSP, for example. The sound processor 15 receives from the sound source / video source 11 a signal Lin (left channel signal), a signal Rin (right channel signal), a signal SLin (surround left channel signal), and a signal SRin (surround right channel signal). ), A signal Cin (center channel signal), and a signal Win (bass signal), a maximum 5.1 channel PCM (Pulse Code Modulation) audio signal (digital signal) is supplied. The sound source / video source 11 corresponds to, for example, a TV tuner or a DVD player. When the audio signal output from the sound source / video source 11 is an analog signal, the audio signal is converted into a digital signal by the A / D conversion circuit 12 and supplied to the audio processing unit 15 via the SW 14 or the like. . On the other hand, when the audio signal output from the sound source / video source 11 is a digital signal, the audio signal is decoded by, for example, the decoder 13 and supplied to the audio processing unit 15 via the SW 14 or the like. The SW 14 is a switch for selecting an audio signal supply source (A / D conversion circuit 12 and decoder 13). The audio processing unit 15 performs predetermined audio signal processing on the input signal, and outputs a 2-channel PCM audio signal composed of a signal Lout (left channel signal) and a signal Rout (right channel signal).

  The speaker 20 (speakers 20L and 20R) outputs sound based on the sound signal processed by the sound processing unit 15. Output signals Lout and Rout of the audio processing unit 15 are converted to analog signals by the D / A conversion circuit 16 and amplified by an amplifier (not shown). The speaker 20L outputs sound based on the output signal Lout of the sound processing unit 15, and the speaker 20R outputs sound based on the output signal Rout of the sound processing unit 15. The speaker 20 is disposed below the display unit 60 in FIG. That is, in this example, the speaker 20 is not disposed across the screen of the display unit 60.

  The video processing unit 17 is a circuit that performs predetermined video signal processing on the video signal supplied from the sound source / video source 11.

  The display unit 60 is a device that performs display based on the video signal processed by the video signal processing unit 17. The display unit 60 is driven by the display driver 18.

  The decoder 13, the audio processing unit 15, the D / A conversion circuit 16, the video processing unit 17, and the display driver 18 described above are controlled by the controller 19.

(Sound image localization processing unit 30)
FIG. 3 illustrates a configuration example of the sound image localization processing unit 30. The sound image localization processing unit 30 separates the input signals Lin and Rin into a low frequency component and a high frequency component, performs separate processing on each of them, and adds them again, thereby increasing the sound image localization position. This circuit generates a signal and outputs it as output signals Lout and Rout.

  The sound image localization processing unit 30 includes low-pass filters (LPF) 31L and 31R, delay units 32L and 32R, high-pass filters (HPF) 34L and 34R, and a phase shift unit 35. A phase inversion unit 36, a virtual sound image processing unit 40, amplifiers 37L and 37R, and adders 33L and 33R. The low-pass filters 31L and 31R and the delay units 32L and 32R process low frequency components of the input signals Lin and Rin, and the high-pass filters 34L and 34R, the phase shift unit 35, and the phase inversion unit 36. The virtual sound image processing unit 40 and the amplifiers 37L and 37R process high frequency components of the input signals Lin and Rin.

  The low-pass filter 31L is a filter that passes a low frequency component of the supplied input signal Lin, and the low-pass filter 31R is a filter that passes a low frequency component of the supplied input signal Rin. is there. The cut-off frequency of the low-pass filters 31L and 31R is set to about 6 to 10 [kHz], for example. The order of the low-pass filters 31L and 31R is preferably 4th or higher.

  The delay unit 32L delays and outputs the signal supplied from the low-pass filter 31L, and the delay unit 32R delays and outputs the signal supplied from the low-pass filter 31R. The delay amount of the delay units 32L and 32R is set to about 1 to 3 [msec], for example. As a result, the delay units 32L and 32R function to delay the low frequency component signal from the high frequency component signal, as will be described later.

  The high-pass filter 34L is a filter that passes high frequency components of the supplied input signal Lin, and the high-pass filter 34R is a filter that passes high frequency components of the supplied input signal Rin. is there. The cutoff frequency of the high-pass filters 34L and 34R is set to about 6 to 10 kHz, for example, similarly to the low-pass filters 31L and 31R. The order of the high-pass filters 34L and 34R is preferably 4th or higher.

  The phase shift circuit 35 has a function of performing different amounts of phase shift on the signals supplied from the high-pass filters 34L and 34R.

  4A shows an example of the configuration of the phase shift circuit 35, and FIG. 4B shows an example of the phase characteristic of the phase shift circuit 35. The phase shift circuit 35 includes APFs (All Pass Filters) 35L and 35R. The APF 35L is a filter that outputs the signal supplied from the high-pass filter 34L by changing only the phase while keeping the amplitude constant, and the APF 35R is the signal supplied from the high-pass filter 34R. On the other hand, it is a filter that changes and outputs only the phase while keeping the amplitude constant. The APFs 35L and 35R have, for example, characteristics L1 and L2 as shown in FIG. 4B, and the APF 35L and the APF 35R have different characteristics. Specifically, for example, when the APF 35L has a phase characteristic such as the characteristic L1, and the APF 35R has a phase characteristic such as the characteristic L2, the phase of the output signal of the APF 35L advances from the phase of the output signal of the APF 35R. It is like that. Alternatively, the APF 35L may have a phase characteristic such as the characteristic L2, and the APF 35R may set a phase characteristic such as the characteristic L1, so that the phase of the output signal of the APF 35L is delayed from the phase of the output signal of the APF 35R. As a result, the viewer feels the spread in the left-right direction with respect to the sound finally output from the speakers 20L and 20R. Any order of the APFs 35L and 35R may be used. For example, a primary or secondary order can be used.

