KR100358695B1 - Controlling Method of Driving Display Device and Controlling Apparatus Thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control method and a drive control device for a display device to prevent the system from malfunctioning by radiation noise generated from the lamp when the lamp is initially turned on.

According to another aspect of the present invention, there is provided a driving control method of a display device including a driving circuit unit including a lamp, the method including applying power to the driving circuit unit before applying power to the lamp, and setting initial image and audio data. Driving the timer connected to the microcomputer to control the driving circuit unit, and to mute the video and audio data, and to mute the video and audio data. Down while being lit.

Accordingly, the microcomputer is not affected by the radiation noise while the high-pressure discharge lamp is turned on, thereby preventing the system from malfunctioning.

Description

Controlling method and driving control device of display device {Controlling Method of Driving Display Device and Controlling Apparatus Thereof}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control method and a drive control device of a display device, and more particularly to a drive control method and a drive control device of a display device to prevent a system from malfunctioning by radiation noise generated from a lamp when the lamp is initially turned on. It is about.

Recently, a projector, a projection television, and the like, which are display devices capable of realizing a large screen image, have been developed and marketed. In a projector or a projection television, a large screen image is realized by enlarging a digested image generated inside the system on a projection lens system and projecting it on a screen. As an image generating apparatus for generating a fire image in such a display apparatus, a liquid crystal display panel (hereinafter referred to as "LCD"), a cathode ray tube, and the like are mainly used. In a display device using an LCD, a desired image is realized by adjusting a transmittance of a light beam generated from a back light according to an electric signal applied to a liquid crystal layer. In display devices requiring high brightness images such as LCD projectors, high-pressure discharge lamps such as metal halide lamps are used as backlights of LCDs. In a conventional display device using a high-pressure discharge lamp, radiation noise generated from the lamp when the lamp is initially turned on affects the driving circuit portion, causing a malfunction of the system.

1 is a block diagram schematically showing a driving control device for controlling the overall power supply and driving of a system in a conventional display device using a high-pressure discharge lamp such as a metal halide. Referring to FIG. The microcomputer 20 which exchanges control signals with each component of the system, the main power supply unit 22 which supplies driving power to each circuit component, and a high voltage signal to the high-pressure discharge lamp The ballast unit 24 for supplying to the control unit, a reset integrated circuit (hereinafter referred to as a "reset IC") 26 for initializing the microcomputer 20, and a control signal of the microcomputer 20 In accordance with the present invention, a signal processor 28 is provided to process initial image, audio data, and system data. When the system power is applied, the stand-by 5V voltage is supplied to the microcomputer 20 and the reset IC 26. The microcomputer 20 is initialized by the reset IC 26 and then waits for user input in a standby state. When the user's input is applied to the microcomputer 20, the microcomputer 20 supplies a control signal to each component of the system. At this time, the main power supply 22 supplies power to each chip constituting the driving circuit, and the ballast section 24 supplies a high voltage signal to the lamp. At the same time, system data and initial image and audio data are set in the signal processor 28 by the control signal of the microcomputer 20, and a cooling fan for cooling the system is operated. In order to light a high-pressure discharge lamp such as a metal halide, an AC high voltage as shown in FIG. 2 is applied. The peak-to-peak voltage value of the AC high voltage for the initial lighting of the lamp is required to be about 25 mA. The ballast part 24 supplies a high voltage signal to the lamp, checks whether the lamp is turned on, and transmits a lighting confirmation signal to the microcomputer 20. In the conventional lamp driving method in which the lamp is turned on and the signal processing of the drive circuit is performed by the microcomputer 20, the radiation noise generated from the lamp when the lamp is turned on affects the whole of the drive circuit including the microcomputer 20. (Electro-Magnetic Interference, EMI) problem occurs. When the AC high voltage for initial lighting is applied to the high-pressure discharge lamp from the ballast part 24, the lamp is turned on by causing an arc (ARC) discharge between the electrodes. At this time, as shown in FIG. Radiated noise is induced from the lamp. As a result, flicker occurs instantaneously in a printed circuit board (hereinafter, referred to as a “PCB”) including circuit components such as the microcomputer 20 located at a short distance from the lamp. In one part of the PCB substrate that is relatively far from the lamp, radiation noise with a relatively low voltage level is induced as shown in FIG. Radiation noise generated when the lamp is turned on causes distortion of the control signals of the driving circuit. In the conventional driving device as shown in FIG. 1, the input / output terminals of the microcomputer 20 are directly connected to other circuit components, and the microcomputer 20 directly controls each component of the system. In such a conventional system, the characteristics of the input / output signal of the microcomputer 20 are changed by radiation noise when the lamp is turned on, and thus the driving device is more likely to malfunction. For example, the output of the reset IC 26 connected to the reset terminal of the microcomputer 20 is distorted by radiation noise, which causes the microcomputer 20 to be reset without performing normal signal processing. In addition, high voltage is applied to the C-MOS input / output terminal of the microcomputer 20 by the radiation noise, and the C-MOS terminal becomes the same as the turn-on state of the silicon controlled rectifier (SCR). It is in an impedance state. When the C-MOS terminal of the microcomputer 20 is an input terminal to which a standby power is applied, the standby voltage of the microcomputer 20 stays at an intermediate level between 0 V and 5 V, so that the microcomputer 20 does not operate normally. And a latch-up condition occurs in which the user's input signal cannot be processed. LCD projectors, which are currently being miniaturized, require high integration of driving circuits. In this case, since the EMI problem that occurs during the initial lighting of the lamp becomes more serious, there is a great difficulty in circuit design.

