Audio signal control device

Abstract

To provide a technology for acquiring an audio signal output from an in-vehicle audio system and adjusting the volume for good use. [Solution] The audio signal control device 1 includes an output control unit 10 that receives an audio signal output from an in-vehicle audio system 120 and outputs an adjusted audio signal by adjusting the audio signal. The output control unit 10 receives volume instruction information or reflection information that reflects the volume instruction information transmitted between the in-vehicle audio system 120 and an amplifier device 110, and outputs an adjusted audio signal by adjusting the audio signal to a volume corresponding to the volume instruction information or the reflection information.

Description

[Technical Field]

[0001] The present disclosure relates to an audio signal control device. [Background technology]

[0002] Patent Document 1 discloses a system in which one or more of a number of non-genuine sound quality improving components are selected and retrofitted between an existing genuine audio system and speaker system for use in a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-63343 Summary of the Invention [Problem to be solved by the invention]

[0004] In-vehicle systems have become commonplace, in which signals are transmitted from an in-vehicle audio system to an amplifier, which then outputs an amplified output signal to speakers. For example, in a system in which a genuine amplifier is interposed between a genuine deck and genuine speakers mounted in a vehicle, audio signals and volume control information are sent from the genuine deck to the amplifier, and an output signal reflecting these is output from the genuine amplifier to the genuine speakers.

[0005] However, the above-described general system configuration is not always desirable. There may be cases where it is desirable to use the audio signal output from an in-car audio system in another device. For example, there may be situations where it is desirable to output audio reflecting the audio signal output from an in-car audio system from a subwoofer or other device, or to use it for other purposes. In such cases, one possible method would be to use the audio output signal from an amplifier to output audio from a subwoofer or tweeter. However, using the audio output signal from the amplifier results in a signal that differs from the original signal, increasing the likelihood of using a restricted signal and potentially resulting in a deterioration in sound quality. For example, if an amplifier performs equalization or filtering, using the audio output signal from the amplifier would result in using the restricted signal after processing. Therefore, the inventors of the present application considered using the audio signal output from the in-car audio system to the amplifier. However, because the audio signal output from the in-car audio system to the amplifier does not reflect the volume separately provided by the in-car audio system to the amplifier, using only the transmitted audio signal as is would result in a discrepancy with the volume adjusted by the amplifier.

[0006] One object of the present disclosure is to provide a technology that can acquire an audio signal output from an in-vehicle audio system and adjust the volume for effective use. [Means for solving the problem]

[0007] The audio signal control device according to the present disclosure includes: An audio signal control device applied to an in-vehicle system including: an in-vehicle audio system that outputs an audio signal; the in-vehicle audio system or another in-vehicle device that transmits volume instruction information; and an amplifier device that, when acquiring the audio signal and the volume instruction information, converts the audio signal into an audio output signal based on a volume level that reflects the volume instruction information and outputs the audio signal, an output control unit that receives the audio signal output from the in-vehicle audio system and outputs an adjusted audio signal obtained by adjusting the audio signal; The output control unit receives information including at least one of the volume instruction information transmitted between the in-car audio system and the amplifier device or reflection information that reflects the volume instruction information transmitted from the amplifier device, and outputs the adjusted audio signal with the audio signal adjusted to a volume corresponding to the volume instruction information or the reflection information. [Effects of the Invention]

[0008] According to the technology of the present disclosure, it is possible to extract an audio signal output from an in-vehicle audio system, adjust the volume, and make good use of it. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic example of an in-vehicle system to which an audio signal control device according to a first embodiment is applied. [Figure 2] FIG. 2 is an explanatory diagram illustrating a schematic example of an in-vehicle system before the audio signal control device according to the first embodiment is applied. [Figure 3] FIG. 3 is an explanatory diagram illustrating a schematic example of an in-vehicle system to which the audio signal control device according to the second embodiment is applied. [Figure 4] Fig. 4(A) is a waveform diagram of an example of an audio signal output from the in-car audio system 120. Fig. 4(B) is a waveform diagram in which the bass band of the audio signal of Fig. 4(A) is amplified by 6 dB by an equalizer. [Figure 5] Figure 5(A) is a waveform diagram of the audio signal in Figure 4(A) after the treble band has been amplified by 6 dB using an equalizer, and Figure 5(B) is a waveform diagram of the audio signal in Figure 4(A) after the audio signal has been amplified by a gain of 2x to increase the volume. [Figure 6]Fig. 6(A) is a waveform diagram of the waveform output from the subwoofer 180 when the audio signal of Fig. 4(A) or Fig. 5(A) is applied to the subwoofer 180. Fig. 6(B) is a waveform diagram of the waveform output from the subwoofer 180 when the audio signal of Fig. 4(B) or Fig. 5(B) is applied to the subwoofer 180. DETAILED DESCRIPTION OF THE INVENTION

[0010] Each of the following items [1] to [6] is an example of technology such as an object or method included in this disclosure.

[0011] [1] An audio signal control device applied to an in-vehicle system including an in-vehicle audio system that outputs an audio signal, the in-vehicle audio system or another in-vehicle device that transmits volume instruction information, and an amplifier device that, when acquiring the audio signal and the volume instruction information, converts the audio signal into an audio output signal based on a volume level that reflects the volume instruction information and outputs the audio signal, an output control unit that receives the audio signal output from the in-vehicle audio system and outputs an adjusted audio signal obtained by adjusting the audio signal; The output control unit receives information including at least one of the volume instruction information transmitted between the in-vehicle audio system and the amplifier device and reflection information that reflects the volume instruction information transmitted from the amplifier device, and outputs the adjusted audio signal having a volume adjusted to a volume corresponding to the volume instruction information or the reflection information. Audio signal control device.

[0012] The audio signal control device of [1] above receives volume instruction information or reflection information reflecting the volume instruction information transmitted between the in-vehicle audio system or other in-vehicle device and the amplifier device, and outputs an adjusted audio signal by adjusting the volume of the audio signal to the volume corresponding to the volume instruction information or reflection information. In this way, the audio signal control device can acquire the audio signal output from the in-vehicle audio system, adjust the volume, and use it effectively.

[0013] [2] The volume instruction information is volume level information, the amplifier device operates, when receiving the volume level information from the in-vehicle audio system or the other in-vehicle device, to adjust the audio signal to a volume level specified by the volume level information and output the audio output signal; The output control unit receives the volume level information, adjusts the audio signal to a volume corresponding to the volume level information, and outputs the adjusted audio signal. The audio signal control device described in [1].

[0014] In a system to which the audio signal control device described in [2] above is applied, when the amplifier device receives volume level information from an in-vehicle audio system or another in-vehicle device, it outputs an audio signal at a volume level specified by the received volume level information. Meanwhile, the audio signal control device can receive volume level information transmitted to the amplifier device from the in-vehicle audio system or the other in-vehicle device, and output an adjusted audio signal adjusted to a volume corresponding to the volume level information. In other words, the audio signal control device can receive information that can specify the actual volume level at which the amplifier device outputs an audio output signal, and then adjust the audio signal to a volume corresponding to the volume level information and output it. Therefore, the audio signal control device described in [2] above can use an audio signal at a volume that corresponds to the actual volume of the audio output by the amplifier device.

[0015] [3] The volume instruction information is information instructing an increase or decrease in the volume level, when the amplifier device receives the information instructing the increase or decrease from the in-vehicle audio system or the other in-vehicle device, the amplifier device sets a new volume level by reflecting the received information instructing the increase or decrease in the volume level set in the amplifier device, and when the amplifier device receives the audio signal in a state set at the new volume level, the amplifier device operates to adjust the audio signal to the new volume level and output the audio output signal; Furthermore, the amplifier device operates to transmit the reflection information including volume level information that specifies a volume level currently set in the amplifier device; The output control unit has an audio signal receiving unit that receives the audio signal and an information receiving unit that receives the reflection information, and outputs the adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume corresponding to the volume level information received by the information receiving unit. The audio signal control device described in [1].

[0016] In a system to which the audio signal control device described in [3] above is applied, when the amplifier device receives information instructing it to increase or decrease the volume level from an in-vehicle audio system or other in-vehicle device, it sets a new volume level by reflecting the received information instructing it to increase or decrease the volume level set in the amplifier device. Then, when an audio signal is received with the new volume level set, it operates to adjust the audio signal to the new volume level and output an audio output signal. In this case, because the in-vehicle audio system or other in-vehicle device provides the amplifier device with "information instructing it to increase or decrease the volume level," even if the audio signal control device receives this information, it is difficult to accurately determine the volume level currently set in the amplifier device. However, the audio signal control device described in [3] above can receive information that can identify the volume level currently set in the amplifier device, and then adjust the audio signal received by the audio signal receiving unit to a volume corresponding to the volume level information and output it. Therefore, the audio signal control device described in [3] above can use an audio signal at a volume that corresponds to the actual volume of the audio output by the amplifier device.

