JPH02179195A - Composite device - Google Patents

Abstract

PURPOSE:To transmit an analog signal between function units without deteriorating a signal quality, and also, to eliminate the need of a signal converting means by using a bus having not only a digital signal channel but also an analog signal channel as a bus to which plural function units having an independent function are connected. CONSTITUTION:Each function unit 2-5 and a controller 6 are connected to a bus 9, and the bus 9 has not only a control signal channel 9C and a digital signal channel 9D but also an analog signal channel 9A. Also, each function unit 2-5 and the controller 6 are provided with connecting circuits 10a-10e for inputting and outputting a digital signal and an analog signal to and from the digital signal channel 9D and the analog signal channel 9A on the bus 9, and processing a control signal on the control signal channel 9C. In such a way, the analog signal can be transmitted between the functions units without deteriorating a signal quality, and since a signal conversion of the analog signal is not executed, A/D and D/A converters become unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a composite device in which a plurality of functional units having independent functions are connected via a bus, and more particularly to a composite device including a functional unit that handles analog signals.

BACKGROUND ART An example of this type of multifunction device is a home multifunction device that connects functional units such as a television monitor, scanner, printer, and facsimile communication unit via a bus, and also connects external devices such as an external telephone line and video tape recorder. There is a terminal device.

Conventionally, such composite terminal devices were developed based on the technology of digital devices such as computer peripherals, so the functional units were provided with connection circuits as shown in Figure 5, and digital signals were used to connect the functional units. It was designed to transmit signals.

In FIG. 5, 21 is an A/D converter, n is a selector,
n is a D/A converter, U is a data signal processing circuit that controls data input/output with bus 5, analyzes commands from bus 5, etc., and 26 is a control signal processing circuit that processes control signals of bus 5. Dechiru.

In the case of the transmitting-side functional unit, the digital data signal remains unchanged, and the analog data signal is converted into a digital signal by the AD converter 21 and output to the bus via the selector n and the data signal processing circuit 24. For the receiving functional unit, the digital data signal on bus δ is
If the source signal is a digital signal, it is inputted as is; if the source signal is an analog signal, it is inputted after being converted to an analog signal by a D/A converter.

Problems to be Solved by the Invention However, there is a problem in that video signals, audio signals, etc. transmitted between functional units inevitably deteriorate in signal quality due to analog-to-digital conversion and digital-to-analog conversion. In order to reduce the deterioration of the A/D converter 21 and the D/A converter, high-precision, high-speed and expensive devices must be used, which poses a problem in that the cost of the device increases.

The present invention has been made in view of the above-mentioned problems, and is capable of transmitting analog signals between functional units without deteriorating the signal quality, and which does not require expensive signal conversion means. The purpose is to provide complex devices such as terminal devices.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses a bus having not only digital signal channels but also analog signal channels as a bus to which a plurality of functional units having independent functions are connected. The unit has a connection circuit for analog signal input/output with the analog signal channel of the bus and digital signal input/output with the digital signal channel of the bus, and information for controlling analog signal input/output by the connection circuit. is provided through a digital signal channel of the bus by a controller or other functional unit connected to the bus.

Note that a connection circuit for a functional unit that requires only one input or output of an analog signal may be configured to allow only the required input or output. Similarly, a connection circuit for a functional unit that requires only digital signal input may be configured to allow only digital signal input. There may be a single controller or multiple controllers.

Effect of the Invention With the above-described configuration, the present invention transmits analog signals as they are between functional units through the analog signal channel of the bus, so there is no deterioration in analog signal quality due to conventional signal conversion, and the signal is not transmitted to the connected circuit. Expensive high-precision, high-speed A/D converters and D/D converters for conversion
Since there is no need to provide an A converter, the connection circuit can be constructed at low cost, and furthermore, the transmission of analog signals between functional units can be controlled through the digital signal channels of the bus.

Embodiment FIG. 1 is a schematic diagram of a composite device according to an embodiment of the present invention. This multifunction device 1 is configured as a multifunction terminal device for home use, and includes a television monitor 2, a printer 3, a scanner 4, and a facsimile communication section 5 as functional units.
It also has a controller 6 for controlling connections between each functional unit, and can also be connected to a telephone line 7 and a video tape recorder 8 as an external device.

(2, 3, 4, 5) and the controller 6 are connected to a bus 9, which, in addition to the conventional control signal channel 9C and digital signal channel 9D, also transmits analog signals. It has an analog signal channel 9A for.

Each functional unit (2, 3, 4, , 5) and the controller 6 have input/output of digital and analog signals with the digital signal channel 9D and analog signal channel 9A of the bus 9, and control on the control signal channel 9C. Connection circuit 10a for signal processing; 1. Ob
, 10c, 10d, and 10e as internal or external circuits. A similar connection circuit 10f is also provided, via which the video tape recorder 8 is connected to the bus 9.

As shown in FIG. 2, the connection circuit 10 includes an analog signal processing circuit 11, a digital signal processing circuit 12, and a control signal circuit 13 corresponding to each signal channel of the bus 9.

Although it is generally advantageous for unit development and system expansion if the connection circuits of all units have the same configuration, the analog signal processing circuit 11 can also be omitted from the connection circuits of units that do not require input/output of analog signals.

