KR101296568B1 - Device for regulating a brightness, method thereof and liquid crystal display module having the same - Google Patents

Abstract

Disclosed are a luminance adjusting device, an adjustment method, and a liquid crystal display module having the same, which eliminate noise and reduce costs.

The luminance adjusting device of the present invention includes first means for modulating a PWM signal in accordance with an event signal for predetermined luminance adjustment, and second means for varying a first alternating current waveform into a second alternating current waveform in accordance with the PWM modulation signal. And a light source for generating light of luminance corresponding to the variable second alternating current waveform.

Brightness Control, PWM, Backlight Unit, Timing Controller, Scaler

Description

Device for regulating a brightness, method approximately and liquid crystal display module having the same

1 is a view schematically showing a liquid crystal display device having a conventional brightness adjusting device.

2 is a schematic view of a liquid crystal display device having a luminance adjusting device according to a first embodiment of the present invention.

3 is a diagram sequentially illustrating a method of adjusting luminance in the luminance adjusting device according to the first embodiment of the present invention of FIG.

4 is a schematic view of a liquid crystal display device having a luminance adjusting device according to a second embodiment of the present invention.

FIG. 5 is a diagram sequentially illustrating a method of adjusting luminance in the luminance adjusting device according to the second embodiment of the present invention of FIG. 4.

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

110, 510: system 130, 530: liquid crystal display module

140, 540: Timing Controller 144, 552: Register

146, 554: PWM signal modulator 150, 543: gate driver

153, 545: data driver 156, 547: liquid crystal panel

160, 560: inverter circuit 165, 563: backlight unit

550: scaler

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to brightness adjustment, and more particularly, to a brightness adjustment device that eliminates noise and reduces costs, and a method of adjusting the same and a liquid crystal display module having the same.

A display device including a liquid crystal display device is provided with a brightness adjustment function that can be adjusted by a user from the outside. By using the brightness adjustment function, the user can enjoy the image of the quality that suits them.

Since the LCD does not emit light by itself, a backlight unit that supplies light from the outside and an inverter circuit that drives the backlight unit are employed.

In the LCD, the inverter circuit is controlled to adjust the brightness of the backlight unit.

The control method of the inverter circuit is roughly divided into a continuous mode method and a burst mode method. The continuous mode method supplies a continuous AC waveform to the lamp while varying the amplitude of the voltage while driving the liquid crystal panel. The burst mode method uses an AC waveform by pulse width modulation (PWM) method when driving the liquid crystal panel. It is a method to supply the lamp periodically.

Since the continuous mode method has a disadvantage in that a variable range of luminance is narrow due to a low dimming ratio, which is the highest luminance / lowest luminance, a burst mode inverter having a high dimming ratio is mainly adopted in recent years.

1 is a view schematically showing a liquid crystal display device having a conventional brightness adjusting device.

Referring to FIG. 1, a conventional liquid crystal display device includes a liquid crystal display module 30 for displaying an image and a system 10 for controlling the liquid crystal display module 30.

The liquid crystal display module 30 includes a liquid crystal panel 47 in which liquid crystal cells Clc are arranged in a matrix, a gate driver 45 for supplying a scan signal to gate lines GL of the liquid crystal panel 47, A data driver 46 for supplying video data to the data lines DL of the liquid crystal panel 47, a backlight unit 55 for irradiating light to the liquid crystal panel 47, and a backlight unit 55. An inverter circuit 50 for driving, a timing controller 40 for controlling the gate driver 45 and the data driver 46 and supplying video data to the data driver 46 are provided.

The system 10 provides video data to the liquid crystal display module 30 and provides various signals for controlling the liquid crystal display module 30.

In addition, the system 10 modulates a predetermined PWM signal in response to an event signal for luminance adjustment generated by an external user, and provides the PWM modulation signal to the liquid crystal display module 30. In the liquid crystal display module 30, a PWM modulated signal is provided to the inverter circuit 50 via the timing controller 40, and an AC signal corresponding to the PWM modulated signal is generated in the inverter circuit 50. As a result, the backlight unit 55 is driven. Accordingly, the backlight unit 55 may be driven according to the brightness desired by the external user.

