JP3718418B2 - In-vehicle audio equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-vehicle audio apparatus that is used by being connected to a mobile phone and that performs audio signal processing and hands-free processing using a built-in DSP.
[0002]
[Prior art]
When the mobile phone is used in a car, the mobile phone is mounted on an in-vehicle audio device that is an in-vehicle adapter.
Then, the microphone and the speaker for the call are switched to the microphone and the speaker of the in-vehicle acoustic device, so that a so-called hands-free call can be performed. At this time, an echo canceller is provided in order to suppress the echo generated when the sound output from the speaker of the in-vehicle acoustic device is input to the microphone of the in-vehicle acoustic device.
That is, during a hands-free call, the echo canceller can be operated to make a good call even in the vehicle.
[0003]
In addition, since there is a lot of noise such as engine noise in the vehicle, a noise canceller for suppressing this noise is also provided in the in-vehicle acoustic device.
Normally, audio signal processing from an acoustic device mounted on a vehicle, echo cancellation processing during noise-free operation, and noise cancellation processing are executed by a DSP (digital signal processor) provided in the in-vehicle acoustic device.
[0004]
FIG. 2 is a block circuit diagram showing a schematic configuration of a conventional in-vehicle acoustic device.
The state shown in FIG. 2 shows a state in which the mobile phone 7 is connected to the hands-free device 100 that is an in-vehicle audio device.
The mobile phone 7 and the hands-free device 100 are connected by a connection cord 13. When the mobile phone 7 is connected to the handsfree device 100 by the connection cord 13, the microphone and the speaker in the mobile phone 7 are switched to the microphone 1 and the speaker 12 connected to the handsfree device 100.
[0005]
Furthermore, the hands-free device 100 is provided with an operation switch 10, and the operation state can be switched between a call state and a call end by operating the operation switch 10.
The hands-free device 100 includes an amplifier 2, a codec (CODEC) 4, a DSP 5, a codec 6, a control device 9, and an amplifier 11. As described above, the echo cancellation processing and noise cancellation processing associated with the hands-free processing are performed by the DSP 5. Executed.
[0006]
The operation when there is an incoming call in such an apparatus will be described.
When the mobile phone 7 receives an incoming call via the antenna 8, the incoming signal is transmitted to the handsfree device 100. Then, a telephone ringing tone sounds from the speaker 12 connected to the handsfree device 100.
When the operation switch 10 is operated in this state, it is switched to a call state and a hands-free call can be performed using the microphone 1 and the speaker 12.
When the call ends, the operation switch 10 is operated to return to the standby state.
[0007]
In such an incoming call operation, transmission routes of various voice signals including a ringing tone will be examined.
First, a ringing tone signal is transmitted from the mobile phone 7 to the speaker 12 via the codec 6, DSP 5, codec 4, and amplifier 11. Also, the received voice signal from the other party is transmitted to the speaker through the same route as the above-mentioned ringing tone signal. The transmitted voice signal is transmitted from the microphone 1 to the mobile phone 7 through the amplifier 2, the codec 4, the DSP 5, and the codec 6.
As described above, in the conventional on-vehicle acoustic device, the ringing tone signal and the incoming / outgoing calling tone signal all pass through the same transmission path and always pass through the DSP 5.
[0008]
[Problems to be solved by the invention]
In the case of a conventional in-vehicle acoustic device, there is no problem when a dedicated DSP is used for hands-free processing of incoming and outgoing calls during a hands-free call. However, in the configuration shown in FIG. When the audio signal processing from the audio equipment is used and the hands-free processing for processing the reception sound signal and the transmission sound signal at the time of the incoming call operation is also used, the DSP processing is switched from the audio processing to the hands-free processing at the time of the incoming call. It takes time for this.
Therefore, there is a problem that the time until the ringing tone is output from the speaker at the time of an incoming call is delayed.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an in-vehicle acoustic device that can ring a ringing tone without delay when a mobile phone receives an incoming call.
[0009]
[Means for Solving the Problems]
The present invention relates to an in-vehicle acoustic device that is connected to a mobile phone and performs audio signal processing and hands-free processing by a built-in DSP, and a ringing tone signal at the time of incoming call of the mobile phone is transmitted by bypassing the DSP. It is comprised so that. In the in-vehicle acoustic device, a control unit that switches the DSP from audio signal processing to hands-free processing while the ringing tone signal bypasses the DSP is provided.
Furthermore, in the on-vehicle acoustic device, a volume control circuit that independently controls only the magnitude of the ringing tone signal is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle acoustic device according to the present invention. Note that the same reference numerals are given to the same components as those in the apparatus shown in FIG. 2, and a detailed description thereof will be omitted.
In the embodiment shown in FIG. 1, the on-vehicle acoustic device 200 is configured as follows.
An audio signal source 14 capable of generating various audio signals is built in, and a selector 15 for selecting and outputting either the audio signal from the audio signal source 14 or the audio signal from the microphone 1. Is provided.
[0011]
A selector 16 is provided for selecting an audio signal from the audio signal source 14 and a received voice signal from the mobile phone 7 and outputting either of them. The signals output via the selectors 15 and 16 are converted into digital signals by the codec 18 and input to the DSP 19.
The DSP 19 can execute so-called hands-free processing such as echo cancellation processing and noise cancellation processing and audio signal processing from the audio signal source 14 in common.
The signal that has passed through the DSP 19 is converted into an analog signal by the codec 20 and supplied to the mobile phone 7 or the selector 24.
[0012]
The ringing tone signal from the cellular phone 7 is configured to be supplied to the volume control circuit 21 via the switch 17.
