Signal processing device

Abstract

A signal processing apparatus includes a controller configured to: (i) acquire a sound source signal for reproducing sound in a vehicle; (ii) acquiring seat information indicating a state of a seat in the vehicle; (iii) determining parameters for reproduction based on the seat information; and (iv) generating a sound signal for outputting the sound from a plurality of speakers disposed in the vehicle based on the sound source signal and the parameter. Corresponding methods and systems are also presented.

Description

Technical Field

[0001] The invention relates to a signal processing device, a signal processing method and a sound system. Background Art

[0002] In the case of a sound system that reproduces music stored in a medium such as a CD, DVD, etc., for example, in a sound room environment, a left speaker and a right speaker are provided separately from each other, and the sound system causes the left speaker and the right speaker to output sounds on the left channel and the right channel, respectively. When a user (listener) listens to the sound at a listening point, the user perceives the direction and position of the sound source through both ears in order to listen to realistic music. In this case, it is assumed that the listening point is, for example, at a predetermined distance and is equidistant from each speaker, and the predetermined distance depends on the distance between the two speakers (for example, 1 to 1.2 times the distance between the two speakers).

[0003] On the other hand, in a sound system to be installed in a vehicle, since a user sits in the vehicle and receives sound, the position of each seat becomes a listening point. In this case, for example, the driving seat of a right-hand drive vehicle is longer from the left speaker than from the right speaker, and is shorter from the right speaker than from the position between the left and right speakers. Therefore, the driving seat of the right-hand drive vehicle deviates from the ideal listening point. Therefore, a sound system to be installed in a vehicle may adopt a technology that corrects the difference in distance from each speaker by adjusting the time alignment of the sound to be output from each speaker, so as to achieve highly realistic sound reproduction.

[0004] The vehicle-mounted sound system disclosed in the published Japanese Unexamined Patent Application No. 2006-324712 includes: a sound processor that performs sound correction processing on a sound signal; a seat controller that sends a control signal to the sound processor; and a main controller that acquires the overall output state of a plurality of seat speakers provided in a vehicle compartment as output information. The seat controller receives the output information from the main controller and sends a control signal corresponding to the output information to the sound processor. The sound processor includes a plurality of sound correction filters corresponding to the output information, and performs a sound correction process of the sound signal by extracting an optimal sound correction filter based on the control signal. Therefore, in the vehicle-mounted sound system according to Patent Document 1, the sound environment in a specific seat is optimized regardless of the sound output state in other seats.

[0005] Published Japanese unexamined patent application No. 2019-161394 discloses a call module that reads parameters corresponding to the model of the vehicle to which the call module is attached from a table and automatically adjusts the sound parameters of a microphone and a speaker according to the read parameters, in which table the distance between the call module and the occupant, the installation angle of the speaker, and the parameters of the volume or effect are stored for each vehicle model.

[0006] In this system in which sound parameters are adjusted depending on the distance between each speaker and a seat provided in a vehicle, when a user changes the state of a seat (such as the position of a seat or the angle of a seat back) from a predetermined state, the positional relationship between a speaker provided at a position other than the seat and the user sitting in the seat changes. Therefore, there is a problem that time alignment is destroyed and sound interference is caused, which results in a loss of sound quality. Summary of the invention

[0007] According to one aspect of the present invention, a signal processing device includes a controller, wherein the controller is configured to:

[0008] (i) obtaining a sound source signal for reproducing sound in a vehicle;

[0009] (ii) acquiring seat information indicating a state of a seat in a vehicle;

[0010] (iii) determining parameters for reproduction based on the seating information; and

[0011] (iv) generating a sound signal for outputting the sound from a plurality of speakers provided in the vehicle based on the sound source signal and the parameter.

[0012] An object of the present invention is to provide a technique for reproducing sound by using appropriate sound parameters according to the state of a seat when reproducing sound in a vehicle.

