KR102167141B1 - Display Device and Driving Method thereof - Google Patents

Abstract

The present invention relates to a display device including a panel, a field of view sensing unit, and a control unit. The panel displays the image. The field of view sensing unit detects the position where the user's gaze stays. The control unit interlocks with the field of view detection unit and changes the brightness of the panel in response to whether the user is staring at the panel.

Description

Display device and driving method thereof

The present invention relates to a display device and a driving method thereof.

With the development of information technology, the market for display devices, which is a connection medium between users and information, is growing. Accordingly, a flat panel display (FPD) such as a liquid crystal display (LCD), an organic light emitting diode display (OLED), and a plasma display panel (PDP). ) Is on the rise. Among them, a liquid crystal display device capable of realizing high resolution and capable of miniaturization as well as enlargement is widely used.

Some of the above-described display devices, for example, a liquid crystal display device or an organic light emitting display device, include a display panel including a plurality of sub-pixels arranged in a matrix form and a driver driving the display panel. The driver includes a scan driver that supplies a scan signal (or a gate signal) to the display panel and a data driver that supplies a data signal to the display panel.

In the above display device, when a scan signal and a data signal are supplied to subpixels arranged in a matrix form, the selected subpixel emits light, thereby displaying an image.

The display device is implemented as a variety of products such as a television, a mobile device (eg, a smartphone), a wearable display device (eg, a smart watch), and a vehicle display device (eg, a navigation device). When the display device is implemented as a display device for user convenience, it needs a function of improving daytime visibility in order to increase user identification. However, in the conventional display device, only a simple function of improving daytime visibility using only illuminance information is proposed, and thus improvement thereof is required.

The present invention for solving the problems of the above-described background technology is to improve reliability by preventing deterioration of the device, to solve the problem due to heat generation, to increase the contrast ratio of the outdoor environment and to reduce power consumption.

The present invention relates to a display device including a panel, a field of view sensing unit, and a control unit as a means for solving the above problems. The panel displays the image. The field of view sensing unit detects the position where the user's gaze stays. The control unit interlocks with the field of view detection unit and changes the brightness of the panel in response to whether the user is staring at the panel.

The controller may increase the brightness of the panel when the user gazes at the panel, and decrease the brightness of the panel when the user does not gaze at the panel.

An illuminance sensing unit for sensing illuminance may be further included, and the controller may increase the brightness of the LEDs when the user gazes at the panel in a state of high illuminance.

An illuminance sensing unit for sensing illuminance may be further included, and the controller may change a duty ratio of a current supplied to the light emitting diodes or a pulse width signal when a user gazes at the panel in a high illuminance state.

It further includes an illuminance sensing unit for sensing illuminance, and the controller may vary the brightness of the panel after deriving an appropriate brightness according to illuminance.

In another aspect, the present invention includes the steps of detecting whether a user is staring at a panel; And changing the brightness of the panel in response to whether a user is staring at the panel.

In the step of varying the brightness, when the user gazes at the panel, the duty ratio of the current supplied to the light emitting diodes or the pulse width signal may be varied to change the brightness of the panel.

The present invention increases, maintains, or decreases brightness (or luminance) in response to illuminance and whether a user gazes, thereby increasing an outdoor environment contrast ratio and reducing power consumption. In addition, since the present invention adjusts the brightness (or luminance) in response to the illuminance and whether the user is staring, it is possible to improve reliability by preventing deterioration of the device and to solve problems caused by heat generation.

1 is a block diagram schematically showing a liquid crystal display device according to a first embodiment of the present invention.
FIG. 2 is a circuit diagram of a sub-pixel shown in FIG. 1;
3 is a view showing an example of implementing a liquid crystal display device as a vehicle display device according to the first embodiment of the present invention.
4 is a diagram for explaining a relationship between a temperature increase and luminous efficiency.
5 is a flow chart showing a method of adjusting brightness of a device according to a first embodiment of the present invention.
6 is a diagram for helping understanding of the description of FIG. 5.
7 is a view showing a change in current according to the presence or absence of brightness control.
8 is a diagram illustrating an example of a configuration of a backlight control signal according to a change in current of FIG. 7.
9 is a flowchart showing a method of adjusting brightness of a device according to a second embodiment of the present invention.
10 is a diagram showing a result of a brightness simulation compared to an outdoor environment contrast ratio.

