JP2008072541A - Audio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an audio device by which a burden to an operation part is alleviated, a listening sound is detected from an image photographed by a camera and sound field adjustment is automatically performed based on a detection result by a simple configuration. <P>SOLUTION: The audio device is provided with: a signal processing part which performs signal processing for increasing and decreasing a signal level of an audio signal to adjust a delay time when the audio signal is outputted; an amplification part which amplifies the audio signal; an output part which outputs the audio signals to a plurality of speakers; a plurality of cameras provided at a casing; a dynamic body detection part which detects a dynamic body based on the variation of pixels of the image information of the plurality of cameras to output dynamic body information indicating that the dynamic body is detected and a control part which specifies a position of the dynamic body after movement from the dynamic body information, calculates a difference with a preset listening position to increase and decrease the signal level of the audio signal and to adjust the delay time to be added to the audio signal in the signal processing part based on the difference. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an audio device for outputting audio signals from a plurality of speakers.

  Conventionally, in an audio apparatus for outputting audio signals from a plurality of speakers, if the distance between the listening position (listening point) and each speaker is different, the volume from each speaker at the listening position and the listening from each speaker are different. The time until the audio signal reaches the position differs, and an optimal sound field may not be obtained at the listening position. For this reason, the signal level of the audio signal from each speaker at the listening position and the arrival time of the audio signal from each speaker to the listening position are measured and output from each speaker so as to obtain an optimum sound field at the listening position. Those equipped with an automatic sound field adjustment function for adjusting an audio signal have become widespread.

  As such an automatic sound field adjustment function, a camera is installed at the sound source so as to reflect the relative position between the speaker and the listener, and the position of the listener is specified by the image captured by the camera, and the position of the listener Patent Document 1 discloses a sound distribution adjustment system for speakers that automatically adjusts sound based on the position of each speaker.

JP 2001-54200 A

  In the technique disclosed in Patent Document 1, the listener is identified by a complicated calculation such as a technique for acquiring and tracking a target (listener) from an image photographed by a camera, a three-dimensional photographing and display technique, and the like. Therefore, the image taken by the camera is required to have a high resolution. However, it is difficult to distinguish a listener from an object similar to a human (for example, a doll). For example, if you have taken a picture of a listener whose camera is indoors and a person walking outdoors from a window, he can distinguish between a listener and a person walking outdoors, or a doll and listener placed indoors. Is difficult to distinguish.

  In addition, in order to identify the listener from images taken of people other than dolls and listeners, the camera was shot by advanced image recognition processing such as target acquisition and tracking technology, three-dimensional imaging and display technology. Since only the listener is detected from the image, the configuration of the apparatus is complicated, and a burden is imposed on the calculation unit in the apparatus.

  The present invention is an audio device that can reduce a burden on a calculation unit with a simple configuration, detect a listener from an image captured by a camera, and automatically adjust a sound field based on the detection result. The purpose is to provide.

  The present invention relates to a signal processing unit that performs signal processing for adjusting a delay time when outputting an audio signal by increasing / decreasing the signal level of the audio signal, and an amplifying unit that amplifies the audio signal output from the signal processing unit. An output unit that outputs audio signals output from the amplification unit to a plurality of speakers; a plurality of cameras provided in a housing; and a moving object that detects a moving object based on a change in pixels of image information of the plurality of cameras A moving body detection unit that outputs moving body information indicating that the moving body is detected, a position after movement of the moving body is specified from the moving body information from the moving body detection unit, and a difference from a preset listening position is obtained. And a control unit that performs control to adjust the signal signal level of the audio signal in the signal processing unit and to adjust the delay time when the audio signal is output. .

  According to the present invention, in the audio device, the burden on the calculation unit is reduced with a simple configuration, and the listener is detected from the image captured by the camera, and the sound field is automatically adjusted based on the detection result. can do.

FIG. 1 is a block diagram showing the configuration of an embodiment of the audio apparatus of the present invention.
The audio device is, for example, an audio visual (AV) amplifier, and inputs a video signal / audio signal output from an external device such as a digital versatile disc (DVD) player, The video signal is output to a monitor or display, and the audio signal is output to a speaker. In the present embodiment, description of the video signal is omitted.

  In FIG. 1, the audio apparatus 1 includes an input unit 2, a signal processing unit 3, an amplification unit 4, an output unit 5, a moving object detection unit 6, and a control unit 7.