In order to perform the brightness adjusting function, the system 10 may include a controller 12 and a PWM signal modulator 14. In addition, dedicated pins 14a and 40a for transmitting and receiving PWM signals are allocated to the output terminal of the system 10 and the input terminal of the liquid crystal display module 30. That is, a PWM signal transmission pin 14a is assigned to the output terminal of the system 10 and a PWM signal receiving pin 40a is assigned to the timing controller 40 of the liquid crystal display module 30. In addition, a PWM signal exclusive cable 20 is connected between the pins 14a and 40a.

Therefore, when an event signal for brightness adjustment is generated by the user, such an event is detected by the controller 12 of the system 10 and a control signal corresponding thereto is provided to the PWM signal modulator 14.

After the PWM signal is modulated in accordance with the control signal by the PWM signal modulator 14, the PWM modulated signal is provided to the timing controller of the liquid crystal display module 30 via the transmission pin and cable for the PWM signal of the system 10.

The PWM modulated signal via the timing controller 40 is provided to the inverter circuit 50.

In the inverter circuit 50, the AC waveform is varied according to the PWM modulation signal, and the AC waveform thus varied is provided to the backlight unit 55, so that the brightness of the backlight unit 55 is variable.

In the conventional liquid crystal display device, as the PWM signal modulator 14 is provided in the system 10, there is a problem that the occupied area for adopting other functions in the system 10 is reduced.

In addition, in the conventional liquid crystal display, since the PWM signal modulator 14 is included in the system 10, a component ratio with respect to the PWM signal modulator 14 increases.

In addition, in the conventional liquid crystal display device, the PWM modulation signal is supplied from the system 10 to the system 10 and the liquid crystal display module 30 through a PWM dedicated cable. In this case, noise caused by electromagnetic waves caused by the PWM signal is generated. There is a problem.

In addition, as the transmission pins for the PWM signal and the receiving pins for the PWM signal are respectively assigned to the system 10 and the liquid crystal display module 30, there is a problem in that the waste of the pins is caused.

Accordingly, an object of the present invention is to provide a luminance adjusting device which eliminates noise and reduces cost, an adjusting method thereof, and a liquid crystal display module having the same.

According to a first embodiment of the present invention for achieving the above object, a brightness adjusting device includes: first means for modulating a PWM signal according to an event signal for adjusting a predetermined brightness; Second means for varying a first alternating current waveform into a second alternating current waveform in accordance with the PWM modulated signal; And a light source for generating light having a luminance corresponding to the variable second alternating current waveform.

According to a second embodiment of the present invention, a luminance adjusting device includes a timing controller for modulating a PWM signal according to an event signal for adjusting a predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; And a backlight unit generating light having a brightness corresponding to the variable second alternating current waveform.

According to a third embodiment of the present invention, a brightness adjusting device includes: a scaler for modulating a PWM signal according to an event signal for adjusting a predetermined brightness; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; And a backlight unit generating light having a brightness corresponding to the variable second alternating current waveform.

According to a fourth embodiment of the present invention, a liquid crystal display module includes: a timing controller for modulating a PWM signal according to an event signal for adjusting a predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; A backlight unit generating light having a luminance corresponding to the variable second alternating current waveform; And a liquid crystal panel displaying a predetermined image according to the light transmittance of the backlight unit.

According to a fifth embodiment of the present invention, a liquid crystal display module includes: a scaler for modulating a PWM signal according to an event signal for adjusting a predetermined brightness; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; A backlight unit generating light having a luminance corresponding to the variable second alternating current waveform; And a liquid crystal panel displaying a predetermined image according to the light transmittance of the backlight unit.

According to a sixth embodiment of the present invention, there is provided a timing controller including a register having a plurality of register values and a PWM signal modulator, an inverter circuit controlled by the timing controller, and a backlight unit driven by the inverter circuit. A method for adjusting luminance in a luminance adjusting device includes: modulating a PWM signal according to an event signal for adjusting a predetermined luminance in the timing controller; Varying a first alternating current waveform into a second alternating current waveform in accordance with the PWM modulated signal in the inverter circuit; And generating light of luminance corresponding to the variable second AC waveform in the backlight unit.

