JP3732313B2 - Video display apparatus having audio circuit and power control method for the apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video display device, and more particularly, to a video display device having an audio circuit for processing a video signal applied from a host or a microphone, and a method for controlling power supplied to the audio circuit. .
[0002]
[Prior art]
Generally, a power supply unit used in a video display device such as a CRT display monitor device used with a computer is designed to be able to provide necessary voltages and currents by internal control. Such a power supply system includes a power cut-off circuit that cuts off the power supplied to the video display device when the power is off.
[0003]
In a video display device provided with an audio circuit, power saving associated with the video circuit is achieved by display power management signaling (DPMS) control according to a video electronics standard association (VESA) recommendation. As is well known, the DPMS power supply system is classified into a normal mode, a standby mode, a suspend mode, and a power-off mode. .
[0004]
The DPMS power supply mode of the video display apparatus is determined by horizontal and vertical synchronization signals and video signals supplied from a host having a video power saving function, that is, a personal computer. First, when all of the horizontal and vertical synchronization signals and the video signal are input from the host, the video display device operates in a steady power supply mode. When only the vertical synchronization signal is input from the host, the power supply mode of the video display device becomes the standby mode. In this mode, a large number of circuits shift to a low power consumption state. On the other hand, when only the horizontal synchronization signal is input from the host, the video display device shifts to the pause mode. In this mode, the power to the audio circuit is cut off and the audio circuit cannot be operated. Finally, if none of the horizontal and vertical synchronization signals and the video signal is input from the host, the video display device enters the power cut-off mode. Even in this mode, the power to the audio circuit is cut off.
[0005]
[Problems to be solved by the invention]
As described above, when the video display device is operated in the power saving mode, particularly in the pause and power cutoff mode, there is a problem that the power supply to the audio circuit is cut off regardless of the intention of the user. This is because the operation and non-operation of the audio circuit are determined depending on the power supply mode of the video display device.
[0006]
Accordingly, an object of the present invention is to provide a video display apparatus and method for controlling an audio circuit power supply independently of a video circuit power supply.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a video display apparatus that performs a power saving function in response to horizontal and vertical synchronization signals and a video signal supplied from a host that supports the power saving function. Means for supplying a power, means for generating a constant voltage using a first power supply, means for supplying a second power supply, and operating by a second power supply; In response, the first and second power supply control signals are generated from the first and second output ports, and the third power supply is supplied through the third output port in response to the key input data input from the key input unit. A microcontroller for generating a control signal; means for shutting off the constant voltage in response to the first power supply control signal; means for shutting off the first power supply in response to the second power supply control signal; Third using the power supply Means for supplying power, means for operating an audio signal from the host, and means for shutting off the third power supply in response to the third power control signal. The present invention provides a video display device that controls a third power source supplied to the audio processing means independently of the video circuit unit.
[0008]
In addition to this device, the present invention also provides a main display that supplies main power in a video display device that performs a power saving function in response to horizontal and vertical synchronization signals and video signals supplied from a host that supports the power saving function. A power supply unit, a constant voltage generation unit that generates a constant voltage necessary for the oscillation circuit unit and the RGB video amplification circuit unit using a main power source, an auxiliary power supply unit that supplies auxiliary power, and an auxiliary power source Generating first and second power control signals from the first and second output ports in response to the horizontal and vertical synchronizing signals and the video signal, and in response to key input data input from the key input unit. A microcontroller that generates a third power control signal through a third output port and a constant voltage generator that supplies the oscillation circuit and the RGB video amplifier circuit in response to the first power supply control signal A first power supply mode control unit for cutting off the constant voltage generated, a second power supply mode control unit for cutting off the main power supplied to the constant voltage generation unit in response to the second power supply control signal, Means for supplying audio power using an auxiliary power supply, an audio circuit operated by the audio power supply, and an audio power control unit for cutting off the audio power supplied to the audio circuit in response to a third power control signal; A video display device is also proposed.
