JP2002112136A - Digital av device and digital av system and system control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital AV system where devices are in bus connection and the devices share a video audio output device provided with an analog input terminal, so as to provide an operating method with satisfactory user- friendliness for displaying desired analog data. SOLUTION: In the system in which the digital devices are in bus connection and their analog input output terminals are connected to allow the devices to share the video audio output device, each digital device is provided with a means, that conducts connection setting to the video audio output device and connection setting to the other device with the input or output terminal, and with a means that allows a required device among the devices connected to the video audio output device, to switch received analog data for the output, as they are, in the case of operating the other digital device 2 is operated, while the digital device 1 uses the video audio output device and displaying analog data, such as timer reservation displays. Thus, even when other digital devices are using the video audio output device, data are displayed automatically and the operation is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AV system including a video / audio output device, which is a conventional analog device, and connected to a plurality of digital devices. The present invention relates to a digital AV device and a system control method that can easily switch a video input of a video / audio output device when operating a function of displaying contents.

[0002]

2. Description of the Related Art In recent years, digital broadcasting services using communication satellites (CS) have started in Europe and the United States, and CS digital multi-channel broadcasting has started in Japan in 1996, and various digital broadcasting services will be started in the future. is there. Along with this, product development of digital AV equipment such as a digital broadcast receiver for receiving digital broadcast data and a digital recording / reproducing apparatus for recording the broadcast data digitally has been performed. As a digital interface for connecting these digital AV devices and communicating data and control signals, an IEEE 1394 serial bus (hereinafter, referred to as 13)
94 bus) and USB (Universal Seria)
l Bus) high-speed serial buses.

[0003] The 1394 bus is a synchronous (Isochronous) transfer for continuously transmitting data such as a digital AV signal at a constant transfer rate, and an asynchronous (Asy) for transmitting a control signal such as a connection control command as needed.
Both transfers can be performed.
The USB includes the synchronous transfer, control transfer used for transmitting and receiving messages, and bulk transfer used for transferring a large amount of data, although the transfer rate is not guaranteed. On the 1394 bus, a control signal “AV / C Dig” for externally controlling various AV devices is provided.
ital Interface Command Se
The standardization of “t” is in progress. Under such circumstances, at the stage when the digital AV devices are widely spread, there are systems in which conventional analog devices and digital AV devices are mixedly connected.

[0004]

In a system for connecting a plurality of digital AV devices using a 1394 bus or the like, the device connection method and data communication are easy. However, in a conventional system in which analog devices and digital AV devices coexist, the connection method between the digital AV devices and the analog devices and the data communication procedure become complicated. This is because, in connection with a conventional analog device, a user needs to correctly connect an input terminal and an output terminal in consideration of the direction of data communication. In digital AV equipment, video data that cannot be handled digitally-for example, an on-screen display (hereinafter referred to as OS) such as an electronic program guide (hereinafter referred to as EPG), timer reservation information, and tape content display.
Since there is data using D), all data cannot be exchanged by digital communication.

[0005] In a basic system including a conventional analog television and a digital broadcast receiver, which is a digital AV device, and a digital recording / reproducing apparatus, at least one of the digital broadcast receiver and the digital recording / reproducing apparatus is analog. Assume that it is connected to a TV. When displaying a broadcast received by a digital broadcast receiver on an analog TV, operating the digital recording / playback device to display the recorded content of the recording medium set (hereinafter referred to as the recorded content search function) or timer reservation content If you want to display
The user needs to switch the input of the analog television, and further, depending on the connection method, may need to switch the input of the digital broadcast receiver. In this case, there is no difference from the conventional connection system between analog devices, and the operability as a digital AV device cannot be utilized. An object of the present invention is to provide a user-friendly operation method in a system in which an analog video / audio output device and a digital AV device coexist.

