Home theater system, audio/video playback device, audio output control device, and volume control method

A CPU in a home theater device transmits current sound volume control status data to a digital television receiving device when a theater mode is set. A CPU in the digital television receiving device updates, when the sound volume control status data has been received from the home theater device, sound volume control status data stored in a memory with the received sound volume control status data. A CPU in the digital television receiving device determines sound volume setting value data after an operation based on sound volume operation information fed from a remote control device and the sound volume control status data stored in the memory, and transmits a CEC command including the determined sound volume setting value data to the home theater device while displaying a ratio of the current sound volume to a maximum value in a sound volume adjustable range of the home theater device on a display.

TECHNICAL FIELD

The present invention relates to a home theater system, an audio/video reproduction device, and an audio output control device, and a volume control method therefor.

BACKGROUND ART

In digital television broadcasting such as terrestrial digital broadcasting or digital satellite broadcasting, high-definition video signals called Hi-vision video signals are transmitted. Audio signals transmitted in the digital television broadcasting are conformable to stereophonic reproduction called surround. More specifically, such audio signals enable stereophonic reproduction using a 5.1 channel surround system.

A 5.1 channel includes a total of five speakers (five channels) including front (left and right) speakers, a center speaker, and surround (left and right) speakers, and a ultrasonic subwoofer speaker (0.1 channels).

In a home theater system conformable to the 5.1 channel surround system, a digital broadcasting conformable television receiver (hereinafter referred to as a digital television receiving device) having a display screen on a front surface of a user is installed. The front speakers are respectively installed on the right and left sides ahead of a user. The center speaker is arranged on the front surface of the user. The subwoofer speaker is installed in a suitable location ahead of the user. The surround speakers are respectively installed on the right and left sides behind the user.

In order to reproduce audio in the digital television broadcasting using the 5.1 channel surround system, a home theater device having a built-in amplifier is connected to the digital television receiving device via an HDMI cable conforming to a HDMI (High-Definition Multimedia Interface) standard. The HDMI cable includes a data line for transmitting and receiving video/audio data (video data and audio data) and a CEC signal line for transmitting and receiving a CEC (Consumer Electronic Control) command for performing control between devices. The six speakers, described above, are connected to the home theater device.

A method for improving an audio reproduction function using the CEC command conforming to the HDMI standard has conventionally been proposed.

In an audio control system discussed in Patent Document 1, for example, a control signal is transmitted to an AV (Audio Visual) amplifier via an HDMI CEC line depending on whether a headphone is connected to a television receiver. Thus, control is performed depending on whether audio can be output.

In a sound volume correction circuit system discussed in Patent Document 2, a control signal is transmitted from an HDMI compatible STB (Set Top Box) to an HDMI conformable television via an HDMI cable. Thus, an amplification degree of an audio signal of a television is adjusted depending on the type of the STB.

Further, Patent Document 3 discusses an output device to which a plurality of external devices including an HDMI source device are connected. If an HDMI signal input to the HDMI source device does not include an audio signal, a sound volume operation by an operator in the output device is invalidated.[Patent Document 1] JP 2009-027678 A[Patent Document 2] JP 2006-352599 A[Patent Document 3] JP 2009-088646 A

SUMMARY OF INVENTION

Technical Problem

As described above, various audio reproduction functions by transmitting and receiving a CEC command between devices connected via an HDMI have been discussed. In a home theater system, however, a technique for enabling improvements in operability and responsibility of a sound volume operation as well as high-precision sound volume adjustment is not discussed.

An object of the present invention is to provide a home theater system enabling improvements in operability and responsibility of a sound volume operation and high-precision sound volume adjustment, an audio/video reproduction device, and an audio output control device, and a volume control method.

Solution to Problem

(1) According to an aspect of the present invention, a home theater system includes an audio/video reproduction device, a display that displays a video, and an audio output control device connected to the audio/video reproduction device via a communication medium, in which the audio/video reproduction device includes an audio data acquisitor that acquires audio data, a sound volume operation information acquisitor that acquires sound volume operation information representing a sound volume operation of the audio output control device, a first transmitter/receiver that transmits the audio data acquired by the audio data acquisitor to the audio output control device via the communication medium, and transmits and receives a command to and from the audio output control device via the communication medium, a storage that stores sound volume control status data relating to sound volume control of the audio output control device, and a first controller that controls the display and the first transmitter/receiver, the sound volume control status data includes maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device, and sound volume setting value data representing a sound volume of the audio output control device, the audio output control device includes a second transmitter/receiver that receives audio data from the audio/video reproduction device via the communication medium, and transmits and receives a command to and from the audio/video reproduction device via the communication medium, an amplifier that outputs an audio signal based on the audio data received by the second transmitter/receiver, and a second controller that controls the second transmitter/receiver and the amplifier and transmits current sound volume control status data relating to the audio output control device to the audio/video reproduction device via the second transmitter/receiver at predetermined timing, the first controller updates, when the sound volume control status data has been received from the audio output control device via the first transmitter/receiver, the sound volume control status data stored in the storage with the received sound volume control status data, determines, when sound volume operation information has been acquired by said sound volume information acquisitor, sound volume setting value data after an operation based on the acquired sound volume operation information and the sound volume control status data stored in the storage, and transmits a command including the determined sound volume setting value data to the audio output control device via the first transmitter/receiver while displaying a ratio of the current sound volume of the audio output control device to a maximum value in the sound volume adjustable range of the audio output control device based on the determined sound volume setting value data and the maximum sound volume value data stored in the storage, and the second controller controls, when the command including the sound volume setting value data has been received from the audio/video reproduction device via the second transmitter/receiver, a sound volume of the amplifier based on the received sound volume setting value data.

In the home theater system, the sound volume control status data is stored in the storage in the audio/video reproduction device. The second controller in the audio output control device transmits the current sound volume control status data in the audio output control device to the audio/video reproduction device via the second transmitter/receiver at predetermined timing.

When the first controller in the audio/video reproduction device updates, when it has received the sound volume control status data from the audio output control device via the first transmitter/receiver, the first controller updates the sound volume control status data stored in the storage with the received sound volume control status data. When the sound volume operation information acquisitor has acquired the sound volume operation information, the first controller determines the sound volume setting value data after the operation based on the acquired sound volume operation information and the sound volume control status data stored in the storage, and transmits the command including the determined sound volume setting value data to the audio output control device via the first transmitter/receiver. Further, the first controller displays the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device on the display based on the determined sound volume setting value data and the maximum sound volume value data stored in the storage.

When the second controller in the audio output control device has received the command including the sound volume setting value data from the audio/video reproduction device via the second transmitter/receiver, the second controller controls the sound volume of the amplifier based on the received sound volume setting value data.

Thus, the storage in the audio/video reproduction device stores the current sound volume control status data in the audio output control device. Therefore, the first controller can recognize the current sound volume of the audio output control device from the sound volume setting value data stored in the storage during the sound volume operation. Thus, the first controller can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The first controller can recognize the maximum value in the sound volume adjustable range of the audio output control device from the maximum sound volume value data stored in the storage. Thus, the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device can be displayed on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the first controller can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device can be instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

(2) The first controller may display the ratio of the current sound volume on the display using a bar. In this case, the user can intuitively and visually grasp the current sound volume.

(3) The bar may include a first bar having a length corresponding to the maximum value in the sound volume adjustable range of the audio output control device and a second bar having a length corresponding to the current sound volume.

In this case, the user can intuitively and visually grasp the current sound volume based on the ratio of the length of the second bar to the length of the first bar.

(4) The first controller may update the sound volume setting value data stored in the storage with the determined sound volume setting value data when the sound volume operation information is acquired by the sound volume operation information acquisitor.

Thus, when the sound volume of the audio output control device is changed by the sound volume operation, the storage stores the newest sound volume setting value data. Therefore, the continuity of the sound volume operation can be maintained.

(5) The audio/video reproduction device may be configured to be settable to a theater mode for transmitting the audio data to the audio output control device, the predetermined timing may include the time when the audio/video reproduction device is set to the theater mode, and the second controller may transmit the current sound volume control status data in the audio output control device to the audio/video reproduction device via the second transmitter/receiver when the audio/video reproduction device is set to the theater mode.

In this case, when the audio/video reproduction device is set to the theater mode, the sound volume control status data stored in the storage is updated to the newest sound volume control status data. Thus, the audio/video reproduction device can determine the sound volume setting value data and perform the sound volume display based on the newest sound volume control status data without transmitting and receiving the command to and from the sound volume output control device during the sound volume operation. As a result, high-precision sound volume adjustment can be made.

