KR100751108B1 - Method and apparatus of distinguish input signal for display - Google Patents

Abstract

An input signal discrimination method of a display apparatus according to the present invention may include: inputting a first signal through a DVI-I connector connected to an external device; Monitoring the HPD detection signal output from the pin of the DVI-I connector; Determining a first signal input through the DVI-I connector as a digital signal or an analog signal according to the presence or absence of a voltage drop of the HPD detection signal; Checking whether the second signal input before the first signal is input through the DVI-I connector is a digital signal or an analog signal; And when the first signal and the second signal are both digital signals or analog signals, the current digital EDID or analog EDID is kept as it is, and when the first signal is a digital signal and the second signal is an analog signal, Reads the digital EDID previously stored in the memory unit and transmits the digital EDID to the external device. When the first signal is the analog signal and the second signal is the digital signal, the analog EDID is stored in the memory unit. And transmitting to the external device.

EDID, DVI-I

Description

Apparatus and method for determining input signal of display device {METHOD AND APPARATUS OF DISTINGUISH INPUT SIGNAL FOR DISPLAY}

1 is a block diagram of an input signal discrimination apparatus according to a first embodiment of the present invention.

2 is a block diagram of an input signal discrimination apparatus according to a second preferred embodiment of the present invention.

3 is a flowchart of a method for determining an input signal according to a preferred embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: control unit

102: memory

104: analog EDID

106: digital EDID

108: DVI-I connector

R: resistance

The present invention relates to an image display device, and more particularly, to an apparatus and method for determining an input signal of a display device capable of connecting an analog device and a digital device.

In general, an interface between a monitor and a personal computer (PC) uses an analog interface or a digital interface.

In general, the analog interface uses a D-Sub method, and the digital interface uses a DVI (Digital Visual Interface) method.

The DVI method is a digital interface method and uses a transition minimized differential signaling (TMDS) technology as a digital interface standard defined by the DDWG (Digital Display Working Group).

Typically, monitors have both D-Sub and DVI ports. Accordingly, when the monitor is connected to a PC equipped with an analog graphics card, the analog display information (hereinafter, referred to as EDID) stored in the internal memory is transmitted to the PC through the D-Sub port. When connected to a PC with a digital graphics card, the digital EDID is transmitted through the DVI port.

Since the EDID defines the basic display characteristics of the monitor, the PC identifies the characteristics of the monitor and outputs a video signal for more efficient display.

As described above, when the monitor is connected to a PC having an analog graphics card or a PC having a digital graphics card, the monitor performs a different operation. Had to be able to identify.

Accordingly, the monitor identifies the inflow of digital signals through the signal identification pin provided on the DVI-D connector and checks the inflow of analog signals through the horizontal sync signal through the D-sub connector. To identify.

However, in the DVI-I interface method, since both a digital signal and an analog signal can be input, a problem occurs during the EDID selection process.

For example, if a user inputs an analog signal while inputting a digital signal through the DVI-I connector or inputs a digital signal after inputting an analog signal, the input signal is changed according to the EDID of the monitor connected to the EDID of the first connected method. The monitor could not output images normally.

In order to overcome this problem, monitoring the input signal in real time has a problem that causes the system to slow down and lose power.

In addition, even if the input signal is monitored in real time, the change of the EDID in conjunction with the detection of the change in the input signal also has a problem that the PC recognizes the wrong EDID due to the delay of the processing time.

Accordingly, there is an urgent need to develop a technology capable of detecting a change in an input signal in real time without putting a load on a host device such as a display device or a PC.

Disclosure of Invention The present invention is to overcome the above-mentioned problems, and is a display device that enables the selection of a suitable EDID according to the input state of a digital signal and an analog signal in a DVI-I interface method capable of receiving both a digital signal and an analog signal. It is an object of the present invention to provide an input signal discrimination apparatus and method.

In addition, another object of the present invention is to monitor the input state of the digital signal and the analog signal using the HPD signal, a display that can detect the change in the input signal in real time without load on the host device, such as a display device or a PC An apparatus and method for determining an input signal of an apparatus are provided.

