JP4484678B2 - Audio output device and audio output method - Google Patents

Description

  The present invention relates to an audio output device and an audio output method, and more particularly to an audio output device and an audio output method for simultaneously outputting audio from an audio reproduction device such as car audio and audio from a mobile phone in an automobile or the like. .

  In general, when using a mobile phone while driving a car or the like, hands-free devices that can be used without touching the mobile phone by the driver are widely used to maintain traffic safety. Yes. Conventionally, there have been the following forms of output of car audio sound and mobile phone sound when the mobile phone is in a call state.

The first is a form in which the car audio sound does not interfere with the call by turning on the mute circuit of the car audio and turning off the audio sound output into the car. For example, when an incoming call signal or a call signal is received from a mobile phone while a mobile phone and a car audio are connected and audio input from the car audio is output to the outside, the audio input from the car audio is output to the outside. 2. Description of the Related Art An output voice switching device that cuts off output and outputs voice input from a mobile phone to the outside is known (see, for example, Patent Document 1).
JP 2002-16678 A

  However, as described in Patent Document 1, in the conventional technique for cutting off the output of audio sound, when the mobile phone is in a call state or an incoming state, the sound of the car audio is completely cut off. There is a problem that not only a driver who makes a call with a mobile phone but also a person other than the driver who is in the car cannot listen to the audio of the car audio.

  In addition, a technology is known in which a mobile phone and a car audio are connected, a sound output from the car audio and a sound output from the mobile phone are input, and the two input sounds are mixed and output. However, in this case, since the sound output from the speaker is a mixture of two sounds, there is a problem that it becomes difficult for the driver to hear the sound of the mobile phone.

  In addition, when a mobile phone and a car audio are connected and the mobile phone is in a call state, the voice input from the mobile phone is output to a speaker near the driver's seat, and the voice input from the car audio is output to the other speakers. A technique for outputting is known. However, if the audio reproduced by the car audio is to output dedicated audio from each of the plurality of speakers, if the audio from the mobile phone is output from the speaker in the vicinity of the driver's seat, Audio will not be output. Therefore, the balance of the sound output from a plurality of speakers is lost, and a person who listens to the sound reproduced by the car audio has a problem that the output sound is uncomfortable.

  The present invention has been made to solve such a problem. In the automobile, the voice from the mobile phone can be easily output to the driver and reproduced by the voice reproduction device. An object of the present invention is to enable sound output using a plurality of channels to be output in a good state to a person other than the driver.

  In order to solve the above-described problems, the present invention is an audio output device that outputs audio signals from a mobile phone and audio signals of a plurality of channels from an audio playback device to a plurality of speakers, and the mobile phone is in a call state. In addition, the multi-channel audio signal input from the audio playback device is downmixed to the audio signal of the channel less than the plurality of channels, so that one or more of the plurality of speakers and the number of speakers smaller than the number of the speakers. An audio signal from the mobile phone is output, and a downmixed audio signal is output to a speaker that does not output the audio signal from the mobile phone among a plurality of speakers.

  According to the present invention configured as described above, when the mobile phone is in a call state, only the voice from the mobile phone is output from one or more speakers, so that the driver can easily hear the voice from the mobile phone. . In addition, since the audio from the audio reproduction device is downmixed and output from the remaining speakers, the audio from the audio reproduction device dedicated to the speaker that outputs audio from the mobile phone is included in the downmixed audio and output. . Thereby, since the balance of the output audio | voice is maintained, persons other than a driver | operator can listen to the audio | voice by an audio | voice reproducing apparatus in a favorable state. Therefore, the sound from the mobile phone and the sound from the sound reproduction device can coexist well.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of an audio system including the audio output device 1 according to the present embodiment.