[0017] [4] The amplifier device sets an amount of amplification or attenuation for each band in response to an external instruction, and when the audio signal is input and the volume instruction information is received, the amplifier device outputs the audio output signal reflecting the amount of amplification or attenuation determined by the setting for each band and a volume level based on the volume instruction information; the amplifier device transmits the reflection information including information on the volume level and information on the amount of amplification or attenuation of a predetermined band determined by the setting; The output control unit has an audio signal receiving unit that receives the audio signal and an information receiving unit that receives the reflection information, and outputs the adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a sound corresponding to the information on the volume level and the information on the amount of amplification or attenuation of the predetermined band received by the information receiving unit. An audio signal control device according to any one of [1] to [3].

[0018] In a system to which the audio signal control device described in [4] above is applied, the amplifier device has an equalizer function. The amplifier device operates to output an audio output signal that reflects the amount of amplification or attenuation determined by the settings for each band and reflects a volume level based on volume instruction information. In such a system, the audio signal control device described in [4] above can adjust the audio signal received by the audio signal receiving unit to a volume corresponding to the volume level determined by the amplifier device and the amount of amplification or attenuation of a specified band, and output it as an adjusted audio signal. For example, if the output destination of the audio signal control device is a device that limits the output to the specified band or a device that prioritizes the specified band, the audio signal can be output at a volume that matches the amount of amplification or attenuation of the specified band of the amplifier device, thereby functioning more effectively.

[0019] [5] A first connector portion having a terminal connected to the in-car audio system; a second connector portion having a terminal connected to the amplifier device; one or more signal transmission lines connected to the first connector portion and the second connector portion; and the first connector portion includes a first terminal portion that receives the audio signal output from the in-vehicle audio system and a second terminal portion that receives the volume instruction information transmitted from the in-vehicle audio system, the one or more signal transmission lines include an audio signal transmission line for transmitting the audio signal from the first terminal unit to the amplifier device via the second connector unit, and an information transmission line having at least one of a function of transmitting the volume instruction information from the second terminal unit to the amplifier device via the second connector unit and a function of transmitting the reflection information transmitted from the amplifier device, a first branch line is provided branching from the audio signal transmission line, a second branch line is provided branching from the information transmission line, the first branch line transmits the audio signal transmitted by the audio signal transmission line to the output control unit; The second branch line transmits the volume instruction information or the reflection information transmitted by the information transmission line to the output control unit. An audio signal control device according to any one of [1] to [4].

[0020] The audio signal control device of [5] above can be installed in place of or in addition to an existing transmission line that transmits audio signals and volume instruction information between an in-vehicle audio system and an amplifier device, if one is available or can be installed. Specifically, this audio signal control device can be used in a configuration in which a first terminal receives an audio signal output from the in-vehicle audio system, a first connector is installed so that a second terminal receives volume instruction information output from the in-vehicle audio system, and a second connector is installed so that the terminal is connected to an amplifier device. When installed in this manner, the first branch line can transmit the audio signal transmitted in the audio signal transmission line to the output control unit. Thus, the output control unit can utilize the audio signal transmitted to the amplifier device. Furthermore, the second branch line can transmit information transmitted in the information transmission line to the output control unit. Thus, the output control unit can utilize the volume instruction information or reflection information. In this way, the audio signal control device of [5] above can be installed in place of or in addition to an existing transmission line, extract the audio signal output from the in-vehicle audio system, adjust the volume, and utilize it effectively.

[0021] [6] A first connector portion having a terminal connected to the in-car audio system; a second connector portion having a terminal connected to the amplifier device; a signal transmission line connected to the first connector portion and the second connector portion; and the first connector portion includes a first terminal portion that receives the audio signal output from the in-vehicle audio system and a second terminal portion that receives the volume instruction information transmitted from the in-vehicle audio system, the signal transmission line includes an information transmission line having at least one of a function of transmitting the volume instruction information from the second terminal unit to the amplifier device via the second connector unit and a function of transmitting the reflection information transmitted from the amplifier device, Furthermore, a branch line that branches off from the information transmission line and transmits information from the information transmission line to the output control unit; a first audio signal transmission line for transmitting the audio signal from the first terminal unit to the output control unit; a second audio signal transmission line for transmitting the audio signal from the output control unit to the amplifier device via the second connector unit; will be established An audio signal control device according to any one of [1] to [4].

[0022] The audio signal control device of [6] above can be installed in place of or in addition to an existing transmission line for transmitting audio signals and volume instruction information between an in-vehicle audio system and an amplifier device if one is available or can be installed. Specifically, this audio signal control device can be used in a configuration in which a first terminal unit receives an audio signal output from the in-vehicle audio system, a first connector unit is installed so that a second terminal unit receives volume instruction information output from the in-vehicle audio system, and a second connector unit is installed so that the terminals are connected to the amplifier device. When installed in this manner, the first audio signal transmission line can transmit an audio signal to the output control unit. Therefore, the output control unit can use the audio signal to be transmitted to the amplifier device. Furthermore, the audio signal control device of [6] above can transmit an audio signal from the output control unit to the amplifier device via the second audio signal transmission line and the second connector unit. Therefore, the amplifier device can also use the audio signal. Furthermore, the branch line can transmit information transmitted on the information transmission line to the output control unit. Therefore, the output control unit can use the volume instruction information or reflection information. In this way, the audio signal control device can be installed in place of or in addition to an existing transmission line, and can extract the audio signal output from the in-car audio system, adjust the volume, and make good use of it.

[0023] First Embodiment The following description relates to the first embodiment. 1-1. Overview of the in-vehicle system Sy1 Fig. 1 conceptually shows an example in which an audio signal control device 1 according to the first embodiment is mounted on a vehicle 190. In the example of Fig. 1, an in-vehicle system Sy1 is mounted on the vehicle 190. The in-vehicle system Sy1 includes an in-vehicle audio system 120, an amplifier device 110, a speaker 140, the audio signal control device 1, a subwoofer 180, and the like.

[0024] The in-vehicle audio system 120 is a system that can transmit audio signals and volume instruction information. Examples of the in-vehicle audio system 120 include an in-vehicle navigation system and an in-vehicle display audio. Typically, the in-vehicle audio system 120 is a genuine product such as a manufacturer option or dealer option, but it does not have to be a genuine product. The volume instruction information may be volume value information or information specifying the degree of increase or decrease in the volume.

[0025] Amplifying device 110 is a device that outputs an output signal obtained by amplifying the audio signal at an amplification level according to the volume instruction information when it receives an audio signal and volume instruction information from in-car audio system 120. Amplifying device 110 may be a genuine amplifier, which is a genuine product, or may not be a genuine product.

[0026] The speaker 140 is a well-known speaker that converts the output signal provided from the amplifier device 110 into sound and generates sound corresponding to the audio signal. The speaker 140 may be a genuine speaker that is a genuine product, or may not be a genuine product.

[0027] In the in-vehicle system Sy1, an audio signal and volume instruction information are transmitted from the in-vehicle audio system 120, and the amplifier device 110 amplifies the audio signal at an amplification level corresponding to the volume instruction information and outputs the amplified output signal to the speaker 140, thereby emitting audio from the speaker 140. Meanwhile, the audio signal control device 1 receives the audio signal and the volume instruction information or reflection information reflecting the volume instruction information transmitted between the in-vehicle audio system 120 and the amplifier device 110, and outputs an adjusted audio signal obtained by adjusting the received audio signal to a volume corresponding to the volume instruction information or the reflection information to the subwoofer. The subwoofer 180 outputs audio corresponding to the adjusted audio signal, and the audio of the audio signal is output from the subwoofer 180 after being adjusted to a volume corresponding to the volume instruction information or the reflection information.

[0028] The in-vehicle system Sy1 shown in Fig. 1 is newly configured by adding an audio signal control device 1 to a system configured as shown in Fig. 2. In the system of Fig. 2, a signal transmission unit 130 is provided between an in-vehicle audio system 120 and an amplifier device 110.

[0029] The signal transmission unit 130 includes a connector unit 132, a signal line unit 136, and a connector unit 134. The connector unit 132 is detachably connected to the connection unit 122 of the in-car audio system 120. The connector unit 132 may be configured by a single connector or may be configured by multiple connectors.

[0030] Signal line unit 136 has a plurality of signal lines arranged between connector unit 132 and connector unit 134, and is capable of transmitting various signals. In the example of Fig. 1, signal line unit 136 is provided with transmission unit 136A having one or more signal lines for transmitting audio signals and transmission unit 136B having one or more signal lines for transmitting volume instruction information, but signal lines other than these may also be included. Furthermore, signal line unit 136 may also include a power supply line to which a power supply voltage is applied, a ground line maintained at a ground voltage, and other lines.

[0031] The connector section 134 is detachably connected to the connection section 114 of the amplifier device 110. The connector section 134 may be configured by a single connector, or may be configured by a plurality of connectors.

