JP2018046526A - Sound device, display device, and television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a speaker unit inconspicuous to improve appearance of a display device.SOLUTION: A sound device (14) includes: a full band speaker unit (101) for outputting sound in a front direction of a display screen (113); and a bass band speaker unit (201) for outputting a bass component of sound. The bass band speaker unit (201) faces a direction different from that of the full band speaker unit (101).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an audio device, a display device, and a television receiver, and for example, relates to an audio device compatible with a three-dimensional multi-channel audio system.

  2. Description of the Related Art Conventionally, in the technical field of video content and the like, a multi-channel audio system has been used in order to improve the realistic sensation of audio output with video. For example, there is a service for delivering 5.1ch or 7.1ch audio via a recording medium such as broadcast or an optical disc, a network, or the like. The multi-channel sound method includes a plurality of sound channels positioned around the listener, and includes a sound image located behind the listener and a sound image moving around the listener in the plurality of sound channels. be able to. 5.1ch and 7.1ch multi-channel sound systems are famous, but in recent years, in addition to the sound channels located around the listener, it further includes sound channels located above and below the listener. A three-dimensional multi-channel sound system has been proposed. For example, the 22.2ch three-dimensional multi-channel sound system has 22 (all bands) + 2 (low frequencies) positioned so as to surround the listener three-dimensionally as defined in ARIB STD-B59. Including acoustic channels.

  (A)-(d) of FIG. 8 shows one structural example of the 22.2ch three-dimensional multi-channel sound system. As shown in FIG. 8A, the three-dimensional space is divided into three layers based on the position of the listener. The layer above the listener is called the top layer, the layer around the listener is called the middle layer, and the layer below the listener is called the bottom layer. As shown in FIGS. 8B to 8D, the 22.2ch three-dimensional multi-channel sound system has nine sound channels in the top layer, ten points in the middle layer, and three points in the bottom layer. , Each included.

  An acoustic device corresponding to the three-dimensional multi-channel acoustic system includes a plurality of speaker units, and the sound of the plurality of acoustic channels shown in (b) to (d) of FIG. Play the signal. A part of the speaker unit constituting the acoustic device may be incorporated in the display device. For example, in an audio device corresponding to a 22.2 ch three-dimensional multi-channel audio system, a plurality of speaker units corresponding to 11 channels positioned in front of the listener are often incorporated in a display device.

  FIG. 9 is a diagram showing the positions of 11 channels on the display device. As shown in FIG. 9, three of the eleven channels (FLc / FC / FRc in FIG. 9) are located in the display screen of the display device. Speaker units corresponding to these acoustic channels cannot be arranged in the display screen. Therefore, as shown in FIG. 9, each acoustic channel of FLc, FC, and FRc is divided into two acoustic channels (Upper Lc and Lower Lc, Upper C and Lower C, FIG. 9) positioned on the upper and lower sides of the display screen. It is possible to divide into Upper Rc and Lower Rc). In the above configuration, there is no acoustic channel in the display screen, so that the speaker unit can be arranged at the position of each acoustic channel.

  FIG. 10 is a front view of a display device 9 including a conventional acoustic device 914. As shown in FIG. 10, the speaker unit (part of) constituting the acoustic device 914 is attached around the display screen 913 of the display device 9. A total of twelve speaker units 901 to 912 corresponding to the plurality of acoustic channels shown in FIG. 9 are arranged around the display screen 913.

Japanese Patent Laid-Open No. 10-304490 (published on November 13, 1998) JP 2008-109209 A (published May 8, 2008)

“Three-DIMENSIONAL MULTICHANNEL STEREOPHONIC SOUND SYSTEM FOR PROGRAMME PRODUCTION Standard ARIB STD-B59” (Revised July 6, 2016) 12-Loudspeaker System for Three-Dimensional Sound Integrated with Flat-Panel Display Satoshi Oode, Kentaro Matsui, Satoshi Ooishi, Takehiro Sugimoto, and Yasushige Nakayama, Japan Broadcasting Corporation (NHK) NAB Broadcast Engineering Conference Proceedings 2014 ... 184-189

  The acoustic device 914 shown in FIG. 10 is desired to reduce the diameter of the speaker units 901 to 912 from the viewpoint of weight, design, and the like. However, when the apertures of the speaker units 901 to 912 are reduced, the ability of the speaker units 901 to 912 to reproduce low-frequency sound is reduced. Therefore, it is conceivable that the acoustic device 914 has a two-way configuration for reproducing low-frequency sound from a sub-speaker unit (woofer, subwoofer, etc.). However, if the audio device 914 further includes a subwoofer, the number of speaker units provided on the display screen side of the display device 9, that is, the number of speaker units visible to the listener increases, and thus the appearance of the display device 9 is impaired. There's a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the appearance of a display device by making the speaker unit inconspicuous in an audio device including a speaker unit provided in the display device. There is to do.

  In order to solve the above-described problem, an acoustic device according to one embodiment of the present invention includes a first speaker unit and a second speaker unit that are disposed outside a display screen of a display device, and outputs a plurality of channels of audio. An audio device for outputting, wherein the second speaker unit outputs a bass component of sound output from the first speaker unit, and the first speaker unit and the second speaker unit are different from each other. It is provided to face the direction.

  According to one embodiment of the present invention, the appearance of a display device can be improved by making a speaker unit inconspicuous.