  In FIG. 1, 10 is a mobile phone, and 20 is an audio playback device such as a DVD player, which outputs audio signals of a plurality of channels. Reference numeral 2 denotes an interface for a mobile phone, which is connected to the mobile phone 10 and receives a call signal indicating that the mobile phone 10 is in a call state from the mobile phone 10 and outputs a call signal to the control unit 5 described later. The mobile phone interface 2 receives an audio signal from the mobile phone 10 when the mobile phone 10 is in a call state, and outputs the audio signal to the audio processing unit 4 described later. Reference numeral 3 denotes an audio reproduction device interface, which is connected to the audio reproduction device 20 and receives an audio signal from the audio reproduction device 20 and outputs the audio signal to an audio processing unit 4 described later. Further, the audio reproduction device interface 3 inputs a reproduction signal indicating that the audio reproduction device 20 is reproducing an audio signal from the audio reproduction device 20, and outputs the reproduction signal to the control unit 5 described later. Note that the audio signal output from the mobile phone 10 corresponds to the first audio signal in the claims, and the audio signal output from the audio reproduction device 20 corresponds to the second audio signal in the claims. Applicable. Here, the audio signal input from the audio reproduction device 20 is a multi-channel audio signal, for example, a 5.1-channel audio signal using substantially six channels, a four-channel audio signal, or a two-channel audio signal. Signal.

  Reference numeral 4 denotes an audio processing unit that receives audio signals output from the cellular phone interface 2 and the audio reproduction device interface 3 and generates a plurality of audio signals corresponding to a plurality of speakers 8a to 8f described later. Reference numeral 6 denotes a D / A converter, which inputs a plurality of audio signals output from the audio processor 4, converts them into analog signals, and outputs them. Reference numerals 7a to 7e denote amplifiers that amplify a plurality of audio signals output from the D / A converter 6 (excluding audio signals output to a subwoofer 8f described later). Reference numerals 8a to 8f denote speakers, and the speakers 8a to 8e excluding the subwoofer 8f output the audio signals amplified by the amplifiers 7a to 7e to the outside. The subwoofer 8f outputs the audio signal output from the D / A conversion unit 6 to the outside.

  Here, as the plurality of speakers 8a to 8f, a left speaker 8a that is disposed on the front left side of a space where a sound image is localized (for example, in a vehicle) and outputs L-channel sound is disposed, and a C channel that is disposed in the front center. A center speaker 8b that outputs the sound of the right channel, a right speaker 8c that is disposed on the front right side and that outputs the sound of the R channel, a sub left speaker 8d that is disposed on the rear left side and outputs the sound of the SL channel, and on the right side of the rear There is a sub light speaker 8e that is arranged and outputs SR channel sound, and a subwoofer 8f that is arranged at an arbitrary position in the space and outputs SW channel low sound.

  Reference numeral 5 denotes a control unit that controls the voice processing unit 4. Specifically, when a call signal is not input from the mobile phone interface 2, in other words, when the mobile phone 10 is not in a call state, the control unit 5 outputs from the audio playback device interface 3. The sound processing unit 4 is caused to input the sound signal thus obtained. In addition, the control unit 5 controls the audio processing unit 4 to perform audio processing on the audio signal input from the audio reproduction device interface 3 to generate a plurality of audio signals corresponding to the plurality of speakers 8a to 8f. The data is output to the D / A converter 6.

  When a call signal is input from the mobile phone interface 2, in other words, when the mobile phone 10 is in a call state, the control unit 5 outputs the audio signal output from the mobile phone interface 2. The audio signal output from the audio playback device interface 3 is input to the audio processing unit 4. In addition, the control unit 5 controls the audio processing unit 4 so that the audio signal input from the cellular phone interface 2 is output to the D / A conversion unit 6 as an audio signal for the C channel in order to output the audio signal to the center speaker 8b. Output. In addition, the control unit 5 controls the audio processing unit 4 to perform audio processing of the 5.1 channel (six channels) audio signal input from the audio reproduction device interface 3, and uses the audio signal for the remaining speakers. In order to output to 8a, 8c, 8d, 8e, and 8f, the D / A converter 6 outputs the audio signals for channels having a number smaller than 5.1 channels (for example, five channels). Here, the audio processing unit 4 performs a downmix process of the audio signal so that the remaining speakers 8a, 8c, 8d, 8e, and 8f excluding the center speaker 8b can realize 5.1 channel audio output.

  FIG. 2 is a block diagram illustrating a configuration example of the audio processing unit 4. As shown in FIG. 2, the audio processing unit 4 includes an audio signal generation unit 11, a sound image localization unit 12, attenuators A1 to A3, switches SW1 and SWt, and adders AD1 and AD2. . In the audio signal generation unit 11, an audio signal for the C channel, an audio signal for the L channel, an audio signal for the R channel, and an audio signal for the SL channel from the audio signal input from the audio reproduction device interface 3 The six audio signals of the SR channel audio signal and the SW channel audio signal are extracted and generated.

