KR19980036991A - Automatic Input Switching Circuit for Video Monitors with Removable Connector Socket Structure - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input selection switching switch circuit of a video signal monitor, and more particularly to a circuit which enables automatic switching of both inputs in a video monitor having a BNC type and a D-SUB type video signal input terminal.

In the circuit of the present invention, the connector socket of the input terminal portion of the D-SUB type is two metal terminals (terminals 1 and 2) whose external conductors are electrically separated, and one of the metal terminals is connected to the earth of the circuit. The other one is a circuit connected to the base side of the driving transistor, and the connector socket of the input terminal portion of the BNC type is two metal terminals (terminals 3 and 4) electrically separated from each other. Is connected to the ground of the driving transistor, and the other end is circuit-connected to the base side of the driving transistor. When the connector plug is inserted into the input terminal of the video monitor, the terminal 1 and the terminal 2 or the terminal 3 and the terminal 4 By driving the external metal portion of the connector plug to form a circuit, the driving transistor and the synchronous signal switching logic IC are automatically driven. Provide and.

Description

Automatic Input Switching Circuit for Video Monitors with Removable Connector Socket Structure

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input selection switching switch circuit of a video signal monitor, and more particularly to a circuit which enables automatic switching of both inputs in a video monitor having a BNC type and a D-SUB type video signal input terminal.

In a video monitor for receiving a video signal and imaging the video signal, an input terminal for inputting a video signal to the video monitor is divided into two types, a BNC type and a D-SUB type, depending on the type of the input cable.

The input terminal is typically configured using a connector.

The connector is the sum of the socket (female) and the plug (male).

Figure 1 shows the structure of the connector of the BNC type and D-SUB type.

Typically, a pin (PIN) is provided inside the socket and the plug, and an outer conductor is formed around the pin.

When the plug is inserted into the connector socket, the outer conductor of the plug and the outer conductor of the socket contact each other, and the pin of the plug and the pin of the socket contact each other to form an electric circuit.

Depending on the type of connector, the pin may include several.

The blue monitor (B), the green signal (G), the red signal (R) and the horizontal synchronization signal (V. Sync) and the vertical synchronization signal (H. Sync) are input as the video monitor as the video signal input. The video monitor amplifies and processes the inputted signals.

On the other hand, when signals are simultaneously input from the two types of input terminals, collisions and interference between signals are caused. Therefore, a switch or an input signal selection circuit for selecting only one of the input signals is required.

In the conventional video monitor, a switching switch having two selection positions of BNC and D-SUB is installed outside the video monitor and the user selects it as the BNC or D-SUB position, thereby preventing collision and interference between the signals. .

As an example of an input switching circuit using a conventional selection switch, the present invention will be described in detail with reference to FIG. 2.

The external changeover switch 200 is a selection changeover switch of the input signal, and the user selects the position of the BNC or the D-SUB.

When the user positions the external switching switch 200 to D-SUB, the base of the driving transistor Q111 is grounded and the DC bias is bypassed so that the driving transistor Q111 is turned off and the transistor switches Q101, Q102, Q103 ) Is also turned OFF so that the signal from the BNC input terminal section 102 is cut off.

On the other hand, since the base of the driving transistor Q112 is subjected to a DC bias, the transistor is turned on and the transistor switches Q104, Q105, and Q106 are each turned on, and the blue signal B from the D-SUB input terminal portion 101, The green signal G and the red signal R are output to the video signal output unit 103 and transmitted to the VIDEO PREAMP. In addition, according to the LOGIC of the synchronization signal switching logic IC 110, the synchronization signal from the BNC input terminal section 102 is cut off, and the horizontal synchronization signal (V. Sync) and the vertical synchronization signal (H) from the D-SUB input terminal section 101 are displayed. Sync) is outputted to the synchronization signal outputting unit 104, and the SYNC. Passed to PROCESSOR.

When the user positions the external switching switch 200 to the BNC, the base of the driving transistor Q112 is grounded and the DC bias is bypassed so that the driving transistor Q112 is turned off, and the transistor switches Q104, Q105, and Q106 are also turned on. Therefore, each turn is turned off, and the signal from the D-SUB is cut off.

On the other hand, since the DC bias is applied to the base of the driving transistor Q111, the transistor is turned on and the transistor switches Q101, Q102, and Q103 are each turned on, and the blue signal B, the green signal G, and the red signal from the BNC are turned on. The signal R is output to the video signal output unit 103 and transmitted to the VIDEO PREAMP. In addition, the synchronization signal from the D-SUB is blocked according to the LOGIC of the synchronization signal switching logic IC 110, and the horizontal synchronization signal (V. Sync) and the vertical synchronization signal (H. Sync) from the BNC input terminal section 102 are synchronized. Is outputted to the signal output unit 104 to SYNC. Passed to PROCESSOR.