Hereinafter, specific details for carrying out the present invention will be described with reference to the accompanying drawings.

The display device described below is implemented as a liquid crystal display device or an organic light emitting display device. However, hereinafter, it should be understood that a liquid crystal display device is described as an example as part of the embodiment.

<First Example>

1 is a block diagram schematically illustrating a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a circuit diagram of a sub-pixel shown in FIG. 1.

1 and 2, the liquid crystal display includes an illuminance sensing unit 120, a field of view sensing unit 125, a timing control unit 130, a gate driving unit 140, a data driving unit 150, and a liquid crystal panel. 160), a backlight unit 170, and a backlight driver 180 are included.

The timing control unit 130 receives a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a clock signal, a data signal, and the like from the outside. The timing control unit 130 controls the operation timing of the data driving unit 150 and the gate driving unit 140 by using timing signals such as a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a clock signal.

Since the timing control unit 130 may determine the frame period by counting the data enable signal of one horizontal period, the vertical synchronization signal and the horizontal synchronization signal supplied from the outside may be omitted. The control signals generated by the timing control unit 130 include a gate timing control signal GDC for controlling the operation timing of the gate driving unit 140 and a data timing control signal DDC for controlling the operation timing of the data driving unit 150. ) May be included.

The gate driver 140 outputs a gate signal while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing control unit 130. The gate driver 140 supplies a gate signal to the liquid crystal panel 160 through the gate lines GL. The gate driver 140 is formed in an IC form or formed on the liquid crystal panel 160 in a gate in panel method.

The data driving unit 150 samples and latches the data signal DATA in response to the data timing control signal DDC supplied from the timing control unit 130, and converts it into an analog form in response to the gamma reference voltage and outputs the sample. The data driver 150 supplies a data signal DATA to the liquid crystal panel 160 through the data lines DL. The data driver 150 is formed in the form of an IC.

The liquid crystal panel 160 displays an image in response to a gate signal and a data signal DATA supplied from a driver including the gate driver 140 and the data driver 150. The liquid crystal panel 160 includes a plurality of sub-pixels SP that control light provided through the backlight unit 170. The plurality of sub-pixels SP has a pixel structure in the form of RGB, RGBW or RGBG.

One sub-pixel includes a switching thin film transistor SW, a storage capacitor Cst, and a liquid crystal layer Clc. The gate electrode of the switching thin film transistor SW is connected to the gate line GL1 and the source electrode is connected to the data line DL1. The storage capacitor Cst has one end connected to the drain electrode of the switching thin film transistor SW and the other end connected to the common voltage line Vcom. The liquid crystal layer Clc is formed between the pixel electrode 1 connected to the drain electrode of the switching transistor SW and the common electrode 2 connected to the common voltage line Vcom.

The liquid crystal panel 160 includes a first substrate on which a thin film transistor is formed, a second substrate on which a color filter is formed, and a liquid crystal layer interposed therebetween. The lower polarizing plate is attached to the lower surface of the first substrate, and the upper polarizing plate is attached to the upper surface of the second substrate. The liquid crystal panel 160 is implemented in a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in plane switching (IPS) mode, a fringe field switching (FFS) mode, or an electrically controlled birefringence (ECB) mode.

The backlight unit 170 provides light to the liquid crystal panel 160. The backlight unit 170 includes light-emitting diodes (hereinafter, referred to as LEDs) that emit light, a light guide plate that converts light emitted from the LED into a surface light source, and optical sheets for condensing and diffusing light emitted from the light guide plate.

