KR100303479B1 - System and method for power saving of display device having usb hub - Google Patents

Abstract

PURPOSE: A system and method for a power saving of a display device having a USB hub is provided to cut off a main power source of a display device through a USB hub by sensing a variation of a video signal and checking a maintaining time by a non-variation of the video signal in a computer main body. CONSTITUTION: A video signal variation sensing unit(120) judges a variation or not of a horizontal synchronization signal and a vertical synchronization signal being inputted from a video card(110). If the synchronization signals are not varied, the video signal variation sensing unit(120) checks a non-variation time by stages, and selectively outputs a standby mode, a suspend mode, and a power off mode control signal. A USB root hub(130) converts a mode input signal being inputted from the video signal variation sensing unit(120) in accordance with a communication protocol and transmits the mode input signal to a downstream display device. A USB hub(210) outputs a control signal for performing a power saving mode being transmitted from an upstream computer main body through an IIC communication line. A micro computer(220) recognizes a control signal being output from the USB hub(210), and selectively outputs a control signal for a standby, a suspend, and a power off through a switching transformer(230).

Description

Power saving device and power saving method for a display device having a USB hub

The present invention relates to a power saving device and a power saving method of a display device having a USB hub, and more particularly, to detect the presence or absence of a video signal change in a computer main body, and to check the duration of the video signal to the non-change. The present invention relates to a power save device and a power save method of a display device having a USB hub that allows main power of the display device to be cut off through the hub.

In general, the Display Power Management System (DPMS) is a function that saves power by managing the power of a display device, a computer peripheral device, in response to the use state of a computer system. Proposed by the Association.

According to the VESA proposal, the computer selectively supplies or blocks the horizontal synchronizing signal and the vertical synchronizing signal to the display device in order to realize different power management states in response to the use state of the computer system. And a power management state corresponding to a state in which the vertical synchronization signal is input.

At this time, the power management state is classified into an on state, a stand-by state, a suspend state, and a power off state. Here, in the On State, both pulse outputs of the horizontal sync signal and the vertical sync signal appear, and in the Stand-by state, only the pulse output of the vertical sync signal appears. In the suspend state, only the pulse output of the horizontal synchronizing signal appears, and in the power off state, neither the horizontal synchronizing signal nor the pulse output of the vertical synchronizing signal appears.

These power management states are sequentially in On State mode, Stand-by state mode, Suspend state mode, and Power off state in response to the continuous passage of time when the computer system is not being used. Power Off State), the power consumption is 80W in normal state, 65W or less in standby state, 25W or less in suspend state, and 5W or less in power off state. The specifications of the device product are specified.

However, it is generally classified into three state modes of normal mode, suspend mode, and off mode, and power consumption is about 100W in normal mode, and in suspend mode. It should be less than 15W, and in case of off mode, it is decided to be less than 5W. In addition, depending on the display device, the sustaining time of each mode can be set directly according to the user's intention.

1 is a configuration block diagram for implementing a power saving system of a general display device.

As shown, the power saving device of the conventional display device is provided in the computer main body, and has a counter therein and blocks the output of the vertical sync signal when there is no change on the screen, and blocks the output of the vertical sync signal. A video card 20 which blocks the output of the horizontal synchronizing signal when the duration of the predetermined time period lasts, and blocks the output of the vertical and horizontal synchronizing signals when the time when the output of the horizontal synchronization signal is interrupted for a predetermined time; In the device 10, it is determined whether the horizontal synchronization signal and the vertical synchronization signal input from the video card 20, and if there is no vertical synchronization signal input from the video card 20, the switching transformer 12 Outputs a control signal for standby mode switching, and outputs a control signal for suspend mode switching when there is no horizontal synchronizing signal. It consists of a microcomputer 11 which selectively outputs a power-off switching control signal in the absence of both smoothing signals.

According to a method of implementing a power saving system of a display device having the above-described configuration, the video card 20 included in the computer main body uses the counter provided therein to counter the time when the video signal output on the screen does not change. If the measured and set first time T1 continues, the vertical synchronization signal output to the microcomputer 11 is cut off.