  The input unit 2 outputs an audio signal input from an external device such as a DVD player to the signal processing unit 3 at the subsequent stage.

  The signal processing unit 3 is a digital signal processor, for example, and decodes the compressed audio signal input from the input unit 2, surround signal processing on the decoded audio signal, and signal level for the audio signal of each channel Signal processing such as adjustment of delay time and adjustment of delay time when audio signals are output.

  The amplifying unit 4 amplifies the audio signal with respect to the audio signal output from the signal processing unit 3.

  A plurality of speakers such as a front left channel speaker (FL speaker) 8, a front right channel speaker (FR speaker) 9, a surround left speaker (SL speaker) 10, and a surround right speaker (SR speaker) 11 are connected to the output unit 5. Has been. The output unit 5 outputs the audio signal output from the amplification unit 4 to a speaker corresponding to each channel.

  The moving object detection unit 6 includes a left camera (L camera) 12 and a right camera (R camera) 13. The L camera 12 and the R camera 13 are, for example, CCD (Charge Coupled Device) cameras, and are arranged at predetermined intervals. The L camera 12 and the R camera 13 are installed at the left and right ends of the front panel of the audio device 1, for example.

  The moving object detection unit 6 includes an image memory (not shown) that stores image information captured by the L camera 12 and the R camera 13. The moving object detection unit 6 acquires image information from the L camera 12 and the R camera 13 every predetermined time, and stores the image information in the image memory. The moving object detection unit 6 compares the previous image information with the current image information for the image information captured by the L camera 12 and the R camera 13, and there is a difference between the previous image information and the current image information. In this case, it is determined that a moving object exists.

FIG. 2 is a diagram for explaining the operation of the moving object detection unit in the audio apparatus according to the present embodiment.
The audio apparatus 1 is used in a closed space such as a room. In that space, there are few objects that are constantly moving, and when this space is taken with a camera at different times, the difference between the image taken at time T and the image taken at time T1 is small. However, as shown in FIG. 2A, when the listener moves from position R to position A, there is a difference between the image captured at time T and the image captured at time T1.

  When the listener moves from position R to position A, the L camera 12 captures an image as shown in FIG. 2B, and the R camera 13 captures an image as shown in FIG. When the listener moves (when there is a moving object), the pixel is changed in the L camera 12 or the R camera 13. The change in pixel is in a range corresponding to the listener's body. The moving object detection unit 6 calculates the position of the listener after the movement using the center of the range of the pixel where the change has occurred as a movement reference point.

FIG. 3 is a diagram for explaining the operation of the position detection unit in the audio apparatus according to the present embodiment.
In FIG. 3A, the number of pixels of the L camera 12 and the R camera 13 is M, the shooting range of the L camera 12 is θmaxL, and the shooting range of the R camera 13 is θmaxR. Further, the L camera 12 and the R camera 13 are arranged at a predetermined interval L. When the moving listener enters the shooting range of the L camera 12 and stops at the listening position (position A) (the position of the movement reference point) is the position of the N1 pixel from the center of the L camera 12 The angle is θα = N1 / (M / 2) × θmaxL (1) from the front of the L camera 12.
It becomes.

Similarly, when the position on the R channel camera is N2 pixels from the center, the angle is θβ = (2 × N2 / M) × θmaxR (2) from the front of the R channel camera.
It becomes.

If the distance from the L channel camera and R channel camera to the moving object is L3,
L3 = L1 / tan (θα) (3)
L3 = L2 / tan (θβ) (4)
And
L1 / tan (θα) = L2 / tan (θβ) (5)
It becomes.

Since the distance between the L camera 15 and the R camera 16 is L,
L = L1 + L2 = L2 {tan (θα) / tan (θβ)} + L2 (6)
Next
L2 = L [tan (θβ) / {tan (θα) + tan (θβ)} (7)
L1 = L-L2 = L [tan (θα) / {tan (θα) + tan (θβ)} (8)
Therefore, the position of the moving object (listener) can be calculated from the above formula.

  Further, as shown in FIG. 3B, when the listener moves forward (in the direction of the L camera 12 and the R camera 13), even when θα of the L camera 12 is constant, θβ of the R camera 13 is changes to θβ ′. L1 ′ or L2 ′ can be obtained from the distances L, θα, θβ ′ between the L camera 12 and the R camera 13 using the equations (6), (7), and (8), and the position of the listener is calculated. can do. By obtaining L1 'or L2', L3 'can be calculated by either (3) or (4).