The illuminance sensing unit 120 detects (or receives) ambient light and converts the sensed ambient light into an electric signal to generate an illuminance signal LIS capable of determining illuminance.

The illuminance detection unit 120 supplies an illuminance signal LIS to the timing control unit 130. The illuminance detection unit 120 detects external light such as an optical sensor, a camera, and an illuminance sensor (Cds), and a sensor unit capable of converting an electric signal into an electric signal, and a sensor unit capable of converting an analog type electric signal into a digital electric signal. It may be composed of a conversion unit or the like.

The visual field sensing unit 125 is a visual field sensing signal capable of finding out exactly where the user's gaze is staying based on a morphological analysis of the shape of the user's face and eyes, and to determine the location where the user's gaze stays. (UES) is created.

The field of view detection unit 125 supplies a field of view detection signal UES to the timing control unit 130. The field of view detection unit 125 is an imaging unit that can detect the shape of a user's face and eyes in the form of an image signal, such as a camera, and an analysis that can perform morphological analysis on the detected image signal and derive a result value. It may be composed of a unit (however, the analysis unit may be included in other devices).

The backlight driving unit 180 generates a backlight control signal BLC for controlling the brightness of LEDs included in the backlight unit 170 in response to a signal supplied from the timing control unit 130. The backlight driver 180 generates a backlight control signal BLC in the form of a pulse width modulation and supplies the generated signal to the LEDs. The backlight driving unit 180 may include a power generation unit, an LED control unit, and an output control unit (output compensation unit).

The liquid crystal display device described above is implemented in various products such as a television, a mobile device (eg, a smart phone), a wearable display device (eg, a smart watch), and a vehicle display device (eg, a navigation device). When the liquid crystal display device is implemented as a display device for user convenience, it needs a function of improving daytime visibility in order to increase user identification.

However, in the conventional liquid crystal display device, only simple functions such as improving daytime visibility using only illumination information are proposed.

Hereinafter, based on an example in which the liquid crystal display device is implemented as a vehicle display device, a navigation device, a problem of the prior art and an embodiment of the present invention for improving the problem will be specified. However, the invention described below should not be interpreted as being limited to a vehicle display device.

3 is a diagram illustrating an example in which a liquid crystal display device is implemented as a vehicle display device according to the first embodiment of the present invention, and FIG. 4 is a diagram for explaining a relationship between a temperature increase and luminous efficiency.

1 and 3, the liquid crystal display device according to the first embodiment of the present invention is implemented as a vehicle display device having a liquid crystal panel 160, an illuminance sensing unit 120, and a field of view sensing unit 125. do. The illuminance sensing unit 120 and the field of view sensing unit 125 function as described with reference to FIG. 1. Positions in which the illuminance sensing unit 120 and the field of view sensing unit 125 are installed may be as shown in FIG. 3, but are not limited thereto.

The liquid crystal display device according to the first embodiment of the present invention uses the illuminance sensing unit 120 to recognize ambient illuminance and varies the brightness of the liquid crystal display device according to the illuminance.

Since humans have a characteristic (Human Visual System; HSV) that perceives the brightness of a display device differently according to the ambient illuminance, when the brightness is varied, the ambient illuminance is used. As described above, many studies have already been conducted on the function of adjusting the brightness of the display device according to the illuminance. However, in the method of adjusting only brightness, in most cases, illuminance acts as a variable.

For example, when a person drives a car in an illuminance of 50000 to 100000 lux, such as in a direct sunlight environment, the daytime illuminance of a liquid crystal display device implemented as a vehicle display device hardly changes, so a high current must be continuously used to realize high brightness. .

As shown in FIG. 4, according to an experiment, it was found that if only the brightness of the liquid crystal display device is adjusted according to the ambient illuminance, the brightness of the device decreases due to an increase in the temperature of the device after a certain period of time.