1 is a front view of a display device according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of a display device according to Embodiment 1. FIG. 3 is a block diagram illustrating a configuration of a signal processing unit included in the acoustic device of the display device according to Embodiment 1. FIG. 6 is a block diagram illustrating a configuration of a display device according to Embodiment 2. FIG. 10 is a front view of a display device according to Embodiment 3. FIG. 10 is a front view of a display device according to Embodiment 4. FIG. 10 is a front view of a display device according to Embodiment 5. FIG. (A) is a figure which shows the top layer in which each acoustic channel is located in a 22.2ch three-dimensional multichannel acoustic system, a middle layer, and a bottom layer, (b) shows the acoustic channel in a middle layer. , (C) shows acoustic channels in the top layer, and (d) shows acoustic channels in the bottom layer. It is a figure which shows the position of the some acoustic channel positioned ahead of a listener in a 22.2ch three-dimensional multi-channel sound system. It is a front view of the conventional display apparatus.

  Hereinafter, embodiments of the present invention will be described in detail. However, the configuration described in this embodiment is merely an illustrative example, and is not intended to limit the scope of the present invention only to that unless otherwise specified. In the following description, “sound” refers to all sounds handled by acoustic products, and includes human voices, background sounds, and musical sounds.

Embodiment 1
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

(Appearance of display device)
FIG. 1 is a front view of a display device 1 according to the present embodiment. As shown in FIG. 1, a plurality of speaker units 101 to 112 and 201 to 212 constituting the acoustic device 14 are attached around the display screen 113 of the display device 1. The acoustic device 14 corresponds to a three-dimensional multi-channel acoustic system, and a plurality of speaker units 101 to 112 and 201 to 212 generate, for example, a sound image located in front of a listener (that is, a localized sound source). Sound field) and a sound image moving around the display device 1 can be reproduced. Note that the acoustic device 14 may further include another speaker unit that is not attached to the display device 1.

  The first speaker units 101 to 112 of the acoustic device 14 are arranged so that the diaphragm faces the front direction of the display screen 113, that is, outputs sound in the forward direction. The second speaker units 201 to 212 of the acoustic device 14 are arranged so that the diaphragm faces the surface direction of the display screen 113, that is, outputs sound in the horizontal direction. Note that at least one of the second speaker units 201 to 212 may be a bus reflex type. In this configuration, the bass reflex second speaker units 201 to 212 output sound in the same direction as the first speaker units 101 to 112, that is, in the forward direction.

  The first speaker units 101 to 112 reproduce audio signals in the entire band (from the low sound range to the high sound range). On the other hand, the second speaker units 201 to 212 are designed to particularly suitably reproduce a low-frequency sound signal. More specifically, the second speaker units 201 to 212 are designed so that the minimum resonance frequency is lower than that of the first speaker units 101 to 112. For example, the second speaker units 201 to 212 may be designed with a larger diameter or a greater weight of the diaphragm than the first speaker units 101 to 112. As will be described in detail later, the speaker units 201 to 212 output a bass component of the sound output from the speaker units 101 to 112. In addition, the speaker units 201 to 212 further reproduce as a surround sound a sound field generated by a sound source localized next to or behind the listener. Hereinafter, the speaker units 101 to 112 are referred to as full-band speaker units 101 to 112 or simply as speaker units 101 to 112, and the speaker units 201 to 212 are referred to as low sound range speaker units 201 to 212.

  As shown in FIG. 1, when the display device 1 is viewed from the front, the low-frequency speaker units 201 to 212 are respectively disposed between two adjacent full-band speaker units 101 to 112. The listener in front of the display device 1 can hardly see the low-frequency speaker units 201 to 212. Therefore, when viewed from the listener, the display device 1 seems to have a small number of speaker units attached around the display screen 113, so that the listener feels the display device 1 smartly. Moreover, you may enlarge the diaphragm of the low sound range speaker units 201-212, maintaining the state where the low sound range speaker units 201-212 are not conspicuous. Thereby, the ability of the low sound range speaker units 201 to 212 to reproduce the low sound can be easily improved.

(Configuration of display device)
A configuration of the display device 1 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a block diagram illustrating a configuration of the display device 1 according to the present embodiment. FIG. 3 is a block diagram illustrating a configuration of the signal processing unit 12 provided in the acoustic device 14 of the display device 1. As shown in FIG. 2, the display device 1 includes an acoustic device 14, a remote controller 16, and a playback unit 17.

  The acoustic device 14 corresponds to the 22.2 ch three-dimensional multi-channel acoustic system, and can reproduce audio signals of a plurality of acoustic channels shown in (b) to (d) of FIG. The acoustic device 14 includes an input unit 11, a signal processing unit 12, an amplification unit 13, a full-band speaker unit 14A, a low-frequency speaker unit 14B, and a control unit 15. The acoustic device 14 is controlled by a control signal transmitted from the remote controller 16 of the display device 1.

  The control unit 15 controls the input unit 11, the signal processing unit 12, and the amplification unit 13. The control unit 15 receives a listener's operation. Moreover, the control signal based on operation is transmitted with respect to each part in the acoustic apparatus 14, and the whole acoustic apparatus 14 is controlled. The control signal transmitted to each part of the audio device 14 may be an input switching signal, a volume adjustment signal, power on / off, sound quality switching, surround processing on / off, and the like.

  The reproduction unit 17 extracts an audio signal from information on content to be reproduced by the display device 1 and transmits the extracted audio signal to the input unit 11 of the acoustic device 14 as an input signal. The input signal includes audio signals of a plurality of acoustic channels (for example, 22.2 ch).

  When the listener operates the remote controller 16 and turns on the display device 1, the control unit 15 activates the acoustic device 14. The control unit 15 energizes each unit of the acoustic device 14 and releases the mute of the amplification unit 13 when the control unit 15 becomes operable. As a result, the acoustic device 14 is in a state capable of outputting sound.

