JP2008288628A - Speaker detector, device and method for setting the number of channels, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily detect whether a speaker is effectively connected to the audio output terminal of an audio apparatus. <P>SOLUTION: The speaker detector which detects whether the speaker 30 is connected to the audio output terminal 40 of the audio apparatus includes a counter electromotive force detector 50 which is electrically connected to the audio output terminal 40 and detects counter electromotive force generated at the voice coil of the speaker 30 and a speaker detector 28 which detects whether the speaker 30 is connected based upon the counter electromotive force. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a speaker detection device that detects whether or not a speaker is connected to an audio device, a channel number setting device that sets the number of channels at the time of audio output of the audio device according to the connection state of the speaker, and a channel number setting method. And control program.

2. Description of the Related Art Conventionally, an audio device that performs multi-channel reproduction using an audio compression method such as a Dolby (registered trademark) digital method or a DTS (Digital Theater Systems) (registered trademark) method is known. In such an acoustic device, a left front speaker disposed on the front left side of the listener, a right front speaker disposed on the front right side, a center speaker disposed substantially in front of the listener, and on the left rear side of the listener. By connecting the left surround speaker to be placed, the right surround speaker to be placed on the right rear side, and six subwoofer speakers that mainly output only the low frequency range, a so-called 5.1 channel realistic sound field is created. it can. The audio apparatus is provided with an output terminal for connecting each of these speakers, and an audio signal corresponding to each channel is output from each output terminal.
On the other hand, in such an audio device capable of multi-channel playback, downmix processing is performed when the number of speakers connected to the audio device is small with respect to the maximum number of channels that can output audio signals. Some have a downmix function to do. For example, when a center speaker that mainly outputs a dialogue part such as a movie is not connected, the downmix process is performed so that the voice of this dialogue part is outputted from another speaker. By performing the downmix process, the number of output channels can be optimized according to the connection state of the speakers and the like.
Japanese Patent Laid-Open No. 10-243499

By the way, in an audio apparatus capable of multi-channel reproduction as described above, it is necessary to correctly set the connection state of the speakers. That is, when it is set that the center speaker is connected even though the center speaker is not connected, for example, the voice of the dialogue part such as a movie is not output. In addition, when it is set that the subwoofer is not connected even though the subwoofer is connected, the sound quality is low due to insufficient bass.
However, manually setting whether or not a predetermined speaker is connected to each audio output terminal corresponding to each audio channel has been a complicated operation. In addition, even when a speaker is connected to each audio output terminal, if there is a disconnection of the speaker cable or a disconnection of the voice coil, it may not be possible to properly reproduce the sound. .
An object of the present invention is to provide a speaker detection device that can easily detect whether or not a speaker is effectively connected to an audio output terminal of the audio device, and a channel at the time of audio output of the audio device according to the connection state of the speaker. An object of the present invention is to provide a channel number setting device, a channel number setting method, and a control program capable of automatically setting the number.

In order to solve the above problems, a speaker detection device of the present invention is a speaker detection device that detects whether or not a speaker is connected to an audio output terminal of an audio device, and is electrically connected to the audio output terminal. A back electromotive force detection unit that detects a back electromotive force generated in the voice coil of the speaker, and a speaker detection unit that detects whether or not the speaker is connected based on the back electromotive force. Features.
According to the above configuration, since the back electromotive force detection unit is electrically connected to the audio output terminal of the acoustic device, when a speaker is connected to the audio output terminal, the back electromotive force generated in the speaker is detected. Can be detected. The speaker detection unit detects whether or not the speaker is connected to the audio output terminal based on the back electromotive force detected by the back electromotive force detection unit. Whether it is connected or not can be detected.

The said structure WHEREIN: It is preferable that the said back electromotive force originates in the wind pressure added to the cone paper of the said speaker.
According to the above configuration, the back electromotive force generated in the voice coil can be detected when wind pressure is applied to the cone paper of the speaker.

In the above configuration, it is preferable that the acoustic device is an on-vehicle acoustic device mounted on a vehicle, and the wind pressure applied to the cone paper is accompanied by opening / closing of a door of the vehicle.
According to the above configuration, since the wind pressure is applied to the cone paper of the speaker by opening and closing the car door, whether or not the speaker is connected to the audio output terminal of the acoustic device when the car door is opened and closed. Detected automatically.

In the above configuration, it is preferable that the acoustic device includes a plurality of audio output terminals, and the speaker detection unit detects whether or not the speaker is connected for each audio output terminal.
According to the above configuration, when the acoustic device has a plurality of audio output terminals, it is possible to detect whether or not a speaker is connected to each audio output terminal.

