KR101500429B1 - Display including photo-detector - Google Patents

Abstract

The present invention relates to a display device including a light sensing part. The display device may include a display panel for displaying an image, a light sensing part including a temperature dependent sub sensing part for sensing external light and being selectively disabled according to an external temperature, and a light sensing part for displaying And a brightness controller for adjusting the brightness of the image.

Display device. Light sensing portion, luminance

Description

A display device including a light sensing part (Display including photo-detector)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a display device including a light sensing part.

2. Description of the Related Art Recently, a cathode ray tube (CRT) has been replaced by an organic light emitting diode (OLED) display, a plasma display panel (PDP), a liquid crystal display LCD) are being actively developed.

In particular, a liquid crystal display device includes a liquid crystal panel having liquid crystal molecules having a dielectric anisotropy injected between a first display panel having a pixel electrode, a second display panel having a common electrode, and a first display panel and a second display panel, .

A desired image is displayed by forming an electric field between the pixel electrode and the common electrode, controlling the intensity of the electric field, and controlling the amount of light passing through the liquid crystal panel. Since the liquid crystal display device is not a self-luminous display device, a backlight unit for providing a backlight to the liquid crystal panel is provided on the back surface of the liquid crystal panel.

BACKGROUND ART [0002] Recently, a technique of adjusting the brightness of a backlight according to external light has been developed in order to reduce power consumption of a backlight unit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device that more accurately measures luminance of external light and adjusts luminance of a displayed image.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to one aspect of the present invention, there is provided a display apparatus including a display panel for displaying an image, a light sensing unit including a temperature-dependent sub-sensing unit that senses external light and is selectively disabled according to an external temperature, And a brightness controller for adjusting the brightness of the image displayed on the display panel according to the detection result of the brightness.

Other specific details of the invention are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

One element is referred to as being "connected to " or " coupled to" another element, either directly connected or coupled to another element, . On the other hand, when one element is referred to as being "directly connected to" or "directly coupled to " another element, it means that no other element is interposed in between. Like reference numerals refer to like elements throughout the specification. "And / or" include each and every combination of one or more of the mentioned items.

Although the first, second, etc. are used to describe various elements, components and / or sections, it is needless to say that these elements, components and / or sections are not limited by these terms. These terms are only used to distinguish one element, element or section from another element, element or section. Therefore, it goes without saying that the first element, the first element or the first section mentioned below may be the second element, the second element or the second section within the technical spirit of the present invention.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, embodiments of the present invention will be described using a liquid crystal display (LCD). However, the present invention can be applied to flat panel display devices such as an organic light emitting diode (OLED) display, a plasma display panel (PDP), and the like. Do.

1 is a block diagram for explaining a display device according to embodiments of the present invention. 2 is an equivalent circuit diagram of one pixel in Fig. In the drawings, four light sensing portions are disposed on the display panel for convenience of explanation, but the present invention is not limited thereto.

1 and 2, a display device according to embodiments of the present invention includes a display panel 300, a signal controller 1000, a gate driver 400, a data driver 500, a backlight driver 800, And a light emitting portion 850.

The display panel 300 includes a plurality of gate lines G1 to Gn, a plurality of data lines D1 to Dm and a plurality of pixels PX, and includes a display unit DA on which an image is displayed, And a non-display portion PA.

The display unit DA includes a first substrate 100 on which a plurality of gate lines G1 to Gn, a plurality of data lines D1 to Dm, a switching device Q and a pixel electrode PE are formed, And a liquid crystal layer 150 interposed between the first substrate 100 and the second substrate 200 to display an image. The gate lines G1 to Gn extend substantially in the row direction and are substantially parallel to each other and the data lines D1 to Dm extend substantially in the column direction and can be substantially parallel to each other.