  When each unit of the audio device 14 is activated, the input unit 11 receives an input signal from the reproduction unit 17. The format of the input signal received by the input unit 11 is various. Here, the format of the input signal is a 22.2 channel audio signal using HDMI (registered trademark) 2.0.

  The input unit 11 receives an input signal including audio signals of a plurality of acoustic channels from the playback unit 17 of the display device 1 using any wired or wireless means (for example, an HDMI cable or an analog pin connector). To do. When the HDMI cable is used, the video signal and the audio signal are superimposed. The input unit 11 extracts an audio signal. The video signal is output to a display device (not shown). The input unit 11 may receive only the audio signal from the display device via the HDMI cable.

  The input unit 11 converts the input signal into an appropriate digital signal and outputs the digital signal to the signal processing unit 12. For example, when the sampling frequency used for signal processing is set to 48 kHz, the input unit 11 converts the sampling frequency of the input signal to 48 kHz. When the input unit 11 receives an analog signal, the input unit 11 converts the analog signal into a digital signal by A / D conversion. When there is no input signal, the input unit 11 may output an audio signal having a sampling frequency of 48 kHz to the signal processing unit 12 as a silence signal (audio signal without audio data).

  The input unit 11 outputs an input signal to the signal processing unit 12. The signal processing unit 12 performs processing described later on the input signal input from the input unit 11, and outputs the full-band speaker signal and the low-frequency speaker signal obtained as a result of the processing to the amplification unit 13.

  The amplifying unit 13 amplifies the full-band speaker signal and the low-frequency speaker signal processed by the signal processing unit 12 and outputs them to the full-band speaker unit 14A and the low-frequency speaker unit 14B. The audio signal transmitted from the signal processing unit 12 to the amplification unit 13 is a digital signal, but the output signals output from the amplification unit 13 to the full-band speaker unit 14A and the low-frequency speaker unit 14B are analog signals. The amplifying unit 13 first converts a digital signal into an analog signal using a D / A converter, and then amplifies the input signal. The amplifying unit 13 outputs the amplified audio signal as an output signal to the full-band speaker unit 14A and the low-frequency speaker unit 14B. Alternatively, the amplifying unit 13 may amplify the digital signal and then convert the digital signal to an analog signal by a switching operation.

  The full-band speaker unit 14A is composed of twelve full-band speaker units 101 to 112 (refer to FIG. 1) mainly for reproducing the mid-high range. The low sound range speaker unit 14B is mainly composed of twelve low sound range speaker units 201 to 212 (see FIG. 1) for reproducing the low sound range. Here, the all-band speaker units 101 to 112 have the arrangement presented in Non-Patent Document 2. The low sound range speaker units 201 to 212 are arranged in the vicinity of each of the full-band speaker units 101 to 112. Each low-frequency speaker unit is preferably arranged as close as possible to the full-band speaker unit. In this configuration, a sound image can be presented in the vicinity of the full-band speaker unit over a wide frequency band for a set including one full-band speaker unit and one low-frequency speaker unit. Humans have a characteristic that when the sound frequency is low, that is, when the sound wavelength is long, it is difficult to sense the localization of the sound image. Therefore, when the sound device 14 outputs sound having a frequency equal to or lower than a predetermined frequency (for example, 80 Hz), the sound device 14 uses more low-frequency speaker units than when outputting sound having a frequency exceeding the predetermined frequency. It may be output. Or you may reproduce | regenerate with the speaker unit (subwoofer) for low sound ranges further provided in the audio equipment 14. Accordingly, it is possible to further enhance the bass reproduction capability of the acoustic device 14.

  The full-band speaker units 101 to 112 reproduce the full-band speaker signal input from the amplifying unit 13. The low sound range speaker units 201 to 212 reproduce the low sound range speaker signal input from the amplification unit 13. The sound output from the all-band speaker units 101 to 112 directly enters the listener's ear. On the other hand, the sound output from the low-frequency speaker units 201 to 212 is diffused by the wall of the room in which the display device 1 is placed, and then enters the listener's ear as diffused sound. Therefore, the listener feels that the diffused sound is spreading in the room. The way the diffused sound is heard depends on the room characteristics (see Embodiment 2).

  Note that different amplifying units 13 may be associated with the all-band speaker units 101 to 112 and the low-frequency speaker units 201 to 212. Generally, the low sound range speaker units 201 to 212 are highly resistant to sound pressure and the like and have a large driving power. Therefore, a powerful amplifying unit 13 may be provided for the low-frequency speaker units 201 to 212, and a standard amplifying unit 13 may be provided for the all-band speaker units 101 to 112. By not providing the powerful amplifying unit 13 for the all-band speaker units 101 to 112, the cost of the amplifying unit 13 can be suppressed.

(Signal processing part)
As illustrated in FIG. 3, the signal processing unit 12 of the acoustic device 14 includes a volume adjustment unit 121, a filter unit 122, a surround processing unit 123, and a mixing unit 124.

  The volume adjustment unit 121 adjusts the level (volume) of the input signal. The volume adjusting unit 121 multiplies the input signal by a coefficient corresponding to the set volume set by the control unit 15 to reflect the listener's set volume in the input signal. The level-adjusted input signal is separated into the sound signals of 11 sound sources located in front of the listener and the sound signals of 11 other sound sources.