[0006]

In order to solve the above-mentioned problems, a plurality of digital AV devices are connected to a bus, communicate control data and AV data, and output one analog video / audio signal between the devices. In a system for sharing devices, when a digital AV device operates a recorded content search function, a timer reservation display function, an EPG display function, and the like, the digital AV device on the bus is connected to the analog video / audio output device. Inquire about the presence of If there is a digital AV device connected to the video / audio output device, the device inquires about the setting state of an input terminal or an output terminal, receives analog data output by the device,
It is controlled so that it is output to an output terminal connected to the video / audio output device as it is. Thereby, even when the analog video / audio output device is being used by another digital AV device, the display can be automatically switched to a target screen as needed, providing user-friendly operability. can do.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing one configuration example of a system for explaining an embodiment of the present invention. As shown in the figure, the present system includes a digital recording / reproducing apparatus 200 for recording and reproducing digital AV data, a digital broadcast receiver 300 for receiving a digital broadcast program using a communication satellite or a terrestrial wave, And an analog TV 400 for displaying programs and recorded / reproduced data. Then, the recording / reproducing device 200 and the broadcast receiver 30
0 is connected by a 1394 bus 100, and an analog output terminal of the recording / reproducing apparatus 200 is connected to the broadcast receiver 300.
Analog cable 1 between the analog input terminal
Connect at 20a. Further, an analog cable 120b is connected between an analog output terminal of the broadcast receiver 300 and an analog input terminal of the TV 400.

Next, an example of the configuration of the digital recording / reproducing apparatus 200 will be described with reference to FIG. A digital recording / reproducing apparatus 200 as one embodiment of the present invention includes a tuner receiving section 201, an analog input section 202, a digital input / output section 203, an analog output section 204, a recording / playback processing section 205, an OSD processing section 206, remote control communication. Part 207,
It comprises a recording input switch unit 208, an output switch unit 209, an analog input terminal 217, an analog output terminal 218, a digital terminal 219, and a control unit 220. The tuner receiving section 201 is a section that receives a broadcast program of a desired channel.

The analog input section 202 is a section for receiving analog AV data from the outside via the analog input terminal 217.

The digital input / output unit 203 is a unit for transmitting and receiving various control commands and digital AV data to and from other devices connected by the 1394 bus 100 via the digital terminal 219. The analog output unit 204 outputs analog AV data to the outside via the analog output terminal 218. The recording / playback processing unit 205 records analog / digital AV data and records the recorded AV data.
This is the part for reproducing data. The OSD processing unit 206
When necessary, this section superimposes a character string message or the like on analog AV data of broadcast data or reproduction data, and outputs a menu setting screen, a recorded content search screen, a timer reservation content screen, and the like. The remote control communication unit 207 is a part that receives a remote control code when a user operates the present apparatus 200 using a remote control.

The recording input switch section 208 is a section for switching AV data input to the recording / playback processing section 205. The switch unit 208 is connected to the digital input / output unit 20.
Terminal 21 for inputting digital AV data received at 3
0, a terminal 211 for inputting broadcast data received by the tuner receiving unit 201, a terminal 212 for inputting analog AV data externally received by the analog input unit 202, and a recording / playback processing unit among the terminals 210 to 212 20
5 is provided with a switch terminal 213 for selecting what is to be input to.

The output switch section 209 is a section for switching AV data output from the apparatus 200. The switch unit 209 is connected to a terminal 2 for inputting recorded AV data.
14. A terminal 215 for directly inputting the AV data input by the recording input switch unit 208 without passing through the recording / playback processing unit 205, and among the terminals 214 to 215, a digital input / output unit 203 and an OSD processing unit are actually The switch 206 includes a switch terminal 216 for selecting an input to the switch 206. The control unit 220 is a part that performs the operation control of the above-described 201 to 209, the function execution processing of the entire apparatus 200, and the control processing.

Next, an example of the configuration of the digital broadcast receiver 300 will be described with reference to FIG. A digital broadcast receiver 300 as one embodiment of the present invention includes a tuner receiving unit 301, an analog input unit 302, a digital input / output unit 303, an analog output unit 304, a decoder 305, and an OS.
It comprises a D processing unit 306, a remote control communication unit 307, a decoder input switch unit 308, an output switch unit 309, an analog input terminal 313, an analog output terminal 314, a digital terminal 315, and a control unit 316.

The tuner receiving section 301 is a section for selecting a desired channel from a plurality of channels through which a digital broadcast program is transmitted. The analog input section 302 is a section that receives external analog AV data via the analog input terminal 313. Digital input / output unit 303
Is a section for transmitting and receiving various control commands and digital AV data to and from other devices connected to the 1394 bus 100 via the digital terminal 315. The analog output unit 304 is a unit that outputs analog AV data to the outside via the analog output terminal 314. Decoder 305
Is a part for demodulating digitally modulated AV data. The OSD processing unit 306 outputs the decoder 305 when necessary.
This is a part that superimposes a character string message or the like on the broadcast data demodulated in step 2, and outputs a menu setting screen, an EPG screen, a timer reservation content screen, and the like. Remote control communication unit 30
Reference numeral 7 denotes a portion for receiving a remote control code when the user operates the receiver 300 using the remote control.