[0013] These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 shows a schematic configuration of a sound system installed in a vehicle;

[0015] Figure 2 schematically shows the arrangement of speaker units included in a vehicle;

[0016] Figure 3 It is the functional block diagram of the head unit;

[0017] Figure 4The positional relationship between a user sitting in a seat and the seat is shown;

[0018] Figure 5A A diagram showing the positional relationship between the angle of a seat back and the position where a sound image is located;

[0019] Figure 5B A diagram showing the positional relationship between the angle of a seat back and the position where a sound image is located;

[0020] Figure 6 This is a diagram of the configuration of the sound system including the head unit;

[0021] Figure 7 is a flowchart of a signal processing method executed by a controller based on a signal processing program according to the embodiment;

[0022] Figure 8 shows the configuration of a head unit according to a second embodiment; and

[0023] Fig. 9 The flowchart of the signal processing method executed by the head unit according to the second embodiment is shown. DETAILED DESCRIPTION

[0024] Embodiments of the signal processing device, signal processing method, and sound system disclosed in the present application will be described below with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

[0025] <First Embodiment>

[0026] Figure 1 1 shows a schematic configuration of a sound system 100 installed in a vehicle 1. Figure 1 As shown, the sound system 100 includes a head unit 10 , a speaker unit 40 , and an ECU 50 .

[0027] The head unit 10 uses a storage medium (such as a CD, a DVD, or a semiconductor memory) as a sound source, reads the content stored in the storage medium, reproduces a sound signal, and outputs sound from a plurality of speaker units 40. In the sound system according to the embodiment, each of the plurality of speaker units 40 (hereinafter, also referred to as a headrest speaker HS) is embedded in the headrest 20H of each seat 20 in the vehicle 1, and sound is mainly output from the headrest speaker HS to a user sitting in each seat 20. In this case, although the headrest speaker HS is located behind the user, sound control can be performed using a head-related transfer function (HRTF) to position a sound image in front of the user. A specific control method will be described later.

[0028] The sound source that provides content to the head unit 10 is not limited to a storage medium, and may be a tuner or a network receiver. For example, the head unit 10 may receive radio and television broadcasts and generate sound signals of these broadcasts (contents). In addition, the head unit 10 may receive content from a user's smartphone or music player, or a server on a network, and generate sound signals based on these contents. When these contents contain image signals, the head unit 10 may reproduce the image signals together with the sound signals, and display the images on the displays 61, 62. The head unit 10 according to this embodiment may be an electronic device (on-board device) with an integrated audio, video, and navigation system, which includes, in addition to an audio function, a video function (such as video reproduction and display of TV broadcasts) and a navigation function that sets a destination and a transfer point in response to a passenger operation and provides route guidance (navigation) to the destination.

[0029] Each seat 20 has a seat portion 210 on which a user sits, a seat back (backrest portion) 220 rotatably connected to the rear end of the seat portion 210, an actuator 230 and a seat sensor 240. The seat portion 210 is slidably attached to a track provided at one side of the vehicle through the bottom 211 of the seat portion 210. Since the track according to this embodiment is provided along the front-rear direction of the vehicle 1, each seat 20 can also move along the track in the front-rear direction. The seat portion 210 has a height adjustment mechanism for adjusting the height of the seat surface. Each seat 20 can have a rotating mechanism that rotates around a vertical axis. For example, the rotating mechanism can rotate 90° to a side oriented state from a front oriented state (wherein the user sitting in the seat faces the driving direction of the vehicle), or rotate 180° to a rear oriented state from a front oriented state.

[0030] The seat back 220 has a backrest 20B that contacts the back of a user sitting in the seat 20, and a headrest 20H that is mounted on the upper end of the backrest 20B and is located behind the head of the user. The headrest 20H may be formed integrally with the backrest 20B, or may be formed separately from the backrest 20B. The headrest 20H formed separately from the backrest 20B can be adjusted in height relative to the backrest 20B. The seat back 220 rotates back from a vertical upright position to a substantially horizontal lying position relative to the seat portion 210. Therefore, the seat back 220 has an adjustment mechanism (tilt mechanism) that adjusts the rotation angle to maintain any desired position.