  The sound image localization unit 12 creates a sound field at a predetermined position in a space such as an automobile by adjusting the level and phase of the audio signal of each channel, the output time, and the like. For example, if the level of the audio signal for the L channel is 1 and the level of the audio signal for the R channel is 0, the audio can be heard only from the left side in the driver seat of the right steering wheel. After that, when the level of the R channel audio signal is raised while the level of the L channel audio signal is lowered, it sounds like the sound gradually moves to the right.

  The attenuator A1 is, for example, a 0 dB attenuator, and supplies the L channel audio signal output from the sound image localization unit 12 to the adder AD1. The attenuator A2 is, for example, a −4.5 dB attenuator, attenuates the C channel audio signal output from the sound image localization unit 12, and supplies the attenuated signal to the switch SW1. The attenuator A3 is, for example, a 0 db attenuator, and supplies the R channel audio signal output from the sound image localization unit 12 to the adder AD2.

  The adder AD1 adds the L channel audio signal passed through the attenuator A1 and the C channel audio signal supplied via the switch SW1, and outputs the result as an L channel audio signal. The adder AD2 adds the R channel audio signal that has passed through the attenuator A3 and the C channel audio signal supplied via the switch SW1, and outputs the result as an R channel audio signal.

  The switch SW1 switches on / off the connection between the attenuator A2 and the adders AD1, AD2. The switch SWt is either an audio signal input from the cellular phone interface 2 or an audio signal generated as an audio signal for the C channel by the audio signal generator 11 and adjusted by the sound image localization unit 12. select.

  Here, SW1 and SWt are controlled by the control unit 5. Specifically, when the control unit 5 receives a call signal from the mobile phone interface unit 2, the control unit 5 turns on SW1 and switches SWt to the mobile phone interface 2 side. When SW1 is turned on, the C channel audio signal that has passed through the attenuator A2 is input to the adder AD1 and the adder AD2. Therefore, the C channel audio signal is combined with the L channel audio signal and the R channel audio signal. When SWt is switched to the mobile phone interface 2 side, the audio signal input from the mobile phone 10 is output as an audio signal for the C channel. Therefore, the sound from the mobile phone 10 is output from the center speaker 8b, and the sound from the sound reproducing device 20 is downmixed and output from the remaining speakers 8a, 8c, 8d, 8e, and 8f.

  On the other hand, when the control unit 5 does not input a call signal from the cellular phone interface 2, the control unit 5 turns off SW1 and switches SWt to the sound image localization unit 12 side. When SW1 is turned off and SWt is switched to the sound image localization unit 12, the audio signal for each channel output from the sound image localization unit 12 is output without being downmixed. Therefore, the sound from the sound reproducing device 20 is output from all the speakers 8a to 8f.

  Next, the operation of the audio output device 1 and the audio output method according to the present embodiment will be described. FIG. 3 is a flowchart showing the operation of the audio output device 1 and the audio output method according to the present embodiment.

  First, the control unit 5 causes the audio signal input from the audio reproduction device 20 to the audio processing unit 4 via the audio reproduction device interface 3 to be output from a speaker of an appropriate channel (step S1). For example, when audio is output from 6 speakers, if the audio signal is a 5.1 channel, audio dedicated to each speaker is output to each speaker. In addition, if the audio signal has four channels, audio is output from the left speaker 8a, the right speaker 8c, the subleft speaker 8d, and the subright speaker 8e. In addition, if the audio signal is for two channels, the audio is output from the left speaker 8a and the right speaker 8c.

  Although not shown in FIG. 2, the configuration is based on audio signals output to the left speaker 8a, the right speaker 8c, the subleft speaker 8d, and the subright speaker 8e in the case of audio signals of four channels. The sound signal output to the center speaker 8b and the subwoofer 8f may be generated, and the sound may be output from all of the six speakers 8a to 8f. In the case of audio signals of two channels, the audio output to the center speaker 8b, the subleft speaker 8d, the subright speaker 8e, and the subwoofer 8f based on the audio signal output to the left speaker 8a and the right speaker 8c. You may make it produce | generate a signal and output an audio | voice from all the six speakers 8a-8f.