According to a seventh embodiment of the present invention, a luminance including a scaler including a register having a plurality of register values and a PWM signal modulator, an inverter circuit controlled by the timing controller, and a backlight unit driven by the inverter circuit A method for adjusting luminance in an adjusting device includes modulating a PWM signal in accordance with an event signal for adjusting a predetermined luminance in the timing controller; Varying a first alternating current waveform into a second alternating current waveform in accordance with the PWM modulated signal in the inverter circuit; And

Generating light having a luminance corresponding to the variable second AC waveform in the backlight unit.

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

First Embodiment

FIG. 2 is a schematic view of a liquid crystal display device having a luminance adjusting device according to a first embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display according to the first exemplary embodiment of the present invention includes a liquid crystal display module 130 for displaying an image and a system 110 for controlling the liquid crystal display module 130.

The system 110 may collectively manage and control all the functions of the liquid crystal display. The system 110 provides the liquid crystal display module 130 with video data for displaying an image and a control signal for controlling the same, for example, a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and the like. The system 110 may provide a signal for adjusting the size for displaying an image of the liquid crystal display module 130. In order to perform this function, the liquid crystal display module 130 may be provided with a scaler. Thus, the system 110 itself can collectively control all functions as the main board.

In FIG. 2, a control unit 112 is provided in the system 110. The control unit 112 is used to limit the control function related to the PWM signal. That is, when an event is generated by the user from the outside, the controller 112 recognizes it and provides it to the liquid crystal display module 130.

The liquid crystal display module 130 includes a liquid crystal panel 156, a gate driver 150, a data driver 153, a backlight unit 165, an inverter circuit 160, and a timing controller 140.

In the liquid crystal panel 156, pixels corresponding to the liquid crystal cell Clc are defined by a plurality of gate lines GL and a plurality of data lines DL. In each pixel, a thin film transistor TFT connected to the gate line GL and the data line DL is formed, and a pixel electrode connected to the thin film transistor TFT is formed. In addition, a common electrode is formed corresponding to the pixel electrode. Accordingly, the thin film transistor TFT is controlled to be switched by the scan signal applied to the gate line GL, and video data supplied to the data line DL is applied to the pixel electrode via the thin film transistor. In addition, a predetermined common voltage is applied to the common electrode. As a result, an electric field is generated by the potential difference between the video data and the common voltage, and the liquid crystal is displaced by the electric field to display a predetermined image.

The gate driver 150 supplies scan signals to the gate lines GL of the liquid crystal panel 156, and the data driver 153 supplies video data to the data lines DL of the liquid crystal panel 156.

The timing controller 140 controls the gate driver 150 and the data driver 153 and supplies video data to the data driver 153. Video data may be provided from system 110.

The backlight unit 165 includes a light source for generating light and an optical sheet for controlling light. The inverter circuit 160 includes a switching circuit for generating on-off switching control to generate an AC waveform from a voltage source, and a transformer for boosting the AC waveform to a high voltage AC waveform.

In the first embodiment of the present invention, the components related to the pixel adjusting device may be the timing controller 140, the inverter circuit 160, and the backlight unit 165.

The timing controller 140 includes a register 144 and a PWM signal modulator 146. Register 144 is assigned a register value capable of generating a plurality of PWM signals. For example, when the register value is '1', the on duty ratio of the PWM signal is 1%, and when the register value is '78', the on duty ratio of the PWM signal is 78%. Therefore, register values 1 to 99 may be designated in the register 144.

The timing controller 140 decodes an externally provided event signal to obtain a corresponding register value in the register 144, generates a PWM control signal, and provides the PWM control signal to the PWM signal modulator 146.

The PWM signal modulator 146 modulates the PWM signal according to the PWM control signal.

Therefore, when the result of decoding the event signal determines that the register value is '35', a register value of '35' is obtained from the register 144, a PWM control signal is generated according to the register value, and according to the PWM control signal. It is modulated with a PWM signal with an on duty ratio of 35%.

The timing controller 140 provides a PWM modulated signal to the inverter circuit 160 and varies from the current AC waveform to a new AC waveform as the switching circuit is turned on / off according to the PWM modulated signal in the inverter circuit 160. This new AC waveform is boosted from the transformer to a high voltage AC waveform and then provided to the backlight unit 165. The backlight unit 165 is driven by the newly changed AC waveform so that the brightness is adjusted.