The decoder input switch section 308 is a section for switching digital AV data input to the decoder 305. The switch unit 308 is connected to the tuner receiving unit 3
Terminal 31 for inputting digital broadcast data received at 01
7. Digital AV received by the digital input / output unit 303
A terminal 318 for inputting data, and terminals 317 to 31
8 includes a switch terminal 319 for selecting a signal to be actually input to the decoder 305.

The output switch unit 309 includes the receiver 300
This is a part for switching AV data output from. The switch unit 309 includes a terminal 310 for inputting analog AV data output from the decoder 305, and a terminal 3 for inputting analog AV data received by the analog input unit 302.
11 and a switch terminal 31 for selecting one of the terminals 310 to 311 to be actually input to the OSD processing unit 306
2

The control section 316 is a section for performing the operation control of the above-mentioned 301 to 309 and the function execution processing and control processing of the receiver 300 as a whole.

Next, referring to FIG.
One configuration example of 00 will be described. The analog TV 400 as one embodiment of the present invention includes a tuner receiving unit 401,
It comprises an analog input unit 402, a video / audio output unit 403, a remote control communication unit 404, an input switch unit 412, an output switch unit 413, and a control unit 405.

The tuner receiving section 401 is a section for receiving a broadcast program of a desired channel.

An analog input section 402 receives an external analog A signal via an analog input terminal 412 or 413.
This is a part for receiving V data. Video / audio output unit 403
Is a part for actually outputting AV data to a monitor, a speaker, or the like. The remote control communication unit 404 is a part that receives a remote control code when the user operates the TV 400 using the remote control.

An input switch section 412 is a section for switching AV data input to the analog input section 402.
The switch unit 412 includes a terminal 406 for inputting AV data received via the analog input terminal 412, a terminal 407 for inputting AV data received via the analog input terminal 413, and terminals 412 to 413. It comprises a switch terminal 408 for selecting an input to the analog input unit 402.

The output switch section 413 is a section for switching AV data to be output on the TV. The switch unit 4
Reference numeral 13 denotes a terminal 409 for inputting broadcast data received by the tuner receiving unit 401, a terminal 410 for inputting AV data output from the analog input unit 402, and a terminal 40.
The switch terminal 411 is used to select a terminal to be actually input to the video / audio output unit 403 from among the terminals 9 to 410.
The control unit 405 is a unit that performs control processing of each of the processing units and the switch unit, and processing of executing functions of the entire TV 400.

Next, an example of a switching function which is a feature of the present invention will be described with reference to FIGS. In this example, the operation of the recorded content search function (the function of displaying a list of recorded contents of the set recording medium) provided in the digital recording / reproducing apparatus 200 will be described. FIG. 5 shows a case where a broadcast program received by the user by the digital broadcast
The receiver 300 and the T when viewing in V400
FIG. 4 is a diagram showing a connection configuration between V400s.

First, in the receiver 300, the terminal 317 and the switch terminal 319 in the decoder input switch section 308
, The broadcast data received by the tuner receiving section 301 is input to the decoder 305 and demodulated to analog. Then, in the output switch unit 309, the terminal 3
By connecting the switch 10 to the switch terminal 312, the demodulated AV data is output from the analog output terminal 314 to the analog cable 120b via the OSD processing unit 306 and the analog output unit 304.

On the other hand, in the TV 400, the input switch unit 4
By connecting the terminal 406 and the switch terminal 408 at 12, the broadcast data from the broadcast receiver 300 input from the analog cable 120b via the analog input terminal 412 is input to the analog input unit 402. Then, by connecting the terminal 410 and the switch terminal 411 in the output switch unit 413, the signal is input to the video / audio output unit 403 via the analog input unit 402. As a result, the broadcast data is displayed 500 on the monitor.

In such a state, the user sets the recording medium 620 in the digital recording / reproducing apparatus 200, and
When the recording content search function button 610 on the remote controller 600 dedicated to 00 is selected, the change in the connection configuration of the recording / reproducing apparatus 200, the receiver 300, and the TV 400 is
As shown in FIG. First, in the recording / reproducing apparatus 200, the control unit 22
0 outputs the data content (date of recording, program name, etc.) recorded on the recording medium 620 to the OSD processing unit 206.
The OSD processing unit 206 generates recorded content search display screen data for displaying the data content, outputs the data to the analog output unit 204, and outputs the data to the analog cable 120a via the analog output terminal 218.