The reason is that the luminance of the device changes depending on the luminance by recognizing the surrounding illumination, but maintaining the maximum luminance (driving the LEDs at the maximum current level to keep the maximum luminance while the illumination is recognized) reliability due to deterioration of the device. And a problem due to heat generation is caused. In addition, this is because power consumption increases along with reliability and heat generation due to deterioration of the device.

Therefore, the liquid crystal display device according to the first embodiment of the present invention further comprises a field of view sensing unit 125 in addition to the illuminance sensing unit 120. In addition to the surrounding illumination, the moment when the user (driver) gazes at the liquid crystal display device implemented as a vehicle display device is recognized through the sensor, and brightness is adjusted in response to the surrounding illumination only during the time the user watches the device. Accordingly, the liquid crystal display device according to the first embodiment of the present invention can prevent deterioration of the device, thereby improving reliability, and also solving a problem due to heat generation, as well as reducing power consumption.

5 is a flowchart showing a method of adjusting brightness of a device according to a first embodiment of the present invention, FIG. 6 is a diagram for helping understanding of the description of FIG. 5, and FIG. 7 is a diagram illustrating a change in current depending on whether or not brightness is adjusted. FIG. 8 is a diagram illustrating a configuration example of a backlight control signal according to a change in current of FIG. 7.

1, 3, 5, and 6, the liquid crystal display 200 implemented as a vehicle display device senses the illuminance through the illuminance sensing unit 120 (S110). Further, it is sensed whether the user USR is staring at the liquid crystal display 200 implemented as a vehicle display device through the view sensing unit 125 (S120).

In this case, if the user USR is not staring at the liquid crystal display device 200 implemented as a vehicle display device (N), the device maintains the LED current of the backlight unit 170 at the same value as before (S140).

This will be described in detail in conjunction with the device as follows. The timing control unit 130 receives an illumination signal LIS and a field of view detection signal UES from the illumination detection unit 120 and the view detection unit 125, respectively.

The timing control unit 130 analyzes the illuminance detection unit 120 and the field of view detection signal UES. As a result of the analysis, it is sensed that the surrounding illumination is high and brightness adjustment is necessary, but it is also detected that the user USR is not staring at the liquid crystal display 200 implemented as a vehicle display device.

Accordingly, the timing control unit 130 supplies a signal to the backlight driver 180 to maintain the same brightness as before. As a result, the backlight driver 180 maintains the backlight control signal BLC for controlling the brightness of the LEDs at the same value as before and supplies the same to the backlight unit 170.

In this way, when the user (USR) is not staring at the liquid crystal display device 200 implemented as a vehicle display device and gazes at the front (1 in Fig. 6), the brightness of the device is maintained the same as before, even if the illuminance is high. (Maintain low brightness) to reduce power consumption.

In this case, the low brightness level may range from 0 to a white luminance range within the specifications of the device, but is not limited thereto. According to this driving method, the daytime visibility of the device decreases, but power consumption is drastically reduced.

On the contrary, when the user USR stares at the liquid crystal display 200 implemented as a vehicle display device while driving (Y), the device increases the LED current of the backlight unit 170 to a different value than before (S130). ).

This will be described in detail in conjunction with the device as follows. The timing control unit 130 receives an illumination signal LIS and a field of view detection signal UES from the illumination detection unit 120 and the view detection unit 125, respectively.

The timing control unit 130 analyzes the illuminance detection unit 120 and the field of view detection signal UES. As a result of the analysis, it is sensed that the surrounding illumination is high and that brightness adjustment is necessary, and that the user (USR) is staring at the liquid crystal display device 200 implemented as a vehicle display device.

For this reason, the timing control unit 130 supplies a signal to increase the brightness differently from the previous one to the backlight driver 180. As a result, the backlight driver 180 changes the backlight control signal BLC for controlling the brightness of the LEDs to an increased value unlike before and supplies it to the backlight unit 170.