In the above-described input switching circuit of the prior art, when the user wants to switch the input of the BNC or D-SUB type, there is a problem that the user must select the selection switch installed outside the video monitor every time.

SUMMARY OF THE INVENTION An object of the present invention is to adopt a connector socket having a detachable structure in a video monitor, so that when a user inserts a BNC or D-SUB type plug into an input terminal of the video monitor, the circuit is connected according to the mechanical characteristics of the connector. It is provided to provide a video monitor device that is configured and automatically switching the input state, the user does not need additional input switching switch operation.

1 is a view showing a structure of a conventional connector and a connector socket used in the present invention,

2 is a circuit diagram showing an example of an input switching circuit in which a selection switch according to the prior art is used;

3 is an input automatic switching circuit of a video monitor of the present invention constructed using a detachable connector socket.

* Description of the symbols for the main parts of the drawings *

10; D-SUB connector socket 20; BNC Connector Socket

11, 21; Socket external conductors 12, 22; PIN

15; D-SUB connector plug 25; BNC connector plug

16, 26; Plug outer conductors 11A and 11B; Metal contact

14, 24; Insulator terminal 1, terminal 2; Electrical contacts

100, 100-1; Input switching circuit section 101; D-SUB input terminal

102; BNC input terminal section 103; Video signal output section

104; Synchronization signal output sections Q101-Q106; Transistor switch

Q111, Q112; Driving transistor 110; Synchronous Signal Switching Logic IC

120; Retriggerable Monostable Multi Vibrator

200; External switch 300; Automatic input switching circuit

Q301, Q303; Bypass drive transistor

Q302, Q304; Bypass transistor

In order to realize the above object, the present invention has a BNC-type video input terminal section 102 and a D-SUB-type video input terminal section 101. For each signal of R, G, and B in the video signal, Six transistor switches (Q101-Q106) for switching both inputs, two driving transistors (Q111, Q112) for controlling the transistor switches, and H. Sync and V. Sync signals for switching the input terminals. A video monitor comprising a synchronization signal switching logic IC (110) for;

The socket (female) of the connector of the input terminal portion 101 of the D-SUB type is formed of two metal terminals (terminals 1 and 2) whose external conductors are electrically separated, and one of the metal terminals is a circuit. Is connected to the ground of the circuit board, and the other one is a circuit connected to the base side of the driving transistor Q111; The socket (female) of the connector of the input terminal portion 102 of the BNC type is formed of two electrically separated metal terminals (terminal 3, terminal 4), one of which is connected to the earth of the circuit, The other one is constructed by being connected to the base side of the driving transistor Q112 in a circuit.

When the plug (male) is inserted into the socket of the input terminal portion of the video monitor of the present invention, the terminal 1 and the terminal 2 or the terminal 3 and the terminal 4 are conducted by an external metal part of the plug (male) and the circuit Is formed to automatically drive the driving transistors Q111 and Q112 and the synchronization signal switching logic IC 110.

EXAMPLE

Hereinafter, a preferred embodiment of the present invention with reference to the accompanying drawings.

The structure of the BNC type and D-SUB type connectors used in the present invention is shown in FIG.

The outer conductor of the connector socket used in the present invention is formed of a conductive metal material and is structurally separated into two conductors 11A and 11B. Electrically, the two metal conductors are insulated and serve as two terminals (terminal 1 and terminal 2).

The two metal conductors 11A and 11B are insulated through the socket body and the insulators 14 and 24.

One of the two metal conductors may be formed integrally with a metal material constituting the socket body.

In circuit description, the two terminals of the connector socket of the present invention serve as both contacts of an electrical switch.

When a plug is inserted into the connector socket, the outer conductor of the plug and the two outer conductors of the socket contact each other. Therefore, when the plug is inserted into the connector socket of the present invention, the contact is connected between the terminals through the outer conductor of the plug.

In an electronic device having a connector socket used in the present invention, a user inserts a connector plug of a BNC or D-SUB type into an input terminal of the electronic device, and automatically detects the connector input form of the input terminal. This is done.

3 is an input automatic switching circuit of a video monitor to which the connector socket of the present invention is applied.

When the user inserts the plug into the D-SUB type connector, both terminals of the socket of the present invention conduct and form a circuit. Therefore, the base of the driving transistor Q111 is grounded and the DC bias is bypassed, thereby driving the driving transistor Q111. ) Is turned off, and the transistor switches Q101, Q102, Q103 are also turned off accordingly, and the signal from the BNC input terminal section 102 is cut off.