  The control unit 7 controls the entire audio apparatus 1. The control unit 7 controls the volume adjustment of the audio signal, the form of outputting the audio signal (stereo output, surround output), and the like based on the instruction signal input from the operation unit (not shown). The audio device 1 has a sound field automatic adjustment function by auto setup or the like, and the control unit 7 measures frequency characteristics, positions, and the like of a plurality of speakers connected to the audio device 1 and is optimal at the reference listening position. In order to obtain sound, the signal processing unit 3 performs control for setting a signal level and adding a delay time to the audio signal of each channel.

  The control unit 7 obtains a difference between the listening position set in advance based on the moving body information from the moving body detection unit 6 and the moving body position based on the moving body information, and the signal processing unit 3 according to the difference. To control the increase / decrease of the signal level of the audio signal of each channel and the adjustment of the delay time when outputting the audio signal. That is, control is performed to increase / decrease the signal level of the audio signal so as to change the listening position based on the moving object information from the moving object detection unit 6, or adjust the delay time so that the output timing is shifted when outputting the audio signal. .

  The position detection unit 6 obtains the position of the listener obtained by the above method, and outputs the obtained position information to the correction control unit 7. The correction control unit 7 obtains a difference between the listening position determined from the position of each speaker and the position of the listener based on the position information based on the position information from the position detection unit 6 and the position information of each speaker. The signal level of the audio signal of each channel and the delay time are adjusted in the signal processing unit 9 of the amplifier unit 3 so as to correspond to the difference.

The operation of the audio device 1 will be described.
In the audio apparatus 1, when the automatic sound adjustment function is activated, the number of speakers input by the listener, the distance between the speakers, and the sound generated from each speaker and collected by a microphone installed at the listening position Based on the above, the signal level, the delay time, etc. are adjusted with respect to the audio signal output from each speaker so as to obtain the optimum sound at the listening position. At this point, the audio signal output from each speaker is adjusted so as to obtain optimum sound at the listening position.

  Thereafter, the moving object detection unit 6 operates to start moving object detection. The L camera 12 and the R camera 13 detect the presence or absence of a moving object at predetermined time intervals. When there is a moving object, the moving object detection unit 6 outputs the moving object information to the control unit 7.

  When the moving body information is input from the moving body detection unit 6, the control unit 7 calculates the difference between the listening position currently set based on the moving body information and the listening position based on the moving body information. Based on the difference, the control unit 7 changes the signal level set for the audio signal of each channel and the delay time to be added so that the position where the moving object moves becomes the listening position where the optimum sound is obtained. .

  As a result, when the listener moves, the position after the movement is automatically set to be the optimum sound. Therefore, every time the listener changes the listening position, it is not necessary to change the setting of the listening position, which is convenient for the listener.

  In realizing this, the audio apparatus 1 includes two cameras, and the movement detection unit 6 detects the reception of the moving object by the change of the pixels in the two cameras, and specifies the position after the movement of the moving object. Therefore, it is not necessary to perform a moving object recognition process that requires complicated calculations. In addition, since the listening position is not changed based on a highly accurate moving object recognition process, moving objects other than the listener are not erroneously detected, and the listening position is not set at an incorrect position.

The block diagram which shows the structure of one Embodiment in the audio apparatus of this invention. The figure for demonstrating operation | movement of the moving body detection part in the audio apparatus of this embodiment. The figure explaining operation | movement of the position detection part in the audio apparatus of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Audio apparatus, 2 ... Input part, 3 ... Signal processing part, 4 ... Amplification part, 5 ... Output part, 6 ... Moving object detection part, 7 ... Control part 8 ... FL speaker, 9 ... FR speaker, 10 ... SL speaker, 11 ... SR speaker, 12 ... L camera, 13 ... R camera

Claims (1)

  From a signal processing unit that performs signal processing to increase / decrease a signal level of an audio signal and adjust a delay time when outputting the audio signal, an amplification unit that amplifies the audio signal output from the signal processing unit, and an amplification unit An output unit that outputs output audio signals to a plurality of speakers, a plurality of cameras provided in a housing, and a moving object is detected based on a change in pixels of image information of the plurality of cameras. A moving body detection unit that outputs moving body information indicating the position of the moving body after moving from the moving body information from the moving body detection unit, obtaining a difference from a preset listening position, and based on the difference An audio comprising: a control unit that performs control to adjust the signal signal level of the audio signal in the signal processing unit and to adjust a delay time when the audio signal is output. Location.

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