(6) The audio output control device may further include a sound volume operator used to perform a sound volume operation of the amplifier, the predetermined timing may include the time when the sound volume operator is performed by the sound volume operator, the second controller may determine, when the sound volume operator has been performed by the sound volume operator, the sound volume setting value data in the audio output control device based on the sound volume operation by the sound volume operator, and transmit a command including the determined sound volume setting value data to the audio output control device via the second transmitter/receiver, and the first controller may update, when a command including the sound volume setting value data has been received from the audio output control device via the first transmitter/receiver, the sound volume setting value data stored in the storage with the received sound volume setting value data.

By such a configuration, the sound volume operation of the audio output control device can be performed on the side of not only the audio/video reproduction device but also the audio output control device. In this case, the sound volume setting value data after the sound volume operation is transmitted from the audio output control device to the audio/video reproduction device so that the newest sound volume setting value data is stored in the storage. As a result, even when the sound volume operation is performed on the side of the audio/video reproduction device after being performed on the side of the audio output control device, the continuity of the sound volume operation can be maintained.

(7) The sound volume control status data may further include mute setting status data indicating whether the audio output control device is set to a mute status.

In this case, the first controller in the audio/video reproduction device can acquire the mute setting status data in the audio output control device simultaneously with the maximum sound volume value data and the sound volume setting value data by receiving the sound volume control status data from the audio output control device. Thus, the audio/video reproduction device can grasp the status of the audio output control device by transmitting and receiving the command a small number of times between the audio/video reproduction device and the audio output control device. As a result, operation responsibility is improved.

(8) The first controller may determine, when the sound volume operation information acquired by the sound volume operation information acquisitor represents an increase or decrease in a sound volume, the sound volume setting value data to increase or decrease by a value larger than one.

In this case, the number of times of the transmission and receiving of the sound volume setting value data is reduced so that a period of time during which the command is transmitted can be shortened. As a result, the speed of the sound volume operation can be increased.

(9) According to another aspect of the present invention, an audio/video reproduction device to be connected to an audio output control device via a communication medium and to be connected to a display includes an audio data acquisitor that acquires audio data, a sound volume operation information acquisitor that acquires sound volume operation information representing a sound volume operation of the audio output control device, a transmitter/receiver that transmits the audio data acquired by the audio data acquisitor to the audio output control device via the communication medium, and transmits and receives a command to and from the audio output control device via the communication medium, a storage that stores sound volume control status data relating to sound volume control of the audio output control device, and a controller that controls the display and the transmitter/receiver, in which the sound volume control status data includes maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device and sound volume setting value data representing a sound volume of the audio output control device, and the controller updates, when sound volume control status data has been received from the audio output control device via the transmitter/receiver, the sound volume control status data stored in the storage with the received sound volume control status data, determines, when the sound volume operation information has been received acquired by the sound volume operation information acquisitor, sound volume setting value data after an operation based on the acquired sound volume operation information and the sound volume control status data stored in the storage, and transmits a command including the determined sound volume setting value data to the audio output control device via the first transmitter/receiver while displaying a ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device on the display based on the determined sound volume setting value data and the maximum sound volume value data stored in the storage.

In the audio/video reproduction device, the storage stores the current sound volume control status data in the audio output control device. Therefore, the controller can recognize the current sound volume of the audio output control device from the sound volume setting value data stored in the storage during the sound volume operation. Thus, the controller can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of the transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The controller can recognize the maximum value in the sound volume adjustable range of the audio output control device from the maximum sound volume value data stored in the storage. Thus, the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device can be displayed on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the controller can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device is instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

(10) According to sill another aspect of the present invention, an audio output control device to be connected to an audio/video reproduction device via a communication medium includes a transmitter/receiver that receives audio data from the audio/video reproduction device via the communication medium, and transmits and receives a command to and from the audio/video reproduction device via the communication medium, an amplifier that outputs an audio signal based on the audio data received by the transmitter/receiver, and a controller that controls the transmitter/receiver and the amplifier and transmits current sound volume control status data in the audio output control device to the audio/video reproduction device via the transmitter/receiver at predetermined timing, in which the sound volume control status data includes maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device and sound volume setting value data representing a sound volume of the audio output control device, and the controller controls, when a command including sound volume setting value data has been received from the audio/video reproduction device via the transmitter/receiver, a sound volume of the amplifier based on the received sound volume setting value data.

According to the audio output control device, the audio/video reproduction device can store the current sound volume control status data in the audio output control device. Therefore, the audio/video reproduction device can recognize the current sound volume of the audio output control device from the stored sound volume setting value data during a sound volume operation. Thus, the audio/video reproduction device can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of the transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The audio/video reproduction device can recognize the maximum value in the sound volume adjustable range of the audio output control device from the stored maximum sound volume value data. Thus, the audio/video reproduction device can display the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the audio/video reproduction device can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device can be instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

(11) According to yet still another aspect of the present invention, a volume control method for controlling, in a home theater system including an audio/video reproduction device, a display, and an audio output control device connected to the audio/video reproduction device via a communication medium, a sound volume of the audio output control device includes the steps of acquiring audio data in the audio/video reproduction device, transmitting the acquired audio data to the audio output control device from the audio/video reproduction device via the communication medium, receiving the audio data from the audio/video reproduction device via the communication medium in the audio output control device, outputting an audio signal from an amplifier based on the audio data received in the audio output control device, storing in a storage sound volume control status data including maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device and sound volume setting value data representing a sound volume of the audio output control device in the audio/video reproduction device, transmitting current sound volume control status data in the audio output control device from the audio output control device to the audio/video reproduction device at predetermined timing, updating, when the sound volume control status data has been received from the audio output control device in the audio/video reproduction device, the sound volume control status data stored in the storage with the received sound volume control status data, acquiring sound volume operation information representing a sound volume operation of the audio output control device in the audio/video reproduction device, determining sound volume setting value data after an operation based on the acquired sound volume operation information and the sound volume control status data stored in the storage in the audio/video reproduction device, transmitting a command including the determined sound volume setting value data from the audio/video reproduction device to the audio output control device, displaying in the display a ratio of the current sound volume of the audio output control device to a maximum value in the sound volume adjustable range of the audio output control device based on the determined sound volume setting value data and the maximum sound volume value data stored in the storage, and controlling, when the command including the sound volume setting value data has been received from the audio/video reproduction device in the audio output control device, a sound volume of the amplifier based on the received sound volume setting value data.

In the volume control method, the storage in the audio/video reproduction device stores the current sound volume control status data in the audio output control device. Therefore, the audio/video reproduction device can recognize the current sound volume of the audio output control device from the sound volume setting value data stored in the storage during the sound volume operation. Thus, the audio/video reproduction device can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of the transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The audio/video reproduction device can recognize the maximum value in the sound volume adjustable range of the audio output control device from the maximum sound volume value data stored in the storage. Thus, the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device can be displayed on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the audio/video reproduction device can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device can be instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

(12) According to a further aspect of the present invention, a volume control method for controlling, in an audio/video reproduction device connected to an audio output control device via a communication medium while being connected to a display, a sound volume of the audio output control device includes the steps of acquiring audio data, transmitting the acquired audio data to the audio output control device via the communication medium, storing in a storage sound volume control status data including maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device and sound volume setting value data representing a sound volume of the audio output control device, updating, when sound volume control status data has been received from the audio output control device, the sound volume control status data stored in the storage with the received sound volume control status data, acquiring sound volume operation information representing a sound volume operation of the audio output control device, determining sound volume setting value data after an operation based on the acquired sound volume operation information and the sound volume control status data stored in the storage, transmitting a command including the determined sound volume setting value data to the audio output control device, and displaying a ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device on the display based on the determined sound volume setting value data and the maximum sound volume value data stored in the storage.

In the volume control method, the storage in the audio/video reproduction device stores the current sound volume control status data in the audio output control device. Therefore, the audio/video reproduction device can recognize the current sound volume of the audio output control device from the sound volume setting value data stored in the storage during the sound volume operation. Thus, the audio/video reproduction device can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The audio/video reproduction device can recognize the maximum value in the sound volume adjustable range of the audio output control device from the maximum sound volume value data stored in the storage. Thus, the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device can be displayed on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the audio/video reproduction device can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device can be instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

(13) According to a still further aspect of the present invention, a volume control method for controlling a sound volume in an audio output control device connected to an audio/video reproduction device via a communication medium includes the steps of receiving audio data from the audio/video reproduction device via the communication medium, outputting an audio signal from an amplifier based on the received audio data, transmitting sound volume control status data including maximum sound volume value data representing a maximum value in a sound volume adjustable range of the audio output control device and sound volume setting value data representing a sound volume of the audio output control device to the audio/video reproduction device, and controlling, when a command including the sound volume setting value data has been received from the audio/video reproduction device, a sound volume of the amplifier based on the received sound volume setting value data.

