KR20040107024A - Display power management control circuit - Google Patents

Abstract

PURPOSE: A display power controlling system is provided to simplify the structure of a power saving circuit in a DPM(Display Power Mode) mode, and to automatically switch on or off the power, supplied from a power transformer, at an output end of the power transformer. CONSTITUTION: The system comprises a transformer(21), the first power smoothing device(22), an output power switch(23), the second power smoothing device(24), the third power smoothing device(25), a switch controller(26), and a microcomputer(27). The first power smoothing device(22) smooths the second power supplied by the transformer(21). The output power switch(23) switches on or off the power supplied by the first power smoothing device(22). The second power smoothing device(24) smooths the power supplied by the output power switch(23). The third power smoothing device(25) smooths the first power supplied by the transformer(21). The switch controller(26) switches on or off the power supplied by the third power smoothing device(25), and at the same time, controls the output power switch(23) by using the first power. The microcomputer(27) supplies a power control signal to the switch controller(26) according to a detection result of a DPM mode.

Description

DISPLAY POWER MANAGEMENT CONTROL CIRCUIT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power control apparatus for a video display device, and more particularly, to a display power control apparatus capable of satisfying a power saving condition required by cutting off B + power supplied to a video in a DPM mode. It is about.

Typical monitors consume about 50% to 80% of the total power consumption of a personal computer (PC). While these monitors dissipate most of the energy consumed from the screen fluorescent surface into visible light, heat consumption, electromagnetic radiation, high energy radiation and acoustic energy, only the fluorescent surface emission is the energy that is useful for the presentation of image information. It is useful only when the image is shown to the user. In other words, when the user does not operate the PC, for example, when the user is left for a long time, the display of the image itself loses meaning.

On the other hand, health problems when exposed to the radiation rash for a long time has been an issue, monitor manufacturers have been doing a lot of research to reduce the radiation rash of the monitor. In addition, the use of PCs continues to increase and is now a major consumer of electrical energy. The US Environmental Protection Agency is pressing computer producers to develop new systems to increase energy efficiency. Thus, low-voltage ICs and microcomputer power management technologies have contributed to reducing consumption when the computer is not in use. However, improving the energy efficiency of a PC is not an easy task until a suitable alternative to the CRT or a more efficient CRT is available.

What is needed to save energy is how to shut down the monitor's high energy consumption circuitry when the display is not in use. This is determined by the period of inactivity from input devices such as modems, mice, keyboards, and the like. Many computers and monitor terminals use technologies such as screen blanking circuitry and screen saver functions. In other words, pressing a key or moving the mouse activates the previous screen again.

This power saving function is called DPM mode (Display Power Management Mode). In DPM mode, it is determined that the monitor is not used depending on the presence or absence of the vertical or horizontal synchronous signal. In this case, it is classified into Suspend / Stand-By mode and off mode, and if both vertical and horizontal sync signals are not inputted to the monitor, it is classified into off mode. It is an operation mode that supplies power only to essential components and cuts off the power supply to other components such as heaters and deflection ICs that consume large power.

According to the energy standard 'ENERGY 2000', the power consumption in the monitor's DPM off mode is limited to within 3W. Therefore, in order to respond quickly to the demands of consumers and buyers according to this international trend, there is an urgent need for technology development to satisfy power consumption within 3W in the DPM off mode.

Referring to the power control method of the conventional monitor using this principle as follows.

The microcomputer in the monitor monitors the horizontal and vertical sync signal inputs from the PC.

As a result of the monitoring, if the vertical and horizontal synchronizing signals are normally input from the PC, it is determined as a normal mode and power is supplied to all circuits normally.

On the other hand, if the vertical and horizontal synchronizing signals are not normally input as a result of the monitoring, it is determined whether only one of the vertical and horizontal synchronizing signals is normally input. Turn off all power circuits except the supplied power.

That is, the horizontal synchronization signal is checked between each pair of the vertical synchronization signals, and if the interval count of the horizontal synchronization signal greatly exceeds the maximum video scan rate of the monitor, it is determined that there is no vertical synchronization signal. In this case, the power consumption of the monitor is reduced by about 80% to 90%.

When all the synchronization signals are not input, it is determined to be in the off mode and all power circuits including the heater power are turned off. Monitor power consumption in this off mode is reduced by more than 98%. This process is repeated if the main power is not cut off.