[0031] The actuator 230 is installed in each seat and drives the seat portion 210 to move forward and backward along the track at one side of the vehicle. The actuator 230 rotates the seat back 220 relative to the seat portion 210. In addition, the actuator 230 moves the seat surface up and down so as to change the distance between the bottom of the seat portion 210 and the seat surface. When the seat 20 has a rotating mechanism that rotates around a vertical axis, the actuator 230 can drive the seat 20 to rotate around the vertical axis.

[0032] The seat sensor 240 detects the state of the seat, such as the position of the seat portion 210, the height of the seat surface, and the angle of the seat back 220, and sends the detection result to the head unit 10. For example, the seat sensor 240 detects the position of the seat portion 210 relative to the track at one side of the vehicle. The seat sensor 240 detects the rotation angle of the seat back 220 relative to the seat portion 210. The seat sensor 240 is, for example, an encoder. The seat sensor 240 can be a camera that captures the interior of the vehicle. In this case, for example, the camera and the head unit 10 calculate the position and posture of the seat in the captured image through image processing. The seat sensor 240 can be a three-dimensional scanner that scans the interior of the vehicle.

[0033] According to the user's operation of a seat operating portion (not shown) provided in the seat portion 210 or provided near the seat, the ECU 50 operates the actuator 230 to control the state of the seat 20. Thus, for example, when a user gets on the vehicle, the user operates the seat operating portion to control the state of the seat 20 to a desired state. The ECU 50 acquires identification information of the user from a smartphone or an IC tag of the user sitting in the seat, and controls the state of the seat 20 to a state determined for each user.

[0034] Figure 2 Schematically shows the arrangement of the speaker unit 40 included in the vehicle. Figure 2 In the drawings, the header side of the drawing is referred to as the front of the vehicle, that is, the forward direction of the vehicle. The footer side of the drawing is referred to as the rear of the vehicle, the left side of the drawing is referred to as the left side of the vehicle, and the right side of the drawing is referred to as the right side of the vehicle.

[0035] exist Figure 2In the example of , 18 speaker units 40 are provided in the vehicle. The arrangement of the speaker units is only an example and is not limited thereto. The speaker unit 40 includes: headrest speakers H1 to H8, which are provided in the headrests 20H (21H to 24H) of the respective seats 20 (21 to 24); and speaker units (hereinafter, referred to as vehicle-side speakers) CS (CTR, FR, WFR, MR, RR, WF, FL, WFL, ML, RL) which are provided at positions other than the seats. That is, in the speaker unit 40, the headrest speakers HS move together with the seats 20, and the vehicle-side speakers CS are fixed to a predetermined position at one side of the vehicle body and do not move together with the seats 20.

[0036] The headrest speaker H1 is provided at the right side of the headrest 21H of the right front seat (driver's seat) 21, and the headrest speaker H2 is provided at the left side of the headrest 21H. The headrest speaker H3 is provided at the right side of the headrest 22H of the left front seat (passenger seat) 22, and the headrest speaker H4 is provided at the left side of the headrest 22H. The headrest speaker H5 is provided at the right side of the headrest 23H of the right rear seat 23, and the headrest speaker H6 is provided at the left side of the headrest 23H. The headrest speaker H7 is provided at the right side of the headrest 24H of the left rear seat 24, and the headrest speaker H8 is provided at the left side of the headrest 24H.