  The phase inversion unit 36 has a function of selecting whether to output the signal supplied from the phase shift unit 35 as it is, or to output the signal by shifting the phase by 180 degrees (phase inversion). Thereby, the phase inverting unit 36 has a function of selecting a condition that makes the viewer feel more spacious with respect to the sound finally output from the speakers 20L and 20R.

  Adjustment of the delay amount in the phase shift circuit 35 and selection of the phase inversion operation in the phase inversion unit 36 can be set from the outside by a control line (not shown).

  The virtual sound source processing unit 40 performs virtual sound image processing on the signals LVin and RVin supplied from the phase inverting unit 36, and an audio signal in which the localization position of the sound image is set at a position corresponding to the virtual tweeters 21L and 21R, respectively. Are generated and output as output signals LVout and RVout.

  The amplifier 37L is an amplifier having a gain Kvtl for amplifying the signal LVout supplied from the virtual sound source processing unit 40, and the amplifier 37R is an amplifier having a gain Kvtr for amplifying the signal RVout supplied from the virtual sound source processing unit 40. By setting the gains Kvtl and Kvtr of these amplifiers, the sound image localization processing unit 30 finally determines the localization position of the sound image of the sound output from the speakers 20L and 20R, as will be described later. It can be raised from the position and set at an arbitrary position, for example, near the center of the screen of the display unit 60. In the following description, the amplifier 37 is appropriately used as a general term for the amplifiers 37L and 37R, and the gain Kvt is appropriately used as a general term for the gains Kvtl and Kvtr.

  The adder 33L is a circuit that adds the output signal of the delay unit 32L and the output signal of the amplifier 37L, and the adder 33R is a circuit that adds the output signal of the delay unit 32R and the output signal of the amplifier 37R.

(Virtual sound image processing unit 40)
FIG. 5 illustrates a configuration example of the virtual sound image processing unit 40. The virtual sound image processing unit 40 includes filters 401 to 404 and 407 to 410 and adders 405, 406, 411 and 412.

  Filters 401 to 404 are filters having acoustic transfer functions Hφ1L, Hφ1R, Hφ2L, and Hφ2R (described later), respectively, and are used for so-called binaural processing. Specifically, the filter 401 filters the input signal LVin using the acoustic transfer function Hφ1L, the filter 402 filters the input signal LVin using the acoustic transfer function Hφ1R, and the filter 403 The input signal RVin is filtered using the acoustic transfer function Hφ2R, and the filter 404 filters the input signal RVin using the acoustic transfer function Hφ2L. The acoustic transfer functions Hφ1L, Hφ1R, Hφ2L, and Hφ2R are stored in a memory (not shown), for example.

  Adders 405 and 406 are circuits for adding the outputs of the filters 401 to 404. Specifically, the adder 405 adds the output signal of the filter 401 and the output signal of the filter 404, and the filter 406 adds the output signal of the filter 402 and the output signal of the filter 403. .

  The filters 407 to 410 are filters having transfer functions G1 to G4 (described later) obtained based on the acoustic transfer functions Hθ1L, Hθ1R, Hθ2L, and Hθ2R (described later), and are generated when sound is output from the speakers 20L and 20R. This is used for so-called crosstalk compensation processing for compensating for crosstalk. Specifically, the filter 407 filters the output signal of the adder 405 using the transfer function G1, and the filter 408 filters the output signal of the adder 405 using the transfer function G2. The filter 409 filters the output signal of the adder 406 using the transfer function G3, and the filter 410 filters the output signal of the adder 406 using the transfer function G4. Yes. The transfer functions G1 to G4 are stored in a memory (not shown), for example.

  Adders 411 and 412 are circuits for adding the outputs of the filters 407 to 410. Specifically, the adder 411 adds the output signal of the filter 407 and the output signal of the filter 410 and outputs the result as an output signal LVout. The filter 412 outputs the output signal of the filter 408 and the output of the filter 409. The signals are added together and output as an output signal RVout.

(Acoustic transfer function)
Next, the acoustic transfer function and how to find it will be described.

  FIG. 6 is a schematic diagram for explaining the acoustic transfer function. 6A shows a state in which sound is output from the speakers 22L and 22R arranged at the positions of the virtual tweeters 21L and 21R, and FIG. 6B shows a state in which sound is output from the speakers 20L and 20R. .

  As shown in FIG. 6A, the viewer 9 in front of the display unit 60 feels the sound output from the speaker 22L with the left ear and the right ear. That is, the acoustic transfer function related to the speaker 22L includes the transfer function Hφ1L until the sound output from the speaker 22L arranged at the position of the position vector φ1 from the viewer 9 is transmitted to the left ear of the viewer 9, and the speaker. There are two transfer functions Hφ1R until the sound output from 20L is transmitted to the right ear of the viewer 9.