A pixel PX of the first substrate 100 is formed in a part of the common electrode CE of the second substrate 200 so as to face the pixel electrode PE of the first substrate 100, A filter CF may be formed. For example, a pixel PX connected to an i-th (i = 1 to n) gate line Gi and a j-th (j = 1 to m) data line Dj is connected to a switching element (Q) and a liquid crystal capacitor (Clc) and a storage capacitor (Cst) connected thereto. Here, the holding capacitor Cst may be omitted as needed. The switching element Q is, for example, a thin film transistor made of LTPS (Low Temperature Polycrystalline Silicon). Although the color filter CF is illustrated as being formed on the second substrate 200 including the common electrode CE, the present invention is not limited thereto and may be formed on the first substrate 100.

On the other hand, the non-display portion PA may be a portion where the first substrate 100 is formed wider than the second substrate 200 and the image is not displayed. The non-display unit PA may be equipped with the light sensing unit 600 and may provide the sensed optical signal to the optical data signal controller 1000_2. The light sensing unit 600 will be described later in detail with reference to FIGS. 8 to 11. FIG.

The signal control unit 1000 receives the original image data signal RGB, the input control signal for controlling the display thereof, and the detection result of the light sensing unit 600, and outputs the image data signal IDAT, the data control signal CONT1, A gate control signal CONT2 and an optical data signal LDAT. The signal controller 1000 may include an image data signal controller 1000_1 and an optical data signal controller 1000_2 as shown in FIG.

 3 is an exemplary block diagram for explaining the video data signal control unit of FIG. FIG. 4 is a view for explaining gamma conversion in the image data signal processing unit of FIG. 3. FIG.

3, the image data signal control unit 1000_1 may include a control signal generation unit 1110, a video data signal processing unit 1120, and a raw luminance signal generation unit 1130. [

The control signal generator 1110 receives external control signals and outputs a data control signal CONT1 and a gate control signal CONT2. Here, the input control signal may include, for example, a vertical synchronization signal Vsinc, a horizontal synchronization signal Hsync, a main clock signal Mclk, a data enable signal DE, and the like.

The data control signal CONT1 is provided to the data driver 500 and controls the operation of the data driver 500. For example, the data control signal CONT1 may be a horizontal start signal for starting the operation of the data driver 500, A load signal for instructing the output of the data voltage, an inversion signal for inverting the polarity of the data voltage with respect to the data common voltage Vcom, and the like. On the other hand, the gate control signal CONT2 is provided to the gate driver 400 to control the operation of the gate driver 400, for example, a scan start signal for starting the operation of the gate driver 400 in each frame, A gate clock signal for controlling the on period of the on-voltage, an output enable signal for adjusting the duration of the gate-on voltage, and the like.

The video data signal processing unit 1120 converts the raw video data signal RGB into a video data signal IDAT and outputs the video data signal IDAT. The image data signal IDAT may be a gamma-converted signal of the original image data signal RGB to improve the image quality of the image displayed on the display panel. That is, the original image data signal RGB has the first gradation, and the image data signal IDAT has the second gradation.

Specifically, the image data signal processing unit 1120 converts the original image data signal RGB (corresponding to the first gamma curve A) having the first gradation (concretely, corresponds to the first gamma curve A) to the second gradation (Corresponding to the second gamma curve B in detail) to the image data signal IDAT. Here, the image data signal processing unit 1120 converts the second gradation corresponding to the first gradation into the image data signal IDAT The original image data signal RGB can be converted into the image data signal IDAT using a stored look-up table (not shown).

The raw luminance signal generator 1130 receives the raw image data signal RGB and provides a raw luminance signal R_LB. Specifically, the raw luminance signal generator 1130 receives the raw image data signals RGB and averages them to determine a representative image data signal, and uses the representative image data signal to correspond to the original luminance of the backlight provided by the light emitting unit 850 And outputs the original luminance signal R_LB.

5 is an exemplary block diagram illustrating an optical data signal controller according to embodiments of the present invention.