1 schematically shows a configuration of a conventional display power control device. A main power control IC 11 for switching the main power transformer for video power supply, a main power transformer 12 for supplying video 80V and 12V voltages under the switching control of the main power control IC 11, and an auxiliary power supply The auxiliary power control IC 13 for switching the auxiliary power transformer for switching, and the auxiliary power transformer 14 for supplying a 5V voltage under the switching control of the auxiliary power control IC (13).

Looking at the operation of the conventional display power control device configured as described above are as follows.

First, in the normal operation, that is, the microcomputer (not shown) as described above monitors the horizontal / vertical synchronization signal input from the PC, and if the vertical and horizontal synchronization signals are normally input from the PC as a result of the monitoring, the normal mode is returned to the normal mode. The main power supply control IC 11 and the auxiliary power supply control IC 13 are operated to judge and supply power normally to all circuits. Accordingly, switching control of the main power supply control IC 11 is performed, and the SMPS main switch transformer 12 generates an 80 V video output voltage and a 12 V output voltage to supply power to each circuit normally. In addition, switching control of the auxiliary power control IC 13 is performed, and the SMPS auxiliary power transformer 14 generates a 5V output voltage to supply 5V power to each part of the circuit so that the device performs normal operation.

On the other hand, if the vertical and horizontal synchronizing signals are not normally input as a result of the monitoring, it is determined whether only one of the vertical and horizontal synchronizing signals is normally input. Turn off all power circuits except the power supplied to the system. When all the synchronization signals are not input, determine the off mode, and turn off all power circuits including the heater power. That is, in the DPM mode (suspend, standby, off mode), the main power control IC 11 and the main power transformer 12 do not operate, and only the auxiliary power control IC 13 and the sub power transformer 14 operate to operate the main power transformer. The 80V and 12V output voltages by 12 are cut off, and only 5V power is supplied by the auxiliary power transformer 14.

This process is repeated if the main power is not cut off.

However, as described above, since the conventional display power controller uses the auxiliary power control IC and the auxiliary power transformer, not only the circuit configuration is complicated but also the product price is increased, and the auxiliary power control IC and the auxiliary power transformer are used. There is a burden on power consumption.

In addition, since the display power control is dualized into the main power control IC and the main power transformer, and the auxiliary power control IC and the sub power transformer, many parts are applied and the control program is increased, which causes the productivity and workability to be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display power supply control device which can simplify a circuit configuration for power saving control in a DPM mode of a video display device and to make a required power consumption level high.

Still another object of the present invention is to control the display power supply by using a DPM signal from the microcomputer to automatically switch on or off the supply voltage or output the power supply voltage output from the power transformer. To provide.

Still another object of the present invention is a means for switching the video output voltage at the power transformer output stage, and control means for supplying or blocking control of the output voltage from the main power transformer by turning on or off the switching means in accordance with the DPM signal level from the microcomputer. To provide a display power control device comprising a.

1 is a block diagram of a conventional display power control device

2 is a circuit diagram of a display power supply control apparatus of the present invention.

<Explanation of symbols for the main parts of the drawings>

21: power transformer 22: first smoothing part

23: output voltage switching unit 24: second smoothing unit

25: third smoothing unit 26: switching control unit

27: Micom

Display power supply control apparatus of the present invention for achieving the above object, the power transformer for supplying the device power, switching means for supplying or cutting off the device power at the output terminal of the power transformer and the control of the microcomputer according to the DPM mode And switching control means for turning on or off the switching means, and a microcomputer for controlling the switching control means by determining a DPM mode.

In addition, the display power control device of the present invention for achieving the above object, the microcomputer to determine the DPM mode and output a power control signal, and a power transformer for generating a first power supply voltage and a second power supply voltage for supplying the device power; First switching means for supplying or blocking a first power voltage at an output terminal of the power transformer; and second switching means for turning on or off the first switching means by inputting a power control signal output from the microcomputer. And third switching means for supplying or blocking a second power supply voltage at an output terminal of the power transformer, and fourth switching means for turning on or off the third switching means depending on whether the first switching means is output. It is characterized by comprising.

In addition, in the display power supply control apparatus of the present invention, the switching means is a switching element for supplying or cutting off any one of a plurality of power supply voltages output from a power transformer, and the other of the plurality of power supply voltages output from the power transformer. It characterized in that it comprises a switching device for turning on or off the switching device depending on whether the power supply.