[0032] 2, an audio signal is provided from the in-vehicle audio system 120 to the amplifier device 110 via a transmission unit 136A, and volume instruction information is provided from the in-vehicle audio system 120 to the amplifier device 110 via a transmission unit 136B. When the amplifier device 110 receives the audio signal and the volume instruction information, it outputs an output signal obtained by amplifying the audio signal at an amplification level according to the volume instruction information to the speaker 140, and sound according to this output is emitted from the speaker 140.

[0033] The in-vehicle system Sy1 of Fig. 1 is configured such that a first connector unit 93 is connected to the connection unit 122 of the system of Fig. 2, and a second connector unit 94 is connected to the connector unit 132, and the audio signal control device 1 is attached to the system. In other words, the in-vehicle system Sy1 of Fig. 1 is configured by adding the audio signal control device 1 to the system of Fig. 2. In the example of Fig. 1, the second connector unit 94 is connected to the connector unit 132, and audio signals and volume instruction information are transmitted via a signal transmission unit, but the second connector unit 94 may also be directly connected to the connection unit 114.

[0034] 1-2. Basic configuration of the audio signal control device 1 As shown in Fig. 1, the audio signal control device 1 includes a main body 2 and a signal line unit 90, and is applied to an in-vehicle system Sy1. The main body 2 includes a housing and an output control unit 10, both of which are not shown, with most or all of the output control unit housed within the housing. The output control unit 10 has a function of receiving an audio signal output from an in-vehicle audio system 120 and outputting an adjusted audio signal obtained by adjusting the audio signal. The signal line unit 90 includes a first connector 93, a second connector 94, and a plurality of signal transmission lines.

[0035] The first connector unit 93 has one or more connectors connected to the connection unit 122 of the in-vehicle audio system 120. The first connector unit 93 may be configured with one connector or multiple connectors. The first connector unit 93 has terminals connected to the in-vehicle audio system 120. Specifically, the first connector unit 93 is provided with a first terminal unit 93A that receives an audio signal output from the in-vehicle audio system 120 and a second terminal unit 93B that receives volume instruction information output from the in-vehicle audio system 120. The connection between the first terminal unit 93A and the in-vehicle audio system 120 may be any connection that allows signals and information to be transmitted between the first terminal unit 93A and the in-vehicle audio system 120, and may be an electrical connection or a connection by a method other than electrical connection (a configuration that allows transmission by a method other than electrical connection). Similarly, the connection between the second terminal unit 93B and the in-car audio system 120 may be in any form that allows signals and information to be transmitted between the second terminal unit 93B and the in-car audio system 120, and may be an electrical connection or a connection by a method other than electrical connection (a configuration that allows transmission by a method other than electrical connection). The first terminal unit 93A is composed of one or more terminals, and in a representative example, a plurality of terminals. The second terminal unit 93B is composed of one or more terminals, and in a representative example, a plurality of terminals. The second connector unit 94 has terminal units 94A and 94B that are connected to the amplifier device 110. Each of the terminal units 94A and 94B is composed of one or more terminals, and in a representative example, a plurality of terminals. The connection between the terminal unit 94A and the amplifier device 110 may be in any form that allows signals and information to be transmitted between the terminal unit 94A and the amplifier device 110, and may be an electrical connection or a connection by a method other than electrical connection (a configuration that allows transmission by a method other than electrical connection). Similarly, the connection form between the terminal portion 94B and the amplifier device 110 may be any form that allows signals and information to be transmitted between the terminal portion 94B and the amplifier device 110, and may be an electrical connection or a configuration in which the connection is made by a means other than electrical connection (a configuration in which transmission is possible by a means other than electrical connection).

[0036] The multiple signal transmission lines connected to the first connector unit 93 and the second connector unit 94 include at least an audio signal transmission line 91A and an information transmission line 92A. The audio signal transmission line 91A is a signal transmission line for transmitting an audio signal from the first terminal unit 93A to the amplifier device 110 via the second connector unit 94. The audio signal transmission line 91A may be configured with a single signal transmission line, or may be configured with multiple signal transmission lines. In a representative example, the audio signal transmission line 91A is configured with multiple transmission lines. The audio signal transmission line 91A may be configured to transmit an audio signal between the in-vehicle audio system 120 and the amplifier device 110, and may be configured to electrically connect the in-vehicle audio system 120 and the amplifier device 110, or may be configured to connect them by a method other than electrical connection (a configuration that enables transmission by a method other than electrical connection). The information transmission line 92A is a signal transmission line having at least one of the functions of transmitting volume instruction information from the second terminal unit 93B to the amplifier device 110 via the second connector unit 94 and transmitting reflection information transmitted from the amplifier device 110. The information transmission line 92A may be configured with a single signal transmission line or multiple signal transmission lines. Suitable examples of the information transmission line 92A include a communication line for communicating in accordance with a communication protocol of an IE-BUS (Inter Equipment Bus) or a CAN (Controller Area Network) bus, and a communication line for communicating using a UART (Universal Asynchronous Receiver Transmitter) system. The information transmission line 92A may be configured to transmit various types of information between the in-vehicle audio system 120 and the amplifier device 110, and may be configured to electrically connect the in-vehicle audio system 120 and the amplifier device 110, or may be configured to connect them by a method other than electrical connection (a method that enables transmission by a method other than electrical connection).

[0037] Furthermore, in the audio signal control device 1, a branch line 91B is provided branching from the audio signal transmission line 91A. The branch line 91B corresponds to an example of a first branch line. And a branch line 92B is provided branching from the information transmission line 92A. The branch line 92B corresponds to an example of a second branch line. The branch line 91B transmits the audio signal transmitted by the audio signal transmission line 91A to the output control unit 10. The branch line 92B transmits the volume instruction information or reflection information transmitted by the information transmission line 92A to the output control unit 10. The audio signal transmitted by the audio signal transmission line 91A is, for example, an analog voltage signal. Note that the audio signal may be a digital signal. The information transmitted by the information transmission line 92A is, for example, digital information.

[0038] The output control unit 10 includes a control unit 12, a volume control unit 14, an input interface 16, and an output interface 18.

[0039] The input interface 16 is a section that receives an audio signal input from the branch line 91B, and is a circuit that receives the input audio signal and provides the audio signal to the volume adjustment unit 14. The input interface 16 is configured, for example, by a differential amplifier, and amplifies the audio signal input from the branch line 91B and outputs the amplified audio signal to the volume adjustment unit 14. The output interface 18 is a section that receives an audio signal input from the volume adjustment unit 14, and is a circuit that outputs the input audio signal to the outside. The output interface 18 is configured, for example, by a buffer amplifier, and has the function of converting the audio signal input from the volume adjustment unit 14 into a signal required by an external device (subwoofer 180 in the example of FIG. 1) and outputting the signal to the external device. For example, if volume adjustment unit 14 has a function to output an audio signal within a predetermined output range (e.g., a range of 0V to 10V), and an external device handles audio signals within a predetermined range (e.g., a range of -5V to 5V), output interface 18 may have a function to convert signals within the output range of volume adjustment unit 14 (e.g., a range of 0V to 10V) into a range handled by the external device (e.g., a range of -5V to 5V).

[0040] The control unit 12 is configured as an information processing device that performs various calculations and controls. The control unit 12 is connected to the information transmission line 92A via a branch line 92B, and has a function of monitoring information transmitted to the information transmission line 92A. The branch line 92B may be configured to electrically connect the information transmission line 92A and the control unit 12, or may be configured to connect them by a method other than electrical connection (a method that allows information to be transmitted by a method other than electrical connection).

[0041] 1-3. Functions related to volume adjustment in the amplifier device 110 In the representative example described below, the in-vehicle audio system 120 is capable of transmitting information instructing the amplifier device 110 to increase or decrease the volume as "volume instruction information" in response to an instruction from an operation device (not shown). The operation device may be an operation unit provided in the in-vehicle audio system 120, or may be an audio operation unit, a rear seat operation switch, a steering switch, or the like, provided separately from the in-vehicle audio system 120.

[0042] The signal line unit 90 has a function as a path for transmitting audio signals and volume instruction information output from the in-car audio system 120 to the amplifier device 110, and a function for transmitting audio signals and information (volume instruction information or reflection information) to the output control unit 10. In a representative example, the information transmission lines 92A are multiple signal transmission lines that enable two-way communication, and have both the function of transmitting volume instruction information and the function of transmitting reflection information.

[0043] 1, when the amplifier device 110 receives volume instruction information from the in-car audio system 120, it outputs an audio signal at an output level according to the received volume instruction information and transmits reflection information to the information transmission line 92A. Specifically, the amplifier device 110 has a function of setting the volume, and amplifies the input audio signal to the volume of the currently set volume and outputs it to the speaker 140.