5, the optical data signal controller 1000_2 outputs the optical data signal LDAT using the raw luminance signal R_LB and the detection result of the light sensing unit 600, and the external luminance detector 1300 and And a brightness control unit 1400.

The external luminance detector 1300 provides the external luminance signal O_LB using the sensing result of the light sensing unit 600. [ Specifically, the upper luminance detector 1300 senses a change in photocurrent corresponding to the external light from the plurality of light sensing units 600 and provides an external luminance signal O_LB corresponding to the brightness of the external light can do.

The brightness controller 1400 adjusts the brightness of the image displayed on the display panel 300 according to the detection result of the light sensing unit 600. Specifically, the luminance controller 1400 uses the external luminance signal O_LB provided from the external luminance detector 1300 and the original luminance signal R_LB provided from the image data signal controller 1000_1, The optical data signal LDAT can be provided to the backlight driver 800 so that the brightness of the backlight is changed. This will be described later in detail with reference to FIG.

The gate driver 400 receives the gate control signal CONT2 and the gate off voltage Voff and sequentially provides the gate on voltage to the plurality of gate lines G1 to Gn. Specifically, the gate driver 400 is enabled in response to a scan start signal for each frame, and can sequentially provide a gate-on voltage to a plurality of gate lines G1 to Gn in response to a gate clock signal.

The data driver 500 generates the video data signals IDAT (i) using the plurality of gradation voltages provided in the gradation voltage supply (not shown), the video data signal IDAT provided from the signal controller 1000 and the data control signal CONT1, ) To the plurality of data lines (D1 to Dm).

The backlight driver 800 adjusts the brightness of the backlight provided by the light emitting unit 850 according to the optical data signal LDAT. The luminance of the backlight provided in the light emitting portion 850 may vary depending on the pulse width or the duty ratio of the optical data signal LDAT, which will be described later in detail with reference to FIG.

The light emitting unit 850 includes at least one light source to provide light to the display panel 300. Specifically, the light emitting portion 850 may be disposed below the display panel 300 to provide a backlight from the lower side of the display panel 300. The light emitting portion 850 may include, for example, a light emitting diode (LED) that is one of the point light sources as shown in FIG. However, the present invention is not limited thereto, and in another embodiment of the present invention, the light source of the light emitting portion 850 may be a light source or a planar light source.

6 is an exemplary block diagram for explaining the luminance controller of FIG.

Referring to FIG. 6, the luminance controller 1400 includes a luminance compensator 1420 and an optical data signal generator 1430.

The luminance compensation unit 1420 uses the raw luminance signal R_LB and the external luminance signal O_LB to provide the luminance signal R_LB '. Specifically, the luminance compensating unit 1420 compensates the raw luminance signal R_LB corresponding to the original luminance of the backlight according to the external luminance signal O_LB corresponding to the luminance of the external light to provide the luminance signal R_LB ' .

Accordingly, the display device according to the embodiments of the present invention can adjust the luminance of the image displayed on the display panel (specifically, the luminance of the backlight) according to the luminance of external light. For example, if the external light is dark, the brightness of the backlight is lowered, whereas when the external light is bright, the brightness of the backlight can be increased. Therefore, the display device according to the embodiments of the present invention not only improves the image quality of the displayed image, but also reduces power consumption in the display device.

The optical data signal generator 1430 provides the optical data signal LDAT corresponding to the brightness signal R_LB '. Specifically, the optical data signal generator 1430 receives the luminance signal R_LB 'compensated according to the luminance of the external light, and provides the optical data signal LDAT corresponding thereto to the backlight driver 800. Here, the pulse width of the optical data signal LDAT provided by the optical data signal generator 1430 can be adjusted according to the luminance signal R_LB '.

7 is a view for explaining the operation of the backlight driving unit of FIG.

7, the backlight driver 800 includes a switching element BLQ that is enabled in response to the optical data signal LDAT and controls the brightness of the light emitting portion 850 according to the optical data signal LDAT can do. Here, the switching element BLQ may be, for example, a transistor which is interposed between the ground voltage and the power supply voltage VADD and receives the optical data signal LDAT as a gate.