In the display power supply control apparatus of the present invention, the switching control means is a switching element for supplying or cutting off any one of a plurality of power supply voltages output from a power transformer and the DPM signal output from the microcomputer as the input And a switching device for turning on or off the switching device.

In addition, the display power control device of the present invention, characterized in that it further comprises a smoothing means for removing the ripple component for stabilization of the power supplied to each circuit portion from the power transformer.

In addition, the display power supply control apparatus of the present invention, characterized in that it further comprises a smoothing means for removing the ripple component for each of the plurality of power sources for stabilizing the power supplied to each circuit portion from the power transformer.

Further, in the display power supply control apparatus of the present invention, the smoothing means for removing the ripple component of the first power supply voltage output from the power transformer, and the smoothing means for removing the ripple component of the second power supply voltage output from the power transformer. Each of which further comprises.

Hereinafter, the configuration and operation of the display power control device of the present invention made as described above with reference to the accompanying drawings will be described as an embodiment.

2 is a circuit diagram showing an embodiment configuration of a display power supply control apparatus according to the present invention.

Referring to FIG. 2, the display power controller of the present invention includes a transformer 21 for supplying device power and a first smoothing unit 22 for smoothing the second power voltage 80V output from the transformer 21. ), An output voltage switching unit 23 for supplying or blocking a second power supply voltage output through the first smoothing unit 22, and a second power supply voltage output from the output voltage switching unit 23. The second smoothing part 24 for smoothing the second smoothing part, the third smoothing part 25 for smoothing the first power supply voltage 12V output from the power supply transformer 21, and the second smoothing part 25. And a switching control section 26 for controlling the output voltage switching section 23 using the first power supply voltage and supplying or cutting off the first power supply voltage output through Accordingly, a microcomputer for supplying a power control signal (DPM signal) to the switching controller 26. (27) is made.

On the other hand, the switching controller 26 is a first switching element (Q2) for supplying or blocking the first power supply voltage (12V) at the output terminal of the power transformer 21, and the power control output from the microcomputer (27) And a second switching element Q4 for turning on or off the first switching element Q2 as a signal (DPM signal).

In addition, the output voltage switching unit 23 may include a third switching element Q1 and a first switching element Q2 for supplying or cutting off the second power supply voltage 80V at the output terminal of the power transformer 21. It characterized in that it comprises a fourth switching element (Q3) for turning on or off the third switching element (Q1) according to whether the output of the first power supply voltage (12V).

In Fig. 2, symbols D1, D2 and D3 are diodes, C1, C2 and C3 are capacitors, and R1 to R6 are resistors.

Referring to the operation of the display power control device of the present invention configured as described above are as follows.

The power transformer 21 generates and outputs a predetermined power supply voltage based on the SMPS as described above. In the present invention, the power supply 21 generates a first power supply voltage of 12V and a second power supply voltage (video output voltage) of 80V. It is assumed to output.

First, the microcomputer 207 of the monitor monitors the horizontal / vertical synchronization signal input from the PC. As a result of the monitoring, if the vertical and horizontal synchronizing signals are normally input from the PC, it is determined as a normal mode and power is supplied to all circuits normally.

In the normal mode, the microcomputer 27 outputs the DPM signal high. When the DPM high signal is applied to the base of the second switching element Q4, the second switching element Q4 is turned on. When the second switching element Q4 is turned on, a bias voltage is applied to the base of the first switching element Q2 to turn on the first switching element Q2. Accordingly, the first power supply voltage 12V output from the power transformer 21 is normally output through the first switching element Q2. At this time, the diode D3 and the capacitor C2 of the third smoothing part 25 remove the ripple component when the first power supply voltage 12V output from the power supply transformer 21 is output and output a stable DC voltage 12V. give.

On the other hand, when the first switching element Q2 is turned on and the 12V first power supply voltage is normally output, the voltage 12V is applied to the base of the fourth switching element Q3 to turn on the fourth switching element Q3. When the fourth switching element Q3 is turned on, a bias voltage is applied to the base of the third switching element Q1 to turn on the third switching element Q1. Accordingly, the second power supply voltage 80V output from the power supply transformer 21 is normally output through the third switching element Q1.

