KR100271277B1 - Power control apparatus of display system - Google Patents

Abstract

The present invention discloses a display for converting a horizontal synchronous signal input from a PC main body into a DC power supply, and controlling the driving operation of the switching transformer using the DC power supply to reduce the minimum power required by the display apparatus when switching off modes. It relates to a power saving device of the device.

The apparatus of the present invention includes a second rectifying unit for converting a horizontal synchronous signal input from the PC main body into a DC power supply, a second switching unit turned on and off by a DC power supply input from the second rectifying unit, and a second switching unit being turned on. In this case, the third switching unit is driven by the pull-down voltage supplied by the second switching unit and outputs the DC power supplied to the primary side of the switching transformer, and the third switching unit is driven by the DC power supply which is turned on and outputting the first. A fourth switching unit for outputting the DC power output from the rectifying unit to the PWM control unit.

Therefore, the present invention detects whether the horizontal synchronization signal is detected by using the microcomputer in the off mode during the DPMS standby mode through the synchronization signal detecting unit, thereby reducing the power consumption of 5W or less supplied to the microcomputer to 1W or less. It provides an excellent effect in reducing the power consumption when the mode is executed.

Description

Power saving device for display device

The present invention relates to a power saving device of a display device, and more particularly, to convert a horizontal synchronous signal input from a PC main body into a DC power supply, and to control switching driving of a switching transformer using the DC power supply to switch off mode. The present invention relates to a power saving device of a display device for reducing the minimum power required by the display device.

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. A power management state corresponding to a state where a signal and a vertical synchronization signal are input is performed.

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 the power off state does not show both the pulse output of the horizontal synchronizing signal and the vertical synchronizing signal.

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 the 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 continuous holding time of each mode may be set directly according to the user's intention.

1 is a block diagram illustrating a configuration of a power saving circuit for performing a power saving mode of a display apparatus according to the prior art.

As shown, a mechanical switch 10 for passively controlling whether AC power is input, and a rectifier 20 for rectifying the AC power input as the mechanical switch 10 is turned on and converting the DC power into DC power. ) And driven by rectified DC power input through starting resistor Rs at initial power input, and driven by power generated by tertiary winding N3 after initial power is input Which is proportional to the number of secondary side and tertiary side windings N2 and N3 depending on the rectified power source driven by the transformer driving unit 30 and the switching action of the transformer driving unit 30 and input to the primary winding N1. Suspension mode control signal or off mode by judging whether the switching transformer 40 for generating and outputting a plurality of DC voltages, and whether the horizontal synchronous signal Hsync and the vertical synchronous signal Vsync input from the PC main body are input. Output control signal Connected to an output terminal of one secondary winding N2 of the microcomputer 50 and the switching transformer 40, which is turned off according to a suspension mode control signal input from the microcomputer 50, Connected to the output terminal of the first switching unit 60 and the other secondary winding (N2) provided in the switching transformer 40 to cut off the DC voltage to the off-mode control signal input from the microcomputer 50 Accordingly, the second switching unit 70 is turned off so that the DC voltage output to the rear end is cut off.

In the switching mode power supply having the above-described configuration, the AC power input is rectified by the bridge diode BD of the rectifying unit 10, and then converted into a DC power in the smoothing capacitor C1, thereby switching transformers (TRANS, 40). Is applied to the primary winding of.

On the other hand, the DC power converted by the smoothing capacitor (C1) operates the transformer drive unit 30 through the starting resistor (Rs), the transformer drive unit 30 is alternating to the secondary side, tertiary side of the switching transformer 40 The switching action is started so that the energy of the form can be released.

That is, when the transformer drive unit 30 starts the switching action, the energy of the alternating current is induced from the primary winding of the switching transformer 40 to one or more secondary and tertiary windings (N2) (N3), 2 The energy induced by the secondary winding N2 is again passed through the diodes D1, D2, D3, and smoothing capacitors C2, C3, C4, and the respective turns ratios of the primary and secondary sides of the switching transformer 40. Are converted to the DC power supply (VOUT1) (VOUT2) (VOUTN) according to the output.

The energy induced to the tertiary side of the switching transformer 40 is converted into a predetermined DC voltage through the diode D4 and the smoothing capacitor C5 and then applied to the transformer driver 30 so that the energy of the transformer driver 30 is reduced. It acts as a driving power source.