The microcomputer 11 then recognizes that the display device 10 is not in use and starts to implement a power saving system. When there is no vertical synchronizing signal input from the video card 20, the standby mode is switched to the switching transformer 12. Outputs a control signal for switching.

Also, by checking the no-output time of the vertical synchronizing signal output from the video card 20, the video card 20 blocks the horizontal synchronizing signal output to the microcomputer 11 when it is longer than the preset T1 and is equal to the set T2. As a result, the microcomputer 11 recognizes this and outputs a control signal for suspend mode switching to the switching transformer 12.

Next, when the horizontal sync signal output from the video card 20 is longer than the preset T2 and is equal to the set T3, the microcomputer 11 cuts off the output of the vertical and horizontal sync signals output from the video card 20. It recognizes and outputs a power-off mode to the switching transformer 12.

However, as described above, in the power saving system of the display apparatus, the internal chip or the microcomputer of the display apparatus constantly checks whether there is a horizontal synchronizing signal and a vertical synchronizing signal, and also internally uses a timer to suspend and off the timing. There was a cumbersome problem to decide.

Accordingly, an object of the present invention is to detect the fluctuation of the video signal in the computer main body so as to solve the above-mentioned problem, and to check the duration of the video signal invariant, the suspension mode when there is no change in the video signal for a predetermined time. Preset display control signals such as stand-by mode, power off mode, etc. are transmitted to the display device using the USB communication protocol so that the display device does not monitor the horizontal or vertical synchronization signal inputted from the USB device. The present invention provides a power saving device and a power saving method of a display device having a USB hub that implements a power saving mode of the display device by a predetermined display control signal transmitted to the hub.

1 is a configuration block diagram for implementing a power saving system of a general display device;

2 is a configuration block diagram for implementing a power saving system of a display apparatus having a USB hub according to the present invention;

3 is a flowchart illustrating a power saving system of a display apparatus having a USB hub according to the present invention.

* Explanation of Signs of Major Parts of Drawings *

100: computer body 110: video card

120: video signal fluctuation detection unit

130: USB Root Herb

200: display device 210: UBS hub

220: microcomputer 230: switching transformer

In the display device according to the present invention for achieving the above object, the present invention provides a variation of the horizontal and vertical synchronization signal output from the video card through the video signal variation detection unit provided in the computer main body; In case of no change, it checks the unchanged duration and converts the control signal for standby mode, suspend mode and power-off mode according to the USB protocol according to the checking result, and converts the power saving mode control signal to the USB root hub. When the signal is transmitted to the USB hub of the display device, the USB hub outputs the control signal input from the computer main body to the microcomputer, and the microcomputer analyzes the input control signal to control the control signal for blocking the secondary output voltage of the switching transformer. It characterized in that the output.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration block diagram for implementing a power saving system of a display device having a USB hub according to the present invention.

As shown in the figure, the computer main body 100 which determines whether there is a change in the horizontal synchronizing signal and the vertical synchronizing signal input from the video card 110, converts and outputs the control signal for the power saving mode according to the USB protocol, and the computer. The display device 200 performs the power saving mode according to the control signal for the power saving mode input from the main body 100.

The computer main body 100 determines whether there is a change in the horizontal synchronizing signal and the vertical synchronizing signal inputted from the video card 110, and checks the non-variable time step by step in the case of no change, in the standby mode, the suspend mode, and the power-off mode. The video signal fluctuation detecting unit 120 selectively outputs a control signal, and the mode control signal input from the video signal fluctuation detecting unit 120 is converted in accordance with the USB protocol to be transmitted to the display apparatus 200 downstream. It is composed of the USB root hub 130.

The display apparatus 200 described above is output from the USB hub 210 and the USB hub 210 to output a control signal for performing a power saving mode transmitted from the computer main body 100 upstream through the IIC communication line. The microcomputer 220 recognizes a control signal for performing the power saving mode and selectively outputs a control signal for standby, suspend, and power-off to the switching transformer 230.

Power saving operation of the display device according to the present invention configured as described above will be described in more detail with reference to the accompanying drawings.

3 is a flowchart illustrating a power saving system of a display apparatus having a USB hub according to the present invention.