A plurality of communication lines 120 are provided between the system 110 and the timing controller 140 of the liquid crystal display module 130. These communication lines are for communication between the system 110 and the timing controller 140. Various control signals for controlling the liquid crystal display module 130 are generated in the system 110 to connect a plurality of communication lines 120. Through the liquid crystal display module 130 may be provided. One of the plurality of communication lines 120 may be used as a line for transmitting an event signal for adjusting luminance. Accordingly, an event signal for adjusting luminance generated by the system 110 may be provided to the timing controller 140 of the liquid crystal display module 130 through a specific communication line.

The event signal provided by the system 110 is generated by the controller 112. When an event is generated by an external user, the controller 112 recognizes the event signal and generates an event signal having a corresponding luminance adjustment value. It may be provided to the timing controller 140. Accordingly, the timing controller 140 decodes such an event signal to vary the PWM signal, and accordingly, the current AC waveform in the inverter circuit 160 is changed into a new AC waveform, and the backlight unit 165 is changed by the new AC waveform. ) Can be adjusted.

FIG. 3 is a diagram sequentially illustrating a method of adjusting luminance in the luminance adjusting device according to the first exemplary embodiment of FIG. 2.

Referring to FIG. 3, the control unit 112 of the system 110 recognizes whether an event for adjusting luminance is generated by the user (S 310). The user may generate an event by pressing a device such as a button mounted on the outside of the liquid crystal display. The user can generate a desired event for brightness adjustment by pressing the button once or multiple times.

The controller 112 recognizes an event generated by the user and checks whether the event is for brightness adjustment (S 312). If necessary, buttons for events other than brightness adjustment may be provided outside the liquid crystal display. In this case, it is necessary to check whether an event has occurred from a button for brightness adjustment among a plurality of buttons. This may be possible by the button being connected to a specific pin assigned for adjusting the brightness of the controller 112. That is, when an event for luminance adjustment is generated from the button, the event is provided to the controller 112 through a specific pin, and accordingly, the controller 112 indicates that the event entered through the specific pin is an event for luminance adjustment. You can check it.

The controller 112 generates an event signal for luminance adjustment based on the event and provides the event signal to the timing controller 140 of the liquid crystal display module 130 through a specific communication line (S 314).

The timing controller 140 generates a PWM control signal according to the event signal with reference to the register 144 (S 316). That is, the timing controller 140 decodes the event signal provided from the system 110 and obtains a corresponding register value from the register 144 based on the decoded result. In the register 144, a plurality of register values indicating each on duty ratio for adjusting brightness are designated. For example, register 144 may be assigned a number of register values with a spacing of 5 between 1 and 99. In such a case, register values may be designated as 1, 5, 10, 15, ... 90, 95, 99.

In this case, when the button is pressed once, the register value 1 is obtained, and when the button is pressed three times, the register value 10 can be obtained.

The timing controller 140 provides the obtained register value to the PWM signal modulator 146. The PWM signal modulator 146 modulates the PWM signal corresponding to the obtained register value (S318). To this end, the PWM signal modulator 146 may be designed to modulate the PWM signal according to a register value in advance. The PWM signal modulator 146 may be implemented in hardware or software.

The timing controller 140 provides a PWM modulated signal to the inverter circuit 160, and an AC waveform is generated in the inverter circuit 160 according to the PWM modulated signal (S 320). That is, the inverter circuit 160 includes a switching circuit and a transformer. The switching circuit is switched on / off by a PWM modulated signal, and the current circuit changes from a current AC waveform to a new AC waveform, and the new AC waveform is transformed by the transformer. Stepped up to a new alternating waveform of high voltage.

The new AC waveform is provided to the backlight unit 165, so that the brightness of the light source is changed as the light source is driven according to the new AC waveform (S 322).

As described above, according to the first exemplary embodiment of the present invention, the PWM signal modulator 146 is embedded in the timing controller 140 instead of being removed from the system 110, thereby reducing the occupying area of the system 110 and adding other functions. It is possible to improve the use efficiency of the liquid crystal display device.