According to the volume control method, the audio/video reproduction device can store the current sound volume control status data in the audio output control device. Therefore, the audio/video reproduction device can recognize the current sound volume of the audio output control device from the stored sound volume setting value data during the sound volume operation. Thus, the audio/video reproduction device can determine the sound volume setting value data without acquiring the current sound volume from the audio output control device. Therefore, the number of times of the transmission and receiving of the command between the audio/video reproduction device and the audio output control device can be reduced during the sound volume operation. As a result, the responsibility of sound volume adjustment can be increased.

The audio/video reproduction device can recognize the maximum value in the sound volume adjustable range of the audio output control device from the stored maximum sound volume value data. Thus, the audio/video reproduction device can display the ratio of the current sound volume of the audio output control device to the maximum value in the sound volume adjustable range of the audio output control device on the display. Therefore, a user can grasp the current sound volume relative to the maximum sound volume of the audio output control device. As a result, the user can intuitively grasp the current sound volume regardless of the type of the audio output control device.

In this case, the audio/video reproduction device can display the ratio of the current sound volume without transmitting and receiving the command to and from the audio output control device. Thus, the speed of sound volume display is increased. Therefore, a change in the sound volume of the audio output control device can be instantly reflected on a change in the sound volume display on the display.

From these results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

Advantageous Effects of Invention

According to the present invention, the operability and the responsibility of a sound volume operation are improved while high-precision sound volume adjustment can be made.

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention will be described in detail referring to the drawings. The embodiments below describe a home theater system.

(1) First Embodiment

(1-1) Configuration of Home Theater System1

FIG. 1is a block diagram illustrating a configuration of a home theater system1according to a first embodiment of the present invention.FIG. 1illustrates a home theater system1that is conformable to a 5.1 channel surround system arranged in a room.

InFIG. 1, a digital broadcasting conformable television receiver (hereinafter referred to as a digital television receiving device)100having a display screen is installed on a front surface of a user310. Front speakers311and312are installed on the left and right sides ahead of the user310. A center speaker313is arranged on the front surface of the user310. A subwoofer speaker314is installed in a suitable location ahead of the user310. Surround speakers315and316are respectively installed on the left and the right behind the user310.

The front speakers311and312, the center speaker313, the subwoofer speaker314, and the surround speakers315and316are hereinafter merely abbreviated as speakers311to316if they need not be distinguished.

The digital television receiving device100contains two small-sized speakers for stereo reproduction. In order to reproduce an audio of digital television broadcasting using the 5.1 channel surround system, a home theater device200and the speakers311and316are connected to the digital television receiving device100. The home theater system1is thus configured. The home theater system1enables the user310to enjoy stereophonic reproduction with a realistic sensation that the user310feels as if he/she were in a movie theater, a concert hall, or a sports stadium while staying at home.

The digital television receiving device100and the home theater device200are connected to each other via an HDMI cable320conforming to an HDMI (High-Definition Multimedia Interface) standard. The HDMI cable320includes a data line321for transmitting and receiving video/audio data (video data and audio data) and a CEC signal line322for transmitting and receiving a CEC (Consumer Electronic Control) command for performing control between devices.

The home theater device200decodes 5.1 channel audio data, and drives the speakers311and316with an amplifier, described below. The 5.1 channel audio data is included in a broadcast signal, and is compressed in an AC-3 (Audio Code number 3) system, for example. The home theater device200makes sound volume adjustment and sound volume control such as mute according to an operation of a remote control device301by the user310in cooperation with the digital television receiving device100.

In the home theater system1according to the present embodiment, a portion, excluding the display103(seeFIG. 2), in the digital television receiving device100, is used as an audio/video reproduction device, the home theater device200is used as an audio output control device, and the display103(seeFIG. 2) in the digital television receiving device100is used as a display.

(1-2) Configuration of Digital Television Receiving Device and Home Theater Device

FIG. 2is a block diagram illustrating a detailed configuration of the digital television receiving device100and the home theater device200in the home theater system1illustrated inFIG. 1.

The digital television receiving device100and the home theater device200are connected to each other via the HDMI cable320. The digital television receiving device100can selectively be set to a television mode and a theater mode. The home theater device200can selectively be set to a theater mode or a mute status.

The theater mode is a mode in which audio based on audio data obtained by the digital television receiving device100is not output from a speaker contained in the digital television receiving device100, described below, but output from speakers311to316connected to the home theater device200. On the other hand, the television mode is a mode in which audio based on audio data obtained by the digital television receiving device100is output from a built-in speaker, described below.

A configuration of the digital television receiving device100will be first described. As illustrated inFIG. 2, the digital television receiving device100includes a tuner101, a decoder102, a display103, an audio outputor104, an HDMI transmitter/receiver105, a CPU106, a memory107, and a remote control light receiver108. The tuner101and the decoder102constitute a content supply source110. A remote control device301is attached to the digital television receiving device100.

The tuner101receives, tunes, and demodulates a digital broadcast signal in terrestrial digital broadcasting, digital satellite broadcasting, or the like, and outputs a video signal and an audio signal having a selected content. The demodulator102decodes a video signal and an audio signal output from the tuner101, and outputs video data and audio data. The display103displays video on a screen based on the video data output from the decoder102. The audio outputor104includes two speakers, and outputs audio from the speakers based on the audio data output from the decoder102.

The remote control device301includes a sound volume operation button for a sound volume operation. The sound volume operation includes sound volume adjustment, mute setting, and mute release. The sound volume operation button includes a sound volume up button for increasing a sound volume, a sound volume down button for decreasing a sound volume, and a mute button for issuing instructions to perform mute setting and mute release. The user310can perform sound volume operations of the speakers in the audio outputor104and the speakers311to316using the sound volume operation button in the remote control device301. In this case, the remote control device301transmits sound volume operation information corresponding to an operation of the sound volume operation button as a light signal. The remote control light receiver108converts, when it has received the sound volume operation information from the remote control device301as a light signal, the light signal into an electric signal, and feeds the electric signal to the CPU106as the sound volume operation information.

If the digital television receiving device100is set to a television mode, the CPU106controls a sound volume of the audio output from the speakers in the audio outputor104based on the sound volume operation information while on-screen displaying the controlled sound volume on the display103. If the digital television receiving device100is set to the theater mode, the CPU106controls a sound volume of the audio output from the speakers311to316in the home theater system1through the home theater device200while on-screen displaying the controlled sound volume on the display103.

The memory107stores status data relating to sound volume control (hereinafter referred to as sound volume control status data) in the home theater device200at the current time point. The sound volume control status data includes maximum sound volume value data, sound volume setting value data, and mute setting status data in the home theater device200.

The maximum sound volume value data is data representing a maximum value in a sound volume adjustable range of the home theater device200. The sound volume control status data may include minimum sound volume value data representing a minimum value in the sound volume adjustable range. If the sound volume control status data does not include minimum sound volume value data, the minimum sound volume value data is zero, for example.

The sound volume setting value data is data representing a value (level) of a sound volume set in the home theater device200. The mute setting status data is data indicating whether the home theater device200is set to a mute status.

The display103includes a cathode ray tube, a liquid crystal display, a plasma display, or the like. The display103has a screen for displaying video of digital broadcasting. The display103displays the current sound volume of the speakers in the audio outputor104or the speakers311to316with the current sound volume superimposed on the video in the digital broadcasting based on the control of the CPU106.

The HDMI transmitter/receiver105communicates with the HDMI transmitter/receiver205in the home theater device200, described below, to transmit video/audio data and a CEC command to the home theater device200and receive a CEC command from the home theater device200. In the HDMI standard, the video/audio data is transmitted in one direction from the HDMI transmitter/receiver105to the HDMI transmitter/receiver205, and the CEC commands are bidirectionally transmitted between the HDMI transmitter/receiver105and the HDMI transmitter/receiver205.

The digital television receiving device100can easily perform sound volume bar display by storing in the memory107both the maximum sound volume value data and the sound volume setting value data at the current time point in the home theater device200. The sound volume bar display refers to display of a sound volume depending on the length of a bar. In the present embodiment, a bar representing a sound volume adjustable range (hereinafter referred to as an adjustable range bar) and a bar representing the current sound volume (hereinafter referred to as a sound volume bar) are displayed on a screen of the display103, as described below.

A configuration of the home theater device200will be described below. As illustrated inFIG. 2, the home theater device200includes a sound volume operator201, a memory202, an amplifier203, a CPU204, and an HDMI transmitter/receiver205.