[0009]
Further, the present invention provides a video display apparatus that performs a video power saving function for a video circuit unit in response to horizontal and vertical synchronization signals and video signals from a host that supports a power saving function including an audio circuit. In the method of controlling, determining whether to request a state change of a number of setting flags associated with audio power saving for an audio circuit; and when requesting a state change of an audio power saving state, A step of determining, a step of determining whether at least one of a number of flags has been changed, and an audio operation flag (AOF) indicating whether or not to activate the audio circuit when at least one of the flags is changed. A step of determining whether or not an active state is set, and an audio operation flag (AOF) is set to an active state A step of supplying power to the audio circuit, a step of setting an audio power state flag (APSTF) indicating whether power is supplied to the audio circuit to an active state, a preset state, or a change Controlling the power saving of the audio circuit independently of the video power saving according to the state, and shuts off the audio power supplied to the audio circuit when the audio operation flag (AOF) is set to the inactive state. And setting the audio power status flag (APSTF) to an inactive state.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a video display apparatus having a conventional audio circuit. First, a video display apparatus having a conventional audio circuit will be described in order to facilitate comparison between the present invention and the prior art. The video display device according to FIG. 1 includes a full-wave rectification unit 10, a main power supply unit 20, a high voltage generation unit 30, a deflection circuit unit 35, a constant voltage generation unit 40, an oscillation circuit unit 50, and an audio circuit 60. . The video display apparatus performs a power saving function of the video circuit in response to horizontal and vertical synchronization signals and a video signal supplied from a host (that is, a personal computer) supporting the video power saving function.
[0011]
The main power supply unit 20 supplies various power sources necessary for the high voltage generation unit 30, the deflection circuit unit 35, the constant voltage generation unit 40, and the like. The high voltage generator 30 applies a high voltage to the CRT 150. The deflection circuit unit 35 deflects electron beams emitted from electron guns (R, G, B electron guns) of the CRT 150 in the horizontal and / or vertical direction. The constant voltage generator 40 generates constant voltages necessary for various oscillations such as amplification of audio and video signals. The oscillation circuit unit 50 and the audio circuit 60 are connected to the constant voltage generation unit 40.
[0012]
The video display device further includes a power cutoff control unit 70, a pause control unit 80, an auxiliary power supply unit 90, and a microcontroller 100. The pause control unit 80, the auxiliary power supply unit 90, and the microcontroller 100 function to control the DPMS power supply mode in response to information from the host.
[0013]
As is well known in the art, the DPMS power supply mode defined by VESA is divided into a normal mode, a standby mode, a pause mode, and a power cut-off mode. According to such a DPMS system, the power consumption of the 20-inch display monitor device is about 130 W in the normal mode, about 30 W in the pause mode, and 8 W or less in the power-off mode.
[0014]
The auxiliary power supply unit 90 according to FIG. 1 constantly supplies a constant DC voltage (for example, 5 V) regardless of the DPMS power control by the microcontroller 100. The microcontroller 100 receives horizontal and vertical synchronization signals H-SYNC and V-SYNC from the host and key input data from a key input unit (not shown), and generates power control signals PSSA and PSSB. Output through output ports A and B. Further, the microcontroller 100 performs a power saving function associated with the video circuit unit using horizontal and vertical synchronization signals H-SYNC, V-SYNC and RGB video signals from the host.
[0015]
When all the horizontal and vertical synchronization signals and video signals are input from the host, the microcontroller 100 recognizes that the current power supply control mode is the normal mode. In this mode, the microcontroller 100 does not generate any of the power control signals PSSA and PSSB. Accordingly, the main power supply unit 20 and the constant voltage generation unit 40 operate as usual.
[0016]
When only the vertical synchronization signal V-SYNC is input from the host, the microcontroller 100 recognizes that the current power supply mode is the standby mode. In this mode, neither power control signal PSSA nor PSSB is generated. In this mode, a large number of circuits shift to a low power consumption state. Since each circuit is in the low power consumption mode in this manner is not directly related to the technical gist of the present invention, description thereof will be omitted.
[0017]
On the other hand, when only the horizontal synchronization signal H-SYNC is input from the host, the microcontroller 100 recognizes that the current power supply mode is the pause mode. In this mode, the microcontroller 100 generates the power control signal PSSB. In response to this signal, the pause control unit 80 disables the constant voltage generation unit 40. As a result, the power supply to the oscillation circuit unit 50 and the audio circuit 60 is cut off, and the operation of the audio circuit becomes impossible.
[0018]
When neither the synchronization signal nor the video signal is input from the host, the microcontroller 100 recognizes that the current power supply mode is the power cutoff mode. In this case, the microcontroller 100 generates the power control signal PSSA so that the main power supply unit 20 is disabled by the power cutoff control unit 70. Accordingly, the power supply to the high voltage generation unit 30, the deflection circuit unit 35, the constant voltage generation unit 40, the oscillation circuit unit 50, and the audio circuit 60 is cut off.
[0019]
As described above, the video display device according to FIG. 1 includes an audio circuit connected to the constant voltage generator 40 so that the video display device operates in a power saving mode (particularly, a pause mode and a power shutdown mode). Then, there arises a problem that the power to the audio circuit is cut off regardless of the user's will. That is, the audio circuit of the video display device operates depending on the power supply mode.
[0020]
Next, the video display apparatus according to the first embodiment of the present invention will be described in detail with reference to FIG. The video display apparatus according to the first embodiment shown in FIG. 2 includes an audio power supply unit 340 separated from the constant voltage generation unit 330. The audio power supply unit 340 is directly connected to the main power supply unit 310 and supplies power (audio power) to the audio circuit 360. The microcontroller 410 generates an audio power control signal PSSC in response to input data input from the key input unit 450. Furthermore, the video display device according to the first embodiment includes an audio control unit 350. The audio power control unit 350 receives the audio power control signal PSSC and cuts off the audio power supplied to the audio circuit 360. With this configuration, the power supply to the audio circuit becomes independent from the video circuit unit in the power saving mode except for the power cut-off mode, and can be controlled according to the user's intention.
[0021]
Full-wave rectification unit 300 is formed of a bridge diode circuit (not shown) and receives an AC voltage of 90 to 260V. As is well known, the main power supply unit 310 includes a boost transformer, a switching transformer, a switching element, a pulse width modulation control circuit, and the like. The main power supply unit 310 supplies various voltages (for example, 6, 14, 25, 30, 80, 200 V, etc.) used in the high voltage generation unit 320, the deflection circuit unit 325, the constant voltage generation unit 330, and the like. . The high voltage generator 320 supplies a high voltage (for example, 6 to 8 KV) to the CRT 470. The deflection circuit unit 325 deflects the electron beam emitted from the electron gun of the CRT 470 in the horizontal and vertical directions. The constant voltage generation unit 330 supplies a constant voltage (for example, 12V) to the oscillation circuit unit 370 and the video amplification circuit unit 460. As is well known, the oscillation circuit unit 370 includes a high voltage oscillator, a deflection control oscillator, horizontal and vertical oscillators, and the like.
[0022]
The video display device includes an auxiliary power supply unit 400, a microcontroller 410, a power cutoff control unit 380, a pause control unit 390, a key input unit 450, an OSD video generation unit 420, a mixer 430, a video amplification circuit unit 460, and a video output unit. (Or an electron gun driving unit) 440 is further provided. The auxiliary power supply unit 400 always supplies a constant DC voltage (for example, 5 V) to the microcontroller 410 regardless of the DPMS control. The microcontroller 410 receives horizontal and vertical synchronization signals H-SYNC and V-SYNC from the host and key input data from the key input unit 450, and generates power control signals PSSA, PSSB and PSSC. The microcontroller 410 controls the OSD video generator 420 to generate an OSD video signal when key input data is input from the key input unit 450 by a user operation. The mixer 430 mixes the OSD video signal from the OSD video generation unit 420 and the main video signal applied from the host through the video amplification circuit unit 460. The mixed video signal is provided to the CRT 470 electron gun through the video output unit 440.
[0023]
The microcontroller 410, the power cutoff control unit 380, the pause control unit 390, and the audio power control unit 350 that constitute the video display device of the first embodiment receive DPMS in response to information from the host and the key input unit. It functions to control the power supply mode and the audio power supply mode.
[0024]
The audio power supply unit 340 is directly connected to the main power supply unit 310 and supplies audio power to the audio circuit 360 independently of the constant voltage generation unit 330. As described above, the microcontroller 410 controls the power supply mode (i.e., video power saving) associated with the video circuit unit using the synchronization signals H-SYNC, V-SYNC and the video signal from the host. Further, the microcontroller 410 uses the key input data from the key input unit 450 to control the power saving mode (ie, audio power saving) associated with the audio circuit unit. .
[0025]
Hereinafter, the audio power supply mode performed by the circuit shown in FIG. 2 will be described in detail. For example, assume that the user has set the audio power saving mode of the display device to a current cut-off mode. In this case, even if only the horizontal synchronization signal H-SYNC is input from the host, that is, even when the video power supply mode of the display device is in the pause mode, the audio power control signal PSSC is the same as in the normal power supply mode. It becomes inactive. Accordingly, the audio power is supplied from the audio power supply unit 340 to the audio circuit 360. That is, the audio circuit 360 operates as usual regardless of the video power saving mode. In this case, audio is supplied to the audio circuit 360 until the video display device shifts to the power cut-off mode.
[0026]
As another example, assuming that the audio power saving mode of the display device is set to the standby mode, the audio power control signal may be output even when the video display device enters the standby mode as well as the pause mode and the power cutoff mode. PSSC is activated. In this case, the audio power controller 350 cuts off the audio power supplied to the audio circuit 360 in response to the audio power control signal PSSC. In such a state, when the display device returns to the normal mode, the audio power controller 350 causes the audio circuit 360 to supply the audio power again.
[0027]
FIG. 3 is a circuit diagram of the audio power supply unit 340 and the audio power control unit 350 shown in FIG. As shown in FIG. 3, the audio power supply unit 340 includes a pass (or programmable) voltage regulator 341. An input terminal L 1 of the pass voltage regulator 341 is connected to the main power supply unit 310, and an output terminal L 2 is connected to the audio circuit 360. A control terminal L3 of the pass voltage regulator 341 is connected to an output terminal of the audio power control unit 350. The audio power supply unit 340 supplies audio power to the audio circuit 360 and is switched on / off in response to a switching control signal from the audio power control unit 350.
[0028]
The audio power control unit 350 includes a PNP bipolar transistor TR1, resistors R1 to R4, and capacitors C1 and C2. The current path (that is, the emitter-collector path) of the transistor TR1 is connected between the control terminal L3 of the pass voltage regulator 341 and the ground, and this control terminal is connected to the output terminal C of the microcontroller 410 through the resistor R4. The resistor R1 is connected between the input terminal L1 of the pass voltage regulator 341 and the control terminal L3. Resistor R2 is coupled between control terminal L3 of pass voltage regulator 341 and the control terminal (ie, base) of the transistor. Resistor R3 is coupled between control terminal L3 of pass voltage regulator 341 and ground. Capacitor C1 is connected between the control terminal of transistor TR1 and ground, and capacitor C2 is connected between microcontroller 410 and ground.
[0029]
When a low-level power control signal PSSC is applied to the input terminal L4 of the audio power controller 350, the transistor TR1 is turned on and the pass voltage regulator 341 is switched on. Accordingly, audio power is supplied from the audio power supply unit 340 to the audio circuit 360. On the other hand, when the high-level power control signal PSSC is applied to the input terminal L4 of the audio power controller 350, the transistor TR1 is turned off and the pass voltage regulator 341 is switched off. As a result, the power supplied from the audio power supply unit 340 to the audio circuit 360 is cut off.
[0030]
Thus, the audio power supply is controlled by the microcontroller 410 independently of the video power supply mode (i.e., standby, pause, and power shutdown mode). Therefore, even when the video display device shifts to the standby mode or the pause mode, the audio circuit 360 can operate regardless of the power supply mode. According to this embodiment, in a power supply mode other than the power cut-off mode, the power supply to the audio circuit 360 can be controlled independently of the video circuit unit and according to the user's intention.
[0031]
FIG. 4 illustrates a second embodiment of the present invention. In FIG. 4, the same reference numerals as much as possible are displayed in the same or corresponding parts as in the circuit configuration of FIG. For simplification of description, description thereof is omitted.
[0032]
In the second embodiment, the audio power supply unit 340a is directly connected to the auxiliary power supply unit 400 and supplies audio power to the audio circuit 360a. The microcontroller 410 generates an audio power control signal PSSC in response to the key input data input from the key input unit 450. The audio power control unit 350a operates to cut off the audio power supplied to the audio circuit 360a in response to the audio power control signal PSSC from the microcontroller 410. Therefore, even if the video display device shifts to a certain power saving mode, if there is a request for audio power saving, the audio circuit 360a can be operated regardless of the DPMS power supply mode.
[0033]
4, the audio power supply unit 340a and the audio power control unit 350a are the same as those in FIG. 3 except that the input terminal L1 of the pass voltage regulator 341 is connected to the auxiliary power supply unit 400 instead of the main power supply unit 310. The circuit configuration is the same as that shown.
[0034]
A method for controlling the audio power supplied to the audio circuit 360 or 360a will be described with reference to FIGS.
[0035]
A control program for performing the method of the present invention is executed by the microcontroller 410. In the color CRT display device of FIG. 2 or FIG. 4, the user can control the audio power supplied to the audio circuit 360 or 360a independently of the video circuit unit according to his / her will.
[0036]
Referring to FIG. 5, in step S100, the user operates a key input unit of the display device to determine whether or not to change a number of setting flag states (preset states) related to audio power saving. Determined. If it is determined in step S100 that there is a flag state change request, the control flow proceeds to step S200. In step S200, the flag state is changed by the flag state changing routine shown in FIG.
[0037]
Referring to FIG. 6, in step S202, an OSD menu related to the audio power saving mode is displayed on the screen of the display device, and the process proceeds to step S204. At this stage, it is determined whether or not to activate the audio circuit. If “NO” in the step S204, the control proceeds to a step S205. At this stage, an audio operation flag (AOF) indicating whether or not to activate the audio circuit is set to an inactive state. Thereafter, in step S216, an audio power saving flag (APSF) indicating whether or not to perform audio power saving is set to an inactive state.
[0038]
If it is determined in step S204 that the operation of the audio circuit is required, an audio operation flag (AOF) is set to an active state (step S206). The control flow then proceeds to step S209, where it is determined whether there is a request for audio power saving. If “YES” in the step S209, the audio power saving mode flag (APSMF) is set to any one of a standby state, a temporary stop, and a power-off state.
[0039]
Specifically, in step S210, it is determined whether an audio standby mode is requested. When the audio standby mode is requested, the audio power saving mode flag (APSMF) is set to the standby state in step S211. Otherwise, it is determined in step S212 whether an audio pause mode is requested. When the audio pause mode is requested in step S212, control proceeds to step S213, and the audio power saving mode flag (APSMF) is set to the pause mode. If the audio pause mode is not requested in step S212, control proceeds to step S214. At this stage, it is determined whether an audio power saving mode is requested. If the audio power saving mode is requested in step S214, the control flow proceeds to step S215 and sets the audio power saving mode flag (APSMF) to the power-off state. Thereafter, control proceeds to step S217. In step S217, an audio power saving flag (APSF) is set to an active state.
[0040]
On the other hand, if “NO” in steps S209 and S214, control proceeds to step S216. At this stage, the audio power saving flag (APSF) is set to an inactive state.
[0041]
Thereafter, in step S203, it is determined whether or not to end the input of the key input data from the key input unit. If the input of the key input data is completed, the control proceeds to step S207, and after closing the OSD menu on the CRT screen, the control proceeds to step S300 in FIG. If the input of key input data is not completed in step S203, the control flow jumps to step S204.
[0042]
After the flag state change routine described above is completed, control proceeds to step S300 in FIG. In step S300, an audio on / off control routine as shown in FIG. 7 is executed.
[0043]
Referring to FIG. 7, it is determined in step S302 whether at least one flag has been changed. If “YES” in the step S302, the control proceeds to a step S303. At this stage, it is determined whether the audio operation flag (AOF) is set to the active state. If “YES” in the step S303, the audio circuit receives an audio power supply from the audio power supply unit in a step S304. Control then proceeds to step S305, where the audio power status flag (APSTF) is set to the active state. Thereafter, the control proceeds to step S500 in FIG.
[0044]
On the other hand, if “NO” in the step S303 in FIG. 7, the power supply to the audio circuit is cut off in a step S306. Subsequently, control proceeds to step S307. At this stage, the audio power status flag (APSTF) is set to an inactive state. Thereafter, the control proceeds to step S500 in FIG.
[0045]
In FIG. 5, when the above-described audio on / off control routine is completed, the control proceeds to step S500. In step S500, the audio power saving control routine shown in FIG. 8 is executed. The audio power saving control routine performs the audio power saving control independently of the video power saving control.
[0046]
Referring to FIG. 8, in step S502, it is determined whether an audio power saving flag is set to an active state. If “YES” in the step S502, the control proceeds to a step S503. At this stage, it is determined whether the video power saving mode (VPSM) is in a standby state. If 'YES' in step S503, control proceeds to step S506, where it is determined whether the audio power saving mode flag (APSMF) is set to the standby state. If “YES” in the step S506, it is determined whether or not the audio power state flag (APSTF) is set in an active state in a step S509. If “YES” in step S509, control proceeds to steps S510 and S511 in sequence, the audio power supply is shut off, and the audio power status flag (APSTF) is set to an inactive state. Thereafter, or if NO in step S509, control proceeds to step S600 of FIG.
[0047]
On the other hand, if the audio power saving mode flag (APSMF) is not set to the standby state in step S506, it is determined in step S512 whether the audio power state flag (APSTF) is set to the inactive state. If "YES" in step S512, control proceeds sequentially to steps S513 and S514, supplying audio power to the audio circuit, and setting the audio power status flag (APSTF) to the active state. Thereafter, or if NO in step S512, control proceeds to step S600 of FIG.
[0048]
If the video power saving mode (VPSM) is not in the standby state in step S503, it is determined in step S504 whether the video power saving mode (VPSM) is in the paused state. If “YES” in the step S504, the control proceeds to a step S507. At this stage, it is determined whether or not the audio power saving mode flag (APSMF) is set to a pause state. In step S507, if “YES”, the control proceeds to step S509, and if “NO”, the control proceeds to step S512.
[0049]
If the video power saving mode (VPSM) is not the pause mode in step S504, it is determined in step S505 whether the video power saving mode (VPSM) is in a power-off state. If “YES” in step S505, control proceeds to step S508, in which it is determined whether the audio power saving mode flag (APSMF) is set to a power-off state. In step S508, “YES” is determined. If so, control proceeds to step S509, and if 'NO', control proceeds to step S512.
[0050]
If the video power saving mode (VPSM) is in the power cut-off state in step S505, the control proceeds to step S600 of FIG.
[0051]
As shown in FIG. 5, in step S600, it is determined whether or not the flag state change is completed. If “YES” in step S600, the control ends. If “NO”, control returns to step S100.
[0052]
The first and second embodiments have been described for the purpose of promoting the understanding of the present invention. However, those having ordinary knowledge in this technical field are within the scope and technical idea of the present invention described in the appended claims. Thus, it can be easily understood that various modifications, additions, and alternatives are possible.
[0053]
【The invention's effect】
According to the present invention, the audio circuit can be operated according to the user's intention regardless of the power saving mode regardless of the power saving mode.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a video display device including a cathode ray tube (CRT) and an audio circuit.
FIG. 2 is a block diagram showing a video display device according to the first embodiment of the present invention.
3 is a circuit diagram of an audio power supply unit and an audio power control unit in FIG. 2;
FIG. 4 is a block diagram showing a video display device according to a second embodiment of the present invention.
FIG. 5 is a flowchart illustrating a method for controlling power supplied to an audio circuit.
6 is a flowchart of a flag state change routine of FIG.
7 is a flowchart of an audio on / off control routine of FIG.
8 is a flowchart of an audio power saving control routine of FIG.
[Explanation of symbols]
310 Main power supply unit
330 Main voltage generator
340 Audio power supply unit
350 Audio power control unit
360 audio circuit
400 Auxiliary power supply
410 Microcontroller

Claims (6)

In a video display device that performs a power saving function in response to horizontal and vertical synchronization signals and a video signal supplied from a host that supports the power saving function:
Means for supplying a first power source;
Means for generating a constant voltage using the first power source;
Means for supplying a second power source;
Operated by the second power source, generates first and second power control signals from first and second output ports in response to the horizontal and vertical synchronization signals and the video signal, and from a key input unit A microcontroller for generating a third power control signal through a third output port in response to input key input data;
Means for interrupting the constant voltage in response to the first power control signal;
Means for shutting off the first power supply in response to the second power control signal;
Means for supplying a third power source using the first or second power source;
Means for operating with the third power source and processing an audio signal from the host;
Means for shutting off the third power supply in response to the third power supply control signal,
A video display device characterized in that the third power source supplied to the audio processing means is controlled independently of a video circuit section. The third power supply means is connected to an input terminal connected to the first or second power supply means, an output terminal connected to the audio processing means, and the third power cutoff means. 2. The pass voltage regulator having a control terminal, wherein the pass voltage regulator supplies the third power to the audio processing means in response to a switching signal from the third power cut-off means to cut off. The video display device described. The third power shut-off means is:
A current path connected between the control terminal of the pass voltage regulator and ground, and a transistor having a control terminal;
A first resistor coupled between the input terminal of the pass voltage regulator and a control terminal of the pass voltage regulator ;
A second resistor coupled between a control terminal of the pass voltage regulator and a control terminal of the transistor;
A third resistor coupled between the control terminal of the pass voltage regulator and the ground;
A fourth resistor coupled between the control terminal of the transistor and the third output port of the microcontroller;
A first capacitor coupled between the control terminal of the transistor and the ground;
The video display device according to claim 2, further comprising a second capacitor connected between the third output port of the microcontroller and the ground. In a video display device that performs a power saving function in response to horizontal and vertical synchronization signals and a video signal supplied from a host that supports the power saving function:
A main power supply for supplying main power;
A constant voltage generation unit that generates a constant voltage necessary for the oscillation circuit unit and the RGB video amplification circuit unit using the main power source;
An auxiliary power supply for supplying auxiliary power;
Operated by the auxiliary power source, generates first and second power control signals from first and second output ports in response to the horizontal and vertical synchronization signals and the video signal, and is inputted from a key input unit. A microcontroller for generating a third power control signal through the third output port in response to the key input data;
A first power supply mode control unit that cuts off the constant voltage supplied from the constant voltage generation unit to the oscillation circuit unit and the RGB video amplification circuit unit in response to the first power supply control signal;
A second power mode control unit that shuts off the main power supplied to the constant voltage generator in response to the second power control signal;
Means for supplying audio power using the main power supply or the auxiliary power supply;
An audio circuit operated by the audio power source;
An audio power control unit that cuts off the audio power supplied to the audio circuit in response to the third power control signal. The audio power supply unit has an input terminal connected to the main power supply unit or the auxiliary power supply unit, an output terminal connected to the audio circuit, and a control terminal connected to the audio power control unit. 5. The video display device according to claim 4, comprising a pass voltage regulator, wherein the pass voltage regulator supplies the third power to the audio circuit in response to a switching signal from the audio power controller, and shuts off. The audio power controller is:
A current path connected between the control terminal of the pass voltage regulator and ground, and a transistor having a control terminal;
A first resistor coupled between the input terminal and the control terminal of the pass voltage regulator of the pass voltage regulator;
A second resistor coupled between a control terminal of the pass voltage regulator and a control terminal of the transistor;
A third resistor coupled between the control terminal of the pass voltage regulator and the ground;
A fourth resistor connected between a control terminal of the transistor and the third output port of the microcontroller;
A first capacitor coupled between the control terminal of the transistor and the ground;
The video display device according to claim 5, further comprising: a second capacitor connected between the third output port of the microcontroller and the ground.

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