Specifically, when the optical data signal LDAT is at a high level, the switching element BLQ of the backlight driver 800 is turned on and the power supply voltage The current flows through the light emitting portion 850 and the inductor L as shown in FIG. At this time, the energy due to the current is stored in the inductor (L). When the optical data signal LDAT becomes low level, the switching element BLQ is turned off and the current flows through the light emitting portion 850, the inductor L and the diode D as a closed circuit . At this time, the energy stored in the inductor L is discharged and the current is reduced. The time during which the switching element BLQ is turned on is adjusted according to the duty ratio of the optical data signal LDAT so that the luminance of the light emitting block LB can be controlled according to the duty ratio of the optical data signal LDAT.

Since the pulse width of the optical data signal LDAT can be adjusted in accordance with the brightness of the external light as described above, the brightness of the light emitting portion 850 can also be controlled corresponding to the brightness of external light. Specifically, when the external light is bright, the pulse width of the optical data signal LDAT is widened to increase the brightness of the backlight provided by the light emitting portion 850, whereas when the external light is dark, the pulse width of the optical data signal LDAT becomes The brightness of the backlight provided in the light emitting portion 850 can be lowered.

Hereinafter, the light sensing unit according to the embodiments of the present invention will be described in detail.

8 is an exemplary block diagram illustrating the light sensing unit of FIG. 9 and 10 are exemplary circuit diagrams of the light sensing unit of FIG. Although the photo sensing unit includes four photodiodes for the sake of convenience, the present invention is not limited thereto.

8 to 10, the light sensing unit 600 senses external light to provide a photocurrent, and includes a temperature independent sub sensing unit 601 and temperature dependent sub sensing units 602_1 to 602_3.

The temperature-independent sub-sensing unit 601 is enabled regardless of the external temperature to provide photocurrent in response to external light. The temperature-independent sub-sensing unit 601 is connected to the first and second nodes N1 and N2 and supplies a photocurrent in the direction from the first node N1 to the second node N2 in response to external light. (PD0). Here, the voltage level of the first node N1 may be higher than the voltage level of the second node N2.

The temperature dependent sub sensing units 602_1 to 602_3 are selectively enabled in response to an external temperature to provide a photocurrent in response to external light. The photodiodes PD1 to PD3, the disable switches SW1 to SW3, And generating units 610_1 to 610_3.

The photodiodes PD1 to PD3 may be connected between the first node N1 and the disable switches SW1 to SW3 to provide photocurrent in response to external light. Here, the photodiodes PD1 to PD3 included in the temperature-dependent sub-sensing units 602_1 to 602_3 may have a higher resistance than the photodiode PD0 included in the temperature-independent sub-sensing unit 601, for example. That is, even if external light of the same brightness is provided at the same temperature, the amount of photocurrent supplied from the photodiodes PD1 to PD3 of the temperature-dependent sub-sensing units 602_1 to 602_3 is controlled by the photodiodes May be less than the amount of photocurrent provided in PD0. However, the present invention is not limited thereto. In another embodiment of the present invention, the resistance of the photodiodes PD1 to PD3 of the temperature-dependent sub-sensing units 602_1 to 602_3 and the photodiode PD0 of the temperature- May be the same.

The disabling switches SW1 to SW3 are connected to the photodiodes PD1 to PD3 and adjust current paths passing through the photodiodes PD1 to PD3 in response to the disable signals DIS1 to DIS3. Thus, the temperature-dependent sub-sensing units 602_1 to 602_3 are turned off by the disable signals DIS1 to DIS3 to pass through the second photodiodes PD1 to PD3 to provide photocurrent in response to external light I can not. That is, the photodiodes PD1 to PD3 can be disabled.