The sound volume operator201is provided for the user310to directly perform the sound volume operation for the home theater device200when the digital television receiving device100is set to the theater mode. The sound volume operator201includes a sound volume up button for increasing a sound volume, a sound volume down button for decreasing a sound volume, and a mute button for issuing instructions to perform mute setting and mute release. Thus, during the theater mode, the user310can perform not only the sound volume operation using the remote control device301but also the sound volume operation using the sound volume operator201in the home theater device200. The sound volume operator201may include a volume adjustment knob of a rotary dial type. In this case, sound volume adjustment with an analog feeling becomes more possible than that in an operation for pressing the sound volume operation button. Some or all of the sound volume up button, the sound volume down button, the mute button, and the volume adjustment knob in the sound volume operator201may be provided in a main body of the home theater device200, or may be provided in a remote control device attached to the home theater device200.

The memory202stores current sound volume control status data in the amplifier203based on the control of the CPU204.

The HDMI transmitter/receiver205communicates with the HDMI transmitter/receiver105in the digital television receiving device100, to receive the video/audio data and a CEC command from the digital television receiving device100and transmit the CEC command to the digital television receiving device100.

The CPU204receives the CEC command and the video/audio data from the CPU106in the digital television receiving device100via the HDMI transmitter/receiver205. The CPU204interrupts the CEC command, and controls an amplification factor (gain) of the amplifier203based on an interruption result. The CPU204controls the amplification factor of the amplifier203based on an instruction from the sound volume operator201.

The amplifier203converts the audio data into an analog audio signal, amplifies the analog audio signal at a controlled amplification factor, and drives the speakers311to316based on the amplified analog audio signal. Thus, audio the sound volume of which has been controlled is output from the speakers311to316.

(1-3) Schematic Operation of Digital Television Receiving Device and Home Theater Device

The outline of operations of the digital television receiving device100and the home theater device200during the sound volume operation will be described. The digital television receiving device100is set to the theater mode.

First, during the sound volume operation (sound volume adjustment, mute setting, or mute release), when the user310presses the sound volume operation button in the remote control device301, the CPU106in the digital television receiving device100acquires sound volume operation information corresponding to an operation of the sound volume operation button via the remote control light receiver108. The CPU106then transmits the CEC command corresponding to the sound volume operation information to the CPU204in the home theater device200via the HDMI transmitter/receiver105, the HDMI cable320, and the HDMI transmitter/receiver205. The CEC command includes sound volume setting value data.

The CPU204interprets the received CEC command, to extract the sound volume setting value data from the CEC command and set the extracted sound volume setting value data in the amplifier203. The CPU204causes the memory202to store the extracted sound volume setting value data. Thus, the amplification factor of the amplifier203is controlled based on the sound volume setting value data. As a result, the sound volume of the audio output from the speakers311to316is controlled.

An operation for the digital television receiving device100to acquire the sound volume control status data from the home theater system200will be described below. The CPU106in the digital television receiving device100transmits the CEC command for requesting the sound volume control status data to the CPU204in the home theater device200via the HDMI transmitter/receiver105, the HDMI cable320, and the HDMI transmitter/receiver205.

The CPU204interprets the received CEC command, to acquire the current sound volume setting value data set in the amplifier203. Further, the CPU204causes the memory202to store the acquired sound volume setting value data while transmitting the CEC command including the sound volume control status data to the CPU106in the digital television receiving device100via the HDMI transmitter/receiver205, the HDMI cable320, and the HDMI transmitter/receiver105. The sound volume control status data includes the maximum sound volume value data, the sound volume setting value data, and the mute setting status data.

The CPU106interprets the received CEC command, to extract the sound volume control status data from the CEC command, and cause the memory107to store the extracted sound volume control status data. The CPU106on-screen displays the adjustable range bar and the sound volume bar on the screen of the display103based on the maximum sound volume value data and the sound volume setting value data included in the extracted sound volume control status data.

The sound volume of the audio output from the speakers311to316will be referred to as a sound volume of the amplifier203and a sound volume of the home theater device200.

(1-4) Example of Sound Volume Bar Display

FIGS. 3aand 3billustrate an example of sound volume bar display in the home theater system1according to the first embodiment. In an example illustrated inFIG. 3a, a sound volume bar display401on the screen of the display103includes an adjustable range bar402representing the sound volume adjustable range of the home theater device200, a sound volume bar403representing the current sound volume of the home theater device200, and a number404representing a ratio of the current sound volume of the home theater device200. In an example illustrated inFIG. 3b, the sound volume bar display401on the screen of the display103includes an adjustable range bar402representing the sound volume adjustable range of the home theater device200and a sound volume bar403representing the current sound volume of the home theater device200.

The length L1of the whole adjustable range bar402corresponds to the maximum value in the sound volume adjustable range of the home theater device200. The length L2of the sound volume bar403corresponds to the current sound volume of the home theater device200. Therefore, a ratio of the length L2of the sound volume bar403to the length L1of the adjustable range bar402represents a ratio of the current sound volume to the sound volume adjustable range. The number404illustrated inFIG. 3arepresents the ratio of the current sound volume to the sound volume adjustable range.

When the digital television receiving device100and the home theater device200are set to the theater mode, as described below, the digital television receiving device100acquires the sound volume control status data from the home theater device200. The sound volume bar display401illustrated inFIGS. 3aand 3bcan be performed based on the maximum sound volume value data and the sound volume setting value data included in the sound volume control status data.

It is assumed that the maximum sound volume value data is 100, and the minimum sound volume value data is zero, for example. In this case, if the sound volume setting value data at the current time point is 50, the sound volume bar403having a length L2corresponding to 50 percent of the length L1of the adjustable range bar402(the maximum length of the sound volume bar403) is displayed. 50 percent of the current sound volume is displayed by the number404.

Alternatively, the sound volume bar403may be displayed by dB (decibel) conversion of the maximum audio value data and the sound volume setting value data. It is assumed that the maximum audio value data is 100, and the minimum sound volume value data is one, for example. In this case, the sound volume adjustable range is 0 dB to +40 dB. If the sound volume setting value data at the current time point is 40, 20 log 40=+32 [dB]. Therefore, the current sound volume is +32 dB. In this case, the ratio of the current sound volume to the sound volume adjustable range is 32/40=80[%]. Therefore, the sound volume bar403having a length L2corresponding to 80 percent of the length L1of the adjustable range bar402is displayed. 80 percent of the current sound volume is displayed by the number404.

In the examples illustrated inFIGS. 3aand 3b, the user310can intuitively and visually recognize the current sound volume of the home theater device200based on the ratio of the length L2of the sound volume bar403to the length L1of the adjustable range bar402. In the example illustrated inFIG. 3a, the user310can recognize the accurate ratio of the sound volume of the home theater device200based on the number404.

(1-5) Detailed Operation of Home Theater System

A sound volume control operation of the home theater system1according to the present embodiment will be described below. The sound volume control operation, described below, is performed when the CPU106in the digital television receiving device100executes a program stored in the memory107while the CPU204in the home theater device200executes a program stored in the memory202.

Thus, control operation subjects of the digital television receiving device100and the home theater device200are respectively the CPU106and the CPU204. In order to simplify the illustration, the digital television receiving device100and the home theater device200will be described below as operation subjects. A CEC command is abbreviated as a command, as needed.

A mute setting status refers to a state where an analog audio signal is not output to the speakers311to316from the amplifier203. In this case, audio is not output from the speakers311to316. A mute release status refers to a state where an analog audio signal is output to the speakers311to316from the amplifier203. In this case, audio is output from the speakers311to316.

In a sequence diagram, described below, mute setting and mute release are respectively written as “mute ON” and “mute OFF”. The mute setting status and the mute release status are respectively written as “mute=ON status” and “mute=OFF status”.

Minimum sound volume value data is zero. Mute setting status data represents a mute setting status (mute ON) and a mute release status (mute OFF).

(a) Setting Operation to Theater Mode

FIG. 4is a sequence diagram illustrating transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200during a theater mode setting operation.FIG. 4illustrates a control operation performed when the remote control device301performs the theater mode setting operation.

InFIG. 4, when the remote control device301issues an instruction to set the theater mode, the digital television receiving device100first transmits a <Request to switch to Theater mode> command to the home theater device200(step S201). This command is a command for requesting switching to the theater mode. The home theater device200releases a mute status of the amplifier203while setting the amplifier203to the theater mode in response to the command received in step S201. Then, the home theater device200transmits a <Reply completion of Theater mode> command to the digital television receiving device100(step S202). This command is a command indicating that the setting of the theater mode is completed. Since then, the home theater device200enters a state where audio data transmitted from the digital television receiving device100can be reproduced.

The digital television receiving device100continues to transmit an <Acquire volume status> command to the home theater device200(step S203). This command is a command for requesting the sound volume control status data. The home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X (current volume)] command to the digital television receiving device100in response to the command received in step S203(step S204). This command is a command for notifying maximum sound volume value data, a mute release status, and current sound volume setting value data “X” as the sound volume control status data. The digital television receiving device100stores the sound volume control status data received in step S204in the memory107.