In this way, when the user USR stares at the liquid crystal display 200 implemented as a vehicle display device while driving (2 in FIG. 6), the brightness of the device is increased in response to the illuminance. At this time, the user USR gazes at the device at the level of approximately 1 to 10 seconds while driving.

Therefore, in consideration of the safety of the user (USR), the brightness can be increased for approximately N (N is an integer of 1 or more) seconds by using the maximum current that the LEDs can provide in order to provide high identification power. According to this driving method, the daytime visibility of the device is automatically improved temporarily and momentarily.

On the other hand, when the user (USR) is not staring at the liquid crystal display device 200 implemented as a vehicle display device and gazes at a front light (1 in FIG. 6), the current supplied to the LEDs of the backlight unit 180 is It can be kept constant as shown in ① of 7.

In contrast, when the user (USR) stares at the liquid crystal display device 200 implemented as a vehicle display device while driving (2 in FIG. 6), the current supplied to the LEDs of the backlight unit 180 is as shown in FIG. 7 Can be variable as well.

The current supplied to the LEDs of the backlight unit 180 is temporarily and momentarily increased in the situation (b) when the user USR gazes at the liquid crystal display 200 implemented as a vehicle display device while driving. However, the current supplied to the LEDs of the backlight unit 180 decreases as in the situations (a) and (c) when the user (USR) does not stare at the liquid crystal display 200 implemented as a vehicle display device while driving. .

As shown in FIG. 8, the backlight control signal BLC is (a) and (c) in the case (b) in which the user USR stares at the liquid crystal display 200 implemented as a vehicle display device while driving. It can be generated with a pulse width signal higher than that of the situation (duty ratio is variable). For example, in the case of (b), the duty ratio of the pulse width signal is increased compared to (a) and (c), whereas in the case of (a) and (c), the duty ratio of the pulse width signal is lower than that of (b).

<Second Example>

9 is a flowchart showing a method of adjusting brightness of a device according to a second embodiment of the present invention, and FIG. 10 is a diagram showing a result of a brightness simulation compared to an outdoor environment contrast ratio.

As shown in FIGS. 1, 3, 6, and 9, the liquid crystal display 200 implemented as a vehicle display device senses the illuminance through the illuminance sensing unit 120 (S210). Then, the appropriate brightness is calculated based on the information on which the illuminance is sensed through the illuminance detection unit 120 (S220). Further, it is sensed whether the user USR is staring at the liquid crystal display 200 implemented as a vehicle display device through the field of view sensing unit 125 (S230).

At this time, if the user USR is not staring at the liquid crystal display 200 implemented as a vehicle display device (N), the device maintains or reduces the LED current of the backlight unit 170 as before (S260). . In addition, the brightness of the liquid crystal panel 160 is maintained or decreased as before (S270).

This will be described in detail in conjunction with the device as follows. The timing control unit 130 receives an illumination signal LIS and a field of view detection signal UES from the illumination detection unit 120 and the view detection unit 125, respectively.

The timing control unit 130 calculates the appropriate brightness based on the signal provided from the illuminance detection unit 120 and analyzes the field of view detection signal UES. As a result of the analysis, it is sensed that the surrounding illumination is high and brightness adjustment is necessary, but it is also detected that the user USR is not staring at the liquid crystal display 200 implemented as a vehicle display device.

Accordingly, the timing control unit 130 prompts the backlight driver 180 to maintain or decrease the brightness as before (the user was staring at the device before, but if it is not the current staring situation, it is switched to a decrease command instead of maintenance). Will supply the signal. As a result, the backlight driver 180 generates the backlight control signal BLC at a value that maintains or decreases the current of the LEDs at the same value as before and supplies the same to the backlight unit 170.

The brightness of the liquid crystal panel 160 may be automatically maintained or decreased as before due to changes in current supplied to the LEDs. In this case, as the current of the LEDs and the data signal (or gamma voltage) supplied to the liquid crystal panel 160 are adjusted together, the luminance may be reduced.