In addition, the channel number setting device of the present invention is electrically connected to the audio output terminal of the audio device, detects a counter electromotive force generated in the voice coil of the speaker, and the counter electromotive force. Based on a speaker detection unit that detects whether or not the speaker is connected based on the connection state of the speaker detected by the speaker detection unit, the number of channels when the audio device performs audio output is set And a channel number setting unit.
According to the above configuration, the channel number setting unit can automatically set the number of channels when the audio device performs audio output according to the connection state of the speaker detected by the speaker detection unit of the speaker detection device. it can.

  Further, the channel number setting method of the present invention includes a back electromotive force detection unit that is electrically connected to a sound output terminal of an audio device and detects a back electromotive force generated in a voice coil of the speaker, and the back electromotive force. Based on a speaker detection unit that detects whether or not the speaker is connected based on the connection state of the speaker detected by the speaker detection unit, the number of channels when the audio device performs audio output is set In the channel number setting method for setting the number of channels at the time of sound output of the acoustic device using the channel number setting unit, the counter electromotive force generated in the voice coil of the speaker is detected by the back electromotive force detection unit, and the speaker detection is performed. Detecting whether or not the speaker is connected based on the back electromotive force, and detecting the number of channels by the channel number setting unit. Setting the number of the channels in accordance with the connection state of the speaker detected by detecting section, characterized by.

  Further, the control program of the present invention is based on the back electromotive force detection unit that is electrically connected to the audio output terminal of the audio device and detects the back electromotive force generated in the voice coil of the speaker. A speaker detection unit for detecting whether or not the speaker is connected, and a channel number for setting the number of channels when the audio device performs audio output according to the connection state of the speaker detected by the speaker detection unit A control program for controlling a channel number setting device including a setting unit using a computer, wherein the counter electromotive force detection unit detects a counter electromotive force generated in a voice coil of the speaker, and the speaker detection And detecting whether or not the speaker is connected based on the back electromotive force, and the channel number setting unit Thereby setting the number of the channels in accordance with the connection state of the speaker detected by over mosquito detection unit, characterized by.

According to the speaker detection device of the present invention, it is possible to easily detect whether or not a speaker is effectively connected to the audio output terminal of the acoustic device.
Further, according to the channel number setting device, the channel number setting method, and the control program of the present invention, the number of channels at the time of sound output of the acoustic device can be automatically set according to the connection state of the speaker.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a multi-channel playback system 100 to which the speaker 30 detection device of the present embodiment is applied. A multi-channel reproduction system 100 shown in FIG. 1 is mounted on a vehicle 10 and enables digital multi-surround reproduction with a maximum of 5.1 channels. The multi-channel reproduction system 100 includes a sound device 20 and a plurality of sound devices connected to the sound device 20. And a speaker 30.

  The audio device 20 shown in FIG. 1 includes six audio output terminals 40 (41 to 46), and is configured to connect a maximum of six speakers 30 (31 to 36). In the present embodiment, the speaker 30 that can be connected to the acoustic device 20 is a left front speaker 31 that is disposed on the front left side of the vehicle 10 and a right front speaker 32 that is disposed on the front side of the passenger. A center speaker 33 disposed in front of the occupant at a substantially central position of the left front speaker 31 and the right front speaker 32, a left surround speaker 34 disposed substantially on the left rear side of the occupant, and substantially behind the occupant A right surround speaker 35 disposed on the right side and a low-frequency speaker 36 (hereinafter referred to as “subwoofer”) that mainly reproduces low-frequency sound can be connected.

  However, as shown in FIGS. 2 and 3, the left front speaker 31 and the right front speaker 32 are mounted in the front doors 11 and 12, respectively, and the center speaker 33 is disposed at a substantially central portion of the console panel 13. The surround speaker 34 and the right surround speaker 35 are provided behind the rear seat 14, and the subwoofer 36 is disposed behind the rear seat 14 and at a substantially central position of the left surround speaker 34 and the right surround speaker 35.

  The audio signal of the channel corresponding to each speaker 30 is output from each audio output terminal 40 provided in the acoustic device 20 shown in FIG. That is, an audio signal for the left front channel is output from the audio output terminal 41 to which the left front speaker 31 is connected, and an audio signal for the right front channel is output from the audio output terminal 42 to which the right front speaker 32 is connected. Is done. Also, a sound signal for the center channel corresponding mainly to the sound of the movie part is output from the sound output terminal 43 to which the center speaker 33 is connected. An audio signal for the left surround channel is output from the audio output terminal 44 to which the left surround speaker 34 is connected, and an audio signal for the right surround channel is output from the audio output terminal 45 to which the right surround speaker 35 is connected. . Further, an audio output terminal 46 to which the subwoofer 36 is connected outputs an audio signal for the subwoofer 36 channel mainly corresponding to the low sound range.