[0044] More specifically, the volume level Va in the in-vehicle audio system 120 can be set to N+1 levels from 0 to N. The value of N is, for example, 63. The in-vehicle audio system 120 increases or decreases the currently set volume level Va in response to an instruction from the operation device (not shown), and when the volume level Va is increased or decreased, the in-vehicle audio system 120 is capable of transmitting information instructing the amplifier device 110 to increase or decrease the volume as "volume instruction information."

[0045] Specifically, for example, when a current volume level Va is set in the in-vehicle audio system 120, the current volume level Va set in the in-vehicle audio system 120 is also stored and set in the amplifier device 110. For example, when the currently set volume level in the in-vehicle audio system 120 is "10," the volume level "10" set in the in-vehicle audio system 120 is also stored in the amplifier device 110 as a set value.

[0046] On the other hand, when the in-vehicle audio system 120 receives an instruction from the operating device to increase the current volume level Va by an increment ΔVa, the in-vehicle audio system 120 updates the volume level setting information so as to set the new volume level to Va+ΔVa, which is the value obtained by adding the volume level increment ΔVa to the current volume level Va, and transmits the increment ΔVa added during the update to the amplifier device 110. The amplifier device 110 then receives the increment ΔVa transmitted from the in-vehicle audio system 120 and updates the setting information so as to set the new volume level setting of the amplifier device 110 to the value (Va+ΔVa) obtained by adding the received increment ΔVa to the volume level Va that was set in the amplifier device 110 immediately before receiving the increment ΔVa. In this way, the volume level set in the in-vehicle audio system 120 is reflected in the volume level set in the amplifier device 110. The volume level increment ΔVa may be a positive value or a negative value. For example, if the current volume level Va setting in the in-car audio system 120 is "10," and an input operation is performed from the operation device to input a command to increase the volume level by "+2," the in-car audio system 120 updates the setting information to reflect the input operation and change the volume level to "12," and transmits the volume level increase amount "+2" added during the update to the amplifier device 110. The amplifier device then receives the transmitted volume level increase amount "+2," and updates the setting information so that the new volume level setting in the amplifier device 110 is "12," obtained by adding the received increase amount "+2" to the volume level "10" that was set in the amplifier device 110 immediately before the reception of the increase amount.

[0047] When an audio signal output from an in-car audio system 120 is input to the amplifier device 110, the amplifier device 110 operates to amplify the input audio signal at an amplification factor corresponding to the volume level Va currently set in the amplifier device 110 and output the amplified signal to the speaker 140.

[0048] In this way, the amplifier device 110 sets the volume level Va, and further operates to transmit information about the volume level Va currently set in the amplifier device 110 to the information transmission line 92A periodically or in response to the establishment of a predetermined condition. In this way, the "information about the volume level Va currently set in the amplifier device 110" transmitted from the amplifier device 110 to the information transmission line 92A is an example of reflection information. The transmission method of the reflection information from the amplifier device 110 may be broadcast transmission that can be transmitted to various devices, or individual transmission that can be transmitted to a specific device. In a typical example, for example, the reflection information is transmitted by broadcast transmission from the amplifier device 110, and the in-car audio system 120 and other devices can receive the reflection information.

[0049] 1-4. Operation of the output control unit 10 The control unit 12 of the output control unit 10 monitors the information communicated on the information transmission line 92A via the branch line 92B, and when the above-mentioned "reflection information" is transmitted from the amplifier device 110 to the information transmission line 92A, it receives the "reflection information" via the branch line 92B. The control unit 12 corresponds to an example of an "information receiving unit that receives reflection information."

[0050] The volume adjustment unit 14 is configured by, for example, an electronic volume, etc. The volume adjustment unit 14 has a function of setting the volume, and has a function of amplifying the audio signal given from the input interface 16 to the volume set therein and outputting it.

[0051] Meanwhile, the control unit 12 has a function of changing and adjusting the volume set in the volume adjustment unit 14. The control unit 12 operates to adjust the volume set in the volume adjustment unit 14 to a volume corresponding to a volume level specified by volume level information received from the information transmission line 92A. Specifically, the control unit 12 sets an amplification factor Ga according to the volume level Va specified by the volume level Va information most recently received from the information transmission line 92A, and operates the volume adjustment unit 14 at the amplification factor Ga thus set. The control unit 12 has a predetermined determination method, such as an arithmetic formula or table, for determining the amplification factor Ga. Once the volume level Va most recently received by the control unit 12 is specified, the amplification factor Ga corresponding to this volume level Va is determined using the arithmetic formula or the table. The arithmetic formula or the table is information for determining the amplification factor Ga based on the volume level Va such that the higher the volume level Va, the higher the set amplification factor Ga. In this way, the control unit 12 determines the amplification factor Ga based on the "volume level Va most recently received by the control unit 12" and the determination method, and stores the determined amplification factor Ga in the control unit 12 as setting information.

[0052] The volume adjustment unit 14 operates to amplify the audio signal provided from the input interface 16 by an amplification factor Ga set in the control unit 12. In other words, the volume adjustment unit 14 adjusts the amplification factor Ga so that the greater the volume level Va most recently received by the control unit 12, the greater the amplification factor Ga, and the smaller the volume level Va most recently received by the control unit 12, the smaller the amplification factor Ga. By adjusting the amplification factor Ga in this manner, the volume adjustment unit 14 adjusts the volume of the audio signal output from the volume adjustment unit 14. The audio signal output from the volume adjustment unit 14, i.e., the audio signal whose volume has been adjusted by the volume adjustment unit 14, is converted by the output interface 18 into a signal suitable for an external device (subwoofer 180 in FIG. 1 ) and output.

[0053] In the representative example described above, the input interface 16 and the volume adjustment unit 14 correspond to an example of an "audio signal receiving unit that receives an audio signal." The audio signal output from the output interface 18 corresponds to an example of an adjusted audio signal. The output control unit 10 outputs an adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume that corresponds to the reflection information received by the information receiving unit.

[0054] 1-5.Examples of effects In this way, the audio signal control device 1 receives volume instruction information or reflection information reflecting the volume instruction information transmitted between the in-vehicle audio system 120 and the amplifier device 110, and outputs an adjusted audio signal obtained by adjusting the volume of the audio signal to the volume corresponding to the volume instruction information or reflection information. Because of this configuration, the audio signal control device 1 can extract the audio signal output from the in-vehicle audio system 120, adjust the volume, and make good use of the audio signal.

[0055] In a system to which the audio signal control device 1 is applied, when the amplifier device 110 receives volume instruction information from the in-vehicle audio system 120, it outputs an audio signal at an output level corresponding to the received volume instruction information. Meanwhile, the audio signal control device 1 receives reflection information transmitted from the amplifier device 110 to the in-vehicle audio system 120 via an output volume instruction information receiving unit, and outputs an adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume corresponding to the reflection information. In other words, the audio signal control device 1 can receive information related to the output level actually output by the amplifier device 110, and then adjust the audio signal to a volume corresponding to the output level and output the audio signal. Therefore, the audio signal control device 1 can use an audio signal at a volume that more accurately corresponds to the volume actually adjusted by the amplifier device 110.

[0056] When an existing transmission line for transmitting audio signals and volume instruction information exists or can be installed between the in-vehicle audio system 120 and the amplifier device 110 as shown in FIG. 2, the audio signal control device 1 can be installed in place of or in addition to this existing transmission line. Specifically, as shown in FIG. 1, the audio signal control device 1 can be used in a configuration in which a first connector unit 93 is installed so that a first terminal unit 93A receives an audio signal output from the in-vehicle audio system 120 and a second terminal unit 93B receives volume instruction information output from the in-vehicle audio system 120, and a second connector unit 94 is installed so that the terminals are electrically connected to the amplifier device 110. When installed in this manner, the branch line 91B can transmit an audio signal transmitted through the audio signal transmission line 91A to the output control unit 10. Therefore, the output control unit 10 can use the audio signal transmitted to the amplifier device 110. Furthermore, the branch line 92B can transmit information transmitted through the information transmission line 92A to the output control unit 10. Therefore, the output control unit 10 can use the volume instruction information or the reflection information. In this way, the audio signal control device 1 can be installed in place of or in addition to an existing transmission line, and can extract the audio signal output from the in-vehicle audio system 120 and adjust the volume for optimal use.

[0057] Second Embodiment Fig. 3 conceptually shows an example in which an audio signal control device 201 according to the second embodiment is mounted on a vehicle 190. In the in-vehicle system Sy2 shown in Fig. 3, parts having the same configuration as those in the in-vehicle system Sy1 in Fig. 1 are assigned the same reference numerals as those in Fig. 1.

[0058] In the in-vehicle system Sy2 shown in FIG. 3, the in-vehicle audio system 120, the amplifier device 110, and the speaker 140 have the same configurations and functions as those in the in-vehicle system Sy1 of FIG.

