KR20070009253A - Liquid crystal display module and its driving method - Google Patents

Abstract

A liquid crystal display module and a driving method thereof are provided to remove a light source unit driver unit, reduce the cost, and provide a thin and lightweight liquid crystal display panel by suppling a driving signal for a light source unit of a liquid crystal display panel. A light source unit(400) supplies light to a liquid crystal display panel(300). A driver unit (200) generates a panel driving signal for driving the liquid crystal display panel and a light source unit driving signal for driving the light source unit. The driver unit is mounted on the liquid crystal display panel using the COG (chip-on-glass) technology. The driver unit includes a gate integrated circuit(221) for driving a gate line(222) of the liquid crystal display panel and a data integrated circuit(211) for driving a data line(212) of the liquid crystal display panel.

Description

Liquid crystal display module and its driving method {LIQUID CRYSTAL DISPLAY MODULE AND ITS DRIVING METHOD}

1 is a block diagram illustrating a conventional liquid crystal display module.

2 is a block diagram illustrating a liquid crystal display module according to a first embodiment of the present invention.

3 is a diagram illustrating a connection relationship between a driving unit and a light source unit illustrated in FIG. 2.

4 is a diagram for describing a transmission path of a light source driving signal generated by the driver illustrated in FIG. 3.

5 is a diagram illustrating a liquid crystal display module according to a second embodiment of the present invention.

6 is a diagram illustrating a liquid crystal display module according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of a light source driving signal that may be generated by the driving unit of the liquid crystal display module according to the first to third embodiments of the present invention.

8 is a flowchart illustrating a method of driving a liquid crystal display module according to the first to third embodiments of the present invention.

<Brief Description of Drawings>

10: power source 20: control unit

30: driver 40: liquid crystal display panel

50: light source unit driver 60: light source unit

100: control unit 200: drive unit

211: data integrated circuit 212: data line

221: gate integrated circuit 222: gate line

300: liquid crystal display panel 310: thin film transistor substrate

320: color filter substrate 400: light source unit

500: main printed circuit board 600: flexible printed circuit

The present invention relates to a liquid crystal display module, and more particularly, to a liquid crystal display module for driving a light source unit by generating a light source unit driving signal in a driving unit of the liquid crystal display module, and a driving method thereof.

Liquid crystal display modules are widely used due to their advantages such as low weight, low voltage driving, and low power consumption. In addition, the application fields are various, and are widely used in various electronic display devices such as monitors of desktop computers, notebook computers, mobile phones, PDAs, TVs, and the like.

As shown in FIG. 1, the control unit 20 of the conventional liquid crystal display module supplies a control signal to the driver 30 driving the liquid crystal display panel 40, and also drives the light source unit 60. 50) to supply a control signal. The power supply 10 supplies a power signal to the driving unit 30 and also supplies a power signal to the light source unit driving unit 50. In particular, the light source unit driver 50 is equipped with an inverter for converting the DC voltage supplied from the power source 10 into an AC voltage, and is further provided with a signal generator for controlling the brightness of the light source unit 60.

As described above, the liquid crystal display module according to the related art has a problem that it is difficult to reduce the thickness and the weight of the liquid crystal display module by the thickness and the area occupied by the light source unit driver. In particular, this problem is maximized when the liquid crystal display module is used as a mobile phone.

SUMMARY OF THE INVENTION An object of the present invention for solving such a conventional problem is to provide a liquid crystal display module and a driving method thereof for removing a light source unit driving unit for driving a light source unit and driving the light source unit using a signal of the panel driving unit.

In addition, since the light source unit driver is removed, manufacturing cost can be reduced, and a thinner and lighter liquid crystal display module is provided.

In order to achieve the above object, a liquid crystal display module according to the present invention includes a liquid crystal display panel; A light source unit supplying light to the liquid crystal display panel; And a driving unit generating a panel driving signal for driving the liquid crystal display panel and a light source driving signal for driving the light source.

The driver may include a gate integrated circuit configured to drive a gate line of the liquid crystal display panel; And a data integrated circuit for driving data lines of the liquid crystal display panel.

In particular, the light source driving signal may be generated using at least one of a gate high voltage, a gate low voltage, and a common voltage generated by the gate integrated circuit.

Alternatively, the light source driving signal may be generated using at least one of an analog pixel signal generated by the data integrated circuit and a data control signal input to the data integrated circuit.

Meanwhile, the liquid crystal display module according to the present invention may further include a switching element positioned between an output end of the driving unit and an input end of the light source unit and selectively turned on or off when an image is implemented on the liquid crystal display panel. .

The switching element is turned on when a data signal is supplied to a data line of the liquid crystal display panel to supply the light source driving signal to the light source unit.