Accordingly, it is an object of the present invention to provide a drive control method of a display device which prevents a system from malfunctioning by radiation noise generated from a lamp when the lamp is initially turned on.

Another object of the present invention is to provide a drive control device for a display device which prevents the system from malfunctioning due to radiation noise generated from the lamp when the lamp is initially turned on.

1 is a block diagram schematically showing a drive control device for controlling the overall power and drive of a system in a conventional display device;

2 is a waveform diagram showing an AC high voltage waveform generally applied to a high voltage discharge lamp of a display device.

3 is a waveform diagram showing waveforms of harmonic radiation noise induced in a portion of the PCB substrate close to the lamp when the high-pressure discharge lamp is turned on;

4 is a waveform diagram showing waveforms of harmonic radiation noise induced in a portion of a PCB substrate far from the lamp when the high-pressure discharge lamp is turned on;

5 is a timing diagram of a control signal illustrating a drive control method of a display device according to an exemplary embodiment of the present invention.

6 is a block diagram schematically illustrating a driving control device for controlling the overall power supply and driving of a system in a display device according to an exemplary embodiment of the present invention.

7 is a flowchart illustrating a process of a system according to whether a lamp is turned on in a display device according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

20,40: Micom 22,42: Main power supply

24,44: ballast part 26,56: reset IC

28: signal processor 46: timer

48: port expansion IC 50: switch

52: EEPROM 54: signal processor

In order to achieve the above object, a driving control method of a display device according to the present invention is a display device including a driving circuit unit including a lamp, comprising: applying power to the driving circuit unit before applying power to the lamp; Setting an initial video and audio data, muting the video and audio data, initially lighting the lamp and driving a timer connected to a microcomputer to control the driving circuit unit; And by the control operation, the microcomputer goes down while the lamp is initially turned on.

A driving control apparatus for a display device according to the present invention is a display device having a driving circuit portion including a lamp, comprising: control means for controlling the driving circuit portion, relaying control signals output from the control means, and the lamp and Port expansion means for supplying to the other driving circuit portion, and timing control means for bringing down the control means according to the control of the port expansion means for a predetermined period during which the lamp is initially turned on.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 7.

5 is a timing diagram of a control signal illustrating a driving control method of a display device according to an exemplary embodiment of the present invention for driving a display device using a high-pressure discharge lamp. In the driving control method of the present invention, in order to prevent the microcomputer from being reset or latched up when the initial lamp is turned on, the microcomputer is turned down while the lamp is turned on so as not to be affected by EMI. Referring to FIG. After initializing the microcomputer to the standby state by applying the input signal, the microcomputer sends a control signal when the input signal of the user is applied so that the main power supply unit supplies main power to each circuit component. After setting, mute the video and audio. At this time, the control signal is exchanged between the circuit parts to stabilize the system. Then, the control signal is sent to the ballast unit so that the ballast unit supplies a high voltage signal to the high-pressure discharge lamp, and at the same time, the disable signal is applied to the reset terminal of the microcomputer for a predetermined time to turn the microcom down. The time for the microcomputer to go down is about 3 seconds, which is enough time for the lamp to light up, so that it is not affected by the radiation noise generated by the lamp during this period. After about 3 seconds, the enable signal is applied again to the reset terminal of the microcomputer to reinitialize the microcomputer. Meanwhile, the ballast unit checks whether the lamp is turned on and prevents the high voltage from being continuously supplied to the lamp by the high voltage supply cut-off device built in the ballast unit when the lamp is not lit. Then, the lamp lighting error signal is transmitted to the microcomputer. If the lamp is not connected properly or there is something wrong with the lamp, continuous supply of high voltage to the lamp may adversely affect the whole system. If the lamp is turned on, send a lamp confirmation signal to the microcomputer. After the microcomputer is reinitialized and the lamp is checked, the video and audio mute are released. The reason why the image and sound mute is applied in the driving control process is that some data may be lost due to radiation noise generated during the lamp lighting process. If the lamp is turned on without the image and sound muting, the set data may be affected by radiation noise, and thus the screen and sound state may appear as an unstable transient state.