  The volume adjustment unit 121 adjusts the level of the input signal input from the input unit 11 to the signal processing unit 12. Also, the volume adjusting unit 121 includes 11 channels (TpFL, TpFC, shown in FIGS. 8B to 8D) positioned on the display screen 113 among the audio signals of a plurality of acoustic channels included in the input signal. TpFR, FL, FLc, FC, FRc, FR, BtFL, BtFC, BtFR) audio signals are output to the filter unit 122. Further, the volume adjusting unit 121 is a sound of other 11 channels (BL, BR, BC, SiL, SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, TpBC shown in (b) to (d) of FIG. 8). The signal is output to the surround processing unit 123.

  The filter unit 122 has 11 channels positioned on the display screen 113 (TpFL, TpFC, TpFR, FL, FLc, FC, FRc, FR, BtFL, BtFC, BtFR shown in (b) to (d) of FIG. 8). The band limiting filter process is performed on the audio signal. That is, the filter unit 122 passes only an audio signal in a predetermined frequency band. Further, the filter unit 122 may perform the same filtering process as that for the 11 channels on a 2-channel audio signal specialized for bass. Or the filter part 122 does not need to perform a filter process to the audio | voice signal of 2 channels specialized in the low sound. In this configuration, the 2-channel audio signal is added to the 11-channel audio signal without being filtered.

  Specifically, the filter unit 122 divides the audio signal input from the volume adjustment unit 121 into an audio signal in a low frequency range and an audio signal in another band. For example, when the band handled by the low-frequency speaker unit is 200 Hz or less, the filter unit 122 applies a high-pass filter (HPF) having a cutoff frequency of 200 Hz to the audio signal output to the full-band speaker unit. The filter unit 122 applies a low-pass filter (LPF) having a cut-off frequency of 200 Hz to the audio signal output to the low-frequency speaker unit. Further, the filter unit 122 may cut an audio signal in a very low frequency range that cannot be reproduced by the low frequency range speaker unit from the low frequency range speaker signal. For example, the filter unit 122 may apply HPF having a cutoff frequency of 50 Hz to a low-frequency speaker signal output from the LPF. Further, the filter unit 122 may correct the reproduction frequency characteristics of the speaker units 101 to 112. The filter unit 122 outputs the output from the HPF as a full-band speaker signal to the amplification unit 13, and outputs the output from the LPF to the mixing unit 124 as a low-frequency speaker signal.

  Since the full-band speaker signal reproduced by the full-band speaker unit is band-limited, it is possible to avoid an excessive input from being input to the full-band speaker unit. Further, since the stroke amount of the diaphragm of the all-band speaker unit is reduced, distortion of the all-band speaker unit can be suppressed, and power consumption of the all-band speaker unit can be reduced. Therefore, the full-band speaker unit can reproduce sound more stably.

  The surround processing unit 123 has 11 channels (BL, BR, BC, SiL, SiR, TpC, TpBL, TpBR, TpSiL, TpSiR, shown in (b) to (d) of FIG. 8 that are not positioned on the display screen 113. A surround sound signal is generated by performing pseudo virtual surround processing on the sound signal of TpBC). The virtual surround process is a process for making a listener perceive as if sound is emitted from a sound source localized at a position where a speaker unit does not exist.

  Specifically, in the virtual surround processing, the surround processing unit performs a filtering process on the audio signal input from the volume adjustment unit using a function simulating a head related transfer function (HRTF). The HRTF is a sound in which the listener can hear the characteristics of the sound path from the position of a virtual sound source to the listener's ear canal (for example, the shape of the human head, shoulders, and pinna). It is used to reflect the influence on the audio signal. The HRTF is created on the assumption that a surround sound signal is reproduced by headphones worn by the listener (binaural method). The surround processing unit filters the audio signal so that when the surround audio signal is reproduced by the speaker unit, the listener can hear the same sound as when listening to the sound by wearing headphones (transoral method). For example, the surround processing is performed by removing in advance the sound that reaches the listener's left ear from the speaker unit on the right side of the listener and the sound that reaches the listener's right ear from the speaker on the left side of the listener. This is realized by performing filter processing. This inverse filter processing is generally referred to as crosstalk cancellation.

  In general, the virtual surround processing as described above has a large amount of calculation, so that the hardware cost of the acoustic device 14 increases. In addition, the reverse filter is effective, the range of the place where the listener can feel the virtual surround effect is narrow, and the sound subjected to the reverse filter process is easily affected by changes in the playback environment. is there. Therefore, the surround processing unit 123 may reproduce an audio signal in which the HRTF is convoluted as a pseudo virtual surround process, or may analyze only the characteristics of the audio signal necessary for localization in a specific direction by analyzing the HRTF. By using, simple frequency filter processing may be performed on the audio signal.

  In addition, the surround processing unit 123 may perform signal level adjustment, delay setting, frequency characteristic correction, and the like on the generated surround sound signal. The surround sound signal is generated on the assumption that it is reproduced from a plurality of speaker units equidistant from the listener. When a plurality of speaker units for reproducing the surround sound signal are not equidistant from the listener, the surround processing unit 123 performs a delay process according to the distance difference, a level correction process according to the distance attenuation, and the like on the surround sound signal. I do.

  The mixing unit 124 acquires, from the filter unit 122, an 11-channel audio signal positioned on the display screen 113 and a 2-channel audio signal specialized for bass. The mixing unit 124 mixes the acquired 11 + 2 channel audio signals according to the arrangement of the full-band speaker unit and the low-frequency speaker unit in the acoustic device 14. Further, the mixing unit 124 adds the audio signal input from the surround processing unit 123 to the mixed audio signal, thereby generating a low-frequency speaker signal reproduced by the low-frequency speaker units 201 to 212. The mixing unit 124 outputs the generated low-frequency speaker signal to the amplification unit 13.