At this time, the diode D1 and the capacitor C1 of the first smoothing part 22 remove the ripple component when the second power supply voltage 80V output from the power supply transformer 21 is applied to the third switching element Q1. The diode D2 and the capacitor C3 of the second smoothing part 24 remove the ripple component when supplying the 80V voltage output through the third switching element Q1 to stabilize the DC 80V voltage. Will print

On the other hand, if both vertical and horizontal synchronization signals are not normally input as a result of the monitoring, it is determined whether any one of the vertical and horizontal synchronization signals is normally input, and if only one of the vertical and horizontal synchronization signals is normal, it is determined as a standby or suspend mode and the heater Turn off all power circuits except the power supplied to the system. When all the synchronization signals are not input, determine the off mode, and turn off all power circuits including the heater power.

That is, in the DPM mode (suspend, standby, off mode), the microcomputer 27 outputs the DPM signal low and the power supply is automatically cut off by the DPM low signal.

The second switching element Q4 is turned off by the DPM low signal output from the microcomputer 27. When the second switching element Q4 is turned off, the base bias voltage of the first switching element Q2 is cut off, so the first switching element Q2 is also turned off. Therefore, the first power supply voltage 12V output from the power supply transformer 21 is cut off. Meanwhile, when the first switching element Q2 is turned off and the supply of the first power supply voltage 12V is cut off, the base bias voltage of the fourth switching element Q3 is cut off, so that the fourth switching element Q3 is also turned off. When the fourth switching element Q3 is turned off, the base bias voltage of the third switching element Q1 is cut off, so the third switching element Q1 is also turned off. When the third switching element Q1 is turned off, the second power supply voltage 80V output from the power transformer 21 is cut off.

Therefore, in the suspend, standby, and off modes, the video B + power is not supplied, thereby satisfying the required power saving control for the DPM.

In the present invention, power saving control is possible by automatically cutting off the B + power supplied to the video in the DPM mode. In particular, the present invention, in the power saving control of the power supplied to each part of the circuit from one power transformer, by using a switching means in the power transformer output stage by automatically supplying or blocking the power supply to control the DPM power saving control conditions with a simple circuit configuration Satisfied.

In order to satisfy the energy saving demand in the video display device, the video B + voltages such as 12V and 80V output from the secondary side of the SMPS transformer may be adjusted by using the DPM signal output from the microcomputer to sufficiently reduce power consumption. Can be.

Claims (8)

A power transformer for supplying device power, switching means for supplying or cutting off the device power at an output terminal of the power transformer, switching control means for turning on or off the switching means under control of a microcomputer according to the DPM mode, and a DPM. And a microcomputer for controlling the switching control means by determining a mode. The switching device of claim 1, wherein the switching means supplies a switching element for supplying or cutting off any one of a plurality of power supply voltages output from a power transformer, and the other of the plurality of power supply voltages output from the power transformer. And a switching element for turning on or off the switching element. The switching device of claim 1, wherein the switching control unit turns on the switching device by inputting a switching device for supplying or cutting off any one of a plurality of power supply voltages output from a power transformer, and a DPM signal output from the microcomputer. Or a switching device for turning off the display power supply. The display power control device according to claim 1, further comprising smoothing means for removing a ripple component for stabilizing power supplied to each circuit part from the power transformer. The display power supply control apparatus according to claim 1, further comprising smoothing means for removing a ripple component for each of a plurality of power sources for stabilizing power supplied to each circuit part from the power transformer. A microcomputer for determining a DPM mode and outputting a power control signal, a power transformer for generating a first power voltage and a second power voltage for supplying device power, and a first power voltage at the output terminal of the power transformer; A first switching means for giving, a second switching means for turning on or off the first switching means by inputting a power control signal output from the microcomputer, and supplying or blocking a second power supply voltage at an output terminal of the power transformer; And a fourth switching means for turning on or off the third switching means depending on whether the first switching means is output or not. 7. The apparatus of claim 6, further comprising smoothing means for removing a ripple component of a first power supply voltage output from the power transformer and smoothing means for removing a ripple component of a second power supply voltage output from the power transformer. Display power control device, characterized in that made. 7. The display power supply control apparatus according to claim 6, wherein smoothing means for removing the ripple component of the second power supply voltage is provided at each of the front and rear ends of the third switching means.