The disable switches SW1 to SW3 may be transistors that are connected between the photodiodes PD1 to PD3 and the second node N2 and receive the disable signals DIS1 to DIS3 as gates. However, the present invention is not limited thereto, and in another embodiment of the present invention, the disable switches SW1 to SW3 may be connected between the first node N1 and the photodiodes PD1 to PD3.

The disable signal generators 610_1 to 610_3 provide the disable signals SW1 to SW3 generated using the external temperature to the disable switches SW1 to SW3. Here, the levels of the disable signals DIS1 to DIS3 may be determined using the external temperature. Specifically, the disable signals DIS1 to DIS3 have a first level at a first temperature, a second level higher than the first level at a second temperature higher than the first temperature, SW1 to SW3 are turned on and the disable switches SW1 to SW3 are turned off at the second temperature.

The disable signal generators 610_1 to 610_3 include output nodes OUT1 to OUT3 for outputting disable signals DIS1 to DIS3 and output nodes OUT1 to OUT3 and diodes D1 and D2 connected to the second node N2, And load portions 650_1 to 650_3 connected between the output nodes OUT1 to OUT3 and the first node N1. Specifically, the disable signal generators 610_1 to 610_3 output disable signals DIS1 to DIS3 whose levels are determined as the resistances of the diodes D1 to D3 vary depending on the external temperature, from the output nodes OUT1 to OUT3, As shown in FIG.

Here, the resistances of the diodes D1 to D3 may vary depending on the temperature-dependent sub-sensing units 602_1 to 602_3. For example, the resistance of the diode D1 included in the first temperature-dependent sub-sensing portion 602_1 may be smaller than the resistance of the diode D3 included in the second temperature-dependent sub-sensing portion 602_3. That is, at the same temperature, the level of the disable signal DIS1 of the first temperature-dependent sub-sensing unit 602_1 may be smaller than the level of the disable signal DIS3 of the second temperature-dependent sub-sensing unit 602_3. This allows the first temperature dependent sub sensing portion 602_1 to be disabled while the second temperature dependent sub sensing portion 602_1 to 602_3 is enabled at the first temperature and the second temperature dependent sub sensing portion 602_1 to 602_3 is enabled at the second temperature higher than the first temperature, And the second temperature dependent sub sensing units 602_1 and 602_3 may be disabled. Therefore, the change in the photocurrent amount of the light sensing unit 600 due to the external temperature can be more effectively reduced. This will be described later in detail with reference to Figs. 11A and 11C.

Meanwhile, the diodes D1 to D3 and the photodiodes PD1 to PD3 of the light sensing unit 600 may be PIN diodes formed on a polysilicon substrate, for example. Specifically, the diodes D1 to D3 and the photodiodes PD1 to PD3 are formed of PIN diodes, so that external light can be selectively provided only to the photodiodes PD1 to PD3.

The load units 650_1 to 650_3 of the disable signal generators 610_1 to 610_3 may be implemented as shown in FIGS. 9 and 10, for example. Referring to FIG.

The disable signal generators 611_1 to 611_3 of the optical sensing unit 600 according to the exemplary embodiment of the present invention include output nodes OUT1 to OUT3 for outputting the disable signals DIS1 to DIS3, And diodes D1 to D3 and output nodes OUT1 to OUT3 connected to the output nodes OUT1 to OUT3 and the second node N2 and transistors 651_1 to 651_3 connected between the first node N1 can do. Here, the gates of the transistors 651_1 to 651_3 may be connected to the second node N2 to act as load units 650_1 to 650_3 for the diodes D1 to D3.

9, the disable signal generators 612_1 to 612_3 of the light sensing unit 600 according to another exemplary embodiment of the present invention may include the output nodes OUT1 to OUT3 and the first node N1 9 except that the gates of the transistors 652_1 to 652_3 connected to the output nodes OUT1 to OUT3 are connected to the output nodes OUT1 to OUT3 to form the load units 650_1 to 650_3 of Fig. Can be the same.