In this way, when the user (USR) is not staring at the liquid crystal display device 200 implemented as a vehicle display device and gazes at the front (1 in Fig. 6), the brightness of the device is maintained the same as before, even if the illuminance is high. (Maintain low brightness) to reduce power consumption. In this case, the low brightness level may range from 0 to a white luminance range within the specifications of the device, but is not limited thereto. According to this driving method, the daytime visibility of the device decreases, but power consumption is drastically reduced.

In contrast, when the user (USR) stares at the liquid crystal display device 200 implemented as a vehicle display device while driving (Y), the device increases or maintains the LED current of the backlight unit 170 at a different value than before. (S240). In addition, the brightness of the liquid crystal panel 160 is increased or maintained unlike before (S250).

This will be described in detail in conjunction with the device as follows. The timing control unit 130 receives an illumination signal LIS and a field of view detection signal UES from the illumination detection unit 120 and the view detection unit 125, respectively.

The timing control unit 130 calculates the appropriate brightness based on the signal provided from the illuminance detection unit 120 and analyzes the field of view detection signal UES. As a result of the analysis, it is sensed that the surrounding illumination is high and that brightness adjustment is necessary, and that the user (USR) is staring at the liquid crystal display device 200 implemented as a vehicle display device.

Accordingly, the timing control unit 130 supplies a signal to the backlight driver 180 to increase or maintain the brightness differently from before (in the case of a situation in which the user stares at the device both before and now, it is switched to a maintenance command instead of an increase). do. As a result, the backlight driver 180 generates a backlight control signal BLC at a value that increases or maintains the brightness of the LEDs and supplies the backlight control signal BLC to the backlight unit 170.

The luminance of the liquid crystal panel 160 may be automatically increased or maintained differently from before due to the change in current supplied to the LEDs. In this case, as the current of the LEDs and the data signal (or gamma voltage) supplied to the liquid crystal panel 160 are adjusted together, the luminance may increase.

In this way, when the user USR stares at the liquid crystal display 200 implemented as a vehicle display device while driving (2 in FIG. 6), the brightness of the device is increased in response to the illuminance. At this time, the user USR gazes at the device at the level of approximately 1 to 10 seconds while driving.

Therefore, in consideration of the safety of the user (USR), the brightness can be increased for approximately N (N is an integer of 1 or more) seconds by using the maximum current that the LEDs can provide in order to provide high identification power. According to this driving method, the daytime visibility of the device is automatically improved temporarily and momentarily.

Meanwhile, in the above description, as an example, the step of calculating the appropriate brightness (S220) is performed after the step 210 of detecting the illuminance. However, this may be performed after the step S230 of sensing the field of view of the user USR and the step S240 of increasing or maintaining the LED current. The reason is that if the user (USR) does not stare at the device, the appropriate brightness is calculated, but if not applied, temporal and electrical losses may occur due to response time or memory use.

Meanwhile, in order to reduce discomfort caused by a change in brightness of the user's (USR) field of view, the timing control unit 130 or the like may gradually change the increase and decrease of the luminance. And in the above example, it was taken as an example that an appropriate brightness calculation was performed as a method for maintaining an appropriate brightness. In this case, the appropriate brightness calculation may be performed linearly or hierarchically according to the ambient illuminance, or a value stored in a lookup table may be referred to.

As a result of implementing the devices of the first and second embodiments of the present invention and experimenting with them in an illuminance of 50000 to 100000 lux, such as in a direct sunlight environment, the brightness is increased without deteriorating the device to improve visibility and reduce power consumption. Could

As shown in FIG. 10, when the luminance of the liquid crystal display device P2 implemented as a vehicle display device increases by 2 times as a result of the experiment, the ambient contrast ratio (ACR) increases by about 3 times compared to the conventional structure P1. I did.

