KR101244657B1 - Apparatus and method for driving of liquid crystal display device - Google Patents

Abstract

The present invention relates to a driving device and a driving method of a liquid crystal display device which can adapt to a sudden change in ambient illuminance.

The driving apparatus of the liquid crystal display according to the present invention includes a liquid crystal display module for displaying an image by adjusting light transmittance, a light detector for detecting a peripheral illuminance of the liquid crystal display module to generate a light detection signal, and the light detection signal. And a backlight control unit for generating light to irradiate the liquid crystal display module and a sensitivity control unit for adjusting the sensitivity of the light sensing unit.

By such a configuration, the present invention sets the sensitivity of the light sensing unit that detects external illuminance and varies the brightness of the liquid crystal display module by a user's operation, thereby preventing flickering in response to a luminance change caused by a sudden change in external illuminance. The eye fatigue of the user can be reduced.

Illuminance, sensitivity, brightness, backlight, user

Description

Driving apparatus and driving method of liquid crystal display device {APPARATUS AND METHOD FOR DRIVING OF LIQUID CRYSTAL DISPLAY DEVICE}

1 is a view schematically showing a driving device of a liquid crystal display according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram illustrating a sensitivity control signal generated by the sensitivity control unit shown in FIG. 1.

3 is a view schematically showing the light sensing unit shown in FIG. 1.

4 is a graph showing the sensitivity according to the resistance of the optical sensor shown in FIG.

FIG. 5 is a view schematically illustrating a driving device of a liquid crystal display according to a second exemplary embodiment of the present invention. FIG.

FIG. 6 is a schematic view of the light sensing unit shown in FIG. 5. FIG.

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

100: liquid crystal display module 110: drive system

112: sensitivity control unit 120: backlight unit

122: light source 124: inverter

130: light detector 132: light sensor

133: storage unit 134: resistance value control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a driving device and a driving method of a liquid crystal display device adapted to adapt to a sudden change in peripheral illuminance.

Recently, various flat panel display devices that can reduce weight and volume, which are disadvantages of cathode ray tubes, have emerged. Examples of such flat panel display devices include a liquid crystal display, a field emission display, a plasma display panel, and a light emitting display.

The liquid crystal display device has a transmission amount of light beam emitted from a back light unit by a liquid crystal panel composed of a plurality of liquid crystal cells and a plurality of control switches for switching the video signal to be supplied to each of the liquid crystal cells. It is adjusted to display a desired image.

The backlight unit includes a light source unit which is a light source and an inverter for controlling the same. Such a backlight unit occupies a substantial portion of the power consumed in the liquid crystal display.

On the other hand, since a liquid crystal display such as a mobile communication terminal or a notebook computer is portable, it requires little power consumption for easy portability and mobility for a long time.

Accordingly, in order to reduce power consumption of the backlight unit, Korean Patent Laid-Open Publication No. 2005-97289 discloses an optical sensor for detecting an external brightness on a liquid crystal display and a lamp for controlling a lamp using the same. Proposed.

However, since the conventional optical sensor and the display device having the same adjust the luminance by controlling the tube current of the lamp according to the change in the external illuminance using the optical sensor, that is, when the illuminance around the optical sensor changes suddenly, Alternatively, when an object passes by, the luminance of the liquid crystal display suddenly changes. Accordingly, the conventional optical sensor and the display device having the same have a problem in that a flicker occurs due to a change in luminance due to a sudden change in external illuminance, thereby increasing eyestrain of the user.

Accordingly, in order to solve the above problems, the present invention is to provide a driving device and a driving method of a liquid crystal display device that can be adapted to a sudden change in the peripheral illumination.

The driving apparatus of the liquid crystal display according to the embodiment of the present invention for achieving the above object is a liquid crystal display module for displaying an image by adjusting the light transmittance, and detects the peripheral illumination of the liquid crystal display module to detect the light detection signal And a light control unit for generating light, a backlight unit for generating light in response to the light detection signal, and irradiating the liquid crystal display module, and a sensitivity control unit for adjusting the sensitivity of the light detection unit.