  Similarly, the viewer 9 feels the sound output from the speaker 22R with the right ear and the left ear. That is, the acoustic transfer function related to the speaker 22R includes the transfer function Hφ2R until the sound output from the speaker 22R arranged at the position of the position vector φ2 from the viewer 9 is transmitted to the right ear of the viewer 9, and the speaker. There are two transfer functions Hφ2L until the sound output from 22R is transmitted to the left ear of the viewer 9.

  These are exactly the same even when sound is output from the speakers 20L and 20R. That is, as shown in FIG. 6B, in the acoustic transfer function related to the speaker 20L, the sound output from the speaker 20L arranged at the position of the position vector θ1 from the viewer 9 is the left of the viewer 9. There are two transfer functions, Hθ1L until the sound is transmitted to the ear and the transfer function Hθ1R until the sound output from the speaker 20L is transmitted to the right ear of the viewer 9. The acoustic transfer function related to the speaker 20R includes a transfer function Hθ2R until the sound output from the speaker 20R arranged at the position of the position vector θ2 from the viewer 9 is transmitted to the right ear of the viewer 9, and the speaker. There are two transfer functions Hθ2L until the sound output from 20R is transmitted to the left ear of the viewer 9.

  These acoustic transfer functions can be obtained by measuring impulse sounds output from the speakers 20L, 20R, 22L, and 22R as impulse responses at the left and right ears of the viewer 9, respectively. For example, the acoustic transfer function Hφ1L is obtained by measuring the impulse sound output from the speaker 22L as an impulse response at the left ear of the viewer 9. The acoustic transfer function Hθ2R is obtained by measuring the impulse sound output from the speaker 20R as an impulse response at the right ear of the viewer 9. That is, the impulse response measured at the ear of the viewer 9 corresponds to an acoustic transfer function from the position of the speakers 20L, 20R, 22L, and 22R that output the impulse sound to the ear of the viewer 9.

The acoustic transfer functions Hφ1L, Hφ1R, Hφ2L, and Hφ2R of the filters 401 to 404 shown in FIG. 5 can use the acoustic transfer functions obtained as described above. Further, the transfer functions G1 to G4 of the filters 407 to 410 shown in FIG. 5 are obtained by substituting the acoustic transfer functions Hθ1L, Hθ1R, Hθ2L, and Hθ2R obtained as described above into the following equations. Can do.

  The virtual sound image processing unit 40 uses the filters 401 to 404 and 407 to 410 in which the transfer functions obtained as described above are set, so that the position of the sound image is positioned at the position of the virtual tweeter 21 with respect to the high frequency component sound. Can be set. Thereby, the sound image localization processing unit 30 sets the localization position of the sound image at the position of the speaker 20 for the low frequency component sound, and sets the localization position of the sound image at the position of the virtual tweeter 21 for the sound of the high frequency component. As a result, the localization position of the sound image of the entire sound is raised from the position of the speaker 20 to the vicinity of the center of the display unit 60.

[Operation and Action]
Next, the operation and action of the audiovisual apparatus 1 of the present embodiment will be described.

(Overview of overall operation)
The sound source / video source 11 outputs an audio signal and a video signal. The video processing unit 17 performs predetermined video processing based on the video signal supplied from the sound source / video source 11. The display driver 18 generates a drive signal for driving the display unit 60 based on the video signal supplied from the video processing unit 17. The display unit 60 performs display based on the drive signal supplied from the display driver 18.

  When an analog audio signal is supplied from the sound source / video source 11, the A / D conversion circuit 12 converts the signal into a digital signal. When the audio signal of the digital signal is supplied from the sound source / video source 11, the decoder 13 decodes the signal. The SW 14 selects the audio signal output from the A / D conversion circuit 12 and the audio signal output from the decoder 13 and supplies the selected audio signal to the audio processing unit 15. The audio processing unit 15 performs predetermined audio signal processing on the input audio signal. In particular, the sound image localization processing unit 30 of the audio processing unit 15 separates the input audio signal into a low frequency component and a high frequency component, performs a delay process on the low frequency component, and performs an operation on the high frequency component. After performing the virtual sound image processing, each of them is added again to generate and output an audio signal that raises the localization position of the sound image from the position of the speaker 20 to the vicinity of the center of the display unit 60. The D / A conversion circuit 16 converts the digital audio signal output from the audio processing unit 15 into an analog signal. The speaker 20 outputs sound based on the analog signal supplied from the D / A conversion circuit 16.

(Sound image localization position setting)
Next, setting of the localization position of the sound image will be described.

  FIG. 7 is a schematic diagram showing the positional relationship between the viewer and the display unit. 7A shows a state in which the viewer views the video from the front of the display unit, FIG. 7B shows a state in which the viewer looks up the display unit and looks at the video, and FIG. 7C shows the viewing. Shows a state in which a person looks down at the display section and looks at an image.