On the other hand, since the base of the driving transistor Q112 is subjected to a DC bias, the transistor is turned on and the transistor switches Q104, Q105, and Q106 are each turned on, and the blue signal B from the D-SUB input terminal portion 101, The green signal G and the red signal R are output to the video signal output unit 103 and transmitted to the VIDEO PREAMP. In addition, according to the LOGIC of the synchronization signal switching logic IC 110, the synchronization signal from the BNC input terminal unit 102 is cut off, and the horizontal synchronization signal (V. Sync) and the vertical synchronization signal (H) from the D-SUB input terminal unit 101 are blocked. Sync) is outputted to the synchronization signal outputting unit 104, and the SYNC. Passed to PROCESSOR.

When the user inserts the plug into the BNC-type connector, both terminals of the socket of the present invention conduct and form a circuit. Therefore, the base of the driving transistor Q112 is grounded and the DC bias is bypassed, thereby driving the driving transistor Q112. Is turned off, and the transistor switches Q104, Q105, and Q106 are also turned off accordingly, and the signal from the D-SUB is cut off.

On the other hand, since the DC bias is applied to the base of the driving transistor Q111, the transistor is turned on and the transistor switches Q101, Q102, and Q103 are each turned on, and the blue signal B, the green signal G, and the red signal from the BNC are turned on. The signal R is output to the video signal output unit 103 and transmitted to the VIDEO PREAMP. In addition, the synchronization signal from the D-SUB is blocked according to the LOGIC of the synchronization signal switching logic IC 110, and the horizontal synchronization signal (V. Sync) and the vertical synchronization signal (H. Sync) from the BNC input terminal section 102 are synchronized. Is outputted to the signal output unit 104 to SYNC. Passed to PROCESSOR.

In the video monitor with the connector socket of the present invention, the user can insert the BNC or D-SUB type connector plug into the input terminal of the monitor device, thereby automatically detecting the type of the connector connected to the input terminal. Is done.

In the video monitor employing the connector structure of the present invention, when a user inserts a BNC or D-SUB type plug into the input terminal of the video monitor, a circuit is formed according to the mechanical characteristics of the connector, and the input state is automatically switched. Effect is achieved.

While the invention has been shown and described with respect to certain preferred embodiments, it will be appreciated that the invention can be modified and modified in various ways without departing from the spirit or scope of the invention as set forth in the claims below. One of ordinary skill in the art will readily know.

Claims (4)

In the socket 10 structure of the electrical connector, The outer conductor 11 is formed of two metal conductors 11A and 11B separated electrically, Each of the metal conductors 11A and 11B constitutes an electrical contact (terminal 1, terminal 2), When the plug 15 is inserted into the connector socket 10, the outer conductor 16 of the plug and the two outer conductors 11A and 11B of the socket 10 come into contact with each other, so that the outside of the socket A connector socket structure, wherein an electrical contact is connected between conductor terminals (terminals 1 and 2). 2. The connector socket structure according to claim 1, wherein the connector socket is configured in the outer conductor of the connector socket (21) of the BNC type in particular. 2. The connector socket structure according to claim 1, wherein the connector socket is configured on an outer conductor of the connector socket (11) in the form of a D-SUB. It has a BNC type video input terminal section 102 and a D-SUB type video input terminal section 101, Six transistor switches (Q101 to Q106) for switching the two inputs with respect to each of R, G, and B signals in the video signal, Two driving transistors Q111 and Q112 for controlling the transistor switches; A video monitor comprising a synchronization signal switching logic IC (110) for switching the H. Sync and V. Sync signals of both input terminal portions, The connector socket of the input terminal portion 101 of the D-SUB type is two metal terminals (terminals 1 and 2) whose external conductors are electrically separated from each other, and one of the metal terminals is connected to the earth of the circuit. One is a circuit connected to the base side of the driving transistor Q111, The connector socket of the BNC-type input terminal section 102 is two metal terminals (terminals 3 and 4) electrically separated, one of which is connected to the earth of the circuit, and the other one of the driving transistors ( It is a structure connected to the base side of Q112) by the circuit, When a connector plug is inserted into an input terminal of the video monitor, the terminal 1 and the terminal 2 or the terminal 3 and the terminal 4 are electrically connected to each other by an external metal part of the connector plug to form a circuit. And Q112) and a synchronous signal switching logic IC 110 for automatically driving the video signal input automatic switching circuit.