Analog signal processing circuit 11 has analog signal channel 9A
This is a circuit that connects the analog signal inside the unit and inputs and outputs the analog signal without converting the signal. The digital signal processing circuit 12 is a circuit that controls input and output of digital signals (data or commands) to and from the digital signal channel 9D, analyzes at least commands related to analog signal input and output, and controls the analog signal processing circuit 11. The control signal processing circuit 13 processes the control signal on the control signal channel 9C and controls the input/output timing of the digital signal processing circuit 12.

In addition, as a control signal related to the connection between units, C
/D (control/data), REQ (data request), and ACK (response).

Next, the connection procedure between functional units will be explained. ,
Here, it is assumed that a video signal is transmitted from the scanner 4 to the television monitor 2. FIGS. 3 and 4 are sequence diagrams showing this procedure and timing diagrams of bus signals.

The controller 6 sets the C/D signal of the control signal channel 9C to L level through the connection circuit foe, and controls the scanner 4.
After sending a unit selection command to select the television monitor 2 to the digital signal channel 9D, the REQ signal of the control signal channel 9C is set to L level.

As the REQ signal goes to L level, the digital signal on digital signal channel 9D is taken into each functional unit, but since the C/D signal is at L level, this digital signal is treated as a command and analyzed. . Note that this command analysis may be performed by the digital signal processing circuit 12 of the connection circuit IO or by the unit internal circuit, but in this embodiment, all commands are analyzed by the digital signal processing circuit 12. .

Since this is a command to select the TV monitor 2 and scanner 4, these units are connected to the connection circuits foa and l.
The ACK signal of control signal channel 9C is set to H level through oc. When the ACK signal becomes H level, the controller 6 returns the REQ signal to H level and opens the digital signal channel 9D. TV monitor 2 and scanner 4
returns the ACK signal to the L level due to this change in the REQ signal.

Next, the controller 6 sets the REQ signal to L level and outputs a channel selection command to the digital signal channel 9D. Here, it is assumed that the command selects the A1 signal of analog signal channel 9A. The connection circuit 10a of the television monitor 2 and the scanner 4, and the digital signal processing circuit 12 of the IOc analyze this command and set the analog signal processing circuit 11 to enable transmission using the A1 signal of the analog signal channel 9A. Set the ACK signal to H level.

When the controller 6 confirms that the ACK signal has become H level, it returns the REQ signal and the C/D signal to H level and opens the digital signal channel 9D. In response, the television monitor 2 and scanner 4 return the ACK signal to the L level.

This completes the connection between the TV monitor 2 and the scanner 4 using the AI double signal of the analog signal channel 9A, and the scanner 4
Transmission of an analog signal (video signal) to the television monitor 2 begins. The input/output of analog signals is the connection circuit 10a,
This is done through the LOC analog signal processing circuit 11.

The end of this signal transmission is instructed by a command issued from the controller 6.

The connection procedures between other functional units or between the functional units and the video tape recorder 8 (external device) are also similar. In this embodiment, the video tape recorder 8 is connected to the television monitor 2, printer 3, or facsimile communication section 5.
analog signal transmission from facsimile communication section 5 to television monitor 2, video tape recorder 8 or printer 3
analog signal transmission from scanner 4 to television monitor 2
, video tape recorder 8, facsimile communication section 5, or printer 3, respectively.

Digital signal channel 9 by channel selection command
By specifying D, it is also possible to transmit digital data using the digital signal channel 9D.

Further, each functional unit can also make a service request to the controller 6 through the digital signal channel 9D.

Although this embodiment provides one independent controller 6, one or more functional units may have the controller function.

Effects of the Invention As is clear from the above description, the present invention uses a bus having not only digital signal channels but also analog signal channels as a bus to which a plurality of functional units are connected, and connects the functional units to the analog signal channels of the bus. It has a connection circuit for analog signal input/output with the bus and digital signal input/output with the digital signal channel of the bus, and information for controlling analog signal input/output by the connection circuit Analog signals can be transmitted between functional units without deteriorating the signal quality, since they are given through the digital signal channel of the bus rather than the controller or other functional units, and there is still no signal conversion of the analog signals, which is expensive and high accuracy.・High-speed A/D converters and D/A converters are no longer required, and analog signal transmission between functional units can be controlled through digital signal channels. This has the advantage that data transmission by signals is also possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a composite device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an example of a connection circuit, and FIGS.
The figure is a sequence diagram and a bus signal timing diagram showing a connection procedure for analog signal transmission between functional units, and FIG. 5 is a configuration diagram of an example of a connection circuit used in a conventional composite device. DESCRIPTION OF SYMBOLS 1...Multifunction device, 2...Television monitor, 3...Printer, 4...Scanner, 5...Facsimile communication section, 6...Controller, 7...Telephone line, 8...
Video cheap reader, 9...Bus, 9A...Analog signal channel, 9C...Control signal channel, 9D
...Digital signal channel, 11...Analog signal processing circuit, 12...Digital signal processing circuit, 13...
・Control signal processing circuit. Name of agent: Patent attorney Shigetaka Awano and 1 other person 2nd
Ward No. A+ Diagram / 7 Blog 5 Evening

Claims (1)

[Claims] A plurality of functional units having independent functions are connected to a bus, the bus having a digital signal channel and an analog signal channel, and the functional unit inputting and outputting analog signals with the analog signal channel and with the digital signal channel. has a connection circuit for inputting and outputting digital signals of the functional unit, and information for controlling the input and output of analog signals by the connection circuit of the functional unit is transmitted from the controller connected to the bus or other functional units to the functional unit. A complex device characterized in that it is provided through a digital signal channel.