However, the present invention is not limited thereto, and in another embodiment of the present invention, the load units 650_1 to 650_3 may be implemented as resistors, for example.

Hereinafter, the operation of the light sensing unit according to the embodiments of the present invention will be described with reference to FIGS. 11A to 11C.

11A to 11C are diagrams for explaining the operation of the light sensing unit according to the embodiments of the present invention.

Referring to FIGS. 11A to 11C, the number of temperature-dependent sub-sensing units 602_1 to 602_3 which are enabled according to the external temperature may be changed in the light sensing unit 600 according to the embodiments of the present invention. That is, the number of the photodiodes PD0 to PD3 that provide the photocurrent corresponding to the external light in the light sensing unit 600 according to the embodiments of the present invention may be changed according to the external temperature.

Specifically, when the external temperature is relatively low, all the temperature-dependent sub-sensing units 602_1 to 602_3 are enabled as shown in FIG. 11A, while as shown in FIGS. 11B and 11C Similarly, some temperature dependent sub sensing units 602_1 to 602_3 may be disabled. That is, the number of photodiodes PD0 to PD3 that provide photocurrent corresponding to external light can be reduced as the external temperature increases.

Accordingly, the light sensing unit 600 according to the embodiments of the present invention can provide the photocurrent without being affected by a change in the external temperature. In particular, a typical photodiode can provide more photocurrent as the external temperature increases, even though the same brightness is provided. In particular, when the relatively dark light is provided, the amount of photocurrent provided by the photodiode may be more affected by the external temperature.

However, in the display device according to embodiments of the present invention, the number of the photodiodes PD0 to PD3 enabled according to the external temperature changes in the light sensing part 600, The change in photocurrent amount can be reduced. Therefore, the display device according to the embodiments of the present invention can more accurately measure the luminance of external light. In addition, since the brightness of the image displayed on the display device can be more accurately controlled, it is possible to improve the image quality of the image displayed on the display panel and reduce power consumption.

Meanwhile, although not shown in the drawing, the light sensing unit according to another embodiment of the present invention may include only a temperature-dependent sub-sensing unit. Specifically, a disabling switch is connected to all the photodiodes included in the light sensing unit to control the change in the amount of photocurrent according to the external temperature by adjusting the number of photodiodes enabled according to the external temperature.

The details of the present invention will be described with reference to the following specific simulation examples. Those skilled in the art will not be described here because they can be sufficiently technically derived.

<Simulation example>

The light sensing unit 600 according to the embodiments of the present invention is implemented as shown in the circuit diagram of FIG. Here, the first photodiode PD0 and the first diode D1 have the characteristics as shown in FIG.

In FIG. 12, reference symbol a denotes a change in photocurrent according to an external temperature change when 7000 lx of light is supplied to the first photodiode PD0, and reference symbol b denotes a change in the photocurrent of the first diode D1 And the amount of penetrating current was shown. In the drawing, the x axis represents the external temperature (unit, K), the y1 axis represents the amount of through current of the first diode D1, and the y2 axis represents the photocurrent of the first photodiode PD0.

On the other hand, the second to fourth photodiodes PD1 to PD3 have a size of 1/10 of that of the first photodiode PD0. That is, the second to fourth photodiodes (PD1 to PD3) used to provide a photocurrent of 1/10 corresponding to external light of the same brightness. The second and third diodes D2 to D3 each have a size two or four times larger than that of the first diode D1. That is, the second and third diodes D2 to D3 have resistances of 1/2 and 1/4 times, respectively, as compared with the first diodes D1 to D3. Each of the transistors constituting the disabling switches SW1 to SW3 and the load units 650_1 to 650_3 has a ratio of the width W to the length L of the channel region, 4 was used. A voltage of 5V was applied to the first node N1 and a voltage of 0V was applied to the second node N2.