A method of driving a liquid crystal display according to an exemplary embodiment of the present invention includes a first step of setting a sensitivity of a light sensing unit and a second step of generating a light sensing signal by detecting peripheral illumination of the liquid crystal display module using the light sensing unit. And a third step of generating light according to the light detection signal and irradiating the liquid crystal display module, and a fourth step of displaying an image by adjusting the light transmittance of the light irradiated to the liquid crystal display module. It is done.

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

1 is a view schematically illustrating a driving device of a liquid crystal display according to a first embodiment of the present invention.

Referring to FIG. 1, a driving device of a liquid crystal display according to a first exemplary embodiment of the present invention detects a liquid crystal display module 100 displaying an image by adjusting light transmittance and peripheral illumination of the liquid crystal display module 100. The light sensing unit 130 to generate the light sensing signal VA, the backlight unit 120 to generate light according to the light sensing signal VA, and irradiate the liquid crystal display module 100 to the light sensing unit. It includes a sensitivity control unit 112 for adjusting the sensitivity of the 130 and the drive system 110 for driving the liquid crystal display module 100.

The liquid crystal display module 110 includes a liquid crystal panel including a plurality of liquid crystal cells formed in a region defined by a plurality of gate lines and a plurality of data lines, and a driving circuit unit for driving the liquid crystal panel.

The driving circuit unit includes a timing controller configured to generate gate and data control signals according to the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable DE, and the dot clock DCLK from the driving system 110; The gate driver generates scan pulses according to the gate control signal and sequentially supplies them to the liquid crystal panel, and converts the data RGB from the drive system 110 into analog video signals according to the data control signal to synchronize the scan pulses. And a data driver for supplying the liquid crystal panel.

The liquid crystal panel displays an image corresponding to the analog video signal by adjusting the light transmittance emitted from the backlight unit 120 according to the analog video signal supplied to be synchronized with the scan pulse.

The driving system 110 generates a vertical synchronizing signal Vsync, a horizontal synchronizing signal Hsync, a data enable DE, and a dot clock DCLK, and supplies the data to the timing controller of the liquid crystal display module 110. RGB and generate it to the timing controller.

In addition, the driving system 110 includes a sensitivity controller 112 for generating a sensitivity control signal SS corresponding to the user's operation US. In this case, the user operates a sensitivity setting key provided separately so that the luminance of the liquid crystal display module 100 does not suddenly change according to the external illuminance of the liquid crystal display module 100. Accordingly, the sensitivity control unit 112 generates sensitivity control signals SS1 to SSn having different on duty W1 to Wn as shown in FIG. 2 corresponding to the number of operations US of the sensitivity setting key. . For example, the sensitivity controller 112 increases the width W1 to Wn of the on duty of the sensitivity control signal SS as the number of operations US of the sensitivity setting key increases.

As illustrated in FIGS. 1 and 3, the light detector 130 includes an optical sensor 132 and a resistance value controller 134.

The optical sensor 132 includes a photo transistor including a collector terminal connected to the driving power supply VDD, an emitter terminal connected to the base power supply VSS through the variable resistor VR, and a base terminal to which light is irradiated. .

When the light 140 is irradiated to the base terminal of the phototransistor, the optical sensor 132 flows a current through the base terminal and turns on the phototransistor, thereby increasing the emitter current in proportion to the base current. The light sensing signal VA is output through the connected emitter terminal. At this time, the sensitivity of the optical sensor 132 is set by the resistance value of the variable resistor (VR) as shown in FIG.

The resistance value controller 134 sets the resistance value of the variable resistor VR connected to the optical sensor 132 so as to correspond to the sensitivity control signal SS supplied from the sensitivity controller 112 of the drive system 110. .

As such, the light detector 130 may set the sensitivity according to the sensitivity control signal SS according to the user's manipulation to generate the light detection signal VA corresponding to the external illuminance 140 of the liquid crystal display module 100. As a result, the external illuminance 140 may be insensitive to a sudden change (when a person or an object passes through the light sensing unit 130).

In FIG. 1, the backlight unit 120 includes a light source unit 122 and an inverter 124.