Thus, the home theater device200is set to the theater mode while the current sound volume control status data is transmitted from the home theater device200to the digital television receiving device100. Thus, the sound volume control status data stored in the memory107in the digital television receiving device100is updated with the newest sound volume control status data.

(b) Sound Volume Adjusting Operation by Single Pressing

In the following description, pressing the sound volume operation button once means an operation for the user310to press the sound volume operation button once (one push operation) for a shorter time than a predetermined time (e.g., 300 ms). A sound volume value (a sound volume level) of the home theater device200is changed by “1” by pressing the sound volume operation button once.

FIG. 5is a sequence diagram illustrating transmission and receiving of a CEC command between the digital television receiving device100and the home theater device200during a sound volume adjusting operation by pressing the sound volume operation button once.FIG. 5illustrates an operation for controlling sound volume adjustment made when a sound volume increasing operation is performed by pressing the sound volume up button once. InFIG. 5, the sound volume value being increased by “1” is displayed as “up volume by 1”.

The digital television receiving device100determines sound volume setting value data to be transmitted to the home theater device200from audio operation information indicating that the sound volume up button in the remote control device301has been pressed and the sound volume setting value data in the sound volume control status data stored in the memory107. At this time, the sound volume control status data stored in the memory107indicates that the current sound volume setting value data in the home theater device200is “X”.

The digital television receiving device100transmits a <Set the volume status with> [“Mute Off”, X+1] command to the home theater device200based on the sound volume setting value data stored in the memory107(step S211). This command is a command for releasing a mute status of the amplifier203while setting sound volume setting value data “X+1” in the amplifier203. The home theater device200releases the mute status of the amplifier203while setting the sound volume setting value data “X+1” based on the command received in step S211.

Then, the digital television receiving device100updates the sound volume setting value data stored in the memory107to the newest sound volume setting value data “X+1” while on-screen displaying a sound volume bar based on the sound volume setting value data “X+1” on the screen of the display103.

If a sound volume decreasing operation is performed by pressing the sound volume down button once, a <Set the volume status with> [“Mute Off”, X−1] command is transmitted instead of the <Set the volume status with> [“Mute Off”, X+1] command in step S211from the digital television receiving device100to the home theater device200. This command is a command for releasing the mute status of the amplifier203while setting sound volume setting value data “X−1” in the amplifier203. Another operation during the sound volume decreasing operation is similar to the operation during the sound volume increasing operation.

Thus, the sound volume value of the home theater device200is changed by “1” by transmitting the CEC command in one step from the digital television receiving device100to the home theater device200. Thus, the responsibility of the sound volume adjustment can be improved.

(c) Sound Volume Adjusting Operation by Long Pressing

In the following description, pressing the sound volume operation button long means an operation for the user310to continuously press the sound volume operation button (a continuous sound volume adjusting operation) for a longer time than a predetermined time (e.g., 300 ms). The sound volume value (the sound volume level) of the home theater device200is changed by “2” or more by pressing the sound volume operation button long.

FIGS. 6 and 7are sequence diagrams illustrating transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200during a sound volume adjusting operation by pressing the sound volume operation button long.FIGS. 6 and 7illustrate an operation for controlling sound volume adjustment made when a sound volume increasing operation is performed by pressing the sound volume up button long.FIG. 6illustrates an example in which the sound volume setting value data is continuously increased by one.FIG. 7illustrates an example in which the sound volume setting value data is increased by a predetermined value larger than one. InFIGS. 6 and 7, the sound volume value (the sound volume level) of the home theater device200being increased by “1” to “5” are respectively displayed as “up sound volume by 1” and “up sound volume by 5”.

First, in the example illustrated inFIG. 6, the sound volume control status data stored in the memory107indicates that the current sound volume setting value data of the home theater device200is “X”.

When the user310presses the sound volume up button in the remote control device301, the digital television receiving device100transmits a <Set the volume status with> [“Mute Off”, X+1] command to the home theater device200based on the sound volume setting value data stored in the memory107(step S221). This command is a command for releasing the mute status of the amplifier203while setting sound volume setting value data “X+1” in the amplifier203. The home theater device200releases the mute status of the amplifier203while setting the sound volume setting value data “X+1” in the amplifier203based on the command received in step S221.

The digital television receiving device100transmits a command <Set the volume status with> [“Mute Off”, X+2] command to the home theater device200after a predetermined standby time T1(e.g., 300 ms) (step S222). This command is a command for maintaining a mute release status of the amplifier203while setting sound volume setting value data “X+2” in the amplifier203. The home theater device200sets the sound volume setting value data “X+2” in the amplifier203based on the command received in step S222.

The digital television receiving device100determines that the sound volume up button is pressed long through a lapse of a standby time T1. Thus, the digital television receiving device100sends a command for maintaining the mute release status of the amplifier203while setting sound volume setting value data that increases by one in the amplifier203for each lapse of a short period T2(e.g., 150 ms) (steps S223to S227). More specifically, the digital television receiving device100sequentially transmits commands respectively including sound volume setting value data “X+3”, “X+4”, “X+5”, “X+6” and “X+7” to the home theater device200in steps S223to S227. The home theater device200sequentially sets the sound volume setting value data “X+3”, “X+4”, “X+5”, “X+6” and “X+7” in the amplifier203based on the commands received in steps S223to S227.

During this time, the digital television receiving device100updates the sound volume setting value data stored in the memory107with the newest sound volume setting value data “X+1” to “X+7” while on-screen displaying a sound volume bar based on the sound volume setting value data “X+1” to “X+7” on the screen of the display103.

In the example illustrated inFIG. 6, after the digital television receiving device100transmits a <Set the volume status with> [“Mute Off”, X+7] command to the home theater device200(after step S227), the sound volume up button is released. Thus, the digital television receiving device100finishes transmitting the CEC commands.

Thus, the remote control device301in the digital television receiving device100can finely adjust the sound volume level of the home theater device200by one.

If the sound volume decreasing operation is performed by pressing the sound volume down button long, CEC commands respectively including sound volume setting value data “X−1”, “X−2”, “X−3”, “X−4”, “X−5”, “X−6” and “X−7” are transmitted instead of the CEC commands respectively including the sound volume setting value data “X+1”, “X+2”, “X+3”, “X+4”, “X+5”, “X+6” and “X+7” from the digital television receiving device100to the home theater device200. Another operation during the sound volume decreasing operation is similar to the operation during the sound volume increasing operation.

The processes in steps S233and S235illustrated inFIG. 7differ from the processes in steps S223and S225illustrated inFIG. 6. More specifically, in the example illustrated inFIG. 6, the digital television receiving device100transmits the <Set the volume status with> [“Mute Off”, X+2] command to the home theater device200in step S223, and transmits a <Set the volume status with> [“Mute Off”, X+5] command thereto in step S225. On the other hand, in the example illustrated inFIG. 7, the digital television receiving device100stops transmitting the CEC commands to the home theater device200, respectively, in steps S233and S235.

If the sound volume decreasing operation is performed by pressing the sound volume down button long, CEC commands respectively including sound volume setting value data “X−1”, “X−2”, “X−4”, “X−6” and “X−7” are transmitted instead of the CEC commands respectively including the sound volume setting value data “X+1”, “X+2”, “X+4”, “X+6” and “X+7” from the digital television receiving device100to the home theater device200. Another operation during the sound volume decreasing operation is similar to the operation during the sound volume increasing operation.

Thus, the sound volume setting value data are thinned so that the number of times of transmission and receiving of the CEC commands is reduced. Thus, a CEC command transmission interval is shortened so that the sound volume of the home theater device200can be quickly adjusted.

(d) Mute Setting Operation and Mute Releasing Operation

FIG. 8is a sequence diagram illustrating transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200during a mute setting operation.FIG. 8illustrates an operation for controlling mute setting performed when the mute setting operation is performed by the mute button.

When the user310performs the mute setting operation by pressing the mute button in the remote control device301, the digital television receiving device100transmits a <Set the volume status with> [“Mute On”, X] command to the home theater device200(step S241). This command is a command for setting the amplifier203to a mute status while setting sound volume setting value data “X” in the amplifier203.

The home theater device200is responsive to the command received in step S241, to set the amplifier203to the mute status while setting the sound volume setting value data “X” in the amplifier203. The home theater device200transmits a <Notify with> [Max Value] [“Mute On”, X] command to the digital television receiving device100(step S242). This command is a command for notifying maximum sound volume value data, a mute setting status, and the sound volume setting value data “X” as the sound volume control status data. The digital television receiving device100updates the sound volume control status data stored in the memory107with the sound volume control status data received in step S242.