[0037] The speaker unit CTR is a center speaker located at the front center of the vehicle. The speaker unit FR is a speaker located at the right front side of the vehicle. The speaker unit WFR is a bass speaker located at the right front side of the vehicle and below the right front seat (driver's seat) 21. The speaker unit MR is a speaker installed at the right side of the roof (approximately in the center of the front-to-rear direction of the vehicle compartment). The speaker unit RR is a speaker located at the right rear side of the roof of the vehicle. The speaker unit WF is a bass speaker located at the rear center of the vehicle. The speaker unit FL is a speaker located at the left front side of the vehicle. The speaker unit WFL is a bass speaker located at the left front side of the vehicle and below the left front seat (passenger seat) 22. The speaker unit ML is a speaker installed at the left side of the roof (approximately in the center of the front-to-rear direction of the vehicle compartment). The speaker unit RL is a speaker located at the left rear side of the roof of the vehicle.

[0038] Each speaker unit 40 may be configured to be wired to the head unit 10, for example, and physically output sound (air vibration) through a diaphragm driven by a sound signal (electrical signal) provided from the head unit 10. Each speaker unit 40 includes a receiver, a driving portion, and a speaker. The receiver may wirelessly receive a sound signal from the head unit 10, and the driving portion may convert the sound signal into an electric signal for driving the speaker and provide the converted signal to the speaker to output sound from the speaker.

[0039] Figure 3 is a functional block diagram of the head unit 10. The sound signal acquisition section 11 acquires a sound source signal for reproducing sound in the vehicle from a sound source device such as a CD, a DVD, a USB memory, or a memory card. The sound signal acquisition section 11 may also acquire a sound source signal from an external sound source device such as a content server or a network attached storage device (NAS) via a network.

[0040] The seat information acquisition portion 12 acquires seat information indicating the state of the seat 20 in the vehicle 1 via the seat sensor 240. The seat information includes at least one of the position of the seat 20, the height of the seat surface of the seat 20, and the angle of the seat back 220, for example.

[0041] The parameter determiner 13 determines the parameters when performing reproduction based on the seat information. Here, the parameters include the time alignment of the sound signal to be provided to each speaker unit 40. In addition to the time alignment, these parameters may also include at least one of the sound pressure and the increase / decrease value depending on the frequency of the sound to be reproduced. In order to calculate these parameters, the parameter determiner 13 calculates the positional relationship between the ear position of the user sitting in the seat 20 (hereinafter, also referred to as the sound receiving position) and the position of each speaker unit 40 based on the seat information, for example.

[0042] Figure 4 The positional relationship between the user sitting in the seat 20 and the seat is shown. For example, when a user with a standard body type sits in the seat 20, the user leans his / her back against the backrest 20B, and his / her head is located in front of the headrest 20H. Therefore, the ear position (sound receiving position) 75 of the user is naturally determined. The difference between the body type of the user who actually gets on the vehicle and the standard body type can be corrected by the user's setting. For example, in the case where the difference is input when the user gets on the vehicle, the parameter determiner 13 stores the value (set value) in the memory, and the sound receiving position can be calculated based on the set value. When the seat sensor 240 has a camera and a three-dimensional scanner, the parameter determiner 13 can detect the difference between the body type of the user sitting in the seat 20 and the standard body type and determine the set value. In addition, when the headrest 20H has a sensor that performs head tracking, the parameter determiner 13 can calculate the sound receiving position based on the head position detected by the sensor. Since each headrest speaker HS is fixed to the headrest 20H, the parameter determiner 13 calculates the positional relationship between the sound receiving position and the headrest speaker HS by calculating the sound receiving position as described above.