(Configuration of speaker unit)
The full-band speaker unit is designed to play audio in the audible band, but in reality, the high-frequency playback capability and low-frequency playback capability of the speaker unit are in a trade-off relationship. is there. Generally, a speaker unit tends to have a low-frequency reproduction capability when the high-frequency reproduction capability is enhanced, and a low-frequency reproduction capability tends to be inferior when a low-frequency reproduction capability is enhanced. Moreover, although the speaker unit is advantageous for low-pitched sound reproduction when the diameter is increased, it is disadvantageous for high-pitched sound reproduction and tends to be reversed when the diameter is decreased. Since the loudspeaker unit can move a large amount of air as the aperture is larger, it also tends to generate a higher sound pressure.

  On the other hand, when a full-band speaker unit is provided in a television or a peripheral device as a display device, it is generally necessary to select a small-diameter speaker unit as the full-band speaker unit due to design and weight constraints. It is. However, the small-diameter full-band speaker unit is disadvantageous in terms of reproduction capability in the low sound range. In addition, when a low sound with a high sound pressure is output to a small-diameter full-band speaker unit, the diaphragm is greatly displaced, causing large distortion in the full-band speaker unit or damaging the full-band speaker unit. The possibility increases.

  Therefore, as described above, the signal processing unit 12 attenuates an audio signal having a certain frequency or less from an audio signal (output signal) output to the full-band speaker unit. The low sound range speaker unit reproduces the low sound instead of the full band speaker unit. Generally, bass has a characteristic that it is easily diffracted because of its long wavelength. Therefore, the listener feels that the low frequency sound output from the low frequency range speaker unit is output from the full-band speaker unit. Therefore, the acoustic device 14 can reproduce the sound field generated by the sound source localized on or near the full-band speaker unit in a wide band. In addition, the full-band speaker unit can output the sound in the middle and high range with high sound pressure without difficulty.

  The low-frequency speaker unit reproduces not only low-frequency sound but also surround sound. In general, as the frequency of sound waves increases, the straightness of sound waves increases. Therefore, the surround sound is diffused by the wall of the room or an object placed in the room while going straight in the horizontal direction. Since the diffused surround sound is not localized (that is, the listener cannot determine the position of the sound source), the listener feels that it is wrapped in the surround sound. Since the surround sound is spread over a wide range, the listener can enjoy the feeling of being surrounded by the surround sound within a wide range of the room. Note that a sound image to be localized at a specific position behind or on the side of the listener may not be localized at the specific position. In this case, the listener obtains a feeling that is encased in the sound. In general, audio signals reproduced by a speaker unit placed behind or beside a listener are classified into two types: a component that provides the listener with a sense of being wrapped in sound and a component that is localized at a specific position. it can. For many content, the former is dominant. The sound image based on the audio signal of the channel located in front of the listener is localized in the vicinity of the acoustic device, whereas the sound image to be localized at a specific position is not localized and is located away from the acoustic device 14. As perceived by the listener. As a result, the listener can obtain a sense of being surrounded by sound to some extent. In a recording sound source called object audio or the like, a component that provides a sense of being wrapped and a component that is localized at a specific position are separated in advance. When reproducing the object audio, the acoustic device 14 may reproduce the component that brings the listener a sense of being wrapped in the sound from the low-frequency speaker unit, while reproducing the component localized at the specific position from another speaker unit. . In this configuration, the acoustic device 14 can perform an acoustic expression closer to the intention of the recording sound source producer.

  The surround sound signal output by the low sound range speaker unit does not necessarily correspond to the acoustic channel on a one-to-one basis. The surround sound signal corresponds to one acoustic channel and may be reproduced by a plurality of speaker units. Thereby, the acoustic device 14 can diffuse the surround sound over a wider area.

  The low sound range speaker unit is preferably excellent in low sound reproduction capability. In general, a speaker unit excellent in low-pitched sound reproduction capability is poor in high-pitched sound reproduction capability. However, the surround sound signal does not necessarily contain a lot of high sound components. In addition, even when the surround sound signal is mainly composed of the low sound component, the listener can obtain a feeling as if it is wrapped in the surround sound. Therefore, the bass speaker unit only needs to reproduce the surround sound signal within the range of the reproduction capability of the high sound. If necessary, the acoustic device 14 may further include a speaker unit for reproducing the high-frequency component of the surround sound signal, and the speaker unit may reproduce the high-frequency component of the surround sound signal. Or the surround process part 123 may perform the equalizer process etc. which emphasize the high frequency component of a surround audio | voice signal.

(Modification)
In one modification, the low-frequency speaker unit is a so-called bass reflex type, and the bass reflex port of the low-frequency speaker unit may open in the same direction as the direction in which the all-band speaker outputs sound. In this configuration, the sound output from the low-frequency speaker unit is emitted from the bass reflex port toward the listener, so that the sound source can be localized at a position closer to the full-band speaker unit. A sound absorbing material may be disposed in the speaker box of the low sound range speaker unit. In this configuration, since the sound absorbing material can reduce the sound other than the low sound, the diffusion of the surround sound emitted from the bass reflex port can prevent other sounds from being disturbed.

  The attenuation frequencies of the full-band speaker unit and the low-frequency speaker unit do not necessarily match. For example, the 150 Hz HPF is applied to the output signal to the all-band speaker unit, while the output signal to the low-band speaker unit is the output signal to the all-band speaker unit multiplied by the 200 Hz LPF. May be. With this configuration, it is possible to improve the performance of the low sound range speaker unit to reproduce low frequency sound. Further, the order of the filter does not need to be high, and may be about 6 dB / oct.