In the receiver 300, the analog input terminal 31
3 is input to the analog input unit 302 from the recording / reproducing apparatus 200. Then, in the output switch unit 309, the terminal 311
To the OSD processing unit 306 and the analog output unit 304 via the analog input unit 302 to connect the recorded content search display screen data via the analog input unit 302, and to the analog cable 120b via the analog output terminal 314. Output to

The TV 400 has a connection configuration similar to that shown in FIG. 5, in which the recorded content search display screen data from the broadcast receiver 300 input from the analog cable 120 b via the analog input terminal 412 is transmitted via the analog input section 402. And input it to the video / audio output unit 403. This allows
The recorded content search display screen data is displayed on a monitor 630
can do.

As described above, only the digital broadcast receiver 300 is directly connected to the analog TV 400,
When a user performs an operation on the recording / reproducing apparatus 200, the analog TV is transmitted via the digital broadcast receiver 300.
The case where an image is displayed on 400 is described. In the connection configuration of FIG. 1, the same effect can be obtained when the recording / reproducing device 200 and the digital broadcast receiver 300 are reversed. For example, when only the recording / reproducing apparatus 200 is connected to the analog TV 400 and an operation such as a program guide display instruction or a timer reservation list display is performed on the digital broadcast receiver 300,
An image can be displayed on the analog TV 400 via the recording / reproducing device 200.

Further, in the analog TV 400 having two or more input terminals, as shown in FIG. 8, both the recording / reproducing apparatus 200 and the digital broadcast receiver 300 are connected to the analog TV 400 using analog cables 120a and 120b.
And the recording / reproducing apparatus 200 and the digital broadcast receiver 3
00 and 1394 bus 100 and analog cable 1
Connection is made using 20c and 120d. Even with such a system, the same effect as described above can be obtained. For example, when the received data of the digital broadcast receiver 300 is displayed on the TV 400 via the analog cable 120b, when the recording / reproducing apparatus 200 performs an operation such as a recording content search function or a timer reservation list display, the recording is performed. Playback device 200
The display screen is displayed on the TV 400 via the analog cable 120b, via the analog cable 120c, via the analog cable 120c, and via the digital broadcast receiver 300.

When the reproduction data of the recording / reproducing apparatus 200 is output to the TV 400 via the analog cable 120a, the digital broadcast receiver 300 is operated to display a program guide or to display a timer reservation list. When,
Analog cable 120 from digital broadcast receiver 300
The display screen can be displayed on the TV 400 via the analog cable 120a via the recording / reproducing apparatus 200 via the recording / playback apparatus 200.

Next, referring to FIG.
Settings required for the digital broadcast receiver 300 will be described. Screen 900 is a screen set by the user in connection with analog TV 400 in recording / playback apparatus 200. On this screen, first, an item 910 sets whether or not the recording / reproducing apparatus 200 is connected to the analog TV 400. When connecting, set TV40 in item 920.
Set the analog output terminal used for connection to 0.

A screen 930 is a screen in which the user sets an analog output terminal used in the recording / reproducing apparatus 200 with a device connected to the 1394 bus 100.
Analog output terminal 1 (output 1) is already TV on screen 900
Since it is assumed to be used for connection with the 400, on this screen, in item 940, whether or not to connect to another device existing on the 1394 bus using the analog output terminal 2 (output 2), and in the case of connection Selects that device.

Similarly, the screen 950 is displayed on the recording / reproducing apparatus 20.
0 is a screen in which the user sets an analog input terminal to be used with a device connected via the 1394 bus 100. On this screen, whether or not to connect to another device existing on the 1394 bus using the analog input terminal 2 (output 2) in item 960, and if so, the device is selected. The setting screens 900, 930, 950 are:
In addition to a method of allowing the user to set any item as one item of other various setting menus, the recording / playback apparatus 2
It is also conceivable to automatically display 00 at the time of initial setting at the time of purchase or when a bus reset occurs.