  Next, the control unit 5 checks whether or not the mobile phone 10 is in a call by checking whether or not a call signal is input from the mobile phone interface 2 (step S2). Here, the mobile phone 10 outputs a call signal and a voice signal to the mobile phone interface 2 when in a call state. If control unit 5 determines that mobile phone 10 is not in a call (NO in step S2), the process returns to step S1.

  On the other hand, when control unit 5 determines that mobile phone 10 is in a call (YES in step S2), control unit 5 determines whether or not the input audio signal uses audio dedicated to the C channel. Check (step S3). For example, when 5.1 channel audio signals are output to the six speakers 8a to 8f, the audio output from the center speaker 8b is dedicated to the C channel. Further, when outputting audio signals of four channels or audio signals of two channels from the speakers 8a to 8f, even if no audio is output from the center speaker 8b or audio is output from the center speaker 8b, C is output. It may not be dedicated to the channel.

  If the control unit 5 determines that the input audio signal does not use the C channel dedicated audio (NO in step S3), the control unit 5 controls the audio processing unit 4 to perform the cellular phone interface 2 The audio signal input to the audio processing unit 4 is output as an audio signal for the C channel. In addition, the control unit 5 controls the audio processing unit 4 to output the audio signal input from the audio reproduction device interface 3 to the audio processing unit 4 to an appropriate channel. As a result, the sound from the mobile phone 10 is output from the center speaker 8b, and the sound from the sound reproducing device 20 is output from an appropriate speaker, in other words, all or any of the remaining speakers 8a, 8c, 8d, 8e, and 8f. Is output (step S4). Then, the process returns to step S2. Here, since the audio dedicated to the C channel is not originally output from the audio reproducing device 20, even when the audio from the mobile phone 10 is assigned as the C channel audio, the audio balance by the audio reproducing device 20 is not lost.

  On the other hand, when the control unit 5 determines that the input audio signal uses the C-channel dedicated audio (YES in step S3), the control unit 5 controls the audio processing unit 4 to use the audio reproduction device. The audio signal input from the interface 3 to the audio processing unit 4 is downmixed (step S5). Specifically, the C channel audio signal is attenuated and added to the L channel audio signal and the R channel audio signal, and the five speakers 8a, 8c, 8d, 8e, 8f excluding the center speaker 8b. To realize 5.1 channel audio.

  And the control part 5 controls the audio | voice processing part 4, and outputs the audio | voice signal input into the audio | voice processing part 4 from the interface 2 for mobile telephones as an audio | voice signal for C channels. Further, the control unit 5 controls the audio processing unit 4 to output the downmixed audio signal as an audio signal for the remaining channels. Thereby, the voice by the mobile phone 10 is output from the center speaker 8b, and the voice by the voice playback device 20 is output from the remaining speakers 8a, 8c, 8d, 8e, and 8f (step S6). Then, the process returns to step S2. Here, the audio reproduction device 20 originally outputs audio dedicated to the C channel. However, since the audio dedicated to the C channel is distributed to other channels by downmix, the audio reproduction by the audio reproduction device 20 is balanced. Will not collapse.

  Here, while the operations of Steps S1 to S6 described above are performed, the control unit 5 checks the presence / absence of an audio signal input to the audio reproduction device interface 3 to reproduce the audio reproduction device 20. To see if is finished. If the control unit 5 determines that the playback of the audio playback device 20 has ended, and the mobile phone 10 is busy, the audio output by the audio playback device 20 is ended and the audio output by the mobile phone 10 is output. continue. Further, when the control unit 5 determines that the reproduction of the audio reproduction device 20 has been completed, if the mobile phone 10 is not in a call, the audio reproduction by the audio reproduction device 20 is terminated, and the above-described operation is terminated. .