  In general, the viewer does not always view the video on the display unit from the front. That is, the viewer 9 views the video from the front of the display unit 60 (FIG. 7A), looks up the display unit 60 and looks at the video (FIG. 7B), or displays the display unit 60. There may be a case where the video is viewed from below (FIG. 7C). These cases correspond to, for example, a case where a viewer sits on the floor and watches a video, or a seat sits on a chair and watches a video. Therefore, for example, assuming that the viewer 9 views the video from the front of the display unit 60, even if the sound image increase amount S is set so that the localization position of the sound image is near the center of the display unit 60, the display unit When the video is viewed while looking up at 60, or when the video is viewed while looking down at the display unit 60, the localization position of the sound image is shifted from the vicinity of the center of the display unit 60. That is, as shown in FIG. 7, the optimum sound image increase amount S for setting the localization position of the sound image at the center of the screen differs depending on the relative positional relationship between the viewer 9 and the display unit 60. In particular, as shown in FIG. 7, the sound image increase amount Sb (FIG. 7B) when the viewer looks up at the display unit 60 and looks at the video, or the sound image rise when the viewer looks down at the display unit 60 and looks at the video. The amount Sc (FIG. 7C) is smaller than the sound image increase amount Sa (FIG. 7A) when the viewer views the video from the front of the display unit 60.

  In this way, the audiovisual apparatus 1 can set the localization position of the sound image at the center of the screen of the display unit 60 even when the relative positional relationship between the viewer 9 and the display unit 60 is different. The amount of increase S can be adjusted.

  A method for adjusting the sound image increase amount S will be described below.

  FIG. 8 is a schematic diagram showing the localization position of the sound image when the viewer is in front of the speaker. 8A shows a state where the localization position of the sound image is near the center of the display unit 60, and FIG. 8B shows a state where the localization position of the sound image is lower than the vicinity of the center of the display unit 60.

  The sound image increase amount S changes according to the volume balance between the volume output by the virtual tweeter 21 and the volume output by the speaker 20. Specifically, when the volume of the speaker 20 is fixed to a certain value and the gain Kvt of the amplifier 37 of the sound image localization processing unit 30 is changed, if the gain Kvt is greater than α (Kvt> α), the sound image When the localization position is set higher than the center of the screen and the gain Kvt is smaller than α (Kvt <α), the localization position of the sound image is set lower than the center of the screen. Here, α is the gain of the amplifier 37 such that the localization position of the sound image is near the center of the screen of the display unit 60.

  Next, a specific method for setting the gain Kvt of the amplifier 37 will be described.

First, as shown in FIG. 8A, the gain α of the amplifier 37 is obtained so that the localization position of the sound image is near the center of the screen of the display unit 60, and the localization position A of the sound image and the viewer at that time are obtained. The angle γ0 of the angle ABC formed by the position B of 9 and the position C of the speaker 20 is obtained. When this gain α and angle γ0 are used, the gain Kvt of the amplifier 37 necessary for setting the localization position of the sound image in the direction of an arbitrary angle γ as shown in FIG. The

  In the audiovisual apparatus 1, the gain Kvt of the amplifier 37 with respect to the angle γ is set based on Expression (2) according to the relative positional relationship with the display unit (for example, FIGS. 7A to 7C). Thus, the localization position of the sound image can be set near the center of the screen of the display unit 60. The specific example is shown below.

  FIG. 9 is a schematic diagram for explaining a method of setting the gain Kvt of the amplifier 37 in a state where the viewer looks up at the display unit and looks at the video. This example shows a method for setting the localization position of the sound image near the center of the display unit 60 when the display unit moves from the position of the display unit 60D to the position of the display unit 60.

  First, the gain α and the angle γ0 of the amplifier 37 when the display unit is arranged at the position of the display unit 60D and the localization position of the sound image is set near the center of the screen of the display unit 60D are obtained. Here, the line connecting the viewer 9 and the speaker 20D is taken as the x-axis.

  Next, the angle γ when the display unit is arranged at the position of the display unit 60 and the localization position of the sound image is set near the center of the screen of the display unit 60 is obtained. Here, the line connecting the viewer 9 and the speaker 20R is taken as the x2 axis.

  Next, the virtually arranged display unit 60R is introduced. As shown in FIG. 9, the display unit 60R is arranged by rotating the display unit 60D by an angle δ about the viewer 9 so that the x axis coincides with the x2 axis. In the display unit 60R related to the x2 axis, the direction of the angle γ0 from the x2 axis is near the center of the screen of the display unit 60R. On the other hand, in the display unit 60 related to the x2 axis, the direction of the angle γ from the x2 axis is near the center of the screen of the display unit 60. The direction of the angle γ from the x2 axis corresponds to a portion slightly lower than the vicinity of the center of the screen in the display unit 60R. That is, in the virtually arranged display unit 60R, the localization position of the sound image is set to a position (corresponding to the angle γ) lower than the vicinity of the center of the screen (corresponding to the angle γ0). 60 is set near the center of the screen.

  The method of obtaining the gain Kvt that can set the localization position of the sound image in the direction of the arbitrary angle γ shown in the equation (2) can also be applied in this case. That is, in FIG. 9, when the display unit is arranged at the position of the display unit 60, the gain Kvt of the amplifier 37 necessary for setting the localization position of the sound image near the center of the screen of the display unit 60 is the gain α , And the angles γ and γ0 can be obtained by substituting them into the equation (2). Although FIG. 9 shows the case where the display unit moves in the direction in which the viewer looks up, the same is true even if the display unit moves in the direction in which the viewer looks down.