That is, the transformer driver 30 outputs a pulse width modulated waveform having a predetermined frequency and duty to drive a switching mode power supply to output a DC power having a predetermined value. It is supplied through (Rs), and after starting, the initial starting power is cut off and the induced voltage on the tertiary side is used as driving power.

The microcomputer 50 is operated by receiving one of the DC power sources VOUT1 output through the secondary winding N2 of the switching mode power supply device as the driving power, and the horizontal synchronization signal Hsync input from the PC main body. It operates the cathode ray tube display device in accordance with the vertical synchronization signal (Vsync).

However, if there is no horizontal synchronizing signal (Hsync) or vertical synchronizing signal (Vsync) input from the PC main body, the microcomputer 50 implements the suspend mode by turning off the first switching circuit unit 60 provided on the output side. If neither the horizontal sync signal (Hsync) nor the vertical sync signal (Vsync) are input from the main body of the PC, the microcomputer 50 implements the off mode by turning off the second switching circuit unit 70 to power the display apparatus. It will implement a power saving mode.

However, the circuit which performs the power saving mode of the display apparatus as described above should not be completely turned off in order to supply power to a separate device such as a microcomputer at all times for power saving mode determination and power unit switching driving. There was a problem that the power saving effect is reduced in mode.

Accordingly, an object of the present invention is to convert the horizontal synchronous signal input from the PC main body to a DC power source to solve the above problems, and to control the switching drive of the switching transformer using the DC power supply when the display device is switched off An object of the present invention is to provide a power saving device for a display device for reducing the minimum power required.

1 is a block diagram illustrating a configuration of a power saving circuit for performing a power saving mode of a display apparatus according to the prior art;

2 is a schematic block diagram illustrating a configuration of a power saving device of a display device according to the present invention.

* Explanation of Signs of Major Parts of Drawings *

120: first rectifying unit 121: fourth switching unit

122: PWM controller 123: second rectifier

124: second switching unit 125: third switching unit

126: first switching unit T1: switching transformer

In order to achieve the above object, AC power input from the outside according to the present invention is converted into DC power through a first rectifying unit so as to be supplied to the primary side of the switching transformer, and the first switching unit is connected to the PWM signal output from the PWM control unit. In the power supply of the display device for driving the switching transformer is switched to generate and output different DC voltage according to the plurality of secondary winding ratio of the switching transformer, the apparatus of the present invention is a DC power supply for the horizontal synchronous signal input from the PC main body A second rectifying unit which converts to a second converter, a second switching unit turned on and off by a DC power input from the second rectifying unit, and driven by a pull-down voltage supplied by the second switching unit when the second switching unit is turned on A third switching unit for outputting DC power supplied to the primary side of the transformer, and a third switching unit being turned on The DC power supply is driven by the DC power outputted from the first holding portion, which is characterized in the fourth switching part configured to to be output to the PWM control.

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

2 is a schematic block diagram illustrating a configuration of a power saving device of a display device according to the present invention.

As shown, the first rectifier 120 for converting AC power input from the outside into a DC power supply to the primary side of the switching transformer T1, and the DC power input from the first rectifier 120 to the starting resistance By the PWM control unit 122 and the PWM signal output from the PWM control unit 122 is input and driven through the output (R1) and outputs a PWM signal whose duty is changed in accordance with the current output to the primary side of the switching transformer (T1) The first switching unit 126, which is driven to switch the switching transformer T1, and a plurality of secondary sides having different turns ratios, and switching which generates and outputs a different DC voltage according to the turns ratio by a current induced in the primary side. A second rectifying unit 123 for converting the horizontal synchronous signal input from the PC main body to the DC power supply, and a second switching unit turned on and off by the DC power input from the second rectifying unit 123 ( 124) and the second switch A third switching unit 125 which is driven by a pull-down voltage supplied by the second switching unit 124 when the heading unit 124 is turned on, and outputs DC power supplied to the primary side of the switching transformer T1; The third switching unit 125 is configured to be driven by a DC power supply that is turned on and output by the fourth switching unit 121 so that the DC power output from the first rectifier 120 can be output to the PWM control unit.

The second rectifier 123 generates DC power when the horizontal synchronous signal is input from the PC main body, and does not generate DC power when the horizontal synchronous signal is not input.

The second switching unit 124 described above is composed of a photo coupler.

The plurality of resistors R6, R7, and R8 of the third switching unit 125 described above are set such that the emitter voltage of the PNP transistor FET is lower than the base voltage.