[0043] Since the vehicle-side speaker CS is located at one side of the vehicle, the parameter determiner 13 calculates the positional relationship between the ear position (sound receiving position) of the user sitting in the seat 20 and the position of each speaker unit 40 based on the seat information (the position of the seat 20, the height of the seat surface, and the angle of the seat back 220). Here, the positional relationship between the sound receiving position and each speaker unit 40 is, for example, the direction and distance of each speaker unit 40 relative to the sound receiving position. The direction of each speaker unit 40 can be indicated by, for example, a rotation angle (hereinafter, also referred to as an elevation angle) when the vertical axis is centered and the front (for example, the driving direction of the vehicle) is 0° and a rotation angle (hereinafter, also referred to as an azimuth angle) when the horizontal axis is orthogonal to the vertical direction and the horizontal direction is 0°. The present invention is not limited to this. For example, a coordinate system is defined in the vehicle, and the position of each speaker unit 40 and the sound receiving position are calculated as coordinates to indicate the positional relationship.

[0044] If the distance between each speaker unit 40 and the sound receiving position is not equal, the sound of the closer speaker unit in the speaker unit 40 arrives faster, while the sound of the farther other speaker unit in the speaker unit 40 arrives slower, resulting in a loss of sound quality. Therefore, the parameter determiner 13 determines the time alignment of the sound signal to be provided to each speaker unit 40 so that if the distance between each speaker unit 40 and the sound receiving position is equal, the sound that would be received at the same time arrives at the sound receiving position of the user sitting in each seat at the same time. In addition, the longer the distance between each speaker unit 40 and the sound receiving position, the higher the sound pressure can be determined by the parameter determiner 13. In addition, the parameter determiner 13 can increase / decrease the volume of the sound of a specific frequency depending on the distance between each speaker unit 40 and the sound receiving position. For example, as the distance is longer, the parameter determiner 13 increases the volume of the sound in the area (high frequency area) above the predetermined frequency.

[0045] The parameter determiner 13 calculates a parameter that controls the position where the sound image is located according to the change in the user's posture caused by the rotation of the seat back 220 . Figure 5A and Figure 5B The positional relationship between the angle of the seat back 220 and the position of the sound image is shown. Figure 5A As shown, when the seat back 200 is in an upright state, the user sitting in the seat 23 faces the traveling direction of the vehicle as shown by arrow 71. On the other hand, the seat back 220 is tilted backward, and in the tilted state, the user sitting in the seat 23 faces the roof side of the vehicle 1 as shown by arrow 72. Figure 5BIn the tilted state, the parameter determiner 13 determines the parameters depending on the angle of the seat back 220 to position the sound image in the direction the user is facing (the direction of the arrow 72).

[0046] For example, when the seat back 220 is in an upright state, the parameter determiner 13 determines parameters so that a sound signal for outputting a front sound (i.e., a sound signal of a left front channel and a right front channel (ch) in the sound signal) is provided to the front speaker units FL, FR in the vehicle. Thus, a sound image is formed in front of the user by the sounds of the left front channel and the right front channel (ch) to be output from the speaker units FL and FR.

[0047] When the seat back 220 is in a tilted state and the user faces the direction of the speaker units ML and MR (the direction of the arrow 72), the parameter determiner 13 determines parameters so that the sound signals of the left front channel and the right front channel (ch) in the sound signal are provided to the speaker units ML, MR. Therefore, a sound image is formed in front of the user in the tilted state by the sounds of the left front channel and the right front channel (ch) to be output from the speaker units ML and MR.

[0048] When the seat back 220 is located Figure 5A and Figure 5B When between the upright state and the tilted state shown (i.e., the user faces the direction between arrows 71 and 72), the parameter determiner 13 distributes the sound signals of the left front channel and the right front channel (ch) to the speaker units FL, FR and the speaker units ML, MR, and determines the distribution ratio as a parameter. Since the sound image is formed on the side of the speaker with a higher distribution ratio, the parameter determiner 13 determines the ratio depending on the angle of the seat back 220. Similarly, when the user faces the direction between the speaker units ML, MR and the speaker units RL, RR, the parameter determiner 13 distributes the sound signals of the left front channel and the right front channel (ch) to the speaker units ML, MR and the speaker units RL, RR, and determines the distribution ratio as a parameter.