[0059] An audio signal control device 201 according to the second embodiment includes a main body unit 202 and a signal line unit 280, and is applied to an in-vehicle system Sy2. The main body unit 202 includes a housing unit (not shown) and an output control unit 210, with most or all of the output control unit 210 housed within the housing unit. In the audio signal control device 201 shown in FIG. 3, the information transmission line 92A and the branch line 92B in the signal line unit 280 have the same configurations and functions as those in the in-vehicle system Sy1 of FIG. 1. The main body unit 202 differs from the main body unit 2 of the audio signal control device 1 of FIG. 1 in that a branch line 290 and an output interface 204 are provided, but otherwise has the same configuration and functions as the main body unit 2.

[0060] In the output control unit 210 of the audio signal control device 201 shown in Fig. 3, the control unit 12, the input interface 16, the volume adjustment unit 14, and the output interface 18 have the same configurations and functions as those in the in-vehicle system Sy1 of Fig. 1. Meanwhile, the output control unit 210 is provided with the above-mentioned branch line 290 and output interface 204. Furthermore, the audio signal control device 201 shown in Fig. 3 is provided with a first audio signal transmission line 291 and a second audio signal transmission line 292.

[0061] 3 also includes a first connector unit 93 having a terminal electrically connected to the in-vehicle audio system 120 and a second connector unit 94 having a terminal electrically connected to the amplifier device 110. Specifically, in the signal line unit 280, in addition to the information transmission line 92A and the branch line 92B, a first audio signal transmission line 291, a second audio signal transmission line 292, the first connector unit 93, and the second connector unit 94 are provided.

[0062] The first connector 93 is provided with a first terminal 93A that receives an audio signal output from the in-vehicle audio system 120 and a second terminal 93B that receives volume instruction information output from the in-vehicle audio system 120. An information transmission line 92A similar to that of the first embodiment is connected to the second terminal 93B. The information transmission line 92A corresponds to an example of a signal transmission line and is connected to the first connector 93 and the second connector 94. The information transmission line 92A has at least one of a function of transmitting volume instruction information from the second terminal 93B to the amplifier 110 via the second connector 94 and a function of transmitting reflection information transmitted from the amplifier 110. In the representative example of the second embodiment, as in the first embodiment, "reflection information" is transmitted from the amplifier 110 to the information transmission line 92A. The branch line 92B has the same configuration and function as in the first embodiment, branches off from the information transmission line 92A, and transmits information (mainly "reflection information") from the information transmission line 92A to the output control unit 210.

[0063] On the other hand, a first audio signal transmission line 291 for transmitting an audio signal from the first terminal unit 93A to the output control unit 210 is connected to the first terminal unit 93A. Therefore, the output control unit 210 receives an audio signal output from the in-vehicle audio system 120 via the first audio signal transmission line 291. The audio signal output from the in-vehicle audio system 120 and received by the input interface 16 is provided to the volume adjustment unit 14 as in the first embodiment, and the volume adjustment is performed in the volume adjustment unit 14 and the output interface 18 as in the first embodiment. On the other hand, the audio signal output from the input interface 16 is provided to the output interface 204 via a branch line 290. The output interface 204 is, for example, a differential amplifier. The audio signal output from the output interface 204 is transmitted to a second audio signal transmission line 292 and provided to the amplifier device 110. The second audio signal transmission line 292 is a transmission line for transmitting an audio signal from the output control unit 10 to the amplifier device 110 via the second connector unit 94, and the audio signal transmitted on the second audio signal transmission line 292 is input to the amplifier device 110 through the transmission unit 136A. Note that the above-mentioned output interface 204 is merely an example, and various functions such as an equalizer function and a gain adjustment function can be added.

[0064] In the audio signal control device 201 of FIG. 3 , if an existing transmission line for transmitting audio signals and volume instruction information exists or can be installed between the in-vehicle audio system 120 and the amplifier device 110 as shown in FIG. 2 , the audio signal control device 201 can be installed in place of or in addition to the existing transmission line. Specifically, as shown in FIG. 3 , the audio signal control device 201 can be used in a configuration in which a first connector unit 93 is installed so that a first terminal unit 93A receives an audio signal output from the in-vehicle audio system 120 and a second terminal unit 93B receives volume instruction information output from the in-vehicle audio system 120, and a second connector unit 94 is installed so that the terminals are electrically connected to the amplifier device 110. When installed in this manner, the first audio signal transmission line 291 can transmit an audio signal to the output control unit 210. Therefore, the output control unit 210 can use the audio signal to be transmitted to the amplifier device 110. Furthermore, since the audio signal control device 201 has a branch line 290 and a second audio signal transmission line 292, it can transmit an audio signal to the amplifier device 110 via the second connector unit 94. Therefore, the amplifier device 110 can also use the audio signal. In this audio signal control device 201, the branch line 92B can transmit information (mainly "reflection information") transmitted over the information transmission line 92A to the output control unit 210. Therefore, the output control unit 210 can use the "reflection information." When the output control unit 210 uses the "reflection information," it can operate in the same manner as the output control unit 10 described above in "1-4. Operation of the Output Control Unit 10" to output an adjusted audio signal. With this configuration, the audio signal control device 201 can be installed in place of or in addition to an existing transmission line such as that shown in FIG. 2, extract the audio signal output from the in-vehicle audio system 120, adjust the volume, and use it effectively.

[0065] Third Embodiment The following description relates to the audio signal control device 1 of the third embodiment. The electrical configuration of the audio signal control device 1 of the third embodiment and the in-vehicle system Sy1 to which this audio signal control device 1 is applied is the same as that shown in Figure 1, and therefore Figure 1 will be referenced as appropriate in the following description. The in-vehicle system Sy1 to which the audio signal control device 1 of the third embodiment is applied has the same configuration and functions as those described above in "1-1. Overview of in-vehicle system Sy1." The audio signal control device 1 of the third embodiment also has the same configuration and functions as those described above in "1-2. Basic configuration of audio signal control device 1," and its installation method in the in-vehicle system Sy1 is also the same as that of the audio signal control device 1 of the first embodiment shown in Figure 1.

[0066] 3-1. Functions related to volume adjustment in the amplifier device 110 In the in-vehicle system Sy1 to which the audio signal control device 1 of the third embodiment is applied, the in-vehicle audio system 120 is also configured to be able to set the volume level Va to N+1 levels from 0 to N. The value of N is, for example, 63. The in-vehicle audio system 120 updates the setting by increasing or decreasing the currently set volume level Va in response to an instruction from the operation device (not shown), and after updating, transmits "volume level information" of the currently set volume to the amplifier device 110. The "volume level information" is information that identifies the volume level Va and corresponds to an example of "volume instruction information."

[0067] In this embodiment, the signal line unit 90 functions as a path for transmitting audio signals and volume instruction information output from the in-car audio system 120 to the amplifier device 110, and also functions to transmit the volume instruction information to the output control unit 10. In a representative example, the information transmission lines 92A are multiple signal transmission lines that enable two-way communication, and have the function of transmitting at least the volume instruction information.

[0068] When the amplifier device 110 receives volume level information from the in-vehicle audio system 120, it operates to convert the received audio signal into an audio output signal amplified by an amplification factor corresponding to the volume level Va specified by the "volume level information" and output the amplified audio signal. More specifically, when the in-vehicle audio system 120 changes the volume level Va set in the in-vehicle audio system 120 in response to an instruction from the operation device (not shown), the in-vehicle audio system 120 transmits information instructing the current volume level Va after the setting change to the amplifier device 110 as "volume instruction information." For example, when an input instructing to set the volume level to "15" is made via the operation device, the in-vehicle audio system 120 sets the volume level to "15" and transmits information instructing the volume level to "15" to the amplifier device 110 as "volume instruction information."

[0069] The amplifier device 110 has a function of setting a volume level, and amplifies an externally input audio signal to a volume corresponding to the volume level currently set in the amplifier device 110 and outputs the amplified signal to the speaker 140. Specifically, when the current volume level in the in-vehicle audio system 120 is set to Va, the amplifier device 110 also stores and sets the current volume level Va set in the in-vehicle audio system 120 to reflect this. For example, when the volume level in the in-vehicle audio system 120 is changed to "10," the in-vehicle audio system 120 transmits "volume level information" specifying the currently set volume level value "10" to the amplifier device 110, and when the amplifier device 110 receives this "volume level information," it updates the volume level setting in the amplifier device 110 to "10."

[0070] In this embodiment, as in the first embodiment, the amplifier device 110 operates to convert the input audio signal into an audio output signal amplified by an amplification factor corresponding to the volume level Va currently set in the amplifier device 110 and output the signal to the speaker 140.

[0071] The amplifier device 110 may be configured to transmit the same reflection information as in the first embodiment to the information transmission line 92A. In this case, the reflection information may include "volume level information," equalizer information, information specifying the balance between the left and right volumes, etc.

