JPS6022883A - Mutual connecting device of reception terminal device - Google Patents

Abstract

PURPOSE:To attain connection state with inexpensive constitution and rich in expanding for recepion terminal devices by providing an interface device changeing over the input and output direction of a signal between each reception terminal device and a common bus line. CONSTITUTION:A video disc 3, a personal computer 4, a VTR5 and a television receiver 6 are installed as the reception terminal devices, and a video signal input/output line and an audio signal input/output line of each device are connected to a bus line 11 via interface devices 7-10. The interface devices 7-10 are provided to change over the input and output direction of a video signal VID and audio signals AD1, AD2 among the video signal input/output line and the audio signal input/output line of each device and the bus line 11, and this changeover operation is controlled by a control signal from a controller 12.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a television receiver and a video tape recorder.

The present invention relates to an interconnection device that connects various receiving terminal devices such as video discs.

[Prior art]

In recent years, the development of various new media that handle images and sounds has progressed, and in ordinary households, various receiving terminal devices such as television receivers, video tape recorders, and video discs are being installed in living spaces and other living spaces. In the future, it is expected that more receiving terminal equipment such as tT star broadcast receivers and 2-character broadcast receivers will be installed.

By the way, these receiving terminal devices are usually interconnected around the television receiver and configured as one receiving system. A dendritic connection method in which the television receiver 1 and the receiving terminal devices 2A to 2D are connected in a tree or branch form as shown, or a cascade connection method in which the television receiver 1 and the receiving terminal devices 2A to 2D are connected in a cascade as shown in FIG. 2 are widely used.

However, when using the dendritic connection method, the number of receiving terminal devices that can be connected is limited by the number of input connectors provided on the TV receiver, and at the same time, the connection cables are disorganized and difficult to handle. It has the disadvantage of becoming. On the other hand, when using the cascade connection method, it is convenient in terms of expandability, but in reality, the method requires adding control signal lines in addition to the video and audio signal lines, which reduces the number of cable cores. As the number of cables increases, standardization of cable specifications is required.

[Object and structure of the invention]

This invention was made in view of the above-mentioned drawbacks.
The object is to provide an interconnection device for receiving terminal devices that can connect each receiving terminal device to each other with an inexpensive configuration, can simplify the connection state, and is highly expandable.

To this end, the present invention installs a bidirectional path line consisting of a video signal line and an audio signal line that are commonly used by each receiving terminal device, and also connects the video signal between each receiving terminal device and this path line. An interface device for switching the output direction of the audio signal and the output direction of the audio signal is provided for each receiving terminal device, and a control signal is given to each interface device using the video signal line or audio signal line that constitutes the pass line. An interconnection control device 2 is provided to control the switching operation of the output direction of the video 414 and audio signals in the interface device, and the output tank for the video 411 and audio signals to the bus line is controlled by the interconnection control device 2. The video signal and audio signal sent to the pass line are arranged so that the remaining receiving terminals can freely use the video and audio signals sent to the pass line.

〔Example〕

FIG. 3 is a block diagram showing one embodiment of the present invention.

In the figure, a video disc device 3. is used as a receiving terminal device. A personal computer 4°, a VTR 5, and a television receiver 6 are installed, and the video signal output lines and audio signal input/output lines of each of these devices are connected to interface devices 7 to 1 provided correspondingly to each device.
It is connected to the Tejas line 11 via o. The pass line 11 is composed of a video signal line 11A, two channels of audio signal lines 11B and 11Cfi, and a ground signal line 11D, of which a control signal line 12A of the control device 12 is connected to the video signal line 11A. .

The interface devices T to 10 are video signal input/output lines and audio signal lines of each device and a pass line 11.
The control device 12 switches the input and output directions of the video signal VID and the audio signals AD1 and AD2 between the interface devices T to 10. It controls production.

FIG. 4 shows device 9' among interface devices 7 to 10.
,F? 2 is a circuit diagram illustrating an example of a detailed explanation of the control device 12 and the control device 12. FIG. In the figure, the interface device 9 is V
It has an input terminal 90 and an output terminal 91 for the video signal for the TR5, and input terminals 92 and 93 and output terminals "f'-94 and 95 for two channels of audio (J). 90-95 and video (l:4
Line 11A and Audio Jin'-Yumirai/11o
, 11c are connected to the video signal lines 11A to 11C, the video signal line VID and the audio signal AD1.
, Analog switch 9 that switches the input/output direction of AD2
6 contacts 96A to 96C are provided, and normally the contacts 96A to 96C are controlled to the state shown in the figure, and the input/output directions of the video signal/signal VID and the audio signals 4'i AD1 and AD2 are set to the (flll) of the bus line/11. From VTR5
The direction towards 41111 and 7' are one. That is,
The interface device 9 connects the video (fJ No. VI
D Oyobi Audio No. 4.1 ADI and AD2 are input and the input mode is set to supply them to the VTR5.