  In this way, the audiovisual apparatus 1 can set the gain Kvt of the amplifier 37 with respect to the angle γ. Therefore, when the viewer inputs information regarding the relative positional relationship with the display unit (for example, FIGS. 7A to 7C) to the audiovisual apparatus 1, the audiovisual apparatus 1 includes the information. Based on this, the gain Kvt of the amplifier 37 is set, and the localization position of the sound image can be set near the center of the screen of the display unit 60. In this case, the viewer may input the angle γ, for example, or may use the sound image increase amount S by utilizing the fact that the sound image increase amount S is determined according to the angle γ.

  FIG. 10 shows an example of a user interface for inputting the relative positional relationship between the viewer and the display unit. For example, the audiovisual apparatus 1 can display such information on the display unit 60 and input information on the relative positional relationship between the viewer and the display unit. The information may be input using, for example, a slider that can set conditions continuously, or by selecting from discrete conditions such as large, medium, and small. May be.

(Operation of delay units 32L and 32R)
Generally, as is known as a so-called preceding sound effect, a human recognizes the direction in which the entire sound is generated by a part of the sound that first reaches both ears. Therefore, in FIG. 1, for example, if a part of the sound whose sound image localization position is near the center of the display unit 60 reaches the viewer first among the sounds that the viewer feels, Then, the user feels that the entire sound is generated from the vicinity of the center of the display unit 60.

  As described above, the audio localization processing unit 30 of the audiovisual apparatus 1 divides the supplied audio signal into a low frequency component and a high frequency component, and the virtual sound source processing unit 40 performs the virtual sound source only for the high frequency component. Processing is performed and the localization position of the sound image is set to rise. On the other hand, for low frequency components, the sound localization processing unit 30 performs delay processing by the delay units 32L and 32R. That is, the audiovisual apparatus 1 first outputs the high frequency component sound from the speaker 20, and outputs the low frequency component sound from the speaker 20 with a slight delay. As a result, the viewer first feels the sound of the high frequency component in which the localization position of the sound image has risen, and feels that the sound has been generated from that position.

  As described above, the delay units 32L and 32R function to highlight the rise in the localization position of the sound image by the virtual sound source processing unit 40 and maximize the effect.

[effect]
As described above, in the present embodiment, the localization position of the sound image of the sound output from the speaker arranged at the lower part of the display unit is raised and set near the center of the screen of the display unit. By matching the localization position and the video display position, it is possible to prevent the viewer from feeling uncomfortable.

  In particular, in the present embodiment, since the virtual sound source processing unit 40 increases the localization position of the sound image, there is no need to add a speaker for increasing the localization position of the sound image to the apparatus, thereby reducing the size of the apparatus. Can be realized.

  In the present embodiment, since the sound image increase amount S can be adjusted, the localization position of the sound image is near the center of the screen of the display unit according to the relative positional relationship between the viewer and the display unit. It is possible to make such an optimal setting.

  In this embodiment, since the sound image increase amount S is set by the gains Kvtl and Kvtr of the amplifiers 37L and 37R, for example, the sound image increase amount S is set by preparing and switching a plurality of sets of acoustic transfer functions. Compared to the adjusting method, the amount of memory for performing the acoustic transfer function can be reduced.

  Furthermore, in this embodiment, since the low frequency component of the audio signal is delayed, the effect of increasing the localization position of the sound image of the virtual sound source processing unit 40 can be maximized by the preceding sound effect.

[Modification 1-1]
In the above embodiment, the sound image localization processing unit 30 is provided with the phase shift unit 35 and the phase inversion unit 36 as shown in FIG. 3, but is not limited to this. For example, only the phase shift unit 35 is provided. Alternatively, only the phase inversion unit 36 may be provided, or both the phase shift unit 35 and the phase inversion unit 36 may not be provided as shown in FIG. The sound image localization processing unit 30A does not include both the phase shift unit 35 and the phase inversion unit 36, and the output signals of the high-pass filters 34L and 34R are directly supplied to the virtual sound source processing unit 40.

[Modification 1-2]
In the above embodiment, in the sound image localization processing unit 30, as shown in FIG. 3, the phase shift unit 35 is arranged in front of the phase inversion unit 36, but the present invention is not limited to this. The phase shifter 35 may be arranged at the subsequent stage of the phase inverter 36 by exchanging the unit 35 and the phase inverter 36. Moreover, although the phase shift unit 35 and the phase inversion unit 36 are arranged in the preceding stage of the virtual sound source processing unit 40, the present invention is not limited to this, and may be arranged in the subsequent stage of the virtual sound source processing unit 40, for example.

[Modification 1-3]
In the above embodiment, as shown in FIG. 3, the sound image localization processing unit 30 inputs the two-channel audio signal composed of the signals Lin and Rin, but the present invention is not limited to this. For example, as shown in FIG. 12, a sound image localization process may be performed after an audio signal of 5 channels is input and downmixed to 2 channels. The sound image localization processing unit 30B receives the signal Lin, the signal Rin, the signal SLin, the signal SRin, and the signal Cin, amplifies them by the amplifiers 51L, 51R, 51SL, 51SR, and 51C, and then supplies the adders 52L and 52R. It is downmixed to a 2-channel audio signal and performs sound image localization processing.