[0072] 3-2. Operation of the output control unit 10 The output control unit 10 receives volume level information transmitted between the in-car audio system 120 and the amplifier device 110, and operates to output an adjusted audio signal that has been adjusted to a volume corresponding to the received "volume level information" from the audio signal input to it.

[0073] The control unit 12 monitors information communicated over the information transmission line 92A via the branch line 92B, and when the above-mentioned "volume instruction information" is transmitted, acquires the "volume instruction information" via the branch line 92B. Specifically, when the in-vehicle audio system 120 transmits information specifying the volume level Va currently set in the in-vehicle audio system 120 to the amplifier device 110 via the information transmission line 92A as "volume instruction information," the control unit 12 can operate to receive this "information specifying the volume level Va."

[0074] In the audio signal control device 1 of this embodiment, the volume adjustment unit 14 also has a function of setting the volume, and a function of amplifying and outputting the audio signal provided from the input interface 16 to the volume set therein. The control unit 12 has a function of changing and adjusting the volume set in the volume adjustment unit 14. The control unit 12 operates to adjust the volume set in the volume adjustment unit 14 to a volume corresponding to the volume level specified by the "volume level information" received from the information transmission line 92A, and adjusts the volume set so that the larger the volume level value, the higher the set volume, and the lower the volume level value, the lower the set volume.

[0075] Specifically, the control unit 12 has a function of receiving the volume level Va, as in the first embodiment, and sets an amplification factor according to the volume level Va specified by the volume level Va information most recently received from the information transmission line 92A, and operates the volume adjustment unit 14 at the amplification factor thus set. The method of determining the amplification factor based on the received volume level Va is the same as the determination method adopted by the control unit 12 in the first embodiment. The control unit 12 stores the amplification factor determined based on the "volume level Va most recently received by the control unit 12" as setting information in the control unit 12. The volume adjustment unit 14 amplifies and outputs an audio signal provided from the input interface 16 by the amplification factor set in the control unit 12. The audio signal amplified and output by the volume adjustment unit 14, i.e., the audio signal whose volume has been adjusted by the volume adjustment unit 14, is converted by the output interface 18 into a signal suitable for an external device (a subwoofer 180 in FIG. 1 ) and output.

[0076] In this embodiment, the input interface 16 and the volume adjustment unit 14 correspond to an example of an “audio signal receiving unit that receives an audio signal.” The audio signal output from the output interface 18 corresponds to an example of an adjusted audio signal.

[0077] <Fourth embodiment> The following description relates to the audio signal control device 1 of the fourth embodiment. The electrical configuration of the audio signal control device 1 of the fourth embodiment and the in-vehicle system Sy1 to which this audio signal control device 1 is applied is the same as that shown in FIG. 1, and therefore FIG. 1 will be referenced as appropriate in the following description. The in-vehicle system Sy1 to which the audio signal control device 1 of the fourth embodiment is applied has the same configuration and functions as those described above in "1-1. Overview of in-vehicle system Sy1." The audio signal control device 1 of the fourth embodiment also has the same configuration and functions as those described above in "1-2. Basic configuration of audio signal control device 1," and the installation method in the in-vehicle system Sy1 is also the same as that of the audio signal control device 1 of the first embodiment shown in FIG. 1.

[0078] The in-vehicle system Sy1 to which the audio signal control device 1 of the fourth embodiment is applied includes all of the configurations and functions described above in "1-3. Functions related to volume adjustment in the amplifier device 110," and further has the following configurations and functions.

[0079] 4-1.Additional operation of amplifier device In the in-vehicle system Sy1 to which the audio signal control device 1 of the fourth embodiment is applied, the amplifier device 110 has an equalizer function. Specifically, the amplifier device 110 is configured to be able to set the amount of amplification or attenuation for each band. The device for instructing this setting may be the in-vehicle audio system 120, another device capable of communicating with the amplifier device 110, or the amplifier device 110 itself. For example, if the in-vehicle audio system 120 has a function for instructing the "amount of amplification or attenuation for each band," when information specifying the "amount of amplification or attenuation for each band" is input through an operation device (not shown), the in-vehicle audio system 120 transmits information identifying the "amount of amplification or attenuation for each band" specified by the input information to the amplifier device 110. In this case, the operation device may be any device that can input information specifying the "amount of amplification or attenuation for each band," and may be an operation unit provided in the in-vehicle audio system 120, an audio operation unit, a rear seat operation switch, a steering switch, or the like, provided separately from the in-vehicle audio system 120. When the amplifier device 110 receives information specifying the "amount of amplification or attenuation for each band" from the car audio system 120, it can operate to adjust the "amount of amplification or attenuation for each band" specified by the information.

[0080] In the following, an example will be given in which the audio band is divided into a "treble band," a "midrange band," and a "bass band" in the amplifier device 110. In this example, the treble band is a band in which the sound frequency falls in a first range. The midrange band is a band in which the sound frequency falls in a second range that is lower than the first range. The bass band is a band in which the sound frequency falls in a third range that is lower than the second range. In this representative example, for example, the in-car audio system 120 has a function of instructing the "amount of amplification or attenuation for each band." Then, when an input operation is performed on the operating device to instruct the amount of amplification or attenuation for the treble band (a band in which the sound frequency falls in the first range), the in-car audio system 120 transmits the "amount of amplification or attenuation for the treble band" instructed by the input operation to the amplifier device 110. Similarly, when an input operation is performed on the operating device to specify the amount of amplification or attenuation of the mid-range (a band of sound frequencies in a second range), the in-car audio system 120 operates to transmit the "amount of amplification or attenuation of the mid-range" specified by the input operation to the amplifier device 110, and when an input operation is performed to specify the amount of amplification or attenuation of the bass band (a band of sound frequencies in a third range), the in-car audio system 120 operates to transmit the "amount of amplification or attenuation of the bass band" specified by the input operation to the amplifier device 110.

[0081] The amplifier device 110 has a function of setting the amount of amplification or attenuation for each of the "treble band," "midrange band," and "bass band." For example, in a default state where no increase or decrease instructions are given from the in-car audio system 120, the amount of amplification or attenuation for each of the "treble band," "midrange band," and "bass band" is set to a reference value (e.g., 0). When information specifying the amount of amplification or attenuation for each of the "treble band," "midrange band," and "bass band" is transmitted from the in-car audio system 120, the amplifier device 110 receives this information and stores the amount of amplification or attenuation for the "treble band," "midrange band," and "bass band" specified by the information as the set value for the amount of amplification or attenuation for each band. The amplifier device 110 is provided with an audio waveform adjustment unit and an amplification unit, and the audio waveform generation unit generates an adjusted audio waveform by adjusting the audio signal input to the amplifier device 110 to a waveform that reflects the amount of amplification or attenuation for the "treble band," "midrange band," and "bass band" set as described above. For example, when the amounts of amplification or attenuation of the "treble band," "midrange band," and "bass band" most recently instructed by the in-car audio system 120 are EQ1, EQ2, and EQ3, respectively, the amplifier device 110 stores these EQ1, EQ2, and EQ3 as the set values ​​of the amounts of amplification or attenuation of each band. Note that in this example, EQ1, EQ2, and EQ3 are values ​​equal to or greater than 0, and when EQ1, EQ2, and EQ3 are greater than 1, they are amounts of amplification, and when EQ1, EQ2, and EQ3 are less than 1, they are amounts of attenuation.

[0082] The amplifier unit provided in the amplifier device 110 amplifies the adjusted audio waveform (a waveform generated by reflecting the amount of amplification or attenuation of the "treble band," "mid-range band," and "bass band" with respect to the input audio waveform) generated by the audio waveform adjustment unit with a set amplification factor and outputs the amplified waveform. The method of determining the amplification factor used in the amplifier unit is the same as in the first embodiment.

[0083] In this example, too, volume instruction information is provided from the in-vehicle audio system 120 to the amplifier device 110 in a manner similar to that of the first embodiment, and the amplifier device 110 sets the volume level Va so as to reflect the volume level Va set in the in-vehicle audio system 120. For example, if the amplifier device 110 has set the volume level to Va at a certain time and receives volume instruction information from the in-vehicle audio system 120 instructing it to increase the volume level by ΔVa, the amplifier device 110 updates the setting so that the received information instructing it to increase or decrease (ΔVa information) is added to the volume level Va currently set in the amplifier device 110, resulting in a new updated volume level Va (Va+ΔVa). In either case, the amplifier device 110 determines an amplification factor corresponding to the currently set volume level in a manner similar to that of the amplifier device 110 in the first embodiment. The amplifier unit amplifies the adjusted audio waveform generated by the audio waveform adjustment unit by the determined amplification factor, and outputs the resulting audio output signal to the speaker 140.