As shown, the video signal fluctuation detecting unit 120 of the computer main body 100 determines whether or not the video signal input from the video card 110 is unchanged (S300), and as a result of the determination that the video signal is unchanged In that case, the invariant time of the video signal starts to be counted.

At this time, it is determined whether the counting time is equal to the set T1 (S311), and if the determination result is the same, the video signal variation detection unit 120 provides a signal for switching the power of the display apparatus 200 to the standby state. After the output (S312) and converts according to the UESB protocol through the UESB root hub 130, and transmitted to the UESB hub 210 of the display device 200 (S320), the UBSB hub 210 through the IIC communication line The microcomputer 220 transmits a standby control signal to the switching transformer 230 according to the signal transmitted from the computer main body 100, and then controls the output power (S330). ) To standby mode.

As a result of the determination of the non-variable time determining step (S311), if the non-variable time is not equal to T1, it is determined whether the non-variable time is larger than the set T1 and equal to T2 (S313). 120 outputs a signal for switching the display apparatus 200 to the suspend mode (S314) and converts the display apparatus 200 to the suspend mode through the same process as the process of switching to the standby mode of the display apparatus 200. Be sure to

As a result of the judgment of the non-variable time determining step (S313), if the non-variable time is not equal to T2, it is determined whether the non-variable time is greater than the set time T2 and equal to T3 (S315), and if the result is the same, the standby mode is switched The display apparatus 200 is switched to the power off mode through the same process as that described above.

A time T1 < T2 < T3 is established as a time compared with the video signal invariant time.

According to the above-described configuration, since the display device does not need to have a separate processor for monitoring vertical or horizontal synchronization, implementing a power saving mode in the display device is simpler than in the related art.

Accordingly, the present invention is to simplify the hardware by controlling the switching transformer provided in the display device in the computer main body, to provide an effect that there is a high efficiency in implementing a power saving system of the display device.

Claims (4)

An apparatus comprising a computer main body and a display device for monitoring a horizontal and vertical synchronization signal to implement a power saving mode of a display device. The computer body, Determining whether there is a change in the horizontal synchronizing signal and the vertical synchronizing signal inputted from the video card, and in the case of no change, if there is no change in the video signal to selectively output the standby mode, the suspend mode, and the power off mode control signal by checking the invariant time step by step. Sensing unit; And It is composed of a USB root hub that converts the mode control signal input from the video fluctuation detection unit according to the USB communication protocol and transmits it to a display device downstream, The display device; A USB hub outputting a control signal for performing a power saving mode transmitted from an upstream computer main body through an IIC communication line; And And a microcomputer configured to recognize a control signal output from the USB hub and selectively output control signals for standby, suspend, and power-off to a switching transformer. A first step of determining whether or not the video signal inputted from the video card is unchanged; A second step of comparing the stepwise time with the set time when the video signal is in the invariant state as a result of the determination in the first step, and outputting a signal for controlling the output power of the switching transformer according to the comparison result; A third step of converting the control signal output in the second step according to the UBS protocol and transmitting it to the UBS hub through the UBS root hub; And The output power control signal of the switching transformer transmitted through the USB hub in the third step is transmitted to the microcomputer comprising a fourth step of controlling down the output state of the switching transformer step by step How to save power. The method of claim 2, wherein the second step; A first judging step of judging whether the video signal invariant time is equal to the set time T1; A first output step of outputting a control signal for switching the display apparatus to the standby mode in the same case as a result of the determination in the first determination step; A second output step of outputting a control signal for switching the display device to the suspend mode when the invariant time is greater than the set time T1 and equal to T2 as a result of the determination in the first determination step; A third determination step of determining whether or not the video signal invariant time is greater than the set time T2 and equal to T3 when the invariant time is not equal to the set time T2; And As a result of the determination in the third judging step, when the invariant time is greater than the set time T2 and equal to T3, a control signal for switching the display device to the power-off mode is output, and the video signal when the invariant time is not equal to T3. And a fourth output step of repeatedly performing the step of determining whether there is no variation. 4. The method of claim 3, wherein the time compared to the video signal invariant time is T1 < T2 < T3.