KR20000031424A - Apparatus for controlling display data channel of monitor - Google Patents

Abstract

PURPOSE: An apparatus for controlling the DDC(Display Data Channel) of a monitor used by connecting 2 computers to a monitor is provided to achieve data receiving and transmitting between 2 computers and a monitor without collis ion as the data communication between the computers and the monitor is proceeded automatically according to the transfer operation of a first selection switch. CONSTITUTION: A first selection switch(600) selects a first DDC output unit and a second DDC output unit. A switch control unit(400) outputs horizontal synchronous signals(Hsync1,Hsync2) outputted from the first DDC output unit and the second DDC output unit, and a control signal by the selection of the first selection switch(600). A second selection switch(500) connects a DDC output unit selected in the first selection switch(600) between the first DDC output unit and the second output unit and a monitor(100) by the control signal. The first DDC output unit is connected to a video card(210) of a first computer(200), and the second DDC output unit is connected to a video card(310) of a second computer(300).

Description

Display information channel control device of monitor

The present invention relates to a display information channel (hereinafter referred to as Display Data Channel) of a monitor.

The recent development of the Plug and Play (P & P) function of computers has made it possible to display various kinds of information of a computer through a two-way communication with a computer. DC is a technology that enables such a function, and there are two types of DC, which is a unidirectional communication standard DC 1 and a recently developed bidirectional communication standard DC 2.

In particular, the DC 2 standard is a serial data bus line (abbreviated as I2C) between a computer and a monitor. Give and take That is, when the monitor and the computer are connected to each other, data is transmitted and received between each other by the above-described I2C of the DC standard, so that the computer's graphic card detects the maximum resolution and the number of colors of the monitor and is related to the screen setting. By transmitting the information to the monitor, the monitor can display the screen information of the image implemented on the current screen.

In addition to the computer's detection of the monitor's information, such a device supports a function of adjusting the monitor's screen on the computer. FIG. 1 is an example showing a structure in which the monitor 10 and the computer 20 are connected by the communication method of the DC standard.

However, the conventional communication method of the DC standard by I2C causes a problem in the monitor 10 provided with two input terminals as shown in FIG. This is because when two computers 20 and 20 'are connected to one monitor 10, when one I2C line connected to one side does not operate, the other I2C line connected to the other side does not operate.

That is, when two computers 20 and 20 'are connected to one monitor 10, when the power of one computer is turned off, the other computer is not affected and is not normally operated. The reason for such a result is that when there are a plurality of I2C lines, if one or more devices that do not operate normally among the devices connected to the I2C lines are difficult to control the entire I2C line.

The present invention has been made to solve this problem, and an object thereof is to provide a DC control apparatus capable of controlling two I2C lines.

Figure 1 is an example showing the structure of the connection between the monitor and the computer by the communication method of the DC standard

FIG. 2 is a diagram illustrating a structure in which a monitor having two DC connectors and two computers are connected; FIG.

3 is a circuit diagram showing a DC control apparatus of the present invention;

Explanation of symbols for main parts of the drawings

100: monitor 110: monitor microcomputer

200: the first computer 210: the microcomputer of the first computer

300: second computer 310: second computer microcomputer

400: switch control unit 500: second selection switch

600: first selection switch

The present invention is characterized in that the two DC input unit detects the horizontal synchronous signal output from the computer to disconnect the abnormal operation of the computer and the monitor.

As shown in FIG. 3, the display information channel control apparatus of the present invention includes a first selection switch 600 for selecting a first DC output unit and a second DC output unit, a first DC output unit, and a second DC device. Switch control unit 400 for outputting a predetermined control signal by selecting the horizontal synchronization signals (Hsync1, Hsync2) and the first selection switch 600 output from the seed output unit, and the first DC output unit by the control signal And a second selection switch 500 connecting the DC output unit selected by the first selection switch 600 and the monitor 100 among the second DC output unit.

The first DC output unit is connected to the video card 210 of the first computer 200, and the second DC output unit is connected to the video card 310 of the second computer 300. The video card 210 of the first computer outputs the first horizontal synchronization signal Hsync1, and the video card 310 of the second computer outputs the second horizontal synchronization signal Hsync2.

The first selection switch 600 selects the first DC output unit and the second DC output unit by a user's manipulation. The first selector switch 600 is composed of a three-terminal switch, and a signal for selecting a first DC output unit, a signal for selecting a second DC output unit, and not selecting both the first DC output unit and the second DC unit. Does not output any one of the signals.