If the mute releasing operation is performed, a <Set the volume status with>[“Mute Off”, X] command is transmitted instead of the <Set the volume status with>[“Mute On”, X] command from the digital television receiving device100to the home theater device200in step S241. A <Notify with> [Max Value] [“Mute Off”, X] command is transmitted instead of the <Notify with> [Max Value] [“Mute On”, X] command from the home theater device200to the digital television receiving device100in step S242.

Thus, even when the sound volume operator201performs a sound volume adjusting operation in the home theater device200, the digital television receiving device100can acquire the newest sound volume control status data in the home theater device200during the mute setting operation or the mute releasing operation.

High-speed responsibility is not requested for the mute setting operation and the mute releasing operation. Therefore, the sound volume control status data is transmitted from the home theater device200to the digital television receiving device100during the mute setting operation and the mute releasing operation so that the sound volume control status data stored in the memory107can be updated to the newest sound volume control status data without deteriorating the responsibility of the sound volume adjusting operation.

(1-6) Effects of First Embodiment

Thus, in the home theater system1according to the present embodiment, when the digital television receiving device100and the home theater device200are set to the theater mode, the CPU106in the digital television receiving device100acquires the current sound volume control status data in the home theater device200, and updates the sound volume setting value data stored in the memory107with the acquired sound volume setting value data. Thus, the CPU106can recognize the current sound volume of the home theater device200from the sound volume setting value data stored in the memory107during an audio operation. Thus, the CPU106can determine the sound volume setting value data after the operation without acquiring the current sound volume from the home theater device200. Therefore, the number of times of transmission and receiving of the CEC commands between the digital television receiving device100and the home theater device200can be reduced during the sound volume operation. As a result, the responsibility of the sound volume operation can be increased.

If the sound volume of the home theater device200is changed using the sound volume operation by the remote control device301, the newest sound volume setting value data is stored in the memory107. Therefore, the continuity of the sound volume operation can be maintained.

The CPU106can recognize the maximum value in the sound volume adjustable range of the home theater device200from the maximum audio value data stored in the memory107. Thus, the ratio of the current sound volume of the home theater device200to the maximum value of the sound volume adjustable range of the home theater device200can be displayed on the screen of the display103.

Particularly, the user310can intuitively and visually grasp the current sound volume based on the ratio of the length of the sound volume bar403to the length of the adjustable range bar402in the sound volume bar display401regardless of the type of the home theater device200.

In this case, the CPU106can display the ratio of the current sound volume without transmitting and receiving the CEC commands to and from the home theater device200. Thus, the speed of the sound volume display is increased. Therefore, the change in the sound volume of the home theater device200is instantly reflected on the change in the sound volume display on the display103.

From the foregoing results, the operability and the responsibility of the sound volume operation are improved while high-precision sound volume adjustment can be made.

Thus, the control operation in the present embodiment can be easily implemented by using the above-mentioned CEC commands.

(2) Second Embodiment

A configuration of a home theater system1according to a second embodiment is similar to the configuration of the home theater system1illustrated inFIG. 1. Configurations of a digital television receiving device100and a home theater device200according to the second embodiment are similar to those illustrated inFIG. 2. The second embodiment differs from the first embodiment in control operations, described below, of a CPU106in the digital television receiving device100and a CPU204in the home theater device200.

(2-1) Detailed Operation of Home Theater System1

FIG. 9is a sequence diagram illustrating transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200by a sound volume adjusting operation in the home theater device200.FIG. 9illustrates control operations performed when a user310presses a sound volume up button in a sound volume operator201of the home theater device200once, presses a volume adjustment knob, and presses a mute button in a time-series manner.

In an example illustrated inFIG. 9, current sound volume setting value data in the home theater device200is “X”.

First, when the user310presses the sound volume up button in the sound volume operator201once, the home theater device200releases a mute status of an amplifier203while setting sound volume setting value data “X+1” in the amplifier203. The home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X+1] command to the digital television receiving device100(step S243). This command is a command for notifying maximum sound volume value data, a mute release status, and the sound volume setting value data “X+1” in the home theater device200as sound volume control status data.

The digital television receiving device100updates sound volume control status data stored in a memory107with the sound volume control status data received in step S243. Since then, the digital television receiving device100uses the updated sound volume control status data in the memory107when a remote control device301performs a sound volume adjusting operation. Thus, continuity of the sound volume control status data is kept depending on whether the sound volume operator201in the home theater device200makes sound volume adjustment and the remote control device301in the digital television receiving device100makes sound volume adjustment.

A case where the user310turns the volume adjustment knob in the sound volume operator201will be described below. The user310can make sound volume adjustment with an analog operating feeling by turning the volume adjustment knob. The user310can make high-speed sound volume adjustment by rotating the volume adjustment knob fast. The home theater device200increases the sound volume setting value data by “1” every time the volume adjustment knob rotates through a predetermined angle in a clockwise direction. The home theater device200decreases the sound volume setting value data by “1” every time the volume adjustment knob rotates through a predetermined angle in a counterclockwise direction.

When the user310starts to turn the volume adjustment knob, the home theater device200sets sound volume setting value data “X+2” in the amplifier203. The home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X+2] command to the digital television receiving device100(step S251). This command is a command for notifying maximum sound volume data, a mute release status, and the sound volume setting value data “X+2” as the sound volume control status data. The digital television receiving device100updates the sound volume control status data stored in the memory107with the sound volume control status data received in step S251.

If the rotational speed of the volume adjustment knob is low, and it takes a predetermined time T3(e.g., 100 ms) for the sound volume setting value data to increase by “1”, the home theater device200transmits a command for notifying the sound volume control status data to the digital television receiving device100every time the sound volume setting value data increases by “1”. For example, the home theater device200transmits a <Notify with>[Max Value] [“Mute Off”, X+3] command to the digital television receiving device100(step S252). This command is a command for notifying maximum sound volume data, a mute release status, and sound volume setting value data “X+3” as the sound volume control status data. The digital television receiving device100updates the sound volume control status data stored in the memory107with the sound volume control status data received in step S252.

In the example illustrated inFIG. 9, the home theater device200transmits the commands including sound volume setting value data that increase by “1” to the digital television receiving device100until the sound volume setting value data increase to “X+15”. The digital television receiving device100sequentially updates the sound volume setting value data stored in the memory107with the received sound volume setting value data.

InFIG. 9, illustration about transmission of the commands until the sound volume setting value data increases from “X+4” to “X+14” is omitted. The home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X+15] command to the digital television receiving device100(step S253). This command is a command for notifying maximum sound volume value data, a mute release status, and sound volume setting value data “X+15” as the sound volume control status data. The digital television receiving device100updates the sound volume control status data stored in the memory107with the sound volume control status data received in step S253.

The CEC commands are then illustrated when the user310increases the rotational speed of the volume adjustment knob. If a period of time during which the sound volume setting value data increases is shorter than a time interval (a predetermined time T3) in which the CEC commands can be transmitted, the home theater device200sets an amount of increase in the sound volume setting value data to a value larger than “1”.

In the example illustrated inFIG. 9, the home theater device200transmits a command including sound volume setting value data, which increases by “5”, to the digital television receiving device100. The home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X+20] command to the digital television receiving device100(step S254). This command is a command for notifying maximum sound volume value data, a mute release status, and sound volume setting value data “X+20” as the sound volume control status data. If the user310further turns the volume adjustment knob at a faster rotational speed, the home theater device200transmits a <Notify with> [Max Value] [“Mute Off”, X+25] command to the digital television receiving device100(step S255). This command is a command for notifying maximum sound volume value data, a mute release status, and sound volume setting value data “X+25” as the sound volume control status data.

The digital television receiving device100sequentially updates the sound volume control status data stored in the memory107with the sound volume control status data received in steps S254and S255.

When the user310presses the mute button in the sound volume operator201, the home theater device200then sets the amplifier203to a mute status. The home theater device200transmits a <Notify with> [Max Value] [“Mute On”, X+25] command to the digital television receiving device100(step S261). This command is a command for notifying maximum sound volume value data, a mute setting status, and the current sound volume setting value data “X+25” as the sound volume control status data. The digital television receiving device100updates the sound volume control status data stored in the memory107with the sound volume control status data received in step S261.

A theater mode setting operation, a sound volume adjusting operation by single pressing, a sound volume adjusting operation by long pressing, a mute setting operation, and a mute releasing operation in the home theater system1according to the second embodiment are similar to those in the first embodiment.

(2-2) Effects of Second Embodiment

In the home theater system1according to the second embodiment, when the sound volume operation of the home theater device200is performed on the side of the home theater device200, the sound volume setting value data after the sound volume operation is transmitted from the home theater device200to the digital television receiving device100. Thus, the newest sound volume setting value data is stored in the memory107every time the sound volume operator201in the home theater device200performs the sound volume operation. As a result, even when the sound volume operation is performed on the side of the digital television receiving device100after the sound volume operation is performed on the side of the home theater device200, the continuity of the sound volume operation can be maintained.