The fourth switching unit 121 is turned off when the third switching unit 125 is turned off because the horizontal synchronization signal is not input from the PC main body. As a result, the DC power output from the first rectifying unit 120 is PWM controlled. Since the PWM signal is not input to the 122, the PWM signal is not output from the PWM controller 122, and thus, the switching transformer T1 is not switched, thereby lowering the minimum power in the off mode.

The operation of the power saving device 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.

First, when AC power is input from the outside to the first rectifier 120 and a horizontal synchronous signal is input through a signal cable connected to the display device from the PC, the first rectifier 120 converts external AC power into DC power. And print it out. In addition, the second rectifier 123 converts the horizontal synchronous signal input from the PC main body into DC power and outputs the DC signal to the photodiode of the second switching unit 124.

Then, the photodiode emits light, and the phototransistor receives the light emitted by the photodiode and is turned on, thereby causing the base end of the transistor of the third switching unit 125 to be pulled down. At this time, since the third switching unit 125 is formed of the PNP type transistor Q3, the third switching unit 125 is turned on and outputs power supplied to the primary side of the switching transformer T1 to the fourth switching unit 121.

In this case, since the fourth switching unit 121 is formed of the NPN transistor Q1, the fourth switching unit 121 is turned on, and the DC power output from the first rectifying unit 120 is output to the PWM control unit 122 through the starting resistor R1. The PWM controller 122 is driven by the power supply.

Then, the PWM controller 122 outputs the PWM signal to the first switching unit 126 so that the field effect transistor Q2 is turned on or off according to the PWM signal to perform the switching operation. Accordingly, the switching transformer T1 is switched to generate a DC voltage on the secondary side.

At this time, the PWM controller 122 senses the voltage supplied to the primary side of the switching transformer T1 to adjust the duty of the PWM signal output to the first switching unit 126.

Next, when the horizontal synchronization signal is not input from the PC main body, the DC power is not output from the second rectifying unit 123, and the second switching unit 124 is turned off. At this time, the resistances R6, R7, and R8 of the third switching unit 125 are set such that the emitter voltage of the PNP transistor Q3 included in the third switching unit 125 is lower than the base voltage. Since the second switching unit 124 is turned off, the third switching unit 125 is also turned off.

Therefore, since the DC power supplied to the primary side of the switching transformer T1 supplied to the fourth switching unit 121 is also cut off, the fourth switching unit 121 is also turned off and the PWM control unit 122 through the starting resistor R1. DC power supplied to the first rectifier 120 is also cut off.

As a result, the PWM controller 122 is not driven, and the PWM signal output to the first switching unit 126 is not output. Therefore, the switching transformer T1 cannot perform the switching operation, and thus, no DC power is generated on the secondary side.

Therefore, as described above, according to the present invention, the synchronization signal detecting unit detects whether the horizontal synchronization signal is detected by using the microcomputer in the off mode during the DPMS standby mode. By reducing the power saving system (DPMS) off-mode performance is excellent in reducing the power consumption.

Claims (5)

The AC power input from the outside is converted into DC power through the first rectifier to be supplied to the primary side of the switching transformer, and the first switching unit is driven to switch the switching transformer according to the PWM signal output from the PWM control unit. In the power supply of the display device that generates and outputs a different DC voltage according to the number of secondary winding ratio, A second rectifying unit converting a horizontal synchronous signal input from the PC main body into a DC power source; A second switching unit turned on or off by a DC power input from the second rectifying unit; A third switching unit which is driven by a pull-down voltage supplied by the second switching unit when the second switching unit is turned on and outputs DC power supplied to the primary side of the switching transformer; And a fourth switching unit configured to be driven by a DC power supply which is turned on and output by the third switching unit so that the DC power output from the first rectifying unit can be output to the PWM control unit. The method of claim 1, wherein the second rectifier; A DC power supply is generated when the horizontal synchronous signal is input from the PC main body, and does not generate a DC power when the horizontal synchronous signal is not input. The method of claim 1, wherein the second switching unit; Power saving device of the display device, characterized in that consisting of a photo coupler. According to claim 1, wherein the plurality of resistors provided in the third switching unit; A power saving device of a display device, characterized in that the value is set so that the emitter voltage of the transistor is lower than the base voltage. The method of claim 1, wherein the fourth switching unit; When the third switching unit is turned off because the horizontal synchronization signal is not input from the PC main body, the DC power output from the first rectifying unit is not input to the PWM control unit so that the PWM signal is not output from the PWM control unit so that the switching transformer is not switched. Power saving device of the display device, characterized in that.