In addition, regardless of the illuminance, when the user's field of view is directed to the front, the mode is switched to the low power consumption mode, which increases the effect of reducing power consumption compared to the conventional structure (approximately 37.5% of the improvement in power consumption compared to the conventional technology). This is because the brightness is increased in response to the illuminance and is temporarily increased and then decreased only when the user gazes without maintaining it for a long time.

Meanwhile, in the first and second embodiments of the present invention, it has been described as an example that the brightness is increased when the ambient illuminance is high. However, in a state where the illuminance is low and the user does not gaze, the brightness may be further lowered than before to further reduce power consumption. That is, the present invention increases, decreases, or maintains brightness according to ambient illuminance, and enables the device to operate in consideration of both outdoor visibility and power consumption.

Meanwhile, in the first and second embodiments of the present invention, it has been described as an example that the illuminance sensing unit and the visual field sensing unit are respectively separated. However, the illuminance detection unit and the field of view detection unit may be integrated into one device such as a camera.

Meanwhile, in the first and second embodiments of the present invention, it has been described as an example that the illuminance detection unit and the field of view detection unit are interlocked (connected) with the timing control unit. However, the illuminance detection unit and the view detection unit may be interlocked with a control unit capable of controlling the brightness.

Meanwhile, in the first and second embodiments of the present invention, a liquid crystal display device is described as an example as part of the embodiment. For this reason, in the above description, it has been described as an example of controlling the backlight driver and the backlight unit to adjust the brightness (or brightness).

However, when the display device is composed of an organic light emitting display device, the brightness of the organic light emitting diode is adjusted according to whether the user gazes or not. In this case, the method of adjusting the brightness of the organic light emitting diode may vary depending on the driving method of the organic light emitting display device, but the data signal, gamma voltage, high potential voltage, and the like are usually adjusted.

As described above, according to the present invention, brightness (or luminance) can be increased, maintained, or decreased in response to illumination and whether the user is staring, thereby increasing the contrast ratio of the outdoor environment and reducing power consumption. In addition, since the present invention adjusts the brightness (or luminance) in response to the illuminance and whether the user is staring, it is possible to improve reliability by preventing deterioration of the device and to solve problems caused by heat generation.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above is in other specific forms without changing the technical spirit or essential features of the present invention by those skilled in the art. It will be appreciated that it can be implemented. Therefore, the embodiments described above are illustrative in all respects and should be understood as non-limiting. In addition, the scope of the present invention is indicated by the claims to be described later rather than the detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

120: illuminance sensing unit 125: visual field sensing unit
130: timing control unit 140: gate driving unit
150: data driver 160: liquid crystal panel
170: backlight unit 180: backlight driver
LIS: Illumination signal UES: Field of view detection signal
BLC: backlight control signal

Claims (8)

A panel that displays an image;
A field of view sensing unit that detects a location where the user's gaze stays;
A control unit that interlocks with the view sensing unit and increases the brightness of the panel when the user gazes at the panel, and decreases the brightness of the panel when the user does not gaze at the panel; And
Including an illuminance sensing unit that detects illuminance,
The control unit calculates the appropriate brightness linearly or hierarchically according to the surrounding illuminance to derive the appropriate brightness according to the illuminance, and the duty of the current or pulse width signal supplied to the LEDs to change the brightness of the panel. A display device, characterized in that the ratio is variable. delete delete delete delete A sensing step of detecting whether a user is staring at the panel;
A calculation step of calculating an appropriate brightness linearly or hierarchically according to the surrounding illumination in order to derive an appropriate brightness according to the illumination intensity; And
A variable step of increasing the brightness of the panel when the user gazes at the panel, and lowering the brightness of the panel when the user does not gaze at the panel,
The variable step is a driving method of a display device, wherein the duty ratio of a current or a pulse width signal supplied to the light emitting diodes is varied to vary the brightness of the panel. delete The method of claim 1,
The control unit
And gradually increasing or decreasing the brightness of the panel in response to whether the user gazes at the panel.

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