The audio device 20 includes a DVD / CD playback device 21 that plays back a DVD or CD, a video display unit 22 that performs display based on a video signal output from the DVD / CD playback device 21, and a DVD / CD playback device 21. A DSP 23 (Digital Signal Processor) that performs a decoding process on the audio signal output from the DSP and separates it into an audio signal corresponding to each channel, and a D that converts the digital audio signal output from the DSP 23 into an analog audio signal / A converter 24 and a power amplifier 25 that amplifies the analog audio signal output from D / A converter 24. The analog audio signal amplified by the power amplifier 25 is supplied to each speaker 30 via each audio output terminal 40.
In addition, the audio device 20 is a DVD based on the sub display unit 26 that displays various operation contents to the user, the operation unit 27 that is operated by the user, the operation instruction content that is input from the operation unit 27, and the like. / The control part 28 (microcomputer) which controls CD reproducing | regenerating apparatus 21 and DSP23 is provided.

However, the DVD / CD playback device 21 plays back video signals and audio signals stored on a DVD (Digital Versatile Disk) or CD (Compact Disc), and the played video signals are output to the video display unit 22. The audio signal is output to the DSP 23. On a DVD, for example, 5.1 channel audio signals are compressed and recorded by a digital Dolby method, a DTS method, or the like.
The DSP 23 performs a downmix process according to the connection state of the speaker 30 and separates the audio signal into a predetermined number of channels so that sound is output with a predetermined number of channels suitable for the connection state of the speaker 30 to the acoustic device 20. To do. For example, when the configuration of the speaker 30 of the audio device 20 corresponds to 5.1 channel, decoding processing is performed so as to separate the audio signal of 5.1 channel, but the center speaker 33 in the configuration of the speaker 30 of the audio device 20 is performed. Is not connected, downmix processing is performed to mix (mix) the audio signal for the center speaker 33 with the audio signal of the other channel, and processing is performed so that the audio is output in 4 channels or 2 channels. Apply.

  The control unit 28 is a microcomputer including a CPU, a RAM, a ROM, and the like (not shown), and controls each unit of the acoustic device 20 by computer control. In the control unit 28, for example, according to a control program stored in the ROM, various processes including a speaker detection process and a channel number setting process, which will be described later, are performed by performing a calculation in the CPU using a part of the RAM as a work area. The function as a speaker detection device and a channel number setting device is exhibited in cooperation with the back electromotive force detection unit 50 described in (1).

  The acoustic device 20 according to the present embodiment includes a back electromotive force detection unit 50 that is used when the above speaker detection process is executed. The back electromotive force detection unit 50 includes a back electromotive force detection unit 50 that is electrically connected to the audio output terminal 40 to which the speaker 30 is connected, and detects the back electromotive force generated in each speaker 30. . Then, based on the detection result of the counter electromotive force in the counter electromotive force detection unit 50, the control unit 28 executes speaker detection processing for determining whether or not the speaker 30 is connected, and the connection state of the speaker 30 to the acoustic device 20 is set. Accordingly, channel number setting processing for setting the number of channels during downmix processing is performed.

The back electromotive force detection unit 50 can be configured using, for example, a digital amplifier when connected to the digital input port of the control unit 28. The back electromotive force detection unit 50 amplifies the back electromotive force generated in the speaker 30, and the control unit 28 may be configured to output as a digital detection signal indicating that a speaker is connected. In this case, the counter electromotive force detection unit 50 can be configured using a comparator instead of a digital amplifier.
On the other hand, when the control unit 28 has an analog input port, the back electromotive force detection unit 50 can be configured using an analog amplifier, a buffer, and the like, and based on the back electromotive force generated in the speaker 30. The control unit 28 can output an analog detection signal indicating that a speaker is connected.