  In another modification, the reproducing unit 17 may supply, to the low-frequency speaker unit, two-channel audio signals specialized for low-frequency sound among 22.2 ch audio channels input to the audio device 14. The two-channel audio signal is added to the output signal to the low-frequency speaker unit. In this configuration, the low-frequency speaker unit can reproduce the low-frequency component of the 11-channel audio signal located in front of the listener and the surround audio signal as well as the 2-channel audio signal specialized for low-frequency sound. Further, a sound image included in the audio signals of the two channels may be defined according to the arrangement of the speaker units of the acoustic device 14. With this configuration, the low-frequency speaker unit can satisfactorily reproduce an audio signal in a band having a relatively high frequency and influencing localization. As a result, the display device 1 can more closely match the video displayed on the display screen 113 and the audio output from the audio device 14, thereby providing the listener with a more immersive video and audio. it can.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the present embodiment, a configuration for adjusting the sound output from the speaker unit according to the characteristics of the room in which the display device is placed will be described. Room characteristics include room size and shape, room wall material and reflection performance, and the location of objects placed in the room.

(Configuration of display device)
The configuration of the display device 2 according to the present embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a configuration of the display device 2 according to the present embodiment. As shown in FIG. 4, the display device 2 further includes a measurement microphone 18 in addition to the configuration of the display device 1 described in the first embodiment (see FIG. 2). The acoustic device 214 of the display device 2 according to the present embodiment further includes a measurement signal input unit 21 and an analysis unit 22 in addition to the configuration of the acoustic device 14 described in the first embodiment.

  The measurement microphone 18 receives diffused sound, that is, sound output from the low-frequency speaker units 201 to 212 and reflected by a wall of the room or the like. The measurement microphone 18 transmits an audio signal generated from the received diffused audio to the measurement signal input unit 21 as an input signal. The measurement signal input unit 21 acquires the audio signal of the output sound output from the low-frequency speaker units 201 to 212 and acquires the sound signal of the diffused sound received by the measurement microphone 18. The measurement signal input unit 21 outputs the acquired two audio signals to the analysis unit 22. The analysis unit 22 analyzes the two audio signals input from the measurement signal input unit 21 and outputs the analysis result to the control unit 15.

(Calibration)
The listener adjusts the speaker unit at the first activation after the acoustic device 214 is installed. Specifically, the listener installs the measurement microphone 18 at the listening position and operates the remote controller 16 to set the acoustic device 214 to the speaker adjustment mode. In the speaker adjustment mode, the control unit 15 outputs a measurement signal to the input unit 11. The measurement signal may be any signal that can measure the frequency characteristics, delay time, etc. of the speaker unit or the room. The measurement signal is preferably a signal from which an impulse response is obtained, such as a time stretched pulse or an M-sequence signal. The measurement signal is output from the low-frequency speaker unit 14B via the input unit 11, the signal processing unit 12, and the amplification unit 13. The output measurement signal is influenced by the installed environment and diffused, and then collected by the measurement microphone 18 and input to the measurement signal input unit 21.

  The measurement signal input unit 21 amplifies the measurement signal collected by the measurement microphone 18 to an appropriate level and performs A / D conversion. Further, based on the measurement trigger from the control unit 15, a measurement signal in an appropriate time range is cut out, and the cut out measurement signal is output to the analysis unit 22.

  The analysis unit 22 analyzes the measurement signal cut out by the measurement signal input unit 21. Specifically, the analysis unit 22 obtains an impulse response by calculation from a time stretched pulse or an M-sequence signal. The analysis unit 22 obtains a plurality of pieces of information such as measurement signal delay and frequency characteristics. An appropriate delay time setting is obtained from the delay of the measurement signal, and an appropriate characteristic correction parameter is obtained from the frequency characteristic of the measurement signal. For example, when the sound is transmitted from the low sound range speaker unit to the listener via the object closest to the low sound range speaker unit, the delay time varies depending on the sound path. Further, the frequency characteristics and sound pressure characteristics of the measurement signal change according to the sound absorption rate and shape of an object installed around the low sound range speaker unit. The signal processing unit 12 corrects the input signal based on the analysis result of the measurement signal by the analysis unit 22. Further, the signal processing unit 12 may correct the frequency characteristic of the low-frequency speaker signal according to the measurement result. Thereby, the acoustic device 214 can reproduce the input signal more satisfactorily.

  Note that, depending on the environment of the display device 2, the analysis unit 22 may obtain a measurement signal with a significantly long transmission time or a measurement signal with a very low sound pressure. For example, when the display device 2 is placed in a room having an extremely high ceiling or an extremely large room, a measurement signal having a significantly long transmission time can be obtained. Further, when the sound absorption coefficient of the wall of the room is high or when the room is open to the outside, a measurement signal having a remarkably low sound pressure can be obtained. In such a case, the control unit 15 may switch the output destination of the surround sound signal from the low-frequency speaker unit to the full-band speaker unit. When the response of a certain low sound range speaker unit is extremely different, the output destination of the surround sound signal may be switched to the adjacent low sound range speaker unit.

  According to the configuration of the present embodiment, it is possible to appropriately adjust the low-frequency sound signal output from the low-frequency speaker units 201 to 212 according to the room characteristics. In addition, since the reverberation sound of the reproduction environment can be obtained more naturally, the listener's immersive feeling can be further enhanced.

[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the first embodiment, the configuration in which the low-frequency speaker units 201 to 212 are located between the all-band speaker units 101 to 112 when the display device 1 is viewed from the front has been described (see FIG. 2). However, the positional relationship between the all-band speaker units 101 to 112 and the low sound range speaker units 201 to 212 is not particularly limited.