The switch controller 400 may include a first horizontal synchronous signal Hsync1 output from the first DC output unit, a second horizontal synchronous signal Hsync2 output from the second DC output unit, and a first selection switch 600. The controller outputs a control signal for selecting one of the first DC output unit and the second DC output unit. A preferred switch controller 400 for generating a control signal for selecting either the first DC output unit or the second DC output unit includes five AND logic gates (AND gates) and one as shown in FIG. It is composed of two logical sum operators (OR gates).

That is, the switch control unit 400 receives the horizontal synchronization signal Hsync1 of the first DC output unit and the first logic gate 410 that performs an AND operation on an inverted signal of a signal for selecting the second DC output unit; The second logic gate 420 and the second logic gate 420 of the second logic gate 420 and the second logic gate 420 for receiving the inverse signal of the horizontal synchronization signal (Hsync2) of the second DC output unit and the signal for selecting the first DC output unit A third logic gate 430 for performing an AND operation on the output signal and the inverted signal of the horizontal synchronization signal Hsync1 of the first DC output unit, the horizontal synchronization signal Hsync2 and the second DC output unit; The fourth logic gate 440 receives the signal for selecting the DC output unit and performs an AND operation, and the inverted signal of the output signal of the fourth logic gate 440 and the signal for selecting the first DC output unit is received. A fifth logical gate 450 for performing an AND operation, and a third paddy field Claim 6 is composed of the logical operator 460 which receives the output signal and the output signal of the fifth logic gate 450 of the gate 430, a logical OR operation.

The second selection switch 500 is a DC output unit and the monitor 100 selected by the first selection switch 600 among the first DC output unit and the second DC output by the control signal output from the switch controller 400. ). The second selection switch 500 includes a first switch device connecting the first DC output unit and the microcomputer 110 of the monitor, and a second switch device connecting the second DC output unit and the microcomputer 110 of the monitor. Consists of

Hereinafter, the operation principle of the present invention will be described.

The first selection switch 600 outputs a high signal and a low signal by a user's manipulation. The first selection switch 600 is a three-phase switch, and outputs a high signal to the 'ga' terminal, or outputs a high signal to the 'b' terminal or a 'ga' with a user's manipulation. It is configured to output low signal to both 'I' terminals.

If a horizontal synchronous signal is generated from the video card 210 of the first computer, a high signal is output to the 'multi' terminal, and a horizontal synchronous signal is generated from the video card 310 of the second computer. When a high signal is output to the terminal, and a horizontal synchronization signal is generated from both the video card 210 of the first computer and the video card 310 of the second computer, both the 'D' terminal and the 'D' terminal A high signal is output. Of course, when the horizontal synchronization signal does not occur in both the video card 210 and the second video card 310 of the first computer, a low signal is output to both the 'da' terminal and the 'la' terminal. At this time, the computer that outputs the horizontal synchronization signal is a computer that operates normally, and the computer that does not output the horizontal synchronization signal is a computer that operates abnormally or does not operate.

According to the signals of the 'a' terminal, the 'I' terminal, the 'da' terminal, and the 'la' terminal, the output signals of the 'e' terminal and the 'bar' terminal of the switch control unit 400 are the logic of the switch control unit 400. The circuit exhibits a truth value as shown in Table 1 below. In Table 1, 'H' means high signal, 'L' means low signal, and '×' means Don't care signal.

end I All la hemp bar L L L L L L L L L H L H L L H L H L L L H H H L L H L L L L L H L H L H L H H L L L L H H H L H H L L L L L H L L H L L H L H L H L H L H H H L H H L L × × H H L H × × H H H L × × H H H H × ×

When the user selects the first DC output unit by operating the first selector switch 600 according to the truth values shown in Table 1, a high signal is outputted at the 'a' terminal and a low at the 'b' terminal. ) Signal is output. Then, when the high signal is output to the 'multi' terminal, that is, when the horizontal synchronization signal is output to the video card 210 of the first computer, the high signal is output to the 'e' terminal and the low signal is supplied to the 'bar' terminal. Is output. As a result, the video card 210 of the first computer and the microcomputer 110 of the monitor are connected to perform data transmission and reception, and the video card 310 of the second computer and the microcomputer 110 of the monitor are not connected.