Next, with reference to FIGS. 10 and 11, a description will be given of a procedure in which the recording / reproducing apparatus 200 switches the input / output of the digital broadcast receiver 300 from FIG. 5 to FIG. Here, it is assumed that the recording / playback apparatus 200 has already
In the item 910 on the screen 930, the connection between the TVs 400 is not set. In the item 940 on the screen 930, the analog output terminal 2 (output 2 on the screen 930) and the digital broadcast receiver 300 (the tuner CS10 on the screen 930) are displayed.
0-T) is set. Also,
It is assumed that the digital broadcast receiver 300 has already “connected” the connection between the TVs 400 in the item 910 on the screen similar to the screen 900 and uses the analog output terminal 1.
Then, in the item 960 on the screen similar to the screen 950, it is set that the analog input terminal 1 (input 1 on the screen 960) is connected to the recording / reproducing apparatus 200.

Based on the above premise, a procedure 1000 for acquiring a TV connection setting will be described first with reference to FIG. When the user sets a recording medium in the recording / reproducing apparatus 200 and operates the recording content search function using a remote controller, a button on the main body, or the like, the recording / reproducing apparatus 200 becomes 1394.
The analog TV 40 is connected to all devices (in this case, only the digital broadcast receiver 300) existing on the bus 100.
It is issued via the 1394 bus 100 by using an arbitrary control command for acquiring a connection state with 0 (step 100).
1). Then, by referring to the response from the other device to the control command, it is determined whether the device is connected to the TV 400 (step 1002). When the device is connected to the TV 400, the TV 4 is actually again connected to the device.
For the analog output terminal used for connection to 00, an arbitrary control command is used to acquire the analog output terminal via the 1394 bus 100 (step 1003). In this case, the digital broadcast receiver 300 transmits the TV
In step 1003, a response to use the analog output terminal 1 is received.

Next, an input / output switching procedure 1100 of the digital broadcast receiver 300 will be described with reference to FIG. The recording / reproducing apparatus 200 acquires the TV connection setting acquisition procedure 1
000 based on the information acquired in 1394 bus 100 connected to TV 400 and connected to the analog output of digital broadcast receiver 300.
The data received from the analog input terminal to which the digital broadcast receiver 300 is connected
An arbitrary control command requesting an output from an analog output terminal connecting between V400s is issued (step 1101). As a result, a response from the other device to the control command is referred to, and if the request is accepted, a display screen of a target recorded content search function is output. If the request is not accepted, the user is notified using a means such as a main body display of the device 200 or voice. FIG. 7 shows an example of a notification screen 700 displayed on the main body display unit.

According to the above procedure, the recording / reproducing apparatus 200 can switch the input / output to / from the digital broadcast receiver 300 when it is desired to display the recorded content search function, the timer reservation content, and the like. Here, the TV connection setting acquisition procedure 1000 in FIG. 10 may be performed at any time, such as when power is turned on or when a bus reset occurs. Step 1001
And step 1002 may be obtained simultaneously using the same control command. Here, in the present embodiment, the digital devices are connected using the 1394 bus 100, but another bus such as a USB may be used. Also, a system in which one TV and two digital devices (the recording / reproducing device 200 and the digital broadcast receiver 300) are connected has been described, but the present invention can be applied to a system in which three or more digital devices are connected. .

[0039]

As described above, according to the present invention, when one digital device uses a video / audio output device, it is necessary to operate another digital device to display analog data. Digital devices obtain connection information with video and audio output devices for all or any devices connected to the control bus, and for devices that are connected to the video and audio output devices, Since the input analog data is switched to be output as it is, the user can display desired data on the video / audio output device without operating one digital device or the video / audio output device. Therefore, the operation is simplified and the burden on the user is reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a recording and playback device according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a digital broadcast receiver according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a video / audio output device according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a state in which broadcast data received by a digital broadcast receiver is displayed on a TV according to an embodiment of the present invention.

FIG. 6 is a diagram showing a state in which analog data of a list of contents of a recording medium set in a recording / reproducing apparatus is displayed on a TV according to an embodiment of the present invention.

FIG. 7 is a diagram showing an example of a configuration of a notification screen displayed on a main body display unit when a recording / playback apparatus cannot switch input / output inside a digital broadcast receiver according to an embodiment of the present invention. .

FIG. 8 is a configuration diagram of a system according to an embodiment of the present invention.

FIG. 9 is a diagram showing a configuration example of a screen displayed to perform connection setting with a TV and connection settings of an output terminal and an input terminal according to an embodiment of the present invention.

FIG. 10 is a flowchart illustrating a procedure in which the recording / reproducing apparatus acquires a connection state between the digital broadcast receiver and the TV according to an embodiment of the present invention.