  Further, for example, as shown in FIG. 13, a sound signal localization process is performed by changing a signal Lin, a signal Rin, and a signal SLin to a two-channel sound signal by inputting a five-channel sound signal and performing a signal SLin, Ordinary virtual surround processing may be performed for SRin. The sound image localization processing unit 30C amplifies the signal Lin, the signal Rin, and the signal Cin by the amplifiers 51L, 51R, and 51C, respectively, supplies them to the adders 52L and 52R, changes the sound signals to two-channel audio signals, and performs sound image localization processing. Is going. The sound image localization processing unit 30C amplifies the signal SLin and the signal SRin by the amplifiers 51SL and 51SR, respectively, and then supplies the amplified signal SLin and the signal SRin to the three-dimensional processing unit 54 via the delay units 53SL and 53SR. After the virtual surround processing is performed in the three-dimensional processing unit 54, the sound image localization processing unit 30C amplifies the output signal by the amplifiers 55SL and 55SR, and synthesizes the result with the sound image localization processing result by the adders 56L and 56R.

[Other variations]
In the above-described embodiment, the speaker 20 is arranged at the lower part of the display unit 60. However, the present invention is not limited to this. For example, the speaker 20 may be arranged at the upper part of the display unit. Even in this case, the virtual sound source processing unit 40 can set the localization position of the sound image by using an acoustic transfer function corresponding to this arrangement.

  In the above embodiment, the cut-off frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R of the sound image localization processing unit 30 are set to predetermined frequencies. For example, the viewer sets this cut-off frequency. You may make it changeable. Thereby, for example, it is possible to set an optimal cutoff frequency for viewers of various ages with different audible sound ranges, and to improve the sense of unity between audio and video.

<3. Second Embodiment>
Next, an audiovisual apparatus according to the second embodiment of the present invention will be described. In the present embodiment, a means for measuring the relative positional relationship between the viewer and the display unit is newly provided, and the localization position of the sound image is controlled based on this means. In addition, the same code | symbol is attached | subjected to the component substantially the same as the audiovisual apparatus which concerns on the said 1st Embodiment, and description is abbreviate | omitted suitably.

[Configuration example]
FIG. 14 shows a configuration example of an audiovisual apparatus according to the second embodiment of the present invention. The audiovisual apparatus 2 includes a camera 71 and a viewer detection unit 72. Other configurations are the same as those in the first embodiment (FIG. 2).

  The camera 71 is provided to measure the relative positional relationship between the viewer and the display unit 60. For example, the camera 71 is arranged at the center of the lower portion of the screen of the display unit 60 so as to catch the viewer in the field of view. Has been.

  The viewer detection unit 72 obtains the relative positional relationship between the viewer and the display unit 60 based on the information supplied from the camera 71 and supplies the result to the sound image localization processing unit 30 of the audio processing unit 15. . As a result, the sound image localization processing unit 30 sets the localization position of the sound image to be near the center of the screen of the display unit 60 based on the positional relationship, as in the first embodiment.

  Here, the camera 71 and the viewer detection unit 72 correspond to a specific example of “positional relationship measuring means” in the present invention.

[Operation and Action]
(Operation of the viewer detection unit 72)
Next, the operation of the viewer detection unit 72 will be described with reference to FIGS. 15 and 16.

  FIG. 15 shows a flowchart of the viewer detection operation in the viewer detection unit 72. FIG. 16 shows the relative positional relationship between the closest viewer and the display unit 60, where (A) shows the case viewed from the front, and (B) shows the case viewed from the side. Note that the variable n is initialized to n = 1 at the start of the flowchart shown in FIG. The display unit 60 has a width w and a height h as shown in FIG.

  First, the viewer detection unit 72 detects the number N of viewers in front of the display unit 60 based on the information supplied from the camera 71 as shown in FIG. 15 (S1).

  Next, in S2, S3, and S31, the viewer detection unit 72 detects the position coordinates of all the viewers detected in S1 with the position of the camera 71 as the origin O. Specifically, first, the position coordinates Pn (xn, yn, zn) are obtained for a certain viewer among the viewers detected in S1 (S2). Next, the variable n is compared with the number of viewers N (S3). If the comparison results do not match, n is incremented (S31), and S2 is performed again. If the comparison results match in S3, the process proceeds to S4.

  Next, in S4, the viewer detection unit 72 selects the viewer (the closest viewer) closest to the display unit 60 among the viewers detected in S1, and determines the position of each viewer obtained in S2. Determine based on the coordinates.

Next, the viewer detection unit 72 obtains the angle γ based on the position coordinates P (x, y, z) of the closest viewer determined in S4. This angle γ is expressed as follows (S5).

  Next, the viewer detection unit 72 determines the gain Kvt of the amplifier 37 of the sound image localization processing unit 30 based on the angle γ determined in S5 (S6). The gain Kvt of the amplifier 37 can be obtained using the equation (2) described in the first embodiment.