In this case, the CEC command is also transmitted in one step every time a status of the sound volume operation button changes. If the rotational speed of the volume adjustment knob is high, the sound volume setting value data are thinned so that the number of times of transmission of the CEC command is reduced. Thus, the quickness of the sound volume display of the digital television receiving device100is not deteriorated.

(3) Operation of Reference Example

As to an operation of a reference example described below, the current sound volume setting value data in the home theater device200is not stored in the memory107in the digital television receiving device100. Thus, the digital television receiving device100is required to acquire the current sound volume setting value data in the home theater device200from the home theater device200every time the sound volume operation is performed.

In the reference example, the sound volume control status data is replaced with sound volume status data including no maximum sound volume value data. The sound volume status data includes sound volume setting value data and mute setting status data. Thus, the digital television receiving device100displays a value of the current sound volume of the home theater device200by a number on the display103. The same sound volume may be represented by different values depending on the type of the home theater device200. Therefore, it is difficult for the user310to intuitively grasp the sound volume of the home theater device200.

(a) Sound Volume Adjusting Operation by Single Pressing

FIG. 10is a sequence diagram illustrating a reference example of transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200during a sound volume adjusting operation by pressing the sound volume operation button once.FIG. 10illustrates an operation for controlling sound volume adjustment made when a sound volume increasing operation is performed by pressing the sound volume up button once.

The digital television receiving device100is set to a theater mode, the current sound volume setting value data is “X”, and the amplifier203is set to a mute status.

First, when the user310presses the sound volume up button in the remote control device301once, the digital television receiving device100transmits a <User Control Pressed> [“Volume Up”] command to the home theater device200(step S101). This command is a command indicating that the user310has pressed the sound volume up button.

When the user310releases the sound volume up button in the remote control device301, the digital television receiving device100transmits a <User Control Released> command to the home theater device200(step S102). This command is a command indicating that the user310has released the sound volume operation button.

The home theater device200recognizes that the user310has pressed the sound volume up button once by the commands received in steps S101and S102. Thus, the home theater device200increases the sound volume setting value data by “1”. As a result, the current sound volume setting value data is “X+1”.

The digital television receiving device100continues to transmit a <Give Audio Status> command to the home theater device200to acquire the current sound volume setting value data in the home theater device200(step S103). This command is a command for requesting the sound volume status data.

The home theater device200transmits a <Report Audio Status> [“Mute Off”, X+1] command to the digital television receiving device100in response to the command received in step S103(step S104). This command is a command for notifying a mute release status and sound volume setting value data “X+1” as the sound volume status data.

The digital television receiving device100confirms that the current sound volume setting value data is “X+1” based on the sound volume status data received in step S104while performing sound volume value display by a number based on the sound volume setting value data “X+1” on the screen of the display103.

If a sound volume decreasing operation is performed by pressing the sound volume down button once, a <User Control Pressed> [“Volume Down”] command is transmitted instead of the <User Control Pressed> [“Volume Up”] command in step S101from the digital television receiving device to the home theater device. A <Report Audio Status> [“Mute Off”, X−1] command is transmitted instead of the <Report Audio Status> [“Mute Off”, X+1] command in step S104from the home theater device to the digital television receiving device. Another operation during the sound volume decreasing operation is similar to an operation during a sound volume increasing operation.

Thus, in the sound volume adjusting operation by single pressing in the reference example, the CEC commands are required to be transmitted and received in four steps to change a sound volume value of the home theater device200by “1”. Therefore, the responsibility of the sound volume operation becomes lower than that in the sound volume adjusting operation by single pressing illustrated inFIG. 5.

(b) Sound Volume Adjusting Operation by Long Pressing

FIG. 11is a sequence diagram illustrating a reference example of transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200during the sound volume adjusting operation by pressing the sound volume operation button long.FIG. 11illustrates an operation for controlling sound volume adjustment made when a sound volume increasing operation is performed by pressing the sound volume up button long.

The digital television receiving device100is set to a theater mode, the current sound volume setting value data is “X”, and the amplifier203is set to a mute status.

First, when the user310presses the sound volume up button in the remote control device301long, the digital television receiving device100transmits a <User Control Pressed> [“Volume Up”] command to the home theater device200(step S111).

In this case, the sound volume up button is pressed long. Thus, the digital television receiving device100does not immediately transmit the <User Control Released> command in step S102illustrated inFIG. 10to the home theater device200but transmits a <Give Audio Status> command to the home theater device200(step S112).

The home theater device200increases the sound volume setting value data by “1” because it recognizes that the user310has pressed the sound volume up button long in steps S111and S112. As a result, the current sound volume setting value data becomes “X+1”.

The home theater device200transmits a <Report Audio Status> [“Mute Off”, X+1] command to the digital television receiving device100(step S113). The digital television receiving device100performs sound volume value display based on the sound volume setting value data “X+1”.

If the sound volume up button continues to be pressed, the digital television receiving device100transmits a <User Control Pressed> [“Volume Up”] command to the home theater device200again (step S114).

Processes in steps S115and S116are similar to the processes in steps S112and S113. In step S116, sound volume setting value data “X+2” is transmitted from the home theater device200to the digital television receiving device100. The digital television receiving device100performs sound volume value display based on the sound volume setting value data “X+2”.

If a long-pressing operation of the sound volume up button is further continued, processes in steps S117, S118and S119, which are similar to the processes in steps S114, S115and S116, are performed. In step S119, sound volume setting value data “X+3” is transmitted from the home theater device200to the digital television receiving device100. The digital television receiving device100performs sound volume value display based on the sound volume setting value data “X+3”.

Thus, during a period of the long-pressing operation of the sound volume up button, the sound volume setting value data is transmitted from the home theater device200to the digital television receiving device100in steps S113, S116and S119. Thus, the digital television receiving device100can perform sound volume value display based on the sound volume setting value data that changes.

When the user310releases the sound volume up button, the digital television receiving device100transmits a <User Control Released> command (step S120). Thus, an operation for controlling an increase in the sound volume of the home theater device200ends.

Thus, in the sound volume adjusting operation by long pressing in the reference example, the CEC commands are required to be transmitted and received in three steps to change the sound volume value of the home theater device200by “1”. It is required to be confirmed whether the <User Control Released> command has been received for the home theater device200to determine whether the sound volume operation is a long pressing operation or a single pressing operation. Thus, the speed of the sound volume adjustment by long pressing decreases.

Further, the digital television receiving device100is required to acquire the CEC command including the sound volume setting value data from the home theater device200for each transmission of the <User Control Pressed>[“Volume Up”] command to perform the sound volume value display on the screen of the display103based on the sound volume setting value data in the home theater device200. Thus, the speed of the sound volume value display decreases. In this case, when the user310gives priority to the speed of the sound volume operation, the sound volume value display changes later than the change in the sound volume of audio actually output from the speakers311to316, or the change in the sound volume value display becomes discontinuous. In order to match the change in the sound volume value display with the sound volume operation, the user310is required to make the speed of the sound volume operation lower. Thus, operability during the sound volume operation is deteriorated.

Thus, in the sound volume adjusting operation by long pressing in the reference example, the number of times of transmission and receiving of the CEC commands for adjusting the sound volume of the home theater device200increases. Therefore, responsibility becomes lower than that in the sound volume adjusting operation by long pressing illustrated inFIGS. 6 and 7.

(c) Mute Setting Operation

FIG. 12is a sequence diagram illustrating a reference example of transmission and receiving the CEC commands between the digital television receiving device100and the home theater device200during the mute setting operation.

FIG. 12illustrates an operation for controlling mute setting performed when the mute setting operation is performed with the mute button.

When the user310presses the mute button in the remote control device301, the digital television receiving device100transmits a <User Control Pressed> [“Mute”] command to the home theater device200(step S131). This command is a command indicating that the user310has pressed the mute button.

When the user310immediately releases the mute button, the digital television receiving device100transmits a <User Control Released> command to the home theater device200(step S132).

The home theater device200recognizes that the user310has pressed the mute button once with the commands received in steps S131and S132. Thus, the home theater device200sets the amplifier203to a mute status.

The digital television receiving device100continues to transmit a <Give Audio Status> command to the home theater device200to acquire the current sound volume setting value data in the home theater device200(step S103).

The home theater device200transmits a <Report Audio Status> [“Mute On”, X] command to the digital television receiving device100in response to the command received in step S133(step S134). This command is a command for notifying a mute setting status and the sound volume setting value data “X” as the sound volume status data.