The driving control apparatus of the display apparatus according to the exemplary embodiment of the present invention for driving the display apparatus according to the driving control method as described above is shown in FIG. 6. Referring to FIG. 6, the driving control apparatus according to the present invention is a whole system. Port for controlling the main power supply 42, the ballast 44, the cooling fan, video and screen mute, and the timer 46 in accordance with the microcomputer 40 and the control signal of the microcomputer 40 to control the (Port) An integrated circuit (hereinafter referred to as "IC") 48, and a timer 46 for controlling the reset terminal of the microcomputer 40 so that the microcomputer 40 goes down while the high-voltage discharge lamp is turned on. And a switch 50 for controlling the power applied to the timer 46 and an electrically erasable PROM for storing the on / off state information of the main power supply 42. Programmable Read Only Memory (hereinafter referred to as "EEPROM") 52, and microcomputer 40 And a signal processor 54 which processes the system data with video and audio data according to a control signal. The main power supply unit 42 supplies main power to each circuit component by a main power supply control signal of the port expansion IC 48. The ballast part 44 performs a function of stably supplying a high voltage signal to the high voltage discharge lamp by the lamp lighting control signal of the port expansion IC 48. In the conventional drive control apparatus shown in FIG. 1, the microcomputer 20 directly controls the main power supply unit 22, the ballast unit 24, a cooling fan, and the like. ) To take charge. In the present invention, when the microcomputer 40 is temporarily down, the main power supply 42, ballast 44 and the cooling fan, etc. should thereby be able to perform a normal function without being affected. For this purpose, a port expansion IC 48 is provided. The port expansion IC 48 has a characteristic of not changing the output control signal which receives and converts the IIC control signal from the microcomputer 40 while power is supplied to the IC 48. That is, unless the microcomputer 40 sends a control signal to change the data of the port expansion IC 48, the port expansion IC 48 maintains the output data value as it is. As a result, the lamp is turned on and the port expansion IC 48 maintains the output data value even when the microcomputer 40 is down, so that the main power supply 42, the ballast 44, and the ballast 44 are driven. Lamp and cooling fan will operate normally. On the other hand, the RC circuit is comprised in the timer 46 connected with the reset IC 56 to the reset terminal of the microcomputer 40. The resistance value and the capacitance value of the RC circuit are adjusted so that the time for the microcomputer 40 to be down is set to about 3 seconds, which is sufficient time for the high-voltage discharge lamp to light up. The switch 50 for supplying power to the timer 46 is controlled by the micom reset signal of the port expansion IC 48.

The operation process of the drive control device is as follows. First, when the system power is applied, the standby-by 5V voltage is applied to the microcomputer 40 and the reset IC 56 so that the microcomputer 40 is initialized and in a standby state. When the user's input signal is received in the standby state, the microcomputer 40 transmits a chip select signal for selecting the port expansion IC 48 to the port expansion IC 48. In addition, an IIC control signal is sent to the selected port expansion IC 48 so that an output terminal value for controlling the main power supply 42 and the cooling fan becomes high. Then, the main power supply 42 supplies main power to each circuit component, and the cooling fan is operated by the cooling fan on signal. At this time, when main power is supplied to each circuit component from the main power supply 42, the internal data value of the EEPROM 52 is converted to " H (High) ". When the internal data value of the EEPROM 52 is "H", it means that the main power supply unit 42 is supplying main power to each circuit component. The internal data value of the EEPROM 52 is "L". (Low) "means a state in which the main power supply unit 42 is off and no power is supplied to each circuit component. The EEPROM 52 has a characteristic of always maintaining data values stored therein even when the chip driving power is turned off. In this case, the microcomputer 40 controls the signal processor 54 to set initial image and audio data. After setting the data, the microcomputer 40 sends a control signal to the port expansion IC 48 to mute the video and audio. After this operation, the port expansion IC 48 applies the lamp ON signal to the ballast unit 44 by the control signal of the microcomputer 40 and simultaneously outputs the microcomputer reset signal as shown in FIG. 6. Send to switch 50. At this time, a high voltage signal is applied to the high-pressure discharge lamp from the ballast part 44 to perform initial lighting, and the switch 50 is activated to apply a driving voltage to the timer 46. As soon as the driving voltage is applied to the timer 46, the data value of the output terminal of the timer 46 changes from low to high as shown in FIG. The comparison waveform in the timer 46 causes the voltage to gradually increase as shown in FIG. 6 by the RC time constant of the RC circuit connected thereto. As soon as this voltage exceeds the reference voltage value set inside the timer 46, the signal (microcom down signal) value of the output terminal of the timer 46 connected to the reset terminal of the microcomputer 40 falls from high to low again. Accordingly, when the reset terminal of the microcomputer 40 is enabled high, the microcomputer 40 is turned down while the output terminal value of the timer 46 remains high. The RC time constant value is adjusted so that the period during which the output terminal value of the timer 46 stays high is about 3 seconds, which is a time sufficient for the lamp to light up. When the reset terminal of the microcomputer 40 operates with enable low, an inverter may be placed between the output terminal of the timer 46 and the reset terminal of the microcomputer 40. As the microcomputer 40 is turned down while the lamp is turned on, the microcomputer 40 is not affected by radiation noise generated when the lamp is turned on. That is, the phenomenon in which the microcomputer 40 is reset or latched-up can be prevented. Meanwhile, since the data values of the output terminals of the port expansion IC 48 do not change even while the microcomputer 40 is down, the main power supply 42, the ballast 44, and the cooling fan operate normally.