The light source driving signal may be adjusted to a plurality of voltage levels so that the light source unit can be dimmed.

On the other hand, the liquid crystal display module according to the invention is characterized in that it further comprises a flexible printed circuit for supplying the light source driving signal generated in the drive unit to the light source unit.

On the other hand, the liquid crystal display module according to the present invention is characterized in that it further comprises a voltage adjusting unit which is located at the output terminal of the driving unit to adjust the voltage level of the light source driving signal.

The driving unit of the liquid crystal display module according to the present invention is mounted on the liquid crystal display panel in a chip-on-glass form.

In order to achieve the above object, a driving method of a liquid crystal display module according to the present invention includes a driving signal generation step of generating a panel driving signal for driving a liquid crystal display panel and a light source driving signal for driving a light source; A light supply step of supplying light to the liquid crystal display panel by a light source unit driven by the light source driving signal; And an image signal display step of realizing an image using the light on the liquid crystal display panel driven by the panel driving signal.

The driving signal generating step may include generating a gate signal for driving a gate line of the liquid crystal display panel; Generating a data signal for driving a data line of the liquid crystal display panel; And generating a light source driving signal for driving the light source using at least one of the gate signal and the data signal.

In particular, the generating of the light source driving signal may include generating the light source driving signal using at least one of a gate high voltage, a gate low voltage, and a common voltage included in the gate signal.

Alternatively, the generating of the light source driving signal may include generating the light source driving signal using at least one of an analog pixel signal and a data control signal included in the data signal.

The generating of the light source driving signal may include generating a light source driving signal having a plurality of voltage levels so that the light source unit can perform dimming control.

On the other hand, the liquid crystal display module according to the invention is characterized in that it further comprises the step of supplying the light source driving signal to the light source unit using a flexible printed circuit located between the drive unit and the light source unit.

On the other hand, the liquid crystal display module according to the invention further comprises the step of selectively turning on or off the switching element located between the output terminal of the driving unit and the input terminal of the light source unit in the image signal display step.

In the image display step, the switching element is turned on to supply the light source driving signal to the light source unit.

Meanwhile, when used in a portable liquid crystal display device such as a mobile phone, a chip on glass (COG) process in which a driving unit is directly mounted on a liquid crystal display panel is implemented to realize a thinner and lighter module.

An embodiment of the present invention describes a liquid crystal display module of a portable liquid crystal display device as an example for convenience.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIGS. 2 to 8.

2 is a block diagram illustrating a liquid crystal display module according to a first embodiment of the present invention.

2, a liquid crystal display module according to a first embodiment of the present invention includes a liquid crystal display panel 300, a light source unit 400 for supplying light to the liquid crystal display panel 300, and a liquid crystal display panel 300. And a driving unit 200 for driving the light source unit 400, and a control unit 100 for controlling the driving unit 200.

As shown in FIG. 3, the liquid crystal display panel 300 includes a color filter substrate 320 and a thin film transistor substrate 310 which are bonded together with a liquid crystal interposed therebetween. The liquid crystal display panel 300 includes a plurality of liquid crystal cells CLC arranged in a matrix at the intersections of the data lines 212 and the gate lines 222. A thin film transistor (TFT) formed in each of the liquid crystal cells CLC receives an image signal supplied from the data line 212 in response to a scan signal supplied from the gate line 222. To supply.

The controller 100 generates a gate control signal for controlling the gate integrated circuit 221 of the driver 200, and generates a data control signal for controlling the data integrated circuit 211 of the driver 200. In addition, the controller 100 supplies the pixel data signal Data input from the outside to the data integrated circuit 211.

The driver 200 includes a gate integrated circuit 221 driving the gate line 222 and a data integrated circuit 211 driving the data line 212. The driver 200 is mounted on a thin film transistor substrate 310 of the liquid crystal display panel 300 in the form of a chip on glass (COG). The driving unit 210 includes a power supply signal from a power supply unit mounted on the main printed circuit board 500, a gate control signal, a data control signal, and a pixel data signal from the control unit 100. Supplied through. Accordingly, the gate integrated circuit 211 sequentially supplies the scan signal of the gate high voltage VGH to the gate lines 222. In addition, the gate integrated circuit 211 supplies the gate low voltage VGL to the gate lines 222 in a period other than the period in which the gate high voltage VGH is supplied.