[0084] In addition to these operations, the amplifier device 110 also operates to transmit, periodically or in response to the satisfaction of a predetermined condition, reflection information including volume level information specifying the volume level Va currently set in the amplifier device 110 and information about the increase / decrease amount for a predetermined band to the information transmission line 92A. In this case, the "volume level information" includes, for example, the value of the volume level Va and information indicating that this value is the volume level currently set in the amplifier device 110. The "information about the increase / decrease amount for a predetermined band" includes, for example, the value of the increase amount EQ3 for the bass band set in the amplifier device 110 and information indicating that this value of EQ3 is the "bass band increase amount" currently set in the amplifier device 110. In this example, the predetermined band is the bass band, but the predetermined band may also be the treble band or the mid-range band. In a typical example, the values ​​of EQ1, EQ2, and EQ3 are included in the reflection information.

[0085] 4-2. Operation of the output control unit 10 The control unit 12 monitors the information communicated through the information transmission line 92A, and when the above-mentioned "reflection information" is transmitted, it receives the "reflection information." The control unit 12 corresponds to an example of an "information receiving unit that receives reflection information."

[0086] As described above, the reflection information acquired by the control unit 12 includes, as volume level information, information specifying the volume level Va, and, as information on the amount of increase or decrease in a predetermined band, information specifying the value of EQ3, which is the amount of amplification or attenuation in the bass band. The control unit 12 then operates to adjust the volume setting of the volume adjustment unit 14 to a volume corresponding to the volume level Va specified by the volume level information received from the information transmission line 92A. Specifically, the control unit 12 determines the amplification factor Ga' used by the volume adjustment unit 14 based on the amplification factor Ga specified by the volume level Va and the amplification factor adjustment value G3 specified by the value of EQ3. The method by which the control unit 12 determines the amplification factor Ga based on the volume level Va is the same as the method by which the control unit 12 determines the amplification factor Ga based on the volume level Va in the first embodiment. The control unit 12 also has a predetermined determination method, such as an arithmetic expression or a table, for determining the amplification factor adjustment value G3. Once the control unit 12 has identified the value of EQ3 most recently received, the gain adjustment value G3 corresponding to this EQ3 value is determined using the above-mentioned arithmetic expression or the above-mentioned table. The above-mentioned arithmetic expression or the above-mentioned table is information for determining the gain adjustment value G3 based on EQ3 such that the larger the value of EQ3, the larger the gain adjustment value G3 to be set. The control unit 12 determines the gain Ga' using the equation Ga' = Ga × G3 based on the gain Ga and gain adjustment value G3 obtained in this way. The determined gain Ga' is then stored in the control unit 12 as setting information. Note that the bands corresponding to the EQ1 and EQ2 values ​​are regions that are cut when outputting from the subwoofer 180, so the gain Ga' is not reflected in the gain Ga'.

[0087] The volume adjustment unit 14 operates to amplify the audio signal provided from the input interface 16 by the gain Ga' set in the control unit 12. In this example, too, the volume adjustment unit 14 adjusts the gain Ga' so that the greater the volume level Va most recently received by the control unit 12, the greater the gain Ga', and the smaller the volume level Va most recently received by the control unit 12, the smaller the gain Ga'. The volume adjustment unit 14 also adjusts the gain Ga' so that the greater the value EQ3 of the amount of amplification or attenuation of the bass band, the greater the gain Ga', and the smaller the value EQ3, the smaller the gain Ga'. By adjusting the gain Ga' in this way, the volume adjustment unit 14 adjusts the volume of the audio signal output from the volume adjustment unit 14. The audio signal adjusted to the set volume by the volume adjustment unit 14 is converted by the output interface 18 into a signal suitable for an external device (subwoofer 180 in FIG. 1 ) and output.

[0088] In this way, the output control unit 10 operates to output an adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume corresponding to the volume level information received by the information receiving unit, and more specifically, outputs an adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume corresponding to the reflection information received by the information receiving unit. In the fourth embodiment, the volume adjustment unit 14 also has the function of amplifying the audio signal provided from the input interface 16 by a set amplification factor and outputting the amplified audio signal. Meanwhile, the control unit 12 changes and adjusts the amplification factor used by the volume adjustment unit 14, thereby changing and adjusting the volume of the audio signal output from the volume adjustment unit 14.

[0089] In the fourth embodiment, the input interface 16 and the volume adjustment unit 14 correspond to an example of an “audio signal receiving unit that receives an audio signal.” The audio signal output from the output interface 18 corresponds to an example of an adjusted audio signal.

[0090] Here, the effect will be explained with reference to waveforms and the like. FIG. 4(A) is a waveform diagram of an example of an audio signal output from the in-car audio system 120. FIG. 4(B) is a waveform diagram in which the bass band of the audio signal of FIG. 4(A) is amplified by 6 dB using an equalizer. FIG. 5(A) is a waveform diagram in which the treble band of the audio signal of FIG. 4(A) is amplified by 6 dB using an equalizer. FIG. 5(B) is a waveform diagram in which the audio signal of FIG. 4(A) is amplified by a gain of 2 times to increase the volume. In this example, when the audio signal of the waveform of FIG. 4(A) is output from the subwoofer 180, the waveform becomes as shown in FIG. 6(A). On the other hand, when the waveform of FIG. 5(A) is output from the subwoofer 180, the waveform becomes as shown in FIG. 6(A). In other words, no matter how the treble band is adjusted, there is little effect when it is output from the subwoofer 180.

[0091] On the other hand, when a signal with a waveform like that of FIG. 4(B) is generated from a signal with a waveform like that of FIG. 4(A) and this signal is output from the subwoofer 180, the waveform becomes as shown in FIG. 6(B). However, generating a waveform like that of FIG. 4(B) requires a DSP or complex adjustments using filter circuits for each band. On the other hand, when the signal of FIG. 5(B) is output from the subwoofer 180, the waveform becomes as shown in FIG. 6(B). In this embodiment, instead of using a signal after complex band-specific adjustments as shown in FIG. 4(B), the idea of ​​generating an audio signal obtained by adjusting the amplification amount as shown in FIG. 5(B) is utilized, making it possible to generate a desired signal without using complex circuits or processing. Furthermore, if a waveform like that of FIG. 4(B) is generated from a waveform like that of FIG. 4(A) using an equalizer or the like, there is a concern that waveform processing, etc., may degrade the sound quality when adjusting the bass band. However, generating a signal like that of FIG. 5(B) alleviates this problem.

[0092] As described above, when an audio signal is input, the audio signal control device 1 of this embodiment does not perform sound quality adjustment on the audio signal (for example, complex waveform processing to adjust the amount of increase or decrease for each band), but instead assumes a filter in the subwoofer 180 and achieves the same effect as sound quality adjustment that adjusts the amount of increase or decrease in the bass band by adjusting only the amplification factor (volume adjustment).

[0093] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, any combination of features of the above-described or following embodiments is possible within a range that does not contradict. Furthermore, any feature of the above-described or following embodiments may be omitted unless explicitly stated as essential. Furthermore, the above-described embodiments may be modified as follows.

[0094] In an in-vehicle audio system 120 of an in-vehicle system to which the audio signal control device of the first, second, third, or fourth embodiment is applied, the in-vehicle audio system 120 can receive reflection information transmitted from the amplifier device 110. In this case, when the in-vehicle audio system 120 receives the reflection information, if the volume level set in the in-vehicle audio system 120 at the time of reception differs from the volume level specified in the reflection information (the volume level set in the amplifier device 110), the in-vehicle audio system 120 can operate to update the volume level set in the in-vehicle audio system 120 to the "volume level specified in the reflection information."

[0095] In the representative example of the above-described embodiment, the in-vehicle audio system 120 is configured as a single device (e.g., a navigation device) and has both the function of outputting the above-described audio signal and the function of outputting the above-described volume signal, but the in-vehicle audio system 120 may be configured by a plurality of devices. For example, in the in-vehicle audio system 120, the device that outputs the audio signal and the device that outputs the volume signal may be separate devices.

[0096] In the above-described embodiment, the volume adjustment unit 14 and the output interface 18 are provided separately, but the function of the output interface 18 may be included in the volume adjustment unit 14. In this case, the output interface 18 can be omitted.

[0097] In the above-described embodiment, in the volume adjustment unit 14, the adjustment of the amplification factor based on Ga and the adjustment of the amplification factor based on the amplification factor adjustment value G3 are adjusted by a single adjustment unit to calculate the amplification factor Ga', but the adjustment unit that adjusts the amplification factor based on Ga and the adjustment unit that adjusts based on the amplification factor adjustment value G3 may be configured separately, and these may function as a volume adjustment unit as a whole.

[0098] The audio signal control device 1 of the fourth embodiment described above is an example in which a part of the audio signal control device 1 of the first embodiment is modified, but it may also be an example in which a part of the audio signal control device 201 of the second embodiment or a part of the audio signal control device 201 of the third embodiment is modified. Specifically, in the in-vehicle system Sy2 of FIG. 3 to which the audio signal control device 201 of the second embodiment is applied, the amplifier device 110 may perform the operation described in "4-1. Additional Operation of Amplifier Device" above. In this example, the output control unit 210 of the audio signal control device 201 may perform the operation described in "4-2. Operation of Output Control Unit 10" above. Alternatively, in the in-vehicle system Sy2 of FIG. 1 to which the audio signal control device 1 of the third embodiment is applied, the amplifier device 110 may perform the operation described in "4-1. Additional Operation of Amplifier Device" above. In this example, the output control unit 10 of the audio signal control device 1 of the third embodiment may perform the operation described in "4-2. Operation of Output Control Unit 10" above.