The inverter 124 generates a light source driving voltage VL for driving the light source unit 122 using input power from the outside, and generates a light source generated according to the light detection signal VA from the light detector 130. Adjust the driving voltage (VL). That is, the inverter 124 reduces the light source driving voltage VL supplied to the light source unit 122 when the light sensing signal VA corresponds to the case where the external illuminance is dark by the light sensing unit 130, and detects the light. The light source driving voltage VL supplied to the light source unit 122 is increased when the light sensing signal VA corresponding to the external illuminance is bright by the unit 130.

The light source unit 122 is driven according to the light source driving voltage VL supplied from the inverter 124 to generate light, and radiates the generated light to the rear surface of the liquid crystal display module 100. To this end, the light source unit 122 includes at least one lamp or at least one light emitting diode driven by the light source driving voltage VL.

On the other hand, the light detector 130 may be embedded in the inverter 124, it may detect the external illuminance according to the external light irradiated from the outside through a hole (not shown).

As described above, the driving device of the liquid crystal display according to the first exemplary embodiment of the present invention generates the sensitivity control signal SS by the user and adjusts the sensitivity of the light detector 130 according to the sensitivity control signal SS. Therefore, insensitivity to sudden changes in external illuminance can reduce flicker due to luminance changes caused by sudden changes in external illuminance, thereby reducing user's eye fatigue.

FIG. 5 is a view schematically illustrating a driving device of a liquid crystal display according to a second exemplary embodiment of the present invention.

Referring to FIG. 5, a driving apparatus of the liquid crystal display according to the second exemplary embodiment of the present invention includes a liquid crystal display module 100, a driving system 110, a backlight unit 120, and a light detector 130. It is configured by.

Since the liquid crystal display module 100 is the same as the first embodiment of the present invention, a detailed description thereof will be replaced with the above description.

Since the driving system 110 is the same as the first embodiment of the present invention except for the method of transmitting the sensitivity control signal SS to the light sensing unit 130, a detailed description thereof will be replaced with the above description. Shall be.

In detail, the driving system 110 transmits the sensitivity control signal SS generated by the sensitivity controller 112 to the light sensing unit 130 through the interface bus line SMbus, or sets the luminance control signal (set by the user). LVS) is transmitted to the inverter 124 via an interface bus line SMbus. At this time, the luminance control signal LVS is generated by the number of times the user separately operates the luminance control key.

First, when the brightness control key is operated by the user, the driving system 110 generates the brightness control signal LVS according to the user's operation, and generates the brightness control signal LVS along with the first address information on the interface bus. Transfer to the line (SMbus).

In addition, when the sensitivity setting key is operated by the user, the driving system 110 generates a sensitivity control signal SS according to the user's operation, and generates the sensitivity control signal SS generated with the second address information on the interface bus. Transfer to the line (SMbus).

As illustrated in FIG. 6, the light detector 130 includes an optical sensor 132, a storage 133, and a resistance adjuster 134.

Since the optical sensor 132 is the same as the first embodiment of the present invention shown in FIG. 3, the description thereof will be replaced with the above description.

The storage unit 133 stores the sensitivity control signal SS transmitted together with the second address information from the driving system 110 through the interface bus line SMbus. In this case, the storage unit 133 does not operate when the address information of the signal supplied through the interface bus line SMbus is not the second address information.

The resistance value controller 134 sets the resistance value of the variable resistor VR connected to the optical sensor 132 so as to correspond to the sensitivity control signal RSS stored in the storage 133.

The backlight unit 120 includes a light source unit 122 and an inverter 124.

The inverter 124 includes a memory 125 that stores the luminance control signal LVS transmitted from the driving system 110 through the interface bus line SMbus along with the first address information. In this case, the memory 125 does not operate when the address information of the signal supplied through the interface bus line SMbus is not the first address information.

The inverter 124 generates a light source driving voltage VL for driving the light source unit 122 using an input power source from the outside, and generates a light source driving voltage according to the luminance control signal LVS stored in the memory 125. The VL is adjusted and the light source driving voltage VL generated according to the light detection signal VA from the light sensing unit 130 is adjusted. That is, the inverter 124 reduces the light source driving voltage VL supplied to the light source unit 122 when the light sensing signal VA corresponds to the case where the external illuminance is dark by the light sensing unit 130, and detects the light. The light source driving voltage VL supplied to the light source unit 122 is increased when the light sensing signal VA corresponds to the case where the external illuminance is bright by the unit 130.