(Appearance of display device)
FIG. 5 is a front view of the display device 3 according to the present embodiment. As shown in FIG. 5, the display device 3 has positions of the low-frequency speaker units 201 to 212 included in the acoustic device 314 compared to the configuration of the display device 1 described in the first embodiment (see FIG. 1). Is different. More specifically, in the display device 1 according to the first embodiment, when the display device 1 is viewed from the front, the low-frequency speaker units 201 to 212 are disposed between the all-band speaker units 101 to 112. . On the other hand, in the display device 3 according to the present embodiment, when the display device 3 is viewed from the front, the low-frequency speaker units 201 to 212 are arranged at the same positions as the all-band speaker units 101 to 112.

  According to the configuration of the present embodiment, when viewed from the listener, that is, when the display screen 113 of the display device 3 is viewed from the front, the low-frequency speaker units 201 to 212 are in the same positions as the all-band speaker units 101 to 112. Therefore, the low sound range speaker units 201 to 212 are less noticeable. Further, since the full-band speaker units 101 to 112 and the low-frequency speaker units 201 to 212 are close to each other, the acoustic device 314 can localize a sound image in the vicinity of the full-band speaker unit over a wide frequency band. .

[Embodiment 4]
The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the first embodiment, the configuration in which the all-band speaker units 101 to 112 and the low-frequency speaker units 201 to 212 are arranged around the entire display screen 113 of the display device 1 (see FIG. 2) has been described. In the third embodiment, a similar configuration (see FIG. 5) has been described. However, in the display device according to another embodiment, a speaker unit may be arranged in a part of the periphery of the display screen. Further, the number of speaker units attached to the display device is not particularly limited.

(Configuration of display device)
FIG. 6 is a front view of the display device 4 according to the present embodiment. As shown in FIG. 6, in the display device 4, the speaker units 101 to 110 and 201 to 208 of the acoustic device 414 are attached only on the upper side and the lower side of the display screen 113. Further, a total of 18 (10 + 8) speaker units are attached to the display device 4. The acoustic device 414 further includes a speaker unit (not shown) separate from the display device 4 instead of the speaker unit arranged on the side of the display screen 113 of the display device 3 according to the third embodiment. You may have.

  In the display device 4, the audio signals of six acoustic channels out of the eleven acoustic channels shown in FIG. 9, that is, TpFL, TpFC, TpFR, BtFL, BtFC, and BtFR are all-band speaker units at corresponding positions. Played by. Audio signals of the other five acoustic channels, that is, FL, FLc, FC, FRc, and FR, are reproduced by two speaker units arranged in the vertical direction. When the listener listens to the sound at an equidistant position from the all-band speaker units arranged in the vertical direction, it feels as if the sound is being output from the middle of the upper and lower speaker units.

  Further, in the display device 4, the audio signals of 11 acoustic channels positioned around the listener shown in FIGS. 8B to 8D are reproduced by the nearest low frequency speaker unit of each acoustic channel. The Specifically, the audio signals of the acoustic channels SiL and BL shown in FIG. 8B are reproduced by the low frequency speaker units 201 and 205. The audio signals of the acoustic channels SiR and BR shown in FIG. 8B are reproduced by the low-frequency speaker units 205 and 212. Also, the audio signal of the acoustic channel BC shown in FIG. 8B is reproduced by the low-frequency speaker units 203 and 210. The audio signals of the acoustic channels TpSiL and TpBL shown in FIG. 8C are reproduced by the low sound range speaker unit 201. The audio signals of the acoustic channels TpSiR and TpBR shown in (c) of FIG. 8 are reproduced by the low-frequency speaker units 201 and 205. The audio signal of the acoustic channel TpBC shown in FIG. 8C is reproduced by the low-frequency speaker units 201 and 203. Note that the surround sound signal is not necessarily reproduced by the nearest low-frequency speaker unit. For example, the audio signal of the acoustic channel TpBL may be reproduced by the low-frequency speaker unit 202, and the audio signal of the acoustic channel TpBR may be reproduced by the low-frequency speaker unit 204. In the above configuration, the listener can be made to feel as if the listener is wrapped in the surround sound signal.

  According to the configuration of the present embodiment, the number of speaker units 101 to 110 and 201 to 208 attached to the display device 4 is smaller than that of the configuration of the first or third embodiment. Become smart.

[Embodiment 5]
The following will describe another embodiment of the present invention with reference to FIG. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the present embodiment, a configuration of a display device including a speaker unit on the back side of the display screen will be described.

(Configuration of display device)
FIG. 7 is a front view of the display device 5 according to the present embodiment. As shown in FIG. 7, in the display device 5, in addition to the configuration of the display device 4 according to the fourth embodiment (see FIG. 6), a bass reproduction speaker unit 301 of the acoustic device 514 is provided on the back side of the display screen 113. It is further arranged. The low-pitched sound reproduction speaker unit 301 outputs sound in the backward direction. The sound output from the bass reproduction speaker unit 301 is reflected by a wall or an object in the room, and then enters the listener's ear as diffused sound.

  Compared with the display device 4 according to the fourth embodiment, the display device 5 has a lower number of low-frequency speaker units arranged on the upper and lower sides of the display screen 113. In other words, in the display device 5, some low-frequency speaker units of the acoustic device 514 are attached to the back side of the display screen 113 instead of the upper side and the lower side of the display screen 113.

  According to the configuration of the present embodiment, since the number of speaker units provided around the display screen 113 of the display device 5 is small, the appearance of the display device 5 can be made smart.