  This completes the viewer detection operation. Thereafter, the amplifier 37 of the sound image localization processing unit 30 is set to the gain Kvt obtained in S6. By repeating this series of operations every predetermined period, the audiovisual apparatus 2 can always control the localization position of the sound image to be near the center of the display unit 60.

[effect]
As described above, in this embodiment, since the relative positional relationship between the viewer and the display unit is measured and the localization position of the sound image is controlled accordingly, the setting by the viewer is required. It can improve the sense of unity between audio and video.

  In the present embodiment, since the localization position of the sound image is controlled based on the position coordinates of the viewer closest to the display unit 60 that most easily feel the discrepancy between the audio and the video, This improves the sense of unity between audio and video.

  In the above embodiment, the camera 71 is arranged at the center of the lower part of the display unit 60. However, the present invention is not limited to this. For example, the camera 71 may be arranged at the center of the upper part of the display unit 60.

<4. Third Embodiment>
Next, an audiovisual apparatus according to the third embodiment of the present invention will be described. In the present embodiment, a means for analyzing the video and audio and determining coordinates where the audio is generated in the screen of the display unit 60 is newly provided, and based on this, the localization position of the sound image is controlled. It is a thing. Note that components that are substantially the same as those of the audiovisual apparatus according to the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  FIG. 17 illustrates a configuration example of an audiovisual apparatus according to the third embodiment of the present invention. The audiovisual apparatus 3 includes a video analysis unit 81. Other configurations are the same as those in the first and second embodiments.

  Based on the video signal and audio signals Lin and Rin supplied from the video processing unit 17, the video analysis unit 81 specifies an audio generation source such as a person who is generating audio on the video, and the display unit 60 It has a function for obtaining the coordinates of the sound source in the screen. Based on the result, the gain Kvt of the amplifier 37 of the sound image localization processing unit 30 is set, and the localization position of the sound image is set at a position where the sound is emitted in the screen of the display unit 60.

  As described above, in this embodiment, since the localization position of the sound image is set at the position of the sound source on the video, it is possible to improve the sense of unity between the sound and the video and to give the viewer a sense of realism. Can do.

  In the above embodiment, the video analysis unit 81 specifies the audio generation source on the video based on the video signal and the audio signals Lin and Rin. However, the present invention is not limited to this. For example, Furthermore, audio signals SLin, SRin, Cin, Win may be used.

  In the above embodiment, video and audio are analyzed to specify the sound source on the video. However, the present invention is not limited to this. For example, sound generation on the video is generated only by the video. The source may be specified.

<5. Fourth Embodiment>
Next, an audiovisual apparatus according to the fourth embodiment of the present invention will be described. In this embodiment, a means for obtaining the frequency band of sound is newly provided, and based on this, the cutoff frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R of the sound image localization processing unit 30 are adjusted. It is intended to be set automatically. In addition, the same code | symbol is attached | subjected to the substantially same component as the audiovisual apparatus concerning the said 1st-3rd embodiment, and description is abbreviate | omitted suitably.

  FIG. 18 shows a configuration example of an audiovisual apparatus according to the fourth embodiment of the present invention. The audiovisual apparatus 4 includes a frequency band analysis unit 91. Other configurations are the same as those in the first to third embodiments. Here, the frequency band analyzing unit 91 corresponds to a specific example of “frequency band measuring means” in the present invention.

  The frequency band analysis unit 91 obtains the frequency band of the audio signal based on the audio signals Lin and Rin. Based on the result, the cutoff frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R of the sound image localization processing unit 30 are dynamically set so as to be, for example, the center frequency of the frequency band. The

  When the cut-off frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R are fixed, for example, an audio signal corresponding to audio mainly composed of lower sounds is sent to the sound image localization processing unit 30. The volume of the frequency component lower than the cutoff frequency and the volume of the higher frequency component when the audio signal corresponding to the audio mainly composed of higher sounds is supplied to the sound image localization processing unit 30 The position of the sound image changes because the balance is different.

  That is, when an audio signal corresponding to audio mainly composed of lower sounds is supplied to the sound image localization processing unit 30, for example, when the center frequency of the frequency band of the audio is lower than the cutoff frequency, The volume of the low frequency component output from the pass filters 31L and 31R is larger than the volume of the high frequency component output from the high pass filters 34L and 34R. Therefore, the effect of the virtual sound source processing performed by the virtual sound source processing unit 40 with respect to a signal having a high frequency component is relatively weak, so that the localization position of the sound image is lower than that near the center of the display unit 60.

  Further, when an audio signal corresponding to audio mainly composed of higher sounds is supplied to the sound image localization processing unit 30, for example, when the center frequency of the frequency band of the audio is higher than the cutoff frequency, The volume of the low frequency component output from the pass filters 31L and 31R is larger than the volume of the high frequency component output from the high pass filters 34L and 34R. Therefore, since the effect of the virtual sound source processing performed by the virtual sound source processing unit 40 is relatively strong with respect to a signal having a high frequency component, the localization position of the sound image is higher than that near the center of the display unit 60.

  On the other hand, when the cutoff frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R of the sound image localization processing unit 30 are dynamically set based on the frequency band of sound, various sound ranges are set. Since an appropriate cut-off frequency is set for the sound source, the sound image localization position on the screen of the display unit 60 can be kept substantially constant.