In addition, the driving unit 200 generates a light source driving signal LDC including a power signal and a control signal for driving the light source unit 400. The light source driving signal LDC is generated using at least one of a scan signal generated by the gate integrated circuit 221 and a common voltage input to the gate integrated circuit 221. For example, the light source driving signal LDC is an AC voltage in which the gate high voltage VGH and the base voltage of the scan signal are alternately repeated. Alternatively, an AC voltage in which the gate low voltage VGL and the base voltage of the scan signal are alternately repeated. Alternatively, an AC voltage in which the gate high voltage VGH and the gate low voltage VGL of the scan signal are alternately repeated. Alternatively, a common voltage of an AC type converted to match the voltage level of the light source driving signal LDC is used. At this time, the voltage level of the scan signal and the common voltage used for the light source driving signal is converted through a clamping circuit in which a plurality of diodes are connected in series or in parallel or in a combination of series and parallel.

The light source driving signal LDC generated by the gate integrated circuit 221 is supplied to the light source unit 400 through the flexible printed circuit 600. The light source unit 400 is driven by the light source driving signal LDC to irradiate light to the liquid crystal display panel 300 when the liquid crystal display panel 300 implements an image. The light source unit 400 is mainly formed of a backlight unit positioned on the rear surface of the liquid crystal display panel 300. At this time, the light source constituting the light source unit 400 is made of a CCFL or LED.

As described above, the liquid crystal display module according to the first exemplary embodiment generates a light source driving signal for driving the light source unit using at least one of a scan signal and a common voltage generated in the gate integrated circuit. Accordingly, the liquid crystal display module according to the first exemplary embodiment of the present invention can drive the light source unit using a light source driving signal without a separate light source unit driver.

5 is a diagram illustrating a liquid crystal display module according to a second exemplary embodiment of the present invention.

The liquid crystal display module illustrated in FIG. 5 has the same components except that a light source driving signal is generated in the data integrated circuit as compared to the liquid crystal display module illustrated in FIG. 4. Accordingly, detailed description of the same components will be omitted.

The data integrated circuit 211 receives data control signals, pixel data, and power signals from the control unit 100 and the power supply unit on the main printed circuit board 500 through the flexible printed circuit 600. Accordingly, the data integrated circuit 211 converts the pixel data into an analog pixel signal and supplies it to the data lines 212. In addition, the data integrated circuit 211 generates at least one of an analog pixel signal and a data control signal by timing control to generate an AC light source driving signal LDC. For example, the light source driving signal LDC is an alternating current type in which an analog pixel signal of low gradation and an analog pixel signal of high gradation are alternately repeated. Alternatively, it is an alternating current form in which an analog pixel signal of low gradation and an analog pixel signal of intermediate gradation are alternately repeated. Alternatively, it is an alternating current form in which an intermediate pixel analog pixel signal and a high gray analog pixel signal are alternately repeated. Alternatively, this is an alternating current in which the positive analog pixel signal and the negative analog pixel signal are alternately repeated. In this case, the analog pixel signal used for the light source driving signal LDC may increase or decrease the voltage level to the extent that the light source unit 400 can be driven.

The light source driving signal LDC generated by the data integrated circuit 211 is supplied to the light source unit 400 through the flexible printed circuit 600. The light source unit 400 is driven by the light source driving signal LDC to irradiate light to the liquid crystal display panel 300 when the liquid crystal display panel 300 implements an image.

As described above, the liquid crystal display module according to the second exemplary embodiment generates a light source driving signal for driving the light source unit by using an analog pixel signal generated in the data integrated circuit. Accordingly, the liquid crystal display module according to the first exemplary embodiment of the present invention can drive the light source unit using a light source driving signal without a separate light source unit driver.

6 is a diagram illustrating a liquid crystal display module according to a third exemplary embodiment of the present invention.

The liquid crystal display module illustrated in FIG. 6 includes the same components except that the liquid crystal display module further includes a switching element that determines whether to apply a light source driving signal in comparison with the liquid crystal display modules illustrated in FIGS. 4 and 5. Accordingly, detailed description of the same components will be omitted.

The switching element 250 is formed between an output terminal of the driver 210 including at least one of a gate integrated circuit and a data integrated circuit and an input terminal of the light source unit 400. The switching element 250 is turned on when the analog pixel signal is supplied to the data line to supply the light source driving signal to the light source unit 400. In this case, since the light source unit 400 is driven only when the image is implemented, power consumption may be reduced.

In addition, the switching element 250 is selectively turned on / off to output only a high logic voltage or a low logic voltage of the light source driving signal. Alternatively, when a high logic voltage or a low logic voltage is continuously applied to the light source unit, the output pattern is changed such that the high / low logic voltages are alternately applied through timing control.

Meanwhile, in the liquid crystal display module according to the present invention, a voltage filter or a buffer is formed at an output terminal of the light source driving signal LDC to adjust the voltage level of the light source driving signal LDC. The voltage filter or buffer generates a constant voltage to supply a control signal of the light source unit 400.