According to an aspect of the present invention, a method for determining an input signal of a display apparatus according to the present invention includes: inputting a first signal through a DVI-I connector connected to an external device; Monitoring the HPD detection signal output from the pin of the DVI-I connector; Determining a first signal input through the DVI-I connector as a digital signal or an analog signal according to the presence or absence of a voltage drop of the HPD detection signal; Checking whether the second signal input before the first signal is input through the DVI-I connector is a digital signal or an analog signal; And when the first signal and the second signal are both digital signals or analog signals, the current digital EDID or analog EDID is kept as it is, and when the first signal is a digital signal and the second signal is an analog signal, Reads the digital EDID previously stored in the memory unit and transmits the digital EDID to the external device. When the first signal is the analog signal and the second signal is the digital signal, the analog EDID is stored in the memory unit. And transmitting to the external device.

The present invention determines whether an input signal is a digital signal or an analog signal by using a Hot Plug Detection (HPD) signal output to a predetermined pin of a DVI-I connector without applying a load to a host such as a display device or a PC.

The configuration of the input signal discrimination apparatus according to the first preferred embodiment of the present invention will be described with reference to FIG.

The controller 100 not only controls the display apparatus as a whole, but also performs an input signal discrimination process according to a preferred embodiment of the present invention. That is, the controller 100 receives the HPD detection signal for the HPD signal output from the predetermined pin of the DVI-I connector through the ADC input terminal and checks whether the step-down drop of the HPD detection signal is detected. When the voltage drop of the HPD detection signal is detected, the controller 100 is connected to the digital device through the DVI-I connector 108 to determine that the digital signal is input, and the digital EDID 106 from the memory unit 102. Read and send to digital device. On the other hand, if the voltage drop of the HPD detection signal is not detected, the controller 100 is connected to the analog device through the DVI-I connector 108 and determines that the analog signal is input, and the analog EDID 104 is stored in the memory unit. Read from 102 and transmit to analog equipment.

The memory unit 102 stores various information including the processing program of the controller 100, and particularly, the digital EDID 106 and the analog EDID 104. The EDID is information in which basic display characteristics of the display device are defined.

The DVI-I connector 108 implements connections with analog and digital devices, in particular with HPD pins for receiving HPD signals. The HPD signal is a signal for detecting a connection with a digital device in the display device.

HPD detection signal generation unit 110 is composed of a resistor (R) connected between the power supply (Vcc) and the HPD pin of the DVI-I connector 108, the signal between the resistor (R) and the HPD pin is HPD detection signal Is output as.

In the first preferred embodiment of the present invention, the controller 100 directly detects the voltage drop of the HPD detection signal, but additionally includes a circuit for outputting a signal indicating the voltage drop of the HPD detection signal. The load of the controller 100 may be reduced.

The configuration of the input signal discrimination apparatus according to the second preferred embodiment of the present invention for providing the control unit 100 with a signal indicating the voltage drop of the HPD detection signal as described above will be described with reference to FIG. 2.

The controller 100 not only controls the display apparatus as a whole, but also performs an input signal discrimination process according to a preferred embodiment of the present invention. That is, the controller 100 receives the signal indicating the voltage drop of the HPD detection signal from the HPD detection circuit 200, and is connected to the digital device or the analog device through the DVI-I connector 108 according to the signal. The digital EDID 106 is read from the memory unit 102 and transmitted to the digital device according to the judgment result, or the analog EDID 104 is read from the memory unit 102 and transmitted to the analog device.

The memory unit 102 stores various information including the processing program of the controller 100, and particularly, the digital EDID 106 and the analog EDID 104. The EDID is information in which basic display characteristics of the display device are defined.

The DVI-I connector 108 implements connections with analog and digital devices, in particular with HPD pins for receiving HPD signals.

The HPD detection circuit 110 receives the resistor R connected between the power supply Vcc and the HPD pin of the DVI-I connector 108 and receives the HPD detection signal output between the resistor R and the HPD pin to convert the AD. The ADC 202 compares the AD value of the HDP detection signal output by the ADC 202 with a predetermined value, and thus, a signal indicating whether there is a voltage drop of the HPD detection signal to the controller 100. The comparator 204 outputs.

An input signal discrimination method applicable to the input signal discrimination apparatus according to the first and second embodiments will now be described with reference to FIG. 3.

The controller 100 monitors the HPD detection signal or the signal indicating the voltage drop of the HPD detection signal, and checks whether the HPD detection signal is the voltage drop (step 300, 302).