9, the first to fourth photodiodes PD0 to PD3 are connected to the first, second, third and fourth photodiodes PD0 to PD3, respectively, by eliminating the disable switches SW1 to SW3 and the disable signal generators 610_1 to 610_3, And connected to the node N1 and the second node N2.

The amount of photocurrent according to temperature was simulated when light of 7000 lx was supplied to the light sensing part of the experimental example and the comparative example, and the result is shown in FIG.

In FIG. 13, reference symbol C denotes the amount of photocurrent depending on temperature in the light sensing part of the experimental example, and reference symbol D denotes the amount of photocurrent according to temperature in the light sensing part of the comparative example. Referring to FIG. 13, it can be seen that, when the same external light is provided but the external temperature is changed, the amount of change in the photocurrent in the photo sensing unit where the number of photodiodes enabled depends on the external temperature is relatively small.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a block diagram for explaining a display device according to embodiments of the present invention.

2 is an equivalent circuit diagram of one pixel in Fig.

3 is an exemplary block diagram for explaining the video data signal control unit of FIG.

FIG. 4 is a view for explaining gamma conversion in the image data signal processing unit of FIG. 3. FIG.

5 is an exemplary block diagram illustrating an optical data signal controller according to embodiments of the present invention.

6 is an exemplary block diagram for explaining the luminance controller of FIG.

7 is a view for explaining the operation of the backlight driving unit of FIG.

8 is an exemplary block diagram illustrating the light sensing unit of FIG.

9 and 10 are exemplary circuit diagrams of the light sensing unit of FIG.

11A to 11C are diagrams for explaining the operation of the light sensing unit according to the embodiments of the present invention.

Figs. 12 and 13 are diagrams explaining the device characteristics used in the simulation example and the results thereof.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

100: first display panel 150: liquid crystal molecules

200: second display panel 300: liquid crystal panel

400: Gate driver 500: Data driver

600: light sensing unit 800: backlight driving unit

850: light emitting portion 1000: signal control portion

1000_1; The video data signal control section

1000_2: Optical data signal control section

Claims (11)

A display panel for displaying an image; A light sensing unit including a temperature dependent sub sensing unit that senses external light but is selectively enabled depending on an external temperature; And And a brightness controller for adjusting the brightness of the image displayed on the display panel according to the detection result of the light sensing unit, The temperature-dependent sub- Photodiodes and A disable switch coupled to the photodiode and responsive to a disable signal to adjust a current path through the photodiode to disable the photodiode; And a disable signal generator for outputting the disable signal using an external temperature. The method according to claim 1, Wherein the light sensing unit further comprises a temperature independent sub sensing unit for sensing the external light and being enabled regardless of the external temperature. 3. The method of claim 2, Wherein the temperature dependent sub sensing unit and the temperature independent sub sensing unit each include a photodiode, Wherein the resistance of the photodiode included in the temperature-dependent sub-sensing unit is greater than the resistance of the photodiode included in the temperature-independent sub-sensing unit. The method according to claim 1, Wherein the temperature dependent sub sensing unit is enabled at a first temperature and disabled at a second temperature higher than the first temperature. delete The apparatus of claim 1, wherein the disable signal generator An output node providing the disable signal; A diode coupled to the output node And a load section connected to the output node and the diode. The method according to claim 6, Wherein the photodiode and the diode are PIN diodes. The method according to claim 6, And the load section includes a transistor. The method according to claim 1, The level of the disable signal is determined using an external temperature, Wherein the disable signal has a first level at a first temperature and a second level at a second temperature higher than the first temperature and lower than the first level. The method according to claim 1, Wherein the temperature dependent sub sensing part includes first and second temperature dependent sub sensing parts, The first temperature dependent sub sensing part is enabled while the second temperature dependent sub sensing part is disabled at a first temperature, Wherein the first and second temperature dependent sub sensing units are disabled at a second temperature higher than the first temperature. The method according to claim 1, Wherein the light sensing unit is mounted on the display panel.

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