Thus, in the mute setting operation in the reference example, the CEC commands are required to be transmitted and received in four steps to set the home theater device200to the mute status. Thus, it takes longer to perform the mute setting than that in the mute setting operation illustrated inFIG. 8.

FIG. 13is a block diagram illustrating a configuration of a home theater system1according to a third embodiment of the present invention.

The home theater system1illustrated inFIG. 13differs from the home theater system1illustrated inFIG. 1in the following points. In the home theater system1illustrated inFIG. 13, a disk recording/reproduction device500is connected to a digital television receiving device100. The disk recording/reproduction device500includes an HDMI transmitter/receiver105, a CPU106and a remote control light receiver108in the digital television receiving device100illustrated inFIG. 2, and does not include a display103, an audio outputor104, and a memory107. The disk recording/reproduction device500includes a disk recording/reproduction unit instead of a tuner101and a decoder102as a content supply source110. The disk recording/reproducer is configured to make video data and audio data recordable as contents in a disk such as a CD (Compact Disk), a DVD (Digital Versatile Disk), or a hard disk and make video data and audio data, which have been recorded in the disk, reproducible.

In the home theater system1according to the present embodiment, the disk recording/reproduction device500is used as an audio data acquisitor in an audio/video reproduction device, and a portion, excluding the content supply source110and the display103, of the digital television receiving device100is used as a portion, excluding the audio data acquisitor, of the audio/video reproduction device. The home theater device200is used as an audio output control device, and the display103in the digital television receiving device100is used as a display.

An input source of the digital television receiving device100is switchable to digital television broadcasting and the digital recording/reproduction device500. An operation performed when the input source of the digital television receiving device100is switched to the disk recording/reproduction device500will be described below.

In this case, video data reproduced by the disk recording/reproduction device500is displayed as video on the display103(seeFIG. 2) in the digital television receiving device100.

If the digital television receiving device100is set to a television mode, audio data reproduced by the disk recording/reproduction device500is output as audio by the audio outputor104(seeFIG. 2) in the digital television receiving device100.

If the digital television receiving device100is set to a theater mode, audio data reproduced by the disk recording/reproduction device500is transmitted from the digital television receiving device100to the home theater device200. In this case, transmission and receiving of CEC commands between the digital television receiving device100and the home theater device200are similar to those in the first or second embodiment.

In the present embodiment, current sound volume control status data in the home theater device200is stored in a memory107in the digital television receiving device100. Sound volume bar display is performed on a screen of the display103in the digital television receiving device100based on sound volume control status data stored in the memory107by a control operation of the CPU106in the digital television receiving device100.

In the home theater system1according to the present embodiment, if audio based on the audio data reproduced by the disk recording/reproduction device500is output from speakers311to316, the operability and the responsibility of a sound volume operation are improved while high-precision sound volume adjustment can be made.

FIG. 14is a block diagram illustrating a configuration of a home theater system1according to a fourth embodiment of the present invention.

The home theater system1illustrated inFIG. 14differs from the home theater system1illustrated inFIG. 1in the following points. In the home theater system1illustrated inFIG. 14, a home theater device200is connected to a disk recording/reproduction device500via an HDMI cable320. A configuration of the disk recording/reproduction device500is similar to the configuration of the disk recording/reproduction device500in the third embodiment. The disk recording/reproduction device500is settable to a normal reproduction mode and a theater mode. A digital television receiving device100is connected to the home theater device200via an HDMI cable320.

In the home theater system1according to the present embodiment, the disk recording/reproduction device500is used as an audio/video reproduction device, the home theater device200is used as an audio output control device, and a display103in the digital television receiving device100is used as a display.

Video data reproduced by the disk recording/reproduction device500illustrated inFIG. 14is transmitted to the digital television receiving device100via the HDMI cable320, the home theater device200and the HDMI cable320. Video data received by the digital television receiving device100is displayed as video on the display103(seeFIG. 2).

If the disk recording/reproduction device500is set to a normal reproduction mode, audio data reproduced by the disk recording/reproduction device500is transmitted to the digital television receiving device100via the HDMI cable320, the home theater device200and the HDMI cable320. Audio data received by the digital television receiving device100is output as audio by the audio outputor104(seeFIG. 2).

If the disk recording/reproduction device500is set to a theater mode, the audio data reproduced by the disk recording/reproduction device500is transmitted to the home theater device200from the digital television receiving device100via the HDMI cable320. The audio data received by the home theater device200is output as audio from speakers311to316. In this case, transmission and receiving of CEC commands between the disk recording/reproduction device500and the home theater device200are similar to the transmission and receiving of the CEC commands between the digital television receiving device100and the home theater device200in the first or second embodiment.

In the present embodiment, current sound volume control status data in the home theater device200is stored in a memory107in the disk recording/reproduction device500. Sound volume bar display is performed on the screen of the display103in the digital television receiving device100based on the sound volume control status data stored in the memory107by a control operation of a CPU106in the disk recording/reproduction device500.

In the home theater system1according to the present embodiment, if audio based on the audio data reproduced by the disk recording/reproduction device500is output from speakers311to316, the operability and the responsibility of a sound volume operation are improved while high-precision sound volume adjustment can be made.

(6) Other Embodiments

While the digital television receiving device100and the home theater device200are connected to each other via the HDMI cable320as a communication medium in the first, second, and third embodiments, the present invention is not limited to this. For example, the digital television receiving device100and the home theater device200may transmit and receive CEC commands via wireless communication. The digital television receiving device100and the home theater device200may be connected to each other via a network such as a wireless or wired Ethernet.

Similarly, the disk recording/reproduction device500and the home theater device200may transmit and receive CEC commands via wireless communication in the fourth embodiment. The disk recording/reproduction device500and the home theater device200may be connected to each other via a network such as a wireless or wired Ethernet. Further, the home theater device200and the digital television receiving device100may be connected to each other via an analog communication wire.

While the CPU106and the memory107implement a sound volume control function in the above-mentioned first to fifth embodiments, the present invention is not limited to this. The CPU106and the memory107may be used to implement another function of the digital television receiving device100in addition to the sound volume control function.

While the adjustable range bar402and the sound volume bar403have a linear shape in the above-mentioned first to fifth embodiments, the adjustable range bar402and the sound volume bar403may have a curved shape.

(7) Correspondences Between Elements in the Claims and Parts in Embodiments

In the following paragraphs, non-limiting examples of correspondences between various elements recited in the claims below and those described above with respect to various preferred embodiments of the present invention are explained.

In the first and second embodiments, the digital television receiving device100(excluding the display103) is an example of an audio/video reproduction device, the display103in the digital television receiving device100is an example of a display, the content supply source110is an example of an audio data acquisitor, the remote control light receiver108is an example of a sound volume operation information acquisitor, the HDMI transmitter/receiver105is an example of a first transmitter/receiver (or a transmitter/receiver), the memory107is an example of a storage, and the CPU106is an example of a first controller (or a controller).

In the third embodiment, the digital television receiving device100(excluding the display103and the content supply source110) is an example of an audio/video reproduction device, the display103in the digital television receiving device100is an example of a display, the disk recording/reproduction device500is an example of an audio data acquisitor, the remote control light receiver108in the digital television receiving device100is an example of a sound volume operation information acquisitor, the HDMI transmitter/receiver105in the digital television receiving device100is an example of a first transmitter/receiver (or a transmitter/receiver), the memory107in the digital television receiving device100is an example of a storage, and the CPU106in the digital television receiving device100is an example of a first controller (or a controller).

In the fourth embodiment, the disk recording/reproduction device500is an example of an audio/video reproduction device, the display103in the digital television receiving device100is an example of a display, the content supply source in the disk recording/reproduction device500is an example of an audio data acquisitor, the remote control light receiver108in the disk recording/reproduction device500is an example of a sound volume operation information acquisitor, the HDMI transmitter/receiver105in the disk recording/reproduction device500is an example of a first transmitter/receiver (or a transmitter/receiver), the memory107in the disk recording/reproduction device500is an example of a storage, and the CPU106in the disk recording/reproduction device500is an example of a first controller (or a controller).

In the first to fourth embodiments, the home theater device200is an example of an audio output control device, and the HDMI cable320is an example of a communication medium. The HDMI transmitter/receiver205in the home theater device200is an example of a second transmitter/receiver (or a transmitter/receiver), the amplifier203is an example of an amplifier, the CPU204is an example of a second controller (or a controller), and the sound volume operator201is an example of a sound volume operator.

The CEC command is an example of a command, the adjustable range bar402is an example of a first bar, and the sound volume bar403is an example of a second bar.

As each of various elements recited in the claims, various other elements having configurations or functions described in the claims can be also used.

INDUSTRIAL APPLICABILITY

The present invention is applicable to various home theater systems capable of stereophonic reproduction of audio.