When the reset terminal value of the microcomputer 40 drops to low again and initializes, the lamp lighting signal transmitted from the ballast unit 44 is checked to perform the following process. Since the lamp is not necessarily turned on, the lamp may not be turned on because there is a problem with the lamp or it is not connected, so the processing according to the presence of the lamp is changed. 7 shows a flow chart showing a process of the system depending on whether a lamp is turned on. Referring to FIG. 7, first, when the lamp is turned on, it is mainly caused by radiation noise from the lamp. The port expansion IC 48 controls the main power supply control signal to be sent to the main power supply 42 once again in case an abnormal state occurs in the power supply 42. Then, after canceling the image and sound muting, the signal processor 54 sets the data once again in case there is an error in the initially set data. From then on, the system will perform normal operations under the user's control. The system shuts down when the user inputs a system off signal to shut down the system. The termination of the system first turns off the lamp and then turns off the main power supplied to each circuit component from the main power supply 42. The reason for ending in this order is that when the main power supplied to each circuit component is turned off while the lamp is turned on, the transient state at this time is displayed on the screen as it is. At the same time, the main power is turned off, and the data of the EEPROM 52 which stores the on / off state information of the main power supply 42 is changed to a value of "L (Low)". The microcomputer 40 then returns to the standby state after maintaining the cooling fan for about three minutes to cool the system.

If the lamp is not normally lit, the microcomputer 40 checks the internal data of the EEPROM 52. Depending on whether the internal data value of the EEPROM 52 is " H " or " L " By reading the data value of the EEPROM 52, the microcomputer 40 may recognize the on / off state of the main power supply 42 regardless of the down process of the microcomputer 40 when the lamp is turned on. If the internal data value of the EEPROM 52 is "H (High)", the microcomputer (40) has failed because the lamp has failed because the lamp has not been properly connected or the lamp has not been properly connected. Will be recognized. In this case, the microcomputer 40 outputs a lamp error signal and sends a control signal to the port expansion IC 48 to turn off the main power supply 42. As the main power supply 42 is turned off, the data value stored in the EEPROM 52 is also converted to " L (Low) ". The cooling fans are then kept running for three minutes to cool the system. Then wait about 40 seconds for the lamp to turn on again in "Standby 2" and then return to the standby mode. The reason for such a waiting time is that the internal characteristics are changed due to overheating due to the lighting characteristics of the high-pressure discharge lamp, so that if a re-ignition is attempted immediately after the failure of the lighting, the possibility of failure will be high. Even if it is turned on, the supply period of the high voltage signal needs to be extended, which may adversely affect the entire system. On the other hand, the applied state of the system power supply may suddenly change depending on the surrounding environment. In a state where the lamp is normally turned on, a sudden event such as a power failure or the user may unplug the system power cord unexpectedly without going through a normal system shutdown process, and the system power may be suddenly turned off. At this time, even when the system power is applied again and the microcomputer 40 is initialized, the same process is performed as in the case of the lamp lighting error. When the microcomputer 40 checks the internal data value of the EEPROM 52 and the value is “L (Low)”, the microcomputer 40 recognizes that the microcomputer 40 has not previously gone through a process for turning on the lamp. In this case, after waiting about 30 seconds in the "standby 1" state to return to the standby mode. For example, as the main power supply unit 42 is turned off due to normal termination or the like, the data value of the EEPROM 52 is converted to " L (Low). &Quot; This is the case when the system power is applied and the microcomputer 40 is initialized. The waiting time in " standby 1 " becomes shorter than in the case of " standby 2 " which had previously failed to turn on due to the lamp characteristic. After the process of "Standby 1" or "Standby 2", the microcomputer 40 in the standby state waits for the user's input signal and then goes through the initial driving control process again when the input signal is applied. That is, while turning on the main power supply unit 42 and setting initial data in the signal processing unit 54, muting the image and sound, and then turning on the lamp, the microcomputer 40 There is a process of controlling the timer 46 to be down.