The interface device 9 is also provided with seven lip-flops (F, F) 97, and one-shot circuits 98A and 98B connected in cascade.

A control signal period identification circuit 98 is provided which includes a NAND game) 98C and an inverter 98D.

7 lip-flop 9T switches the analog switch 96 when the set output (Q) is "1", that is, when it is in the set state.
to drive the interface device 9 to the output mode (that is, from the VTR side) and send the signals MID and A to the line side.
It is used to put DI and AD2 into a state in which it sends out signals, and when the inverter 99 gives the ``1'' signal, it goes into the reset state, and when the period identification circuit 9B gives the detection signal, it goes into the set state.

The cycle identification circuit 98 identifies whether or not the cycle of the control signal CTL applied from the control device 12 via the video signal line 11A matches the cycle assigned in advance to the interface device 9. As shown in a), the control signal CTL of period T is generated from the control device 12, and when this control signal CTL is applied to the input of the one-shot circuit 98A via the inverter 99, the control signal CTL from the one-shot circuit 98A is generated. A one-shot pulse wP1 having a pulse width TI as shown in FIG. 5(c) is generated in synchronization with the leading edge of CTLO. Thereafter, the next-stage one-shot circuit 98B is triggered by the trailing edge of this one-shot pulse WPI, and the one-shot pulse WP 2 of pulse mT2 is generated from this one-shot pulse circuit 98B as shown in FIG. 5(d). Reru. This one-shot pulse wPl is applied to a Nant gate 98C which receives a control signal CTL from an inverter 99 as one input. Therefore, if the control signal CTL shows the "1" level during the generation period of the one-shot pulse wP2, the NAND condition is established during this period, and this NAND game) 98C
A zero signal is generated. This "o" signal is inverted by the inverter 98D and becomes a "1" signal p1
It is applied to the set input of the slip flop 97. That is, only when the control signal CTI is "1" during the generation period of the one-shot pulse wP2, the fifth
As shown in Figure (e), a detection signal p of ``1'' is generated to set the 7-rip 7μ tube 97. Therefore, the period T of the control signal CTL is assigned to a different value for each interface device in advance, and If the pulse width of the one-shot pulse WPI of the one-shot circuit 98A in each interface device is determined by adjusting the variable resistor VR, corresponding to the assigned period T, the seven lip-flops 97 of one specific interface device can be adjusted. set state and still set the interface device to output mode.

In order to select and set only one specific interface device to the output mode in this way, the control device 12 includes a selection switch circuit 120 that selects the receiving terminal device to be set to the output mode, and a selection switch circuit 120 that selects the receiving terminal device to be set to the output mode. An arithmetic processing unit (CPU) 121 is provided which generates a control signal CTL with a period assigned in advance to the receiving terminal equipment. The video signal is sent to the video signal line 11A inside.

Therefore, when one of the receiving terminal devices to be set to the output mode is selected in the selection switch circuit 120, the control signal CT with the period corresponding to the selected receiving terminal device is
L connects each interface device T through the path line 11
Commonly given to 10.

Then, in each of the interface devices T to 10, the clip-flop 97 is brought into the re-cent state by the leading edge of the first terminal harless forming the control signal CTL at this time. As a result, all the interface devices 7 to 10 are returned to the input mode. However, the second signal forming the control signal CTL is
When the source pulse is given, this control signal J
One-shot time 1 corresponding to the cycle of issue CTL? '+';
98. The seven lip-flops 97 of one interface device having a pulse width of .about. are set, and only that interface device is set to output mode.

As a result, only the receiving terminal equipment connected to the interface device set to the output mode of
1 for video signal VID and audio signal AD
1. When AD2 is not ready to be sent, the remaining receiving terminal equipment receives the video signal VID sent to the path line 11.
and audio signal ADI.

Now you can freely input and use AD2.

By the way, each of the interface devices 7 to 10 is not provided with a power supply device, but the analog switch 9
6 and the flip-flop 9T, the DC voltage E generated from the power supply device 123 of the control device 12 is superimposed on the video signal VID via the resistor R6, and is supplied to each interface device T to 10. This is ensured by smoothing by the choke coil L and capacitor C1 in the interface devices 7 to 10.

On the other hand, the fixed side contact of the contact 96C of the analog switch 96 in each interface device δT~10 has a resistor R.
1 and R2 (R+ < R2) are connected to the ground potential, and when any one of the interface devices 7 to 10 is set to output mode, the DC level of the video signal line 11A is set to 2/3·El [V -] and two or more interface devices are in output mode.