  As described above, according to the present embodiment, the cutoff frequency of the low-pass filter and the high-pass filter is dynamically set according to the supplied audio signal. In contrast, the localization position of the sound image can be kept almost constant.

  In the above embodiment, the frequency band analyzing unit 91 obtains the frequency band based on the audio signals Lin and Rin. However, the present invention is not limited to this. For example, in addition to the audio signals Lin and Rin, The frequency band may be obtained using the signals SLin, SRin, Cin, and Win.

  Although the present invention has been described with reference to some embodiments, the present invention is not limited to these embodiments, and various modifications can be made.

  For example, in each of the second to fourth embodiments, similarly to the first embodiment, either or both of the phase shift unit 35 and the phase inversion unit 36 of the sound image localization processing unit 30 may be omitted. Good.

  For example, in each of the second to fourth embodiments, the phase shift unit 35 and the phase inversion unit 36 of the sound image localization processing unit 30 may be interchanged as in the first embodiment. Further, the phase shift unit 35 and the phase inversion unit 36 of the sound image localization processing unit 30 may be arranged at the subsequent stage of the virtual sound source processing unit 40.

  For example, in each of the second to fourth embodiments, similarly to the first embodiment, an input signal to the sound image localization processing unit 30 may be input as a 5-channel audio signal.

  For example, in each of the second to fourth embodiments, similarly to the first embodiment, the speaker 20 may be arranged on the upper part of the display unit.

  For example, in the second and third embodiments, similarly to the first embodiment, the cutoff frequencies of the low-pass filters 31L and 31R and the high-pass filters 34L and 34R of the sound image localization processing unit 30 are set as follows. The viewer may be able to set.

  DESCRIPTION OF SYMBOLS 1-4 ... Audio visual apparatus, 7, 7L, 7R ... Sound image, 9 ... Viewer, 11 ... Sound source / video source, 12 ... AD converter circuit, 13 ... Decoder, 14 ... SW, 15 ... Audio processing part, 16 ... DA converter, 17 ... Video processing unit, 18 ... Display driver, 19 ... Controller, 20, 20L, 20R, 22L, 22R ... Speaker, 21, 21L, 21R ... Virtual tweeter, 30, 30A, 30B, 30C ... Sound image localization processing Part, 31L, 31R ... low pass filter (LPF), 32L, 32R, 53SL, 53SR ... delay part, 33L, 33R, 405, 406, 411, 412, 52L, 52R, 56L, 56R ... adder, 34L, 34R: High pass filter (HPF), 35: Phase shift unit, 35L, 35R: APF, 36: Phase inversion unit, 37, 37L, 37R, 51L, 5 R, 51SL, 51SR, 51C, 55SL, 55SR ... amplifier, 40 ... virtual sound source processing unit, 54 ... three-dimensional processing unit, 60 ... display unit, 71 ... camera, 72 ... viewer detection unit, 81 ... video analysis unit, 91: frequency band analysis unit, 401-404, 407-410 ... filter, Hφ1L, Hφ1R, Hφ2L, Hφ2R, Hθ1L, Hθ1R, Hθ2L, Hθ2R ... acoustic transfer function, G1-G4 ... transfer function, Lin, Rin, SLin, SRin, Cin, Win, Lout, Rout, LVin, RVin, LVout, RVout ... signal, S, S0, Sa, Sb, Sc ... sound image increase, γ, γ0 ... angle

Claims (10)

A display unit for displaying images;
A speaker for generating audio corresponding to the video;
An audio processing unit that generates an audio signal to be supplied to the speaker by a predetermined process;
The audio processing unit includes a sound image localization processing unit that generates an audio signal that sets a localization position of the sound image of the audio to an arbitrary position on a screen of the display unit. The audiovisual apparatus according to claim 1, wherein a plurality of the speakers are arranged above or below the display unit. 3. The audiovisual apparatus according to claim 2, wherein the sound image localization processing unit localizes a sound image of a low frequency audio component on one of the upper part and the lower part of the display unit, and localizes a sound image of a high frequency audio component on the other side. apparatus. A positional relationship measuring means for measuring a relative positional relationship between the display unit and the viewer;
The audiovisual apparatus according to claim 1, wherein the sound image localization processing unit controls a localization position of the sound image based on the measured positional relationship. The video / audio apparatus according to claim 1, wherein the sound image localization processing unit controls a localization position of the sound image based on content of the video. The audiovisual apparatus according to claim 1, wherein the sound image localization processing unit controls a localization position of a sound image of an audio component having a frequency higher than a predetermined frequency in the audio. The audiovisual apparatus according to claim 6, wherein the predetermined frequency is preset based on an audio frequency band. It further has a frequency band measuring means for measuring the frequency band of voice,
The audiovisual apparatus according to claim 6, wherein the predetermined frequency is obtained based on the frequency band. The audiovisual apparatus according to claim 6, wherein the sound image localization processing unit further generates a phase difference between left and right audio signals of an audio component having a frequency higher than the predetermined frequency. The audiovisual apparatus according to claim 6, wherein the sound image localization processing unit further delays an audio component having a frequency lower than the predetermined frequency.

Images