[0049] The sound signal generator 14 generates a sound signal for outputting sound from the plurality of speaker units 40 based on the sound source signal and the parameter.

[0050] The output controller 15 supplies a sound signal to each of the plurality of speaker units 40 via the amplifier 104 , and outputs sound from each of the plurality of speaker units 40 .

[0051] Figure 6 1 is a configuration diagram of the sound system 100 including the head unit 10. Figure 6In the embodiment, the elements required for describing the features of the embodiment are mainly shown, and general elements are not shown for simplicity. Figure 6 Each element shown is only functional and conceptual, and is not necessarily configured as shown in a physical sense. For example, the distributed and / or integrated version of each functional block is not limited to the version shown, and all or part of it can be functionally or physically distributed or integrated in any unit depending on various loads, usage conditions, etc.

[0052] like Figure 6 As shown, the head unit 10 is an information processing device (computer) having an amplifier 104 and a controller 101, a memory 102, and an input / output interface (IF) 103 interconnected by a connection bus 110. Figure 6 In the embodiment, the head unit 10 is configured to include the amplifier 104 , but the head unit 10 (signal processing device) may be separated from the amplifier 104 .

[0053] The controller 101 controls the entire head unit. The controller 101 is composed of, for example, a central processing unit (CPU), a microprocessing unit (MPC), a main storage device, etc. The controller 101 is also referred to as a controller or a processor. The controller 101 is not limited to a configuration with a single processor, but can be a multi-processor configuration. The signal controller 101 connected through a single socket can adopt a multi-core configuration. The main storage device is used as, for example, a working area of ​​the controller 101, a storage area for programs and data, and a buffer for communication data. The main storage device includes, for example, a random access memory (RAM), or a combination of a RAM and a read-only memory (ROM).

[0054] The memory 102 is an auxiliary memory that stores programs executed by the controller 101 and operation setting information. The memory 102 is not limited to an internal storage device built into the head unit 10, but may also be an external storage device or an external storage device such as a network attached storage device (NAS). The memory 102 is, for example, a hard disk drive (HDD), a solid state drive (SSD), an erasable programmable ROM (EPROM), a flash memory, a USB memory, a memory card, etc.

[0055] The input / output IF 103 is an interface for performing data output / input to / from other devices (such as a content server, a speaker unit 40, an amplifier 104, and an ECU). The input / output IF 103 performs data output / input to / from devices such as a disk drive that reads data from a storage medium such as a CD or a DVD, an operation portion that receives a user's operation, a display 61, 62 that provides a display to the user, and a communication module. In addition, the input / output IF 103 performs data output / input to / from devices such as a tuner that receives radio and television broadcast waves, a reader / writer that reads / writes data in a storage medium such as a memory card, a camera (seat sensor, head sensor), a microphone, and other sensors. The operation portion is an input device that receives the user's operation and inputs operation information indicating these operations to the controller 101. The operation portion may also be, for example, a button, a switch, a dial (rotation knob), a lever, etc. The operation portion may also be a touch panel that is arranged to overlap on the display surface of the display 61. The display 61, 62 is an output device for displaying information about music reproduction, for example, to the user. The communication module is an interface for performing communication with other devices (such as a content server and a speaker unit) via a communication line. A plurality of the above elements may be provided separately, or a part of these elements may not be provided.

[0056] In the head unit 10, the controller 101 acts as a processor by executing application programs such as Figure 3 The sound signal acquisition part 11, the seat information acquisition part 12, the parameter determiner 13, the sound signal generator 14 and the output controller 15 are shown. However, at least a part of the processing of the processor can be provided by a digital signal processor (DSP), an application specific integrated circuit (ASIC), etc. Some processors can be dedicated large-scale integrated circuits (LSI) (such as field programmable gate arrays (FPGA)) or other digital circuits. At least some processors may include analog circuits.