FIG. 11 is a flowchart illustrating a procedure in which the recording / playback apparatus switches input / output of the digital broadcast receiver according to an embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Nobuhiko Nozoe 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Digital Media Development Division, Hitachi, Ltd. (72) Inventor, Takeo Okochi 1410, Inada, Hitachinaka-shi, Ibaraki Stock Hitachi Digital Media Products Division F-term (reference) 5C025 AA25 BA21 BA30 CA02 CA18 CB07 DA08

Claims (13)

[Claims] An analog output terminal, at least one analog terminal among analog input terminals, a bus connection terminal,
In a digital AV device having means for communicating control data between other digital AV devices connected to a bus and means for outputting, inputting, or inputting / outputting desired video / audio data to or from another digital AV device, When the analog output terminal and the bus connection terminal of the digital AV device are connected to the analog input terminal and the bus connection terminal of the other digital AV device, respectively, the analog input terminal is connected to the other digital AV device via the bus. A digital AV device having means for issuing a switching request for transmitting data received at a terminal from an analog output terminal. 2. An analog output terminal, at least one analog terminal among analog input terminals, a bus connection terminal,
In a digital AV device having means for communicating control data between other digital AV devices connected to a bus and means for outputting, inputting, or inputting / outputting desired video / audio data to or from another digital AV device, When the analog input terminal and the bus connection terminal of the digital AV device are connected to the analog output terminal and the bus connection terminal of another digital AV device, respectively, A digital AV device that switches so that data received at an analog input terminal is output from an analog output terminal when a switching request for transmitting data received at the terminal from an analog output terminal is received. 3. A digital AV device according to claim 1, wherein a switch request is issued, but when a notification that switching cannot be performed is received from the other digital AV device, the fact is displayed on the screen or voiced to the user. Digital AV equipment for notifying. 4. The digital AV device according to claim 2, wherein when the switching request is received, if the switching cannot be performed, a notification to that effect is given. 5. The digital AV device according to claim 1, further comprising means for setting whether to connect to a video / audio output device having an analog input terminal. . 6. The digital AV device according to claim 5, further comprising means for acquiring a connection state between the video and audio output device and another device via the bus. 7. The digital AV device according to claim 5, further comprising means for setting an analog output terminal used when connecting to the video / audio output device. 8. The digital AV device according to claim 7, further comprising means for acquiring an analog output terminal used when connecting the other device to the video / audio output device via the bus. Digital AV equipment characterized. 9. The digital AV device according to claim 1, wherein at least one of an analog output terminal and an analog input terminal used for connection with another device existing on the bus. A digital AV device having means for setting one. 10. The digital AV device according to claim 9, further comprising means for acquiring at least one setting state of an analog output terminal and an analog input terminal with respect to another device via said bus. Digital AV features
machine. 11. The digital AV device according to claim 1, wherein said bus is a 1394 serial bus. 12. A device for communicating control data between at least one analog terminal among an analog output terminal and an analog input terminal, a bus connection terminal, another digital AV device connected to the bus, and another digital AV device. In a digital AV system including a plurality of digital AV devices having means for outputting, inputting, or inputting / outputting desired video / audio data, and a video / audio output device having one or more analog input terminals, In a state where the analog output terminal and the bus connection terminal of the digital AV device are connected to the analog input terminal and the bus connection terminal of another digital AV device, respectively, the one digital AV device is connected to the other digital AV device via the bus. Switching request to transmit data received at the analog input terminal to the AV device from the analog output terminal The digital audio / video device is configured to switch to output the data received at the analog input terminal from the analog output terminal and output the data to a desired video / audio output device. Digital AV system. 13. A means for communicating control data between at least one analog terminal among an analog output terminal and an analog input terminal, a bus connection terminal, another bus-connected digital AV device, and another digital AV device. Control system in a digital AV system comprising a plurality of digital AV devices having means for outputting, inputting, or inputting / outputting desired video / audio data, and video / audio output devices having one or more analog input terminals In the state where the analog input terminal and the bus connection terminal of the other digital AV device are connected to the analog output terminal and the bus connection terminal of the one digital AV device, the other digital AV device is connected to the video / audio output device. When using, the one digital AV device is operated to convert analog data. To output an image to an audio / video output device, the one digital AV device issues a switching request for transmitting data received at an analog input terminal from the analog output terminal to another digital AV device via the bus. A system control method wherein another digital AV device receiving the data switches the data received at an analog input terminal so that the data is output from an analog output terminal.