That is, when there is an incoming call in the mobile phone 7, the control device 23 detects this, closes the switch 17 and transmits the ringing tone signal to the volume control circuit 21, and the ringing tone signal is input from the selector 16 to the codec 18. Is prohibited.
[0013]
The ringing tone signal input to the volume control circuit 21 in this way is selected by the selector 24 at a predetermined timing, and is output from the amplifier 26 to the speaker 12 via the volume control circuit 25 to be a ringing sound. .
The control device 23 controls these various circuits, and the operation switch 22 switches between a call state and a call end.
[0014]
The operation at the time of incoming call in the apparatus of FIG. 1 will be described.
In the present invention, a ringing tone signal is transmitted by bypassing the DSP 19 when a call is received.
In other words, the ringing tone signal is emitted from the speaker 12 without being subjected to the DSP processing by the DSP 19. During this time, the DSP 19 is switched from audio signal processing for processing the audio signal from the audio signal source 14 to hands-free processing.
That is, the DSP 19 is switched to a state in which echo cancellation processing and noise cancellation processing can be performed.
When the operator who has heard the ringing sound from the speaker 12 operates the operation switch 22, the acoustic device 200 transitions to a call state and can perform a hands-free call.
[0015]
Next, when the call is finished, the operation switch 22 is operated to switch the DSP 19 to the audio signal processing again, and the audio signal from the audio signal source 14 is reproduced.
That is, in the apparatus according to the present invention, the DSP 19 is set to perform the audio signal processing from the audio signal source 14 at the time of waiting for a call, and is switched so that the DSP 19 performs the hands-free process at the time of the incoming call. It is switched to perform audio signal processing.
[0016]
Next, transmission paths for various audio signals when a call is received will be described.
First, a ringing tone when a call is received is input from the mobile phone 7 to the volume control circuit 21 via the switch 17. The volume control circuit 21 is a dedicated control circuit for the ringing tone that can adjust only the volume of the ringing tone.
At this time, the control device 23 controls the selector 16 so as not to output the ringing tone signal to the codec 18.
Therefore, the ringing tone signal is input to the volume control circuit 21 only through the switch 17.
[0017]
The ringing tone signal from the volume control circuit 21 is output to the volume control circuit 25 when the selector 24 is selected. Unlike the volume control circuit 21, the volume control circuit 25 is used to control the volume of not only the ringing tone but also the received sound.
An output signal from the volume control circuit 25 is output to the speaker 12 via the amplifier 26.
Thus, the ringing tone signal is configured to be transmitted to the speaker 12 by bypassing the DSP 19.
While the ringing tone signal is being outputted around the DSP 19, the DSP 19 is switched from the audio signal processing to the hands-free processing by the operation of the control device 23.
[0018]
Following the ringing tone, a received voice signal is input from the mobile phone 7 to the selector 16. Since the selector 16 is set to block the signal from the audio signal source 14 and select the signal from the mobile phone 7 at this stage, the received voice signal from the mobile phone 7 is sent from the selector 16 to the codec 18. Entered.
Next, a so-called hands-free process of echo cancellation and noise cancellation is performed by the DSP 19 and transmitted to the selector 24 via the codec 20.
[0019]
Here, since the selector 24 is switched to transmit the received voice signal, the received voice signal is output to the volume control circuit 25 and transmitted to the speaker 12 via the amplifier 26. The transmitted voice signal is output from the microphone 1 to the selector 15 via the amplifier 2.
Here, since the selector 15 is set to block the signal from the audio signal source 14 and select only the transmission voice signal from the microphone 1, the transmission voice signal is transmitted to the codec 18. Next, the transmission voice signal is transmitted to the mobile phone 7 through the DSP 19 and the codec 20.
[0020]
【The invention's effect】
As described above, according to the present invention, the ringing tone from the mobile phone is transmitted by bypassing the DSP, so the audio signal processing and the hands-free processing are combined with one DSP. In the in-vehicle acoustic device, it is not necessary to process the ringing tone by the DSP, so that the ringing tone can be output from the speaker without a time delay when a call is received.
In addition, if a separate volume control circuit for independently controlling only the magnitude of the ringing tone signal is provided, the control of the volume levels of the ringing tone and the receiving tone can be simplified.
That is, if the ringing volume is adjusted by a volume control circuit that independently controls only the magnitude of the ringing tone signal, the ringing volume can be fixed as long as the same mobile phone is used.
The volume of the incoming call is adjusted by a common volume control circuit for the ringing tone and the incoming call in accordance with the standard incoming call volume, and if the set value is stored in the memory, the volume adjustment operation is not frequently performed during a call. There is an advantage that it can be saved.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram showing an embodiment of an in-vehicle acoustic device of the present invention.
FIG. 2 is a block diagram showing a configuration of a conventional in-vehicle acoustic device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Microphone 2 Amplifier 7 Cellular phone 12 Speaker 14 Audio signal sources 15 and 16 Selector 18 Codec 19 DSP
20 Codec 17 Switch 21 Volume Control Circuit 22 Operation Switch 23 Controller 24 Selector 25 Volume Control Circuit

Claims (3)

In an in-vehicle acoustic device that is connected to a mobile phone and performs audio signal processing and hands-free processing by a built-in DSP,
An in-vehicle acoustic apparatus configured to transmit a ringing tone signal at the time of an incoming call of the mobile phone, bypassing the DSP. The in-vehicle audio device according to claim 1,
A vehicle-mounted acoustic device comprising a control unit that switches the DSP from audio signal processing to hands-free processing while the ringing tone signal bypasses the DSP. The in-vehicle audio device according to claim 1,
A vehicle-mounted acoustic device comprising a volume control circuit that independently controls only the magnitude of the ringing tone signal.

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