In addition, the liquid crystal display module according to the present invention is capable of dimming control. That is, the liquid crystal display module according to the present invention may adjust the brightness of the screen of the liquid crystal display by controlling the intensity of the light source unit according to the brightness control voltage input from the system. To this end, the driver 210 generates a light source driving signal having three or more voltage levels by using analog pixel signals of low gradation, middle gradation, and high gradation. For example, as shown in FIG. 7, the light source driving signal LDC is supplied with the first light source voltage VL1 level during the first period T1 and the first light source voltage VL1 during the second period T2. The second light source voltage VL2 level lower than the level and higher than the third light source voltage VL3 level is supplied.

Next, a method of driving the liquid crystal display module according to the present invention will be described in detail with reference to FIG. 8.

First, a light source driving signal is generated using any one of a gate integrated circuit driving a gate line of a liquid crystal display panel and a data integrated circuit driving a data line (S10).

The light source driving signal is generated using at least one of a scan signal and a common voltage generated in the gate integrated circuit, or generated using an analog pixel signal generated in the data integrated circuit.

The light source unit is driven by the generated light source driving signal to supply light to the liquid crystal display panel (S20).

The liquid crystal display panel is driven by the gate integrated circuit and the data integrated circuit, and the image is displayed using the light generated by the light source unit driven by the light source driving signal (S30).

And a switching element 250 that is turned on or off when the data signal is supplied to the data line at the output terminal of the driver 200. Specifically, the switching element 250 is more preferably turned on when the data signal is supplied to the data line to prevent unnecessary power consumption.

As described above, the liquid crystal panel module and the driving method thereof according to the present invention supply driving signals of the light source unit from the driving unit for driving the liquid crystal display panel, thereby reducing the cost of using components.

In addition, since the light source unit driver does not need to be provided, a thin and light liquid crystal display panel is provided.

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 (18)

A liquid crystal display panel; A light source unit supplying light to the liquid crystal display panel; And a driving unit generating a panel driving signal for driving the liquid crystal display panel and a light source driving signal for driving the light source. The method of claim 1, And the driving unit is mounted on the liquid crystal display panel in the form of a chip on glass. The method of claim 1, The driver may include a gate integrated circuit for driving a gate line of the liquid crystal display panel; And a data integrated circuit for driving data lines of the liquid crystal display panel. The method of claim 3, wherein And the light source driving signal is generated using at least one of a gate high voltage, a gate low voltage, and a common voltage generated by the gate integrated circuit. The method of claim 3, wherein And the light source driving signal is generated using at least one of an analog pixel signal generated by the data integrated circuit and a data control signal input to the data integrated circuit. The method of claim 1, And a switching element positioned between an output end of the driving unit and an input end of the light source unit, the switching element being selectively turned on or off when an image is implemented on the liquid crystal display panel. The method of claim 6, And the switching element is turned on when a data signal is supplied to a data line of the liquid crystal display panel to supply the light source driving signal to the light source unit. The method of claim 1, And the light source driving signal may be adjusted to a plurality of voltage levels to enable dimming control of the light source unit. The method of claim 1, And a flexible printed circuit for supplying the light source driving signal generated by the driver to the light source unit. The method of claim 1, And a voltage adjusting unit positioned at an output terminal of the driving unit to adjust a voltage level of the light source driving signal. A driving signal generating step of generating a panel driving signal for driving the liquid crystal display panel and a light source driving signal for driving the light source; A light supply step of supplying light to the liquid crystal display panel by a light source unit driven by the light source driving signal; And an image signal display step of realizing an image using the light on the liquid crystal display panel driven by the panel driving signal. The method of claim 11, The driving signal generation step Generating a gate signal for driving a gate line of the liquid crystal display panel; Generating a data signal for driving a data line of the liquid crystal display panel; And generating a light source driving signal for driving the light source using at least one of the gate signal and the data signal. The method of claim 12, Generating the light source driving signal And generating the light source driving signal by using at least one of a gate high voltage, a gate low voltage, and a common voltage included in the gate signal. The method of claim 12, Generating the light source driving signal And generating the light source driving signal using at least one of an analog pixel signal and a data control signal included in the data signal. The method of claim 11, Generating the light source driving signal And generating, by the light source unit, light source driving signals having a plurality of voltage levels so as to enable dimming control. The method of claim 11, And supplying the light source driving signal to the light source unit using a flexible printed circuit positioned between the driver and the light source unit. The method of claim 11, And selectively turning on or off a switching element positioned between an output end of the driver and an input end of the light source unit in the image signal display step. The method of claim 17, And driving the switching element to supply the light source driving signal to the light source unit during the image display step.

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