  As described above in detail, according to the present embodiment, when the mobile phone 10 is not in a call, the control unit 5 outputs audio signals of a plurality of channels to the plurality of speakers 8a to 8f, and the mobile phone 10 When a call is in progress, the audio signals of a plurality of channels input from the audio playback device 20 are downmixed to audio signals of a smaller number of channels, and the audio signal from the mobile phone 10 is output to the center speaker 8b. The audio processing unit 4 is controlled to output the downmixed audio signal to the remaining speakers 8a, 8c, 8d, 8e, and 8f. As a result, the driver can listen only to the voice from the mobile phone 10 from the center speaker 8b, so that the driver can easily hear the voice from the mobile phone 10. Further, since the sound from the sound reproducing device 20 is downmixed and output from the remaining speakers 8a, 8c, 8d, 8e, and 8f, passengers other than the driver feel uncomfortable with the sound from the sound reproducing device 20. And can listen well. Therefore, the sound from the mobile phone 10 and the sound from the sound reproduction device 20 can coexist well without losing the original sound feeling.

  In addition, although the said embodiment demonstrated the example of the audio system using the six speakers 8a-8f, this invention is not limited to this. For example, a system that uses only two speakers so that it can output audio signals of up to two channels, or a system that uses four speakers so that it can output audio signals of up to four channels, The present invention can also be applied to a system using seven speakers so that audio signals of up to seven channels (for example, 6.1 channels) can be output. For example, when the audio from the mobile phone 10 is output from any speaker, as in the case where the audio signals of four channels are output to four speakers, the audio audio output from that speaker is lost. Any system can be used as long as the system is unbalanced.

  In the above embodiment, the 5.1 channel audio signal from the audio reproduction device 20 is downmixed to the 5 channel audio signal including the SW channel audio signal, but the present invention is not limited to this. For example, a 5.1 channel audio signal can be downmixed to an L channel, an R channel, an SL channel, and an SR channel audio signal, or an SW channel audio signal can be converted from the 5.1 channel audio signal. The audio signals of the removed five channels may be downmixed into audio signals for four channels of L channel, R channel, SL channel, and SR channel.

  In the above embodiment, the down-mixed audio signals are output to the remaining speakers 8a, 8c, 8d, 8e, and 8f excluding the center speaker 8b from which the audio from the mobile phone 10 is output. The invention is not limited to this. For example, a 5.1 channel audio signal is downmixed into two channel audio signals, and the downmixed audio signal is output to an appropriate speaker among the remaining speakers 8a, 8c, 8d, 8e, and 8f. Alternatively, a monaural downmixed audio signal may be output to an appropriate speaker among the remaining speakers 8a, 8c, 8d, 8e, and 8f.

  Here, in the downmix to two channels, for example, the L channel audio signal, the SL channel audio signal, and the C channel audio signal are synthesized to generate an L channel audio signal, and R This is realized by synthesizing an audio signal for the channel, an audio signal for the SR channel, and an audio signal for the C channel to generate an audio signal for the R channel. Also, downmixing to monaural includes, for example, an L channel audio signal, a C channel audio signal, an R channel audio signal, an SL channel audio signal, and an SR channel audio signal. To generate a monaural audio signal.

  Moreover, in the said embodiment, although the speaker for outputting the audio | voice by the mobile telephone 10 is made into the center speaker 8b, this invention is not limited to this. For example, the sound from the mobile phone 10 may be output to a speaker in the vicinity of a driver's seat of a car (a right speaker 8c in the case of a right handle and a left speaker 8a in the case of a left handle). As a result, the voice from the mobile phone 10 is output from closer to the driver, so that the driver can more easily hear the voice from the mobile phone 10.

  Moreover, in the said embodiment, although the speaker for outputting the audio | voice by the mobile telephone 10 is made into one of the center speakers 8b, this invention is not limited to this. For example, when the automobile is a right handle, the center speaker 8b and the light speaker 8c are used to output sound from the mobile phone 10, or when the automobile is a left handle, the sound from the mobile phone 10 is output. Therefore, the center speaker 8b and the left speaker 8a may be used. As a result, only the voice from the mobile phone 10 is output from the speaker in the vicinity of the driver, so that the driver can more easily hear the voice from the mobile phone 10. Here, since the audio from the audio reproduction device 20 is output from the remaining four speakers, the way of downmixing by the audio processing unit 4 is, for example, in the case of a 5.1 channel audio signal, the audio signal of the 4 channels In addition, it is necessary to downmix the audio signal of two channels or a monaural audio signal.