When this happens, the DC level of the video signal line IIA is set to 1/2·Ii+ [V) or less. In addition, in the control device 12, resistors R3 to R5 are connected in series between the power supply voltage El and the contact potential, and a first reference voltage v1 obtained at the connection point between the resistor R3 and the resistor R4 and a noise filter are connected to each other in series. Compare the DC level of the video signal line 11A via the choke coil L and the capacitor Co, and if the DC level of the video signal line IIA is 2//3°E+[V], one interface A comparator 125 is provided that provides a confirmation signal ID to CPU 121 that the device is set to output mode. Also, the second reference voltage v2 obtained at the connection point of the resistor R4 and the resistor R5 is compared with the DC level of the video signal line 11A, and the DC level of the line 11A is 1/'2.
- A comparator 126 is provided which outputs an abnormality detection signal AL indicating that two or more ink face devices are in the output mode when it is less than El [■].

As a result, the CPU 121 uses the video signal line 11A.
Whether or not the interface device corresponding to the cycle of the control signal CTL sent to 2 has entered the output mode, and
It detects whether two or more interface devices are in output mode, and if two or more interface devices are in output mode, it sends out the control signal CTL again, and only one interface device is in output mode. It is configured so that

Note that since the DC voltage E1 is superimposed on the video signal line 11A for the above-described control, the contact 96
A DC cant capacitor CI+C is connected between the fixed side contact of C and the video signal input terminal 90 and output terminal 91.
2 are connected.

In this embodiment, each receiving terminal device such as the video disc device 3 can be connected to the path line 11 consisting of four signal lines, so that inexpensive European connection cables and connectors can be used. . Further, since each device is connected in cascade via the interface devices 7 to 10, the connection state can be made extremely simple, and it is highly expandable.

Furthermore, the control signal is
Since two signal lines are shared, the number of core wires of the connecting cable can be reduced, making it economical.

In this embodiment, the period of the control signal is identified by a logic circuit including a one-shot circuit, but it may also be identified by a counter, a timer, or the like.

〔Effect of the invention〕

As explained above, the present invention installs a bidirectional path line consisting of a video signal line and an audio signal line that are commonly used by each receiving terminal device, and also connects each receiving terminal device with this path line. An interface device that switches the input/output direction of video signals and audio signals is provided for each receiving terminal device, and a control signal is provided to each interface device using the video signal line or audio signal line that constitutes the pass line. , an interconnection control device is provided for controlling the input/output direction switching operation of the video signal and audio signal in each interface device, and the interconnection control device controls the transmission right of the video signal and audio signal to the bus line to a desired one. It is configured so that the video signal and audio signal sent to the receiving terminal equipment can be freely used by the remaining receiving terminal equipment, and the video signal and audio signal sent out to the path line. This allows connections to be made in an extremely simple connection state, and is also highly expandable.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams showing typical examples of conventional interconnection methods, FIG. 3 is an overall block diagram showing an embodiment of the present invention, and FIG. 4 is a detailed configuration of the interface heating and control device. A circuit diagram showing an example, FIG. 5 is a time chart for explaining the operation of the circuit shown in FIG. 4. 1.6.Meeting...Television receiver, 3ψΦ...Video disc device, 411...e personal computer, 51
1II book・VTR, to 7・10・φ・-interface 14fff, 11 fist・φ・pass line, 12...Keyaki control device, 96...φ analog switch, 97...@
Flip-flop, 98...period identification circuit, 12
0 disaster...selection switch circuit, 121-・φ・CPU
,,. Patent applicant: Nippon Gakki Mfg. Co., Ltd. Agent: Masa Yamayo Ikugi (1 other person)

Claims (1)

[Scope of Claims] a. A bidirectional video signal input/output line and a bidirectional audio input line commonly installed in a plurality of receiving terminal devices each having a video signal input and output terminal and an audio signal input and output terminal. a video signal input terminal, a video signal output terminal, and an audio signal input terminal connected to the video signal input and output terminals and the audio signal input and output terminals of each of the receiving terminal devices; Switching and connecting the video signal input terminal or the previous video signal output terminal to the audio signal output terminal and the video signal input/output line, and switching the audio signal input terminal or the audio signal output terminal to the audio signal output line. an analog switch to be connected, and a cycle identification circuit that outputs a matching signal when the cycle of a control signal sent to either one of the video signal input/output line and the audio signal output line matches a pre-assigned cycle; The analog switch is reset by the control signal and set by the coincidence signal, and the set output signal drives the analog switch, and connects the video signal input terminal and audio signal input terminal to the video signal input/output line and the audio signal output line, respectively. an interface device consisting of a clip-flop that is switched and connected and provided corresponding to each receiving terminal device, and a receiving terminal device that sends a video signal and an audio signal to the video signal output line and the audio signal input/output line, respectively. A selection switch to be selected and a control signal having a period assigned in advance to the interface device corresponding to the receiving terminal device selected by the selection switch are sent to one of the video signal input/output line and the audio signal input/output line. and an interconnection control device comprising a control signal generation circuit for transmitting a video signal and an audio signal from a desired receiving terminal device to the remaining receiving terminal devices among the plurality of receiving terminal devices. An interconnection device for receiving terminal equipment that made it possible.