In addition, when the user operates the first selection switch 600 to select the second DC output unit, a low signal is output to the 'a' terminal and a high signal is output to the 'b' terminal. Then, when the high signal is output to the 'la' terminal, that is, when the horizontal synchronization signal is output to the video card 310 of the second computer, the high signal is output to the 'bar' terminal, and the low signal is supplied to the 'ma' terminal. Is output. As a result, the video card 310 of the second computer and the microcomputer 110 of the monitor are connected to perform data transmission and reception, and the video card 310 of the second computer and the microcomputer 110 of the monitor are not connected.

If the user does not select both the first DC output unit and the second DC output unit by operating the first selection switch 600, a low signal is output to both the 'ga' terminal and the 'b' terminal. Then, the phases of the output signals of the 'ma' terminal and the 'bar' terminal are changed according to the phases of the signals output to the 'multi' terminal and the 'la' terminal. That is, the video card 210 of the first computer and the video card 310 of the second computer are connected to the video card that outputs the horizontal synchronization signal and the microcomputer 110 of the monitor to perform data transmission and reception.

For example, when a high signal is output at the 'D' terminal and a low signal is output at the 'D' terminal, a high signal is output at the 'D' terminal and a low signal is output at the 'Bar' terminal. As a result, the video card 210 of the first computer and the microcomputer 110 of the monitor are connected to perform data transmission and reception, and the video card 310 of the second computer and the microcomputer 110 of the monitor are not connected. In addition, when the low signal is output at the 'D' terminal and the high signal is output at the 'D' terminal, the low signal is output at the 'M' terminal and the high signal is output at the 'Bar' terminal. As a result, the video card 310 of the second computer and the microcomputer 110 of the monitor are connected to perform data transmission and reception, and the video card 210 of the first computer and the microcomputer 110 of the monitor are not connected.

As a result, the present invention provides a horizontal synchronization signal when a low signal is output to both the 'a' terminal and the 'b' terminal, that is, when the user selects nothing between the first DC output unit and the second DC output unit. The microcomputer 110 of the monitor is connected to the video card to perform data transmission and reception. In this case, when the horizontal synchronization signal is generated in both the video card 210 of the first computer and the video card 310 of the second computer, the switch controller 400 installed in the DC control apparatus of the present invention is in an initial state. It is configured to connect the microcomputer 110 of the monitor to the video card 210 of the first computer.

In the truth table of Table 1 implemented by the present invention, since the user does not need to select both the first DC output unit and the second DC output unit by operating the first selection switch 600, the 'a' terminal and ' If the high signal is output to both terminals, it can be ignored.

Since the present invention can be applied to a monitor configured with two DC input units by improving the DC system of the monitor, two computers can be connected to one monitor. In this case, the present invention automatically performs data communication between the monitor and the computer according to the switching operation of the first selection switch, so that data transmission and reception between the two computers and the monitor are performed without collision.

Claims (4)

In a bidirectional DDC system connected to a monitor, A first selection switch for selecting one of the first DDC output unit and the second DDC output unit by a user's operation; Outputting a control signal for selecting any one of the first DDC output unit and the second DDC output unit by selecting a horizontal synchronization signal output from the first DDC output unit and the second DDC output unit and a first selection switch; Switch control unit; And, And a second selection switch connecting the monitor and the DDC output unit selected by the first selection switch among the first DDC output unit and the second DDC output unit by the control signal. The method of claim 1, wherein the first selection switch does not select a signal for selecting the first DDC output unit, a signal for selecting the second DDC output unit, and both the first DDC output unit and the second DDC output unit by a user's manipulation. Display information channel control device, characterized in that the three-terminal switch for outputting any one of the signals. The method of claim 2, wherein the switch control unit A first logic gate configured to perform an AND operation on the inverted signal of the horizontal synchronization signal of the first DDC output unit and the signal of selecting the second DDC output unit; A second logic gate configured to perform an AND operation on the horizontal synchronization signal of the second DDC output unit and the inverted signal of the signal for selecting the first DDC output unit; A third logic gate configured to perform an AND operation on the inverted signal of the output signal of the second AND product and the horizontal synchronization signal of the first DDC output unit; A fourth logic gate configured to perform an AND operation on the horizontal synchronization signal of the second DDC output unit and the signal for selecting the second DDC output unit; A fifth logic gate configured to perform an AND operation on the inverted signal of the output signal of the fourth AND operator and the signal for selecting the first DDC output unit; And a sixth logic gate configured to receive the output signal of the third logical product operator and the output signal of the fifth logical product operator and perform a logical sum operation. The method of claim 1, wherein the second selection switch A first switch connecting the first DDC output unit and the monitor micom by the control signal; And a second switch connecting the second DDC output unit and the monitor micom by the control signal.