Next, the operation of the present embodiment including speaker detection processing and channel number setting processing will be described. First, in describing the operation, a detection principle for detecting whether or not the speaker 30 is connected will be described.
The recent vehicle 10 has good airtightness. For example, when the door is closed as shown in FIG. 3 from the state where the door is open as shown in FIG. 2, the air pressure in the vehicle interior increases.
Here, the speaker 30 shown in FIGS. 1 to 3 has a general configuration in which a cone paper is vibrated to generate sound by passing a current through a voice coil sandwiched between permanent magnets. When changing from the state shown in FIG. 2 to the state shown in FIG. 3, that is, when the door (front door 12) of the car is closed, air pressure is applied to the cone paper as indicated by an arrow, and the cone paper vibrates. To do. When the cone paper vibrates, the voice coil vibrates contrary to the normal operation of the speaker 30, and a back electromotive force is generated in the voice coil. In this way, by detecting the back electromotive force generated in the voice coil by opening and closing the door of the vehicle 10, it is detected whether or not the speaker 30 is electrically connected to the audio output terminal 40. Yes. That is, when the cone paper of the speaker 30 is vibrated, the voice coil also moves to generate a current, and a potential difference appears at both ends of the boil coil. Thus, the speaker 30 detects the back electromotive force generated in the voice coil by utilizing the reverse operation of the original operation of the speaker 30, that is, the same operation as that of the microphone. It is made to detect whether it is electrically connected to.

A specific operation procedure will be described with reference to FIG.
In the present embodiment, detection of the back electromotive force is triggered by the opening of the car door as a trigger. However, a detection signal indicating the open / closed state of the door of the car is input to the control unit 28. If the control unit 28 detects that the door of the vehicle has changed from the closed state to the open state based on the detection signal indicating the open / closed state of the vehicle (step S1: Y), it waits until the next door of the vehicle is closed. (Step S2). When the control unit 28 detects that the door of the vehicle has changed from the open state to the closed state based on the detection signal indicating the open / close state of the vehicle (step S2: Y), each audio output terminal 40 is electrically connected. The back electromotive force detection unit 50 determines whether or not a back electromotive force is detected (step S3). Next, since the speaker 30 is electrically connected correctly to the audio output terminal 40 from which the back electromotive force is detected, whether or not the speaker 30 corresponding to each audio output terminal 40 is connected is set, and the speaker 30 is set to the DSP 23. The downmix process is performed so that the number of channels corresponds to the connection state of (2), and the process ends (step S4).
However, in the sound device 20, for example, the audio signal stored after being compressed by the Dolby Digital method or the DTS method is subjected to a decoding process in the DSP 23 so that the audio signal is output in 5.1 channel. Yes. In step S3, for example, when it is detected in the audio device 20 that the center speaker 33 is not connected, the DSP 23 outputs the center channel sound signal from the other speaker 30 so that the center channel sound signal is output from the other speaker 30. A downmix process is performed to mix the signal with the audio signal of the other channel.

  According to the embodiment described above, the back electromotive force detection unit 50 is electrically connected to the plurality of audio output terminals 40 provided in the acoustic device 20, and thus the speaker 30 is provided for each audio output terminal 40. When is connected, back electromotive force generated in the speaker 30 can be detected. And since the speaker 30 detection part detects whether the speaker 30 is connected to the audio | voice output terminal 40 by the back electromotive force detected by the back electromotive force detection part 50, a user does not need to operate, It is possible to easily detect whether or not the speaker 30 is connected.

  Moreover, according to the said embodiment, when wind pressure is added to the cone paper of the speaker 30 with opening and closing of the door of a car, the back electromotive force produced in a voice coil is detectable. For this reason, the user does not need to perform an operation for detecting whether or not the speaker 30 is connected, and the speaker 30 is automatically connected to the audio output terminal 40 on the acoustic device 20 side when entering or leaving the car. Since it is detected whether or not is connected, it does not require a user's trouble. In addition, since the configuration is such that it is detected whether or not the speaker 30 is electrically connected based on whether or not the back electromotive force is detected by the back electromotive force detection unit 50. Therefore, the speaker cable is disconnected or the voice coil is disconnected. Etc. can also be detected.

  For this reason, it is possible to detect whether or not a predetermined speaker 30 is electrically connected correctly for each audio output terminal 40. Further, in the connected state of the speaker 30, a channel for performing a downmix process Number is set. For this reason, the setting of the number of channels at the time of audio output at the time of the downmix processing in the acoustic device 20 can be set according to the connection state of the speaker 30 without the user performing a special operation simply by opening and closing the door of the car. Automatically set correctly.

The embodiment described above is one aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above-described embodiment, the case where the number of channels at the time of downmix processing is set when the number of channels when the audio device 20 performs audio output is set according to the connection state of the speaker 30 is taken as an example. However, the present invention is not limited to this. The configuration of the speaker 30 installed in the vehicle 10 does not correspond to 5.1 channel multi-surround, and the 3WAY configuration that outputs the audio signal of the same channel divided into a high range, a mid range, and a low range, or In the case of a 2-way configuration that outputs separately in the high sound range and the low sound region, the number of channels corresponding to the configuration of the speaker 30 when performing the decoding process in the DSP 23 is set according to the connection state of the speaker 30 It may be.