In addition, according to the first embodiment of the present invention, since the event signal generated in the system 110 may be provided to the timing controller 140 using an existing communication line, a PWM signal is generated in the system in the related art. As a separate PWM signal dedicated cable is provided to provide this to the liquid crystal display module, noise generated while the PWM signal passes through the PWM signal dedicated cable is not generated in the present invention, thereby improving product quality.

In addition, according to the first embodiment of the present invention, it is possible to reduce the cost by eliminating the need for the pins provided in each of the system and the liquid crystal display module in order to transmit the PWM signal generated in the system to the PWM signal cable as in the prior art Furthermore, these pins can be used for other purposes, which can improve the efficiency of the product.

Second Example

4 is a schematic view of a liquid crystal display device having a luminance adjusting device according to a second embodiment of the present invention.

Referring to FIG. 4, the liquid crystal display according to the second exemplary embodiment includes a liquid crystal display module 530 for displaying an image and a system 510 for controlling the liquid crystal display module 530.

The second embodiment of the present invention is basically the same as the first embodiment of the present invention, except that the register 144 and the PWM signal modulator 146 are provided in the timing controller 140 in the first embodiment of the present invention. In contrast, in the second embodiment of the present invention, the register 552 and the PWM signal modulator 554 are provided in the scaler 550, and it should be noted that there is a difference between the two embodiments.

In the second embodiment of the present invention, the components having the same functions as those of the first embodiment of the present invention will be briefly described, and the components having technical features in comparison with the first embodiment of the present invention will be described in detail. Explain. Therefore, the components briefly described in the second embodiment of the present invention will be easily understood with reference to the first embodiment of the present invention described above in detail.

The liquid crystal display module 530 includes a liquid crystal panel 547, a gate driver 543, a data driver 545, a backlight unit 563, an inverter circuit 560, a scaler 550, and a timing controller 540. .

In general, the scaler 550 is to adjust the resolution. In the present invention, in addition to the function of adjusting the resolution, a function of modulating the PWM signal for adjusting the luminance is further added.

Therefore, the following scaler 550 is a well-known resolution adjustment function, so further description will be omitted, and mainly describes the PWM signal modulation function.

The scaler 550 includes a register 552 and a PWM signal modulator 554. Register 552 is assigned a register value capable of generating multiple PWM signals. For example, when the register value is '1', the on duty ratio of the PWM signal is 1%, and when the register value is '78', the on duty ratio of the PWM signal is 78%. Accordingly, register values 552 through 1 may be assigned to registers 552.

The scaler 550 decodes an externally provided event signal to obtain a corresponding register value in the register 552, generates a PWM control signal, and provides the PWM control signal to the PWM signal modulator 554.

The PWM signal modulator 554 modulates the PWM signal according to the PWM control signal.

Therefore, when the result of the event signal is decoded, it is determined that the register value is '35', a register value of '35' is obtained from the register 552, and a PWM control signal is generated according to the register value, and according to the PWM control signal. It is modulated with a PWM signal with an on duty ratio of 35%.

The scaler 550 provides a PWM modulated signal to the inverter circuit 560 and varies from the current AC waveform to a new AC waveform as the switching circuit is turned on / off in accordance with the PWM modulated signal in the inverter circuit 560, This new alternating current waveform is boosted from the transformer to a high voltage alternating current waveform and then provided to the backlight unit 563. The backlight unit 563 is driven by the newly changed AC waveform so that the brightness is adjusted.

A plurality of communication lines 520 are provided between the system 510 and the scaler 550 of the liquid crystal display module 530. These communication lines are for communication between the system 510 and the scaler 550, and various control signals for controlling the liquid crystal display module 530 are generated in the system 510 and are provided through the plurality of communication lines 520. The liquid crystal display module 530 may be provided. One of the plurality of communication lines 520 may be used as a line for transmitting an event signal for adjusting luminance. Accordingly, an event signal for adjusting luminance generated by the system 510 may be provided to the scaler 550 of the liquid crystal display module 530 through a specific communication line.

The event signal provided by the system 510 is generated by the controller 512. When an event is generated by an external user, the controller 512 recognizes the event signal and generates an event signal having a corresponding luminance adjustment value. It may be provided to the scaler 550. Accordingly, the scaler 550 decodes the event signal to vary the PWM signal, and thus, the inverter circuit 560 converts the previous AC waveform into a new AC waveform. The brightness can be adjusted.