When a voltage drop of the HPD detection signal occurs, the controller 100 determines that a digital signal is input. When the digital signal is input, the controller 100 checks whether the previous input signal is a digital signal (step 304). If the previous input signal is a digital signal, the controller 100 maintains the current state. In order to receive and output a digital signal from a digital device connected through the I connector 108, the digital EDID 106 is read from the memory unit 102 and transmitted to the digital device (step 306).

If the voltage drop of the HPD detection signal does not occur, the controller 100 determines that an analog signal is input. When the analog signal is input, the control unit 100 checks whether the previous input signal is an analog signal (step 308). If the previous input signal is an analog signal, the controller 100 maintains a current state, and if the previous input signal is a digital signal. In order to receive and output an analog signal from an analog device connected through the DVI-I connector 108, the analog EDID 104 is read from the memory unit 102 and transmitted to the analog device (step 310).

In the above-described embodiments of the present invention, the control unit 100 exemplarily monitors the HPD detection signal. However, when the EDID data is requested or the user requests to change the input signal in consideration of the load weighting of the control unit 100. Alternatively, the HPD detection signal may be checked in response to an event such as power on.

Embodiments of the present invention described above include a computer readable medium including program instructions for performing various computer-implemented operations. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has an advantage in that a suitable EDID can be selected according to the input state of the digital signal and the analog signal in the DVI-I interface method capable of receiving both the digital signal and the analog signal.

In addition, the present invention has the advantage that it is possible to detect the change in the input signal in real time without loading the host device such as a display device or a PC by monitoring the input state of the digital signal and the analog signal using the HPD signal.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible.

Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

Claims (8)

Inputting a first signal through a DVI-I connector connected to an external device; Monitoring the HPD detection signal output from the pin of the DVI-I connector; Determining a first signal input through the DVI-I connector as a digital signal or an analog signal according to the presence or absence of a voltage drop of the HPD detection signal; Checking whether the second signal input before the first signal is input through the DVI-I connector is a digital signal or an analog signal; And If both the first signal and the second signal are digital signals or analog signals, the current digital EDID or analog EDID is kept as it is, If the first signal is a digital signal and the second signal is an analog signal, the digital EDID stored in the memory unit is read and transmitted to the external device. If the first signal is an analog signal and the second signal is a digital signal, And reading out an analog EDID previously stored in a memory unit and transmitting the analog EDID to the external device. The method of claim 1, And detecting a signal transmitted from the external device as a digital signal when the voltage drop of the HPD detection signal occurs. The method of claim 1, The monitoring method of the HPD detection signal is performed in real time or when the user input signal change request or the power-on when the input signal discrimination method of the display device. A DVI-I connector connected to an external device and receiving a first signal transmitted from the external device; A comparator for monitoring the HPD detection signal output from the pin of the DVI-I connector and checking whether the HPD detection signal has a voltage drop; A control unit configured to receive a signal output from the comparator, determine whether the first signal is a digital signal or an analog signal, and control to transmit a digital EDID or an analog EDID to the external device; And And a memory unit in which the digital EDID or the analog EDID is stored. The controller determines whether the second signal input before the first signal is input through the DVI-I connector is a digital signal or an analog signal, If both the first signal and the second signal are digital signals or analog signals, the current digital EDID or analog EDID is kept as it is, When the first signal is a digital signal and the second signal is an analog signal, the digital EDID stored in the memory unit is read and transmitted to the external device. When the first signal is an analog signal and the second signal is a digital signal, the input signal discrimination of the display apparatus is controlled to read and transmit the analog EDID previously stored in the memory unit to the external device. Device. The method of claim 4, wherein The controller may determine the signal transmitted from the external device as a digital signal when the voltage drop of the HPD detection signal is generated. The method of claim 4, wherein The control unit controls to monitor whether or not the voltage drop of the HPD detection signal in real time or to control whether to monitor the voltage drop of the HPD detection signal when the user changes the input signal or the power-on. Signal discrimination device. delete The method of claim 4, wherein Between the DVI-I connector and the comparator, a resistor for measuring the voltage drop of the HPD detection signal output through the DVI-I connector, and an ADC for AD conversion of the HPD detection signal is further configured. Input signal determination device of the display device.

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