  In the embodiment, the position where the sound image localization unit 12 performs sound image localization is not mentioned. For example, when sound from the mobile phone 10 is output from the center speaker 8b, You may make it sound-image-localize the sound by the audio | voice reproduction apparatus 20 in places other than a driver's seats, such as a seat. This makes it easier for the driver to hear the voice from the mobile phone 10, and passengers other than the driver can better hear the voice from the voice playback device 20.

  In addition, the said embodiment is only what showed the example of actualization in implementing this invention, and the technical scope of this invention should not be interpreted limitedly by this. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

  INDUSTRIAL APPLICABILITY The present invention is useful for a sound output device that outputs sound from a mobile phone from a speaker while outputting sound from a sound reproduction device such as car audio from a speaker in a space such as an automobile.

It is a block diagram which shows the structural example of the audio system containing the audio | voice output apparatus by this embodiment. It is a block diagram which shows the structural example of the audio | voice processing part of the audio | voice output apparatus by this embodiment. It is a flowchart which shows the operation | movement of the audio | voice output apparatus by this embodiment, and an audio | voice output method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Audio | voice output apparatus 2 Interface for mobile telephones 3 Interface for audio | voice reproduction apparatuses 4 Audio | voice processing part 5 Control part 10 Mobile phone 20 Audio | voice reproduction apparatus

Claims (5)

An audio processing unit that inputs a first audio signal output from a mobile phone and inputs a second audio signal reproduced by an audio reproduction device, and generates and outputs a plurality of audio signals corresponding to a plurality of speakers. When,
When the mobile phone is not in a call state, a multi-channel audio signal is generated from the second audio signal, the multi-channel audio signal is output to the plurality of speakers, and the mobile phone is in a call state In this case , when the audio signals of the plurality of channels use audio dedicated to the predetermined channel , the first audio signal is output to the speaker of the predetermined channel among the plurality of speakers, and the audio of the plurality of channels is output. The signal is downmixed to audio signals of a number of channels equal to or less than the number of channels excluding the predetermined channel, and the downmixed audio signal is output to the remaining speakers, while the audio signals of the plurality of channels are When the dedicated audio is not used, the multi-channel audio is output to the plurality of speakers. And a control unit which controls the audio processing unit to output the items,
An audio output device comprising: The audio processing unit downmixes the audio signals of the plurality of channels to a number of channels equal to or less than the number of speakers that do not output the first audio signal among the plurality of speakers. The audio output device according to 1. The sound processing unit includes a sound image localization unit that performs sound image localization using sound based on the second sound signal output from the plurality of speakers,
The control unit controls the sound image localization unit to localize a sound image to a place other than the vicinity of the speaker that outputs the first audio signal when the mobile phone is in a call state. Item 2. The audio output device according to Item 1. A first step of checking in the control unit whether or not the mobile phone is in a call;
In the first step, when the control unit determines that the mobile phone is not in a call, a second channel outputs audio signals of a plurality of channels reproduced by the audio reproducing device to a plurality of speakers. Steps,
In the first step, when the control unit determines that the mobile phone is in a call, the control unit determines whether or not the multi-channel audio signal uses audio for a predetermined channel. A third step to examine and
In the third step, when the control unit determines that the audio signal of the plurality of channels uses audio dedicated to the predetermined channel, the audio signal of the plurality of channels is excluded from the plurality of channels. A fourth step of downmixing to less than a few channels of audio signals;
In the third step, when the control unit determines that the audio signal of the plurality of channels uses the audio dedicated to the predetermined channel , the mobile phone is connected to the speaker of the predetermined channel among the plurality of speakers. And outputting the audio signal downmixed by the fourth step to a speaker that does not output the audio signal from the mobile phone among the plurality of speakers, and
In the third step, when the control unit determines that the audio signal of the plurality of channels does not use the audio dedicated to the predetermined channel, the audio signal of the plurality of channels is output to the plurality of speakers. 6 steps,
Voice output method with At the fifth step, a seventh step of determining whether the call of the portable telephone is finished by the control unit,
At the seventh step, when the call of the mobile phone is determined by the control unit has been finished, the output audio signals of a plurality of channels, wherein the sound reproducing apparatus is reproduced in a plurality of loudspeakers 8 And the steps
The audio output method according to claim 4 , further comprising:

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