FIG. 5 is a diagram sequentially illustrating a method of adjusting luminance in the luminance adjusting device according to the second exemplary embodiment of FIG. 4.

Referring to FIG. 5, the controller 512 of the system 510 recognizes whether an event for adjusting brightness is generated by a user (S710). The user may generate an event by pressing a device such as a button mounted on the outside of the liquid crystal display. The user can generate a desired event for brightness adjustment by pressing the button once or multiple times.

The controller 512 recognizes the event generated by the user, and checks whether the event is for brightness adjustment (S712). If necessary, buttons for events other than brightness adjustment may be provided outside the LCD, in which case it is necessary to check whether an event has occurred from a button for brightness adjustment among a plurality of buttons. . This may be possible by the button being connected to a specific pin assigned for adjusting the brightness of the controller 512. That is, when an event for luminance adjustment is generated from the button, the event is provided to the controller 512 through a specific pin, and accordingly, the controller 512 indicates that the event entered through the specific pin is an event for luminance adjustment. You can check it.

The controller 512 generates an event signal for luminance adjustment based on the event and provides the event signal to the scaler 550 of the liquid crystal display module 530 through a specific communication line (S 714).

The scaler 550 generates the PWM control signal according to the event signal with reference to the register 552 (S716). That is, scaler 550 decodes the event signal provided from system 510 and obtains a corresponding register value from register 552 based on the decoded result. In the register 552, a plurality of register values indicating each on duty ratio for adjusting brightness are designated. For example, register 552 may be assigned a number of register values with a spacing of 5 between 1 and 99. In such a case, register values may be designated as 1, 5, 10, 15, ... 90, 95, 99.

In this case, when the button is pressed once, the register value 1 is obtained, and when the button is pressed three times, the register value 10 can be obtained.

The scaler 550 provides the obtained register value to the PWM signal modulator 554. The PWM signal modulator 554 modulates the PWM signal corresponding to the obtained register value (S 718). For this purpose, the PWM signal modulator 554 may be designed to modulate the PWM signal according to a register value in advance. The PWM signal modulator 554 may be implemented in hardware or software.

The scaler 550 provides a PWM modulated signal to the inverter circuit 560, and an AC waveform according to the PWM modulated signal is generated in the inverter circuit 560 (S 720). That is, the inverter circuit 560 includes a switching circuit and a transformer. The switching circuit is switched on / off by a PWM modulated signal, and the current circuit changes from a current AC waveform to a new AC waveform, and the new AC waveform is transformed by the transformer. Stepped up to a new alternating waveform of high voltage.

The new AC waveform is provided to the backlight unit 563, so that the brightness of the light source is changed as the light source is driven according to the new AC waveform (S 722).

From the above, according to the second embodiment of the present invention, since the PWM signal modulator 554 is built in the scaler 550 instead of being removed from the system 510, it is possible to add another function by reducing the occupied area of the system 510. It is possible to improve the use efficiency of the liquid crystal display device.

In addition, according to the second embodiment of the present invention, since the event signal generated in the system 510 may be provided to the scaler 550 using an existing communication line, a PWM signal is generated in the system in the related art. As a separate PWM signal dedicated cable is provided to provide a liquid crystal display module, noise generated while the PWM signal passes through the PWM signal dedicated cable is not generated in the present invention, thereby improving product quality.

In addition, according to the second embodiment of the present invention, in order to transmit the PWM signal generated in the system to the PWM signal-only cable as in the prior art, the pins provided in each of the system and the liquid crystal display module are not required, thereby reducing the cost. Furthermore, these pins can be used for other purposes, which can improve the efficiency of the product.

As described above, according to the present invention, since the PWM signal modulator is embedded in the scaler or the timing controller instead of being removed from the system, it is possible to add another function by reducing the occupied area of the system to improve the use efficiency of the liquid crystal display device. Can be.

According to the present invention, since the event signal generated in the system can be provided to the scaler or the timing controller using an existing communication line, a conventional PWM signal is generated in the system to provide it to the liquid crystal display module. As the signal dedicated cable is provided, noise generated while the PWM signal passes through the PWM signal dedicated cable is not generated in the present invention, thereby improving product quality.