[0099] In the above-described embodiment, the control unit 12 acquires information transmitted through the information transmission line 92A via the branch line 92B, but this is not limiting. For example, instead of the information transmission line 92 and the branch line 92B in the configurations of FIGS. 1 and 3 , the second terminal unit 93B and the main body unit 2 or the main body unit 202 may be connected via a first information transmission line, and the terminal unit 94B and the main body unit 2 or the main body unit 202 may be connected via a second information transmission line, so that information is transmitted between the in-car audio system 120 and the amplifier device 110 via the main body unit 2 or the main body unit 202. In this case, the control unit 12 may acquire the information as it passes through the main body unit 2 or the main body unit 202.

[0100] The method of transmitting volume instruction information between the in-vehicle audio system 120 and the amplifier device 110 is not limited to the electrical transmission method described in the above embodiment, but may be transmission via an optical fiber cable, Wi-Fi (registered trademark) method, or other wireless communication method.

[0101] When a volume level is set in the amplifier device 110, if the amplifier device 110 has a function of changing the currently set volume level to a new volume level in accordance with a predetermined change condition when the change condition is met, the amplifier device 110 may transmit information specifying such a new volume level as the reflection information. Even in such a case, the audio signal control device 1 and the audio signal control device 201 can adjust the audio signal in the same manner as in the above-described embodiment by receiving the reflection information.

[0102] In the above-described embodiment, an example is shown in which volume instruction information is transmitted from the in-vehicle audio system 120 to the amplifier device 110, but the present invention is not limited to this example. If an in-vehicle device other than the in-vehicle audio system 120 is capable of operating to instruct an increase or decrease in the volume level and is configured such that volume instruction information can be transmitted from the other in-vehicle device to the amplifier device 110 or other devices, the amplifier device 110 may receive the volume instruction information transmitted from the other in-vehicle device and generate an audio output signal based on this volume instruction information in the same manner as in the above-described embodiment. In this case, the other in-vehicle device may be any device capable of instructing an increase or decrease in the volume level, such as an audio operation unit provided separately from the in-vehicle audio system 120, a rear seat operation switch, or a steering switch.

[0103] In a representative example of the fourth embodiment, the amplifier device 110 sets the amount of amplification or attenuation for each band in response to an instruction from the in-vehicle audio system 120, but is not limited to this example. Examples of a device that provides the amplifier device 110 with information instructing the amount of amplification or attenuation for each band include an audio operating unit provided separately from the in-vehicle audio system 120 and a rear seat operating switch.

[0104] The audio signal control device of the above-described embodiment is assumed to be applied to an in-vehicle system in which the volume of the audio output signal output from the amplifier device 110 is reduced as the volume level set in the amplifier device 110 or the in-vehicle audio system 120 is reduced, and the volume adjustment unit 14 is also set to reduce the set volume as the volume level value received by the control unit 12 is reduced, but is not limited to this example. When the audio signal control device is applied to an in-vehicle system in which the volume of the audio output signal output from the amplifier device 110 is increased as the volume level value set in the amplifier device 110 or the in-vehicle audio system 120 is reduced, the volume adjustment unit 14 may be set to increase the set volume as the volume level value received by the control unit 12 is reduced.

[0105] In the above-described embodiment, the audio signal transmission line and the information transmission line are configured separately, but audio signals, volume instruction information, reflection information, and other information may be transmitted via a common transmission line.

[0106] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is intended to include all modifications within the scope indicated by the claims or the scope equivalent to the claims. [Explanation of symbols]

[0107] 1,201: Audio signal control device 10,210: Output control section 12: Control unit (information receiving unit) 14: Volume control section 16: Input interface 18: Output interface 90: Signal line section 91A: Audio signal transmission line (signal transmission line) 91B: Branch line (first branch line) 92A: Information transmission line (signal transmission line) 92B: Branch line (second branch line) 93: First connector part 93A: 1st terminal part 93B: 2nd terminal part 94: Second connector part 94A: Terminal part 94B:Terminal section 110: Amplifier equipment 114: Connection part 120: Car audio system 122: Connection part 130: Signal transmission section 132: Connector part 134: Connector part 136: Signal line section 136A: Transmission section 136B: Transmission section 140: Speaker 180: Subwoofer 190: Vehicle 291: First audio signal transmission line 292: Second audio signal transmission line Sy1, Sy2: In-vehicle systems

Claims

1. An audio signal control device applied to an in-vehicle system, comprising: an in-vehicle audio system that outputs an audio signal; the in-vehicle audio system or another in-vehicle device that transmits volume instruction information; and an amplifier device that, when acquiring the audio signal and the volume instruction information, converts the audio signal into an audio output signal based on a volume level that reflects the volume instruction information, and outputs the audio output signal, wherein the amplifier device is provided outside the in-vehicle audio system, an output control unit that receives the audio signal output from the in-vehicle audio system and outputs an adjusted audio signal obtained by adjusting the audio signal; an information transmission line that is detachably provided outside the in-vehicle audio system and the amplifier device and that transmits information transmitted from the amplifier device; a branch line branching from the information transmission line outside the amplifier device; and the volume instruction information is information instructing an increase or decrease in the volume level, When the amplifier device receives the information instructing the increase or decrease from the in-vehicle audio system or the other in-vehicle device, the amplifier device operates to reflect the received information instructing the increase or decrease in the volume level set in the amplifier device to set a new volume level, and when the amplifier device receives the audio signal in a state where the volume level has been set to the new volume level, the amplifier device operates to adjust the audio signal to the new volume level and output the audio output signal, and further operates to transmit reflection information including volume level information specifying the volume level currently set in the amplifier device, the information transmission line forms a path for transmitting the volume instruction information to the amplifier device, and a path for transmitting the reflection information transmitted from the amplifier device to an outside of the amplifier device; the branch line forms a path for transmitting the reflection information transmitted in the information transmission line to the output control unit; The output control unit has an audio signal receiving unit that receives the audio signal and an information receiving unit that receives the reflection information transmitted by the branch line, and outputs the adjusted audio signal obtained by adjusting the audio signal received by the audio signal receiving unit to a volume corresponding to the volume level information received by the information receiving unit. Audio signal control device.

2. the amplifier device sets an amount of amplification or an amount of attenuation for each band in response to an external instruction, and when the audio signal is input and the volume instruction information is received, outputs the audio output signal reflecting the amount of amplification or the amount of attenuation determined by the setting for each band and a volume level based on the volume instruction information; the amplifier device transmits the reflection information including information on the volume level and information on the amount of amplification or attenuation of a predetermined band determined by the setting; The output control unit adjusts the audio signal received by the audio signal receiving unit to a sound corresponding to the volume level information and the amount of amplification or attenuation of the predetermined band received by the information receiving unit, and outputs the adjusted audio signal.

2. The audio signal control device according to claim 1.

3. a first connector portion having a terminal connected to the in-vehicle audio system; a second connector portion having a terminal connected to the amplifier device; one or more signal transmission lines connected to the first connector portion and the second connector portion; and the first connector portion includes a first terminal portion that receives the audio signal output from the in-vehicle audio system and a second terminal portion that receives the volume instruction information transmitted from the in-vehicle audio system, the one or more signal transmission lines include an audio signal transmission line for transmitting the audio signal from the first terminal unit to the amplifier device via the second connector unit, and an information transmission line having at least one of a function of transmitting the volume instruction information from the second terminal unit to the amplifier device via the second connector unit and a function of transmitting the reflection information transmitted from the amplifier device, a first branch line branching from the audio signal transmission line; a second branch line that branches off from the information transmission line and is the branch line; the first branch line transmits the audio signal transmitted by the audio signal transmission line to the output control unit; The second branch line transmits the volume instruction information or the reflection information transmitted by the information transmission line to the output control unit.

3. The audio signal control device according to claim 1 or 2.

4. a first connector portion having a terminal connected to the in-vehicle audio system; a second connector portion having a terminal connected to the amplifier device; a signal transmission line connected to the first connector portion and the second connector portion; and the first connector portion includes a first terminal portion that receives the audio signal output from the in-vehicle audio system and a second terminal portion that receives the volume instruction information transmitted from the in-vehicle audio system, a first audio signal transmission line for transmitting the audio signal from the first terminal unit to the output control unit; a second audio signal transmission line for transmitting the audio signal from the output control unit to the amplifier device via the second connector unit; will be established 3. The audio signal control device according to claim 1 or 2.

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