[0057] [Signal processing method]

[0058] Figure 7 1 is a flowchart of a signal processing method executed by the controller based on the signal processing program according to this embodiment. For example, when the accessory power supply of the vehicle 1 is turned on and power has been supplied to the head unit 10, or reproduction of content has been instructed by a user's operation, the controller 101 starts Figure 7 Repeatedly execute the process until the accessory power of the vehicle 1 is turned off, the operation of the head unit 10 is stopped, or the termination is instructed by the user's operation. Figure 7 process. Figure 7The repetitive cycle of the process can be sufficient to perform music reproduction in near real time. For example, when the sound signal is stored in a buffer for several milliseconds to several seconds, the repetitive cycle of the process can be sufficient to repeat the process several times within the buffer period.

[0059] In step S10 , the controller 101 acquires a sound source signal from a sound source device (such as a CD, a DVD, a semiconductor memory, etc.).

[0060] In step S20 , the controller 101 acquires seat information indicating the position of each seat 20 , the angle of the seat back 220 , the height of the seat surface, and the like via the seat sensor 240 .

[0061] In step S30, the controller 101 determines parameters based on the seat information to correct the change in the positional relationship with the vehicle-side speaker CS caused by the seat being moved. For example, the controller 101 adjusts the time alignment of the sound signal to be provided to each speaker unit 40 for the change in the distance between the vehicle-side speaker CS and the sound receiving position caused by the movement of the seat position. The controller 101 determines the allocation of the sound signal to be provided to each speaker unit 40 depending on the angle of the seat back 220.

[0062] In step S40 , the controller 101 generates a sound signal to be supplied to each speaker unit 40 based on the sound source signal acquired in step S10 and the parameter determined in step S30 .

[0063] In step S50 , the controller 101 supplies the sound signal generated in step S40 to each speaker unit 40 , and outputs the sound.

[0064] [Effects of Embodiment]

[0065] (1) The head unit 10 (signal processing device) according to this embodiment acquires seat information indicating the state of the seat 20, determines parameters when performing reproduction based on the seat information, and generates a sound signal based on the sound source signal and the parameters. Therefore, even if the positional relationship between the sound receiving position and each speaker unit 40 changes according to a change in the state of the seat, the head unit 10 according to this embodiment determines parameters (such as time alignment) accordingly, and reproduces the sound using appropriate sound parameters.

[0066] (2) In this embodiment, the seat information includes at least one of the position of the seat 20, the height of the seat surface in the seat, and the angle of the seat back 220. Therefore, the head unit 10 grasps the state of the seat and reproduces the sound using appropriate sound parameters.

[0067] (3) In this embodiment, the parameters include the time alignment of the sound signal to be supplied to each speaker unit 40. The parameters may also include at least one of the sound pressure of the sound to be output from each speaker and the increase / decrease value depending on the frequency of the sound. Therefore, the head unit 10 according to this embodiment reproduces the sound by using appropriate sound parameters.

[0068] (4) The head unit 10 according to the embodiment replaces the sound signal to be supplied to each speaker unit 40 depending on the angle of the seat back 220. The head unit 10 distributes the sound signal for outputting the front sound to the plurality of speakers depending on the angle of the seat back 220. Therefore, the head unit 10 according to the embodiment forms a sound image in front of the user depending on the seat back 220.

[0069] <Second Embodiment>

[0070] Figure 8 is a block diagram showing the configuration of a head unit 10A according to the second embodiment. Fig. 9 The flow of the signal processing method performed by the head unit 10A according to the second embodiment is shown. Compared with the above-mentioned first embodiment, this embodiment is different in the configuration of changing the state of the seat 20 according to the mode selected by the user, and the other configurations are the same. Therefore, in this embodiment, the same constituent elements as those of the above-mentioned first embodiment are represented by the same reference numerals, and their description is omitted.