The light source unit 122 is driven according to the light source driving voltage VL supplied from the inverter 124 to generate light, and radiates the generated light to the rear surface of the liquid crystal display module 100. To this end, the light source unit 122 includes at least one lamp or at least one light emitting diode driven by the light source driving voltage VL.

As described above, the driving device of the liquid crystal display according to the second exemplary embodiment of the present invention transmits the sensitivity control signal SS through the interface bus line SMbus, thereby eliminating the need for a separate line. ) And insensitive to a sudden change in external illuminance by adjusting the sensitivity of the light sensing unit 130 according to the sensitivity control signal SS to prevent flickering due to a luminance change caused by a sudden change in external illuminance. The eye fatigue of the user can be reduced.

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.

As described above, the driving device and driving method of the liquid crystal display according to the embodiment of the present invention detects the external illuminance and sets the sensitivity of the light sensing unit that varies the brightness of the liquid crystal display module by a user's operation. Eye fatigue of the user may be reduced by preventing flickering due to a change in luminance caused by a sudden change.

Claims (14)

A liquid crystal display module for displaying an image by adjusting light transmittance; A light detector for detecting a peripheral illuminance of the liquid crystal display module to generate a light detection signal; A backlight unit generating light in response to the light detection signal and irradiating the liquid crystal display module; A sensitivity control unit for generating a sensitivity control signal corresponding to a user's operation to adjust the sensitivity of the light sensing unit, and having a driving system for driving the liquid crystal display module; The light detector An optical sensor configured to set a sensitivity by a resistance value of a resistor to generate the light sensing signal according to the ambient illuminance; And a resistance value adjusting unit for adjusting the resistance value of the resistor in accordance with the sensitivity control signal. delete delete delete The method of claim 1, The backlight unit is A light source unit for irradiating light to the liquid crystal display module; And an inverter for driving the light source unit according to the light detection signal. 6. The method of claim 5, The driving system generates a brightness control signal for varying the brightness of the liquid crystal display module by a user's operation and supplies the brightness control signal to the inverter through an interface bus line or adjusts the resistance value through the interface bus line. It supplies to a part, The drive apparatus of the liquid crystal display device characterized by the above-mentioned. The method of claim 6, The inverter includes a memory for storing the brightness control signal supplied from the driving system through the interface bus line according to first address information, and the light source unit according to the brightness control signal and the light sensing signal stored in the memory. Driving device of the liquid crystal display device, characterized in that for driving. The method of claim 6, The resistance control unit may include a storage unit for storing the sensitivity control signal supplied through the interface bus line according to second address information from the driving system, wherein the resistance value controller is configured to correspond to the sensitivity control signal stored in the storage unit. A drive device for a liquid crystal display device, characterized in that the resistance value is adjusted. A first step of setting a sensitivity of the light detector by generating a sensitivity control signal corresponding to a user's operation; A second step of generating an optical sensing signal by detecting peripheral illuminance of the liquid crystal display module using the optical sensing unit; A third step of generating light according to the light detection signal and irradiating the liquid crystal display module; A fourth step of displaying an image by adjusting a light transmittance of light irradiated to the liquid crystal display module; The light detector An optical sensor configured to set a sensitivity by a resistance value of a resistor to generate the light sensing signal according to the ambient illuminance; And a resistance value adjusting unit for adjusting the resistance value of the resistor in accordance with the sensitivity control signal. delete The method of claim 9, The third step is Generating a light source driving voltage according to the light sensing signal using an inverter; And driving the light source unit to generate light according to the light source driving voltage. The method of claim 11, And generating a brightness control signal for varying the brightness of the liquid crystal display module by a user's operation. 13. The method of claim 12, The inverter stores the brightness control signal supplied through the interface bus line according to the first address information in a memory, and generates the light source driving voltage according to the brightness control signal and the light sensing signal stored in the memory. A method of driving a liquid crystal display device. 13. The method of claim 12, The first step is to store the sensitivity control signal supplied through the interface bus line according to the second address information in a storage unit, and to adjust the sensitivity of the light sensing unit to correspond to the sensitivity control signal stored in the storage unit. A method of driving a liquid crystal display device.

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