As such, even when the lamp fails to be turned on or when the system power is unexpectedly cut off, the overall system operation can be performed stably by providing a corresponding process.

As described above, in the driving control method and driving control apparatus of the display device according to the present invention, the microcomputer is temporarily turned down during the initial lighting of the high-voltage discharge lamp so that the microcomputer is not affected by radiation noise generated during the lamp lighting process. do. Accordingly, it is possible to effectively prevent the system from malfunctioning due to the EMI effect generated during the initial lamp lighting. In addition, by providing a process in case of accidental situation that may occur while the system power is supplied or when the lamp does not light, the overall system operation can be always performed stably.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (16)

A display device comprising a driving circuit portion including a lamp, Applying power to the driving circuit unit before applying power to the lamp; Setting initial image and sound data; Muting the video and audio data; Initial lighting the lamp and driving a timer connected to a microcomputer to control the driving circuit unit; And controlling the microcomputer to be down while the lamp is initially turned on by a control operation of the timer. The method of claim 1, And continuously applying power to the driving circuit unit by a port expansion driver which relays control signals of the microcomputer so that the driving circuits other than the microcomputer operate normally while the microcomputer is down. Driving control method of display device. The method of claim 1, Confirming that power is continuously applied to the driving circuit unit when the lamp is turned on after applying power to the lamp; Unmuting the video and audio data; And resetting the image and sound data. The method of claim 3, wherein Turning off the lamp when a system off signal is applied to the micom; And turning off the power applied to the driving circuit unit after the lamp is turned off. The method of claim 1, Checking whether power is supplied to the driving circuit unit when the lamp is not turned on after applying power to the lamp; Generating a lamp error signal indicating that the lamp has failed to light when the power is applied; Turning off the power applied to the driving circuit unit; And waiting for a predetermined time for re-lighting of the lamp, and then receiving an input signal from a user. The method of claim 5, And if the power supply is stopped, waiting for a predetermined time to turn on the lamp, and then receiving an input signal from the user. A display device comprising a driving circuit portion including a lamp, Control means for controlling the driving circuit unit; Port expansion means for relaying the control signals output from the control means and supplying the lamps and the other driving circuits; And timing control means for bringing down the control means according to the control of the port expansion means for a predetermined period during which the lamp is initially turned on. The method of claim 7, wherein And the port expansion means maintains the output signal even while the control means is down. The method of claim 7, wherein And a resistor-capacitor circuit portion connected to said timing control means to adjust a period during which said control means is down. The method of claim 7, wherein A ballast unit which supplies power to the lamp according to the control signal of the port expansion means and detects whether the lamp is lit and transmits a confirmation signal to the control means; A main power supply unit supplying power to the other driving circuit unit according to a control signal of the port expansion unit; A memory for storing on / off state information of the main power supply; A signal processor configured to set initial image and sound data according to a control signal of the control means; And switching means for supplying power to said timing control means in accordance with a control signal of said port expansion means. The method of claim 10, Before supplying power to the lamp, the port expansion means supplies power to the other driving circuit portion under the control of the control means, mutes the initial image and audio data, and the signal processing portion controls the control means. And setting the initial image and sound data. The method of claim 11, And the port expansion means controls the switching means to apply power to the timing control means to control the ballast part to supply power to the lamp and to turn down the control means. . The method of claim 12, When the lamp is unsuccessful when the control means is down and initialized again, the control means checks the data in the memory and generates a lamp error signal when the main power supply is in the on state. And controlling the main power supply to be turned off. The method of claim 12, When the lamp is turned on when the control means is down and initialized again, the control means controls the port expansion means to release the image and sound mute and controls the signal processor to control the image and sound data. Drive control device of the display device, characterized in that for setting again. The method of claim 14, And the control means controls the port expansion means to switch the power supplied to the lamp and then switch the power supplied to the other driving circuit part when the end signal is input from the user. delete