That is, in the case of the 3WAY configuration, the vehicle 10 mainly reproduces a tweeter that mainly reproduces high-frequency sound, a middle speaker (or full-range speaker) that mainly reproduces middle-range sound, and low-range sound. Three types of subwoofer speakers are mounted for the left channel and the right channel, respectively. On the other hand, in the case of the 2-way configuration, two types of speakers for the left channel and the right channel are provided in the vehicle 10, which are a full-range speaker that mainly reproduces mid to high range sound and a subwoofer that mainly reproduces low range sound, respectively. Is mounted.
At this time, according to the same procedure as in FIG. 4, the presence / absence of connection of each speaker is detected, and when it is detected that the tweeter is not connected, the decoding processing in the DSP 23 becomes the number of channels corresponding to the 2WAY configuration. Can be set as follows. Further, when it is detected that a tweeter is connected, the decoding process in the DSP 23 can be set so that the number of channels corresponds to the 3WAY configuration.

  In the above embodiment, the detection of the counter electromotive force is started with the opening of the car door as a trigger. However, the detection signal input from the counter electromotive force detection unit is always monitored. You may keep it.

It is a schematic diagram which shows schematic structure of the multichannel reproduction | regeneration system of this Embodiment. It is a figure which shows the speaker structural example of this Embodiment. It is explanatory drawing for demonstrating the operation | movement of this Embodiment. It is a flowchart which shows the operation | movement of this Embodiment.

Explanation of symbols

10 Vehicle 11, 12 Front door (car door)
20 Audio device 21 DVD / CD playback device 22 Video display unit 23 DSP (decoder)
24 D / A converter 25 Power amplifier 28 Control unit 30 (31-36) Speaker 40 (41-46) Audio output terminal 50 Back electromotive force detection unit 100 Multi-channel playback system

Claims (7)

A speaker detection device that detects whether or not a speaker is connected to the audio output terminal of the acoustic device,
A back electromotive force detection unit that is electrically connected to the audio output terminal and detects a back electromotive force generated in the voice coil of the speaker;
A speaker detection unit for detecting whether or not the speaker is connected based on the back electromotive force;
A speaker detection device comprising: The speaker detection device according to claim 1,
The back electromotive force is generated due to wind pressure applied to the speaker cone paper,
The speaker detection apparatus characterized by this. The speaker detection device according to claim 2,
The acoustic device is an in-vehicle acoustic device mounted on a vehicle,
The wind pressure applied to the cone paper is accompanied by the opening and closing of the door of the car,
The speaker detection apparatus characterized by this. In the speaker detection apparatus according to any one of claims 1 to 3,
The acoustic device has a plurality of audio output terminals,
The speaker detection unit detects whether or not the speaker is connected to each audio output terminal;
The speaker detection apparatus characterized by this. A back electromotive force detection unit that is electrically connected to a sound output terminal of the acoustic device and detects a back electromotive force generated in the voice coil of the speaker;
A speaker detection unit for detecting whether or not the speaker is connected based on the back electromotive force;
A channel number setting unit for setting the number of channels when the audio device performs audio output according to the connection state of the speaker detected by the speaker detection unit;
A device for setting the number of channels. A back electromotive force detection unit that is electrically connected to a sound output terminal of the acoustic device and detects a back electromotive force generated in a voice coil of the speaker; and whether the speaker is connected based on the back electromotive force Audio of the audio device using a speaker detection unit that detects the sound and a channel number setting unit that sets the number of channels when the audio device performs audio output according to the connection state of the speaker detected by the speaker detection unit In the channel number setting method to set the number of channels at the time of output,
The counter electromotive force detection unit detects a counter electromotive force generated in the voice coil of the speaker,
The speaker detection unit detects whether the speaker is connected based on the back electromotive force,
Setting the number of channels according to the connection state of the speaker detected by the speaker detection unit by the channel number setting unit;
Channel number setting method characterized by. A back electromotive force detection unit that is electrically connected to a sound output terminal of the acoustic device and detects a back electromotive force generated in a voice coil of the speaker; and whether the speaker is connected based on the back electromotive force A channel number setting unit, and a channel number setting unit that sets the number of channels when the audio device performs audio output according to the connection state of the speaker detected by the speaker detection unit A control program for controlling a device using a computer,
The counter electromotive force detection unit detects a counter electromotive force generated in the voice coil of the speaker,
The speaker detection unit detects whether the speaker is connected based on the back electromotive force,
Causing the number of channels setting unit to set the number of channels according to the connection state of the speakers detected by the speaker detection unit;
A control program characterized by

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