(Additional notes)
A television receiver including the display device and the tuner described in the above embodiment is also included in the invention described in this specification.

[Example of software implementation]
The control blocks (in particular, the input unit 11, the signal processing unit 12, the amplification unit 13, the control unit 15, the measurement signal input unit 21, and the analysis unit 22) of the acoustic devices 14, 214, 314, 414, and 514 are integrated circuits (ICs). It may be realized by a logic circuit (hardware) formed on a chip) or the like, or may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the acoustic devices 14, 214, 314, 414, and 514 are recorded such that a CPU that executes instructions of a program that is software that realizes each function, the program and various data are readable by a computer (or CPU). In addition, a ROM (Read Only Memory) or a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
The acoustic device (14, 214, 314, 414, 514) according to the aspect 1 of the present invention is a first device disposed outside the display screen (113) of the display device (1, 2, 3, 4, 5). An acoustic device that includes a speaker unit (full-band speaker units 101 to 112) and a second speaker unit (low-frequency speaker units 201 to 212), and outputs a plurality of channels of sound, wherein the second speaker unit includes: The low frequency component of the sound output from the first speaker unit is output, and the first speaker unit and the second speaker unit are provided to face in different directions.

  According to the above configuration, since the first speaker unit and the second speaker unit are directed in different directions, the second speaker unit is not visible to the listener facing the first speaker unit. Absent. Therefore, the acoustic device can be shown thinly to the listener.

  The acoustic device according to aspect 2 of the present invention is the acoustic device according to aspect 1, in which the second speaker unit outputs a second sound corresponding to a sound field generated by a virtual sound source located away from the acoustic device. Further, it may be output.

  According to the above configuration, the second sound output from the second speaker unit is reflected and diffused by the wall or the like of the room where the acoustic device is placed, and then enters the listener's ear from various directions. Therefore, it is possible to give the listener a realistic feeling that is wrapped in the sound field formed by the sound source.

  The acoustic device according to aspect 3 of the present invention is the acoustic apparatus according to aspect 1 or 2, wherein at least one of the second speaker units is a bus reflex type, and the bus reflex second speaker. The sound output from behind the unit may be output in the same direction as the sound output from the first speaker unit.

  According to said structure, the audio | voice output from the back of at least 1 2nd speaker unit can be output in the same direction as the audio | voice output from a 1st speaker unit.

  In the acoustic device according to aspect 4 of the present invention, in any one of the aspects 1 to 3, the plurality of channels may conform to a three-dimensional multi-channel acoustic system. According to said structure, the audio | voice corresponding to a three-dimensional multichannel acoustic system can be output.

  The acoustic device according to aspect 5 of the present invention is the acoustic device according to any one of the aspects 1 to 4, wherein the first speaker unit outputs sound in the forward direction of the display screen, and the second speaker unit The bass component of the sound may be output in at least one of the upper, lower, left, and right directions of the display screen.

  According to said structure, the listener in front of the display screen of a display apparatus can hear the audio | voice output from a 1st speaker unit directly, and the audio | voice output from a 2nd speaker unit. Can hear the sound diffused or reflected by the walls of the room. Therefore, it is possible to give the listener a realistic sensation that is wrapped in a sound field integrated with the video displayed on the screen.

  The acoustic device according to aspect 6 of the present invention is the acoustic device according to any one of the aspects 1 to 5 described above, in which when the sound having a frequency equal to or lower than the predetermined frequency is output, more second sounds than when the sound exceeding the predetermined frequency is output. You may output an audio | voice using a speaker unit.

  According to the above configuration, the listener can more easily perceive the low-frequency localization by outputting sound having a predetermined frequency or less from a large number of second speaker units.

  The display device (1, 2, 3, 4, 5) according to aspect 7 of the present invention may include the acoustic device according to any one of the above aspects 1 to 6 and the display screen. Moreover, the television receiver according to aspect 8 of the present invention may include the display device according to aspect 6 described above. According to said structure, there can exist an effect similar to one of the audio equipment mentioned above.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

1, 2, 3, 4, 5 Display device 113 Display screen 14, 214, 314, 414, 514 Sound device 101-112 Full-band speaker unit (first speaker unit)
201-212 Low-frequency speaker unit (second speaker unit)

Claims (8)

An acoustic device that includes a first speaker unit and a second speaker unit disposed outside a display screen of a display device, and outputs a plurality of channels of audio,
The second speaker unit outputs a bass component of sound output from the first speaker unit,
The acoustic apparatus, wherein the first speaker unit and the second speaker unit are provided so as to face different directions.   2. The audio device according to claim 1, wherein the second speaker unit further outputs a second sound corresponding to a sound field generated by a virtual sound source located at a location distant from the audio device. .   At least one of the second speaker units is a bass reflex type, and sound output from the back of the second speaker unit of the bus reflex type is output from the first speaker unit. The sound device according to claim 1, wherein the sound device is output in the same direction as the sound to be played.   The acoustic device according to claim 1, wherein the plurality of channels conform to a three-dimensional multi-channel acoustic system. The first speaker unit outputs sound in the forward direction of the display screen,
The said 2nd speaker unit outputs the low-pitched sound component of the said audio | voice in at least any one direction among the up-down-left-right direction of the said display screen, The any one of Claim 1 to 4 characterized by the above-mentioned. The acoustic device described.   6. When outputting a sound having a frequency lower than a predetermined frequency, the sound is output using more second speaker units than when outputting a sound exceeding the predetermined frequency. The acoustic device according to any one of the above.   A display device comprising the acoustic device according to claim 1 and the display screen.   A television receiver comprising the display device according to claim 7.

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