[0071] like Figure 8 As shown, the head unit 10A according to this embodiment has a mode acquisition part 16. When the user who operates the operation part selects a mode, the mode acquisition part 16 performs control to change the state of the seat 20 according to the selected mode. For example, when the user sets the position of the seat 20, the height of the seat surface of the seat 20, and the angle of the seat back 220 to a desired state and performs a registration (preset) operation, the head unit 10A detects the state of the seat 20 through the seat sensor 240 and stores the detected state in the memory.

[0072] The head unit 10A is operated by the operation part according to Fig. 9 The process of adjusting parameters is used to select multiple modes. The multiple modes may not be executed Fig. 9 OFF mode and execution of the process Fig. 9 The user may register a plurality of states of the seat 20, such as mode A, mode B, and mode C, and select one of the plurality of states.

[0073] For example, when the accessory power supply of the vehicle 1 is turned on and power is supplied to the head unit 10, or when the reproduction of the content is instructed by the user's operation, the playback is started. Fig. 9 Repeatedly execute until the accessory power of the vehicle 1 is turned off, the operation of the head unit 10A is stopped, or the termination is instructed by the user's operation. Fig. 9 process.

[0074] In step S1, the controller 101 acquires the mode selected by the user. In step S3, the controller 101 determines whether the off mode is selected. Here, when the off mode is selected ("yes" in step S3), the controller 101 ends Fig. 9 When the open mode is selected (“No” in step S3 ), the controller 101 moves to step S5 .

[0075] In step S5, the controller 101 reads the preset state of the seat from the memory, and sends a control signal to the actuator 230 to set the state of the seat 20 to the preset state. The process after step S10 is the same as the above. Figure 7 That is, the controller 101 determines the parameters based on the state of the seat after the preset in step S5, and reproduces the sound.

[0076] Therefore, the head unit 10A according to this embodiment changes the state of the seat according to the mode selected by the user, and then reproduces the sound by using the appropriate sound parameter according to the state of the seat 20 after the change.

[0077] While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It will therefore be appreciated that various other modifications and variations may be made without departing from the scope of the invention.

Claims

1. A signal processing device comprising a controller, wherein the controller is configured to: (i) obtaining a sound source signal for reproducing sound in a vehicle; (ii) acquiring seat information indicating a state of a seat in the vehicle; (iii) determining parameters for reproduction based on the seat information; as well as (iv) generating a sound signal for outputting the sound from a plurality of speakers provided in the vehicle based on the sound source signal and the parameter.

2. The signal processing device according to claim 1, wherein: The seat information includes at least one of: a position of the seat, a height of a seat surface of the seat, and an angle of a seat back.

3. The signal processing device according to claim 1, wherein: The parameters include a time alignment of a sound signal to be provided to each of the plurality of speakers.

4. The signal processing device according to claim 3, wherein: The parameter also includes at least one of a sound pressure of a sound to be output from each of the plurality of speakers, and an increase / decrease in volume of the sound at a specific frequency.

5. The signal processing device according to claim 1, wherein: The controller replaces a sound signal to be provided to each of the plurality of speakers depending on an angle of a seat back of the seat.

6. The signal processing device according to claim 1, wherein: The controller distributes a sound signal for outputting a front sound in the vehicle to the plurality of speakers depending on an angle of a seat back of the seat.

7. The signal processing device according to claim 1, wherein: The controller changes the state of the seat according to a mode selected by a user from among a plurality of modes, and acquires seat information indicating the state of the seat after the change.

8. A signal processing method performed by a controller, the method comprising: (a) obtaining a sound source signal for reproducing sound in a vehicle; (b) acquiring seat information indicating a state of a seat in the vehicle; (c) determining parameters for reproduction based on the seat information; as well as (d) generating a sound signal for outputting the sound from a plurality of speakers provided in the vehicle based on the sound source signal and the parameter.

9. A sound system comprising: The signal processing device according to claim 1; A sensor for detecting a state of the seat; as well as A plurality of speakers output sound based on the sound signal.

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