According to the present invention, the pins provided in each of the system and the liquid crystal display module are not required to transmit the PWM signal generated by the system to the PWM signal dedicated cable, thereby reducing the cost and furthermore, the pins can be used for other purposes. Improve the use efficiency of the product.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the 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 (19)

First means for modulating the PWM signal in accordance with the event signal for predetermined brightness adjustment; Second means for varying a first alternating current waveform into a second alternating current waveform in accordance with the PWM modulated signal; And A light source generating light having a brightness corresponding to the variable second alternating current waveform; The first means, A register to which a register value corresponding to the event signal is designated; And And a PWM signal modulator for modulating the PWM signal corresponding to the register value. 2. An apparatus according to claim 1, wherein said first means is either a timing controller or a scaler. delete 2. The luminance adjusting device of claim 1, wherein a plurality of register values corresponding to different event signals are specified in the register. 5. The luminance adjusting device of claim 4, wherein each of the register values represents different on duty ratios of PWM signals. A timing controller for modulating the PWM signal according to the event signal for adjusting the predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; And A backlight unit generating light having a brightness corresponding to the variable second alternating current waveform; The timing controller includes: A register to which a register value corresponding to the event signal is designated; And And a PWM signal modulator for modulating the PWM signal corresponding to the register value. delete 7. The luminance adjusting device of claim 6, wherein a plurality of register values corresponding to different event signals are specified in the register. 10. The luminance adjusting device of claim 8, wherein each of the register values represents different on duty ratios of PWM signals. A scaler for modulating the PWM signal according to the event signal for adjusting the predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; And A backlight unit generating light having a brightness corresponding to the variable second alternating current waveform; The scaler is, A register to which a register value corresponding to the event signal is designated; And And a PWM signal modulator for modulating the PWM signal corresponding to the register value. delete 11. The luminance adjusting device according to claim 10, wherein a plurality of register values corresponding to different event signals are specified in the register. 13. The luminance adjusting device of claim 12, wherein each of the register values represents different on duty ratios of PWM signals. A timing controller for modulating the PWM signal according to the event signal for adjusting the predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; A backlight unit generating light having a luminance corresponding to the variable second alternating current waveform; And A liquid crystal panel which displays a predetermined image according to the transmittance of light of the backlight unit, The timing controller includes: A register to which a register value corresponding to the event signal is designated; And And a PWM signal modulator for modulating the PWM signal corresponding to the register value. A scaler for modulating the PWM signal according to the event signal for adjusting the predetermined luminance; An inverter circuit for varying a first AC waveform into a second AC waveform according to the PWM modulated signal; A backlight unit generating light having a luminance corresponding to the variable second alternating current waveform; And A liquid crystal panel which displays a predetermined image according to the transmittance of light of the backlight unit, The scaler is, A register to which a register value corresponding to the event signal is designated; And And a PWM signal modulator for modulating the PWM signal corresponding to the register value. A method for adjusting luminance in a brightness adjusting device comprising a timing controller including a register with a plurality of register values and a PWM signal modulator, an inverter circuit controlled by the timing controller, and a backlight unit driven by the inverter circuit. To Modulating a PWM signal according to an event signal for adjusting a predetermined brightness in the timing controller; Varying a first AC waveform into a second AC waveform in accordance with the PWM modulated signal in the inverter circuit; and Generating light having a luminance corresponding to the variable second alternating current waveform in the backlight unit. 10. A method for adjusting luminance in a luminance adjusting device comprising a scaler including a register and a PWM signal modulator with a plurality of register values, an inverter circuit controlled by the scaler, and a backlight unit driven by the inverter circuit. , Modulating a PWM signal in accordance with an event signal for adjusting a predetermined brightness in the scaler; Varying a first AC waveform into a second AC waveform in accordance with the PWM modulated signal in the inverter circuit; and Generating light having a luminance corresponding to the variable second alternating current waveform in the backlight unit. The method of claim 16 or 17, wherein modulating the PWM signal, Obtaining a register value corresponding to the event signal in the register; And And modulating a PWM signal corresponding to the obtained register value by the PWM signal modulator. 18. The method of claim 16 or 17, wherein each of said register values represents different on duty ratios of PWM signals.

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