KR20100068740A - Light quantity detecting circuit and liquid crystal display device using the same and driving method thereof - Google Patents

Abstract

PURPOSE: A light amount detection circuit and liquid crystal display using the same and their driving method prevent the distortion of the light quantity detection signal by the change of the surrounding environment. The reliability of the light amount detection can be improved. CONSTITUTION: According to the optical sensor(PS1) is the first electric source signal and the first detection control signal, the optical detection signal corresponding to the quantity of light which is income is outputted. According to the dark sensor(PS2) is the second electric source signal from outside and the second detection control signal, the device characterization signal corresponding to the property of being for its own included of device is outputted.

Description

LIGHT QUANTITY DETECTING CIRCUIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME AND DRIVING METHOD THEREOF

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light quantity detecting circuit, and more particularly, to a light quantity detecting circuit, a liquid crystal display device using the same, and a driving method thereof, which can prevent the light quantity detecting signal from being distorted by a change in the surrounding environment, thereby improving reliability of the light quantity detecting. It is about.

Recently, flat panel displays include liquid crystal displays, field emission displays, plasma display panels, and light emitting displays. These flat panel display devices are actively applied to laptops, desktop monitors, and mobile terminals due to their excellent resolution, color display, and image quality.

Among the flat panel display devices, the liquid crystal display device displays an image by adjusting light transmittance of the liquid crystal cells according to a video signal. An active matrix type liquid crystal display device in which switching elements are formed for each liquid crystal cell is suitable for displaying moving images. In this case, a thin film transistor is mainly used as the switching element. Such a liquid crystal display includes a back light unit that irradiates light of constant brightness to a liquid crystal cell in order to display an image.

In the conventional liquid crystal display, power consumption is increased due to the backlight which generates light having a constant brightness. In other words, since the liquid crystal display maintains the brightness of the liquid crystal cell constant regardless of the brightness of the surrounding environment, the power consumption of the backlight is increased. Accordingly, in order to reduce the power consumption of the backlight, a light amount detection circuit may be provided to adjust brightness of the backlight according to the light amount detection signal.

However, a problem arises in that the light amount detection signal generated by the light amount detection circuit is distorted by the change of the surrounding environment. In detail, the light quantity detection circuits may have different deviations due to a plurality of process factors, and the output characteristics may be distorted according to the temperature and illuminance rate of change because they are sensitive to changes in ambient temperature. In particular, when the light amount detection circuit is provided in the liquid crystal panel in which the liquid crystal cells are formed, the light amount detection signal is distorted by the surrounding liquid crystal cell driving signals, thereby reducing the reliability of the light amount detection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the light quantity detection circuit and the liquid crystal display using the same and the driving thereof to prevent the light quantity detection signal is distorted by the change of the surrounding environment to improve the reliability of the light quantity detection It is about a method.

According to an aspect of the present invention, there is provided a light amount detection circuit, including: an optical sensor configured to output a light detection signal corresponding to an amount of light incident according to a first power signal and a first detection control signal from the outside; A dark sensor connected in parallel with the optical sensor and outputting an element characteristic signal corresponding to a characteristic of an element provided in accordance with a second power signal and a second detection control signal from the outside; And a difference current between the light detection signal and the device characteristic signal as a light quantity current signal, connected to the output terminals of the optical sensor and the dark sensor connected in parallel, and correcting the detected light quantity current signal according to a reference voltage source from the outside. And a light amount detection correction unit for generating and outputting a light amount signal.

In addition, the light amount detection circuit according to an embodiment of the present invention for achieving the above object detects and outputs a light detection signal corresponding to the amount of light incident from the outside and a device characteristic signal corresponding to the characteristics of the device provided itself A detection sensor unit; An I / V conversion unit for performing self reset according to a reset control signal from the outside and converting each current into a voltage when the photo detection signal and the device characteristic signal are respectively input from the detection sensor unit; And generating and outputting a light quantity signal by detecting a difference voltage between a light quantity detection voltage and a device characteristic voltage converted into a voltage through the I / V converter, and correcting the detected level of the difference voltage according to a gain value set by a user. And a light amount signal correcting unit.

In addition, the liquid crystal display according to the embodiment of the present invention for achieving the above objects is a liquid crystal panel having a plurality of pixel areas; A gate and data driver driving gate and data lines of the liquid crystal panel; Any one of the above-described light amount detection circuits for generating and outputting a light amount signal corresponding to an external brightness of the liquid crystal panel; And a timing controller for generating data and gate control signals to control the data and gate drivers, and generating a plurality of control signals for controlling the light quantity detection circuits to control the light quantity detection circuits.

The driving method of the light amount detection circuit according to an embodiment of the present invention for achieving the above object is a light detection corresponding to the amount of light incident according to the first power signal and the first detection control signal from the outside using an optical sensor Outputting a signal; Outputting an element characteristic signal corresponding to a characteristic of an element provided in accordance with a second power signal and a second detection control signal from the outside by using a dark sensor connected in parallel with the optical sensor; And detecting a difference current between the light detection signal and the device characteristic signal as a light quantity current signal at the output terminals of the optical sensor and the dark sensor connected in parallel, and correcting the detected light quantity current signal according to a reference voltage source from the outside. It characterized in that it comprises a step of generating and outputting.

In addition, the driving method of the light amount detection circuit according to an embodiment of the present invention for achieving the above object corresponds to the light detection signal corresponding to the light amount incident from the outside using the detection sensor unit and the characteristics of the device itself provided Detecting and outputting device characteristic signals; Performing self reset according to a reset control signal from the outside using an I / V converter, and converting each current into a voltage when the photodetection signal and the device characteristic signal are respectively input; And generating and outputting a light quantity signal by detecting a difference voltage between the light quantity detection voltage and the device characteristic voltage converted into the voltage and correcting the level of the detected difference voltage according to a gain value set by a user. It is done.

In addition, a method of driving a liquid crystal display according to an exemplary embodiment of the present invention for achieving the above object includes a liquid crystal panel having a plurality of pixel regions, a gate and a data driver for driving gates and data lines of the liquid crystal panel. A method of driving a liquid crystal display device, the method comprising: displaying an image by adjusting light transmittance; And a driving method of the above-described light amount detection circuit for generating and outputting a light amount signal corresponding to the external brightness of the liquid crystal panel.

The light amount detection circuit according to the embodiment of the present invention having the above characteristics, the liquid crystal display using the same, and a driving method thereof can improve the reliability of light amount detection by preventing the light amount detection signal from being distorted due to a change in the surrounding environment. have.

Hereinafter, a light amount detecting circuit according to an embodiment of the present invention having the above characteristics, a liquid crystal display using the same, and a driving method thereof will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a light amount detection circuit according to an embodiment of the present invention.

1 is a light sensor PS1 that outputs a light detection signal P_V corresponding to a light amount incident according to a first power signal VDD and a first detection control signal VG1 from the outside. ; It is connected in parallel with the optical sensor PS1 and outputs the device characteristic signal D_V corresponding to the characteristics of the device provided in accordance with the second power signal VSS and the second detection control signal VG2 from the outside. Dark sensor PS2; And a difference current between the light detection signal P_V and the device characteristic signal D_V, which is connected to the output terminals of the optical sensor PS1 and the dark sensor PS2 connected in parallel, as the light quantity current signal P_I, and detected light quantity. A light amount detection correction unit GVM is provided to generate and output a light amount signal Lout by correcting the current signal P_I according to a reference voltage source Vref from the outside.

As described above, since the optical sensor PS1 is configured to receive light from the outside, its current or voltage is variable in response to the inherent characteristics of the element constituting the optical sensor PS1 and the amount of incident light. However, the dark sensor PS2 is configured not to receive light from the outside so that its current or voltage is variable only according to the characteristics of its own element forming the dark sensor PS2. Here, the light sensor PS1 and the dark sensor PS2 may be configured of at least one NMOS transistor (NMOS TFT), respectively.

The optical sensor PS1 and the dark sensor PS2 configured as described above receive the first power signal VDD and the second power signal VSS, respectively, and simultaneously input the first and second detection control signals VG1 and VG2. Each output signal, i.e., the light detection signal P_V and the device characteristic signal D_V, is outputted. Since the photodetection signal P_V and the device characteristic signal D_V simultaneously outputted are canceled at the input node P of the light amount detection correction unit GVM, only the difference current P_I remains.

The difference current P_I is input to the light quantity detection correcting unit GVM as the light quantity current signal P_I, and the light quantity detection correcting unit GVM is the light quantity current signal P_I according to the reference voltage source Vref input from the outside. The amount of current is corrected and output to the outside. The light quantity detection correcting unit GVM may include at least one operational amplifier AMP and a first capacitor C1 connected in parallel to an input terminal and an output terminal of the operational amplifier AMP.

As described above, the light amount detecting circuit according to the embodiment of the present invention includes a light sensor PS1 through which light is incident and a dark sensor PS2 through which light is blocked, so that the internal element of the light detection signal P_V Only the difference current value (P_V-D_V) minus the device characteristic signal D_V that varies according to the characteristic is used as the light quantity current signal P_I. The light sensor PS1 and the dark sensor PS2 have only a difference depending on whether light is incident or not, and are equally affected by the surrounding environment such as temperature or humidity. Therefore, since the difference value obtained by subtracting the element characteristic signals D_V which are equally influenced from the light detection signal P_V detected by the optical sensor PS1 is used as the light quantity detection current signal P_I, The reliability can be further improved.

2 is a block diagram showing a light amount detecting circuit according to another embodiment of the present invention. 3 is a waveform diagram illustrating control signals for driving the light amount detection circuit shown in FIG. 2.

The light amount detecting circuit shown in FIG. 2 detects and outputs a light detection signal P_V corresponding to the amount of light incident from the outside and an element characteristic signal D_V corresponding to the characteristic of the device provided therein. ); The self reset is performed according to the reset control signal Rst from the outside, and when the light detection signal P_V and the device characteristic signal D_V are respectively input from the detection sensor unit DS, each current is converted into a voltage. An I / V converter RS for outputting the same; And detecting a difference voltage between the light amount detection voltage PV_V and the device characteristic voltage DV_V converted into a voltage through the I / V conversion unit RS, and setting the level of the detected difference voltage by a user. A light quantity signal correcting section (GMS) for generating and outputting a light quantity signal (Lout) by correcting according to the value k is provided.

In addition, the light amount detection circuit of the present invention may further include an AC / DC converter ADC for converting the light amount signal Lout into a digital data value to generate light detection data L_Data as necessary.

The detection sensor unit DS may include an optical sensor configured to generate and output a light detection signal P_V corresponding to the amount of incident light according to the first power signal VDD and the first detection control signal VG1 from the outside. PS1 and the dark sensor PS2 which outputs an element characteristic signal D_V corresponding to a characteristic of an element provided in accordance with the second power signal VSS and the second detection control signal VG2 from the outside. Equipped.

Here, since the optical sensor PS1 is configured to receive light from the outside, the amount of current varies according to the inherent characteristics of the element constituting the optical sensor PS1 and the amount of incident light. However, the dark sensor PS2 is configured to not receive light from the outside so that the amount of current varies only according to the characteristics of its own element forming the dark sensor PS2. Here, the light sensor PS1 and the dark sensor PS2 may be configured of at least one NMOS transistor (NMOS TFT), respectively.

The optical sensor PS1 and the dark sensor PS2 configured as described above receive the first power signal VDD and the second power signal VSS, respectively, and simultaneously input the first and second detection control signals VG1 and VG2. In response to the output signal, i.e., the photodetection signal P_V and the device characteristic signal D_V, which are generated respectively, are supplied to the I / V converter RS.

The I / V converter RS converts a current of the photodetection signal P_V input from the optical sensor PS1 into a voltage using a reference voltage source Vref from the outside, and the first converter SAMP1. A second capacitor C2 connected in parallel to an input terminal and an output terminal of the first converter SAMP1 and a first capacitor SAMP1 connected in parallel to the input terminal and the output terminal of the first converter SAMP1 according to a reset control signal Rst from the outside. Is a first reset switching element T1 for resetting), and is configured to detect and output the light amount detection voltage PV_V output through the first converter SAMP1 in response to a third detection control signal VG3 from the outside. A second converter SAMP2 for converting a current of the device characteristic signal D_V input from the dark sensor PS2 into a voltage using the first detection switching device T3 and the reference voltage source Vref, and the second Second capacitor connected in parallel with the converter (SAMP2) input and output (C2), a second reset switching element T2 connected in parallel to the input terminal and the output terminal of the second converter SAMP2 to reset the second converter SAMP2 according to the reset control signal Rst, and the third The second detection switching device T4 detects and outputs the device characteristic voltage DV_V output through the second converter SAMP2 in response to the detection control signal VG3.

Referring to FIG. 3, the first and second reset switching devices T1 and T2 are turned on when the reset control signal Rst is input from the outside and are connected to the inputs of the first and second converters SAMP1 and SAMP2, respectively. Correct the current and voltage across the terminal and output terminal in the same way. The first and second reset switching elements T1 and T2 may include at least one NMOS transistor NMOT TFT.

When the photodetector signal P_V is input from the photo sensor PS1 by the first detection control signal VG1, the first converter SAMP1 receives the photodetection signal input using the reference voltage source Vref from the outside. The light amount detection voltage PV_V is generated by converting the current I of P_V into the voltage V. FIG. Since the light quantity detection voltage PV_V is simultaneously affected by the amount of light applied to the optical sensor PS1 and the external environment, the level is detected at every detection according to the amount of light applied to the optical sensor PS1 and its environmental elements. This can be changed. Here, the first converter SAMP1 may be implemented using at least one operational amplifier.

When the element characteristic signal D_V is input from the dark sensor PS2 according to the second detection control signal VG2 input in the same manner as the first detection control signal VG1, the second converter SAMP2 receives a reference from the outside. The device characteristic voltage DV_V is generated by converting the current I of the device characteristic signal D_V input to the voltage V using the voltage source Vref. The device characteristic voltage DV_V is only affected by external environmental factors applied to the dark sensor PS2, for example, temperature and humidity. Therefore, although the level may change at every detection depending on the environmental factors applied to the dark sensor PS2, the change width is smaller than the level change width of the light quantity detection voltage PV_V which is affected by the light quantity. Here, the second converter SAMP2 may be implemented using at least one operational amplifier like the first converter SAMP1.

The first detection switching device T3 is provided at an output terminal of the first converter SAMP1, and is turned on according to a third detection control signal VG3 to be output through the first converter SAMP1. (PV_V) is supplied to the light quantity signal correcting section (GMS).

Similarly, the second detection switching device T4 is provided at the output terminal of the second converter SAMP2, and is turned on according to the third detection control signal VG3 to be output through the second converter SAMP2. The characteristic voltage DV_V is supplied to the light quantity signal corrector GMS.

The light quantity signal correcting unit GMS may control the light quantity detection voltage PV_V, the second converter SAMP2, and the second detection switching element T4 input through the first converter SAMP1 and the first detection switching element T3. The differential low voltage of the device characteristic voltage DV_V input through the signal is detected. In detail, the light quantity signal corrector GMS receives the light quantity detection voltage PV_V and the device characteristic voltage DV_V simultaneously. Since the light amount detection voltage PV_V and the device characteristic voltage DV_V simultaneously inputted are canceled by the correction calculator GAMP included in the light amount signal correcting unit GMS, only the difference voltages (PV_V)-(DV_V) are provided. Will remain.

In addition, the correction calculator GAMP included in the light amount signal correcting unit GMS detects the difference voltage (PV_V)-(DV_V) between the light amount detection voltage PV_V and the device characteristic voltage DV_V. The light amount signal Lout is output by correcting the level of the difference voltages (PV_V)-(DV_V) detected according to the input gain value k. Here, the gain value k input from the outside may be a correction voltage value preset by the user. The correction voltage value is a preset value for compensating the deviations according to the process deviation of the light quantity detection circuit, the environmental deviation in which the light quantity detection circuit is configured, and the drive deviation of the light quantity detection circuits. In this case, the gain value k is used to correct the slope of the deviations, and thus may be preset to have a continuous value.

As described above, the light amount detection circuit according to another embodiment of the present invention includes an optical sensor PS1 to which light is incident and a dark sensor PS2 to block light, thereby providing an internal element at a light amount detection voltage PV_V. Only the difference voltage value (PV_V-DV_V) obtained by subtracting the device characteristic voltage DV_V that varies according to the characteristics of is used as the detection value of the light quantity signal Lout. The light sensor PS1 and the dark sensor PS2 have only a difference depending on whether light is incident or not, and are equally affected by the surrounding environment such as temperature or humidity. Therefore, the gain value k is obtained by using the difference value obtained by subtracting the device characteristic voltage DV_V that is equally influenced from the light quantity detection voltage PV_V detected by the optical sensor PS1 as the detection value of the light quantity signal Lout. In this way, the reliability of the light amount detection circuit can be further improved.

4 is a configuration diagram illustrating a liquid crystal display device including the light amount detection circuit illustrated in FIG. 1 or 2.

The liquid crystal display shown in FIG. 4 includes a liquid crystal panel 2 having a plurality of pixel regions; A data driver 4 driving the data lines DL1 to DLm of the liquid crystal panel 2; A gate driver 6 driving the gate lines GL1 to GLn of the liquid crystal panel 2; A light amount detection circuit 12 for generating and outputting a light amount signal Lout corresponding to the external brightness of the liquid crystal panel 2 with the above-described characteristics with reference to FIGS. 1 and 2; Generates data and gate control signals GCS and DCS to control the data and gate drivers 4 and 6 and to control a plurality of control signals VG1 to VG3 and Rst for controlling the light amount detection circuit 12. A timing controller 8 which generates and controls the light quantity detection circuit 12; A backlight 10 irradiating light onto the liquid crystal panel 2; And a backlight driver 14 for driving the backlight 10 according to the light amount signal Lout to adjust the luminance of light irradiated to the liquid crystal panel 2.

The liquid crystal panel 2 includes a thin film transistor (TFT) formed in each pixel area defined by a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm, and a liquid crystal capacitor connected to a TFT. (Clc). The liquid crystal capacitor Clc is composed of a pixel electrode connected to a TFT and a common electrode facing each other with the pixel electrode and the liquid crystal interposed therebetween. The TFT supplies the data signals from the respective data lines DL1 to DLm to the pixel electrodes in response to the scan pulses from the respective gate lines GL1 to GLn. The liquid crystal capacitor Clc charges the difference voltage between the data signal supplied to the pixel electrode and the common voltage supplied to the common electrode, and adjusts the light transmittance by varying the arrangement of liquid crystal molecules according to the difference voltage. The storage capacitor Cst is connected to the liquid crystal capacitor Clc in parallel so that the voltage charged in the liquid crystal capacitor Clc is maintained until the next data signal is supplied. The storage capacitor Cst is formed by overlapping the pixel electrode with the previous gate line and the insulating layer interposed therebetween. In contrast, the storage capacitor Cst is formed by overlapping the pixel electrode with the storage line and the insulating layer interposed therebetween.

The data driver 4 includes a data control signal DCS from the timing controller 8, for example, a source start pulse (SSP), a source shift clock (SSC), and a source output enable (SCS). The video data VData arranged from the timing controller 8 is modulated into an analog voltage, that is, a video signal using a source output enable (SOE) signal or the like. Specifically, the data driver 4 latches the image data VData input according to the SSC and then one horizontal line every one horizontal period in which scan pulses are supplied to the gate lines GL1 to GLn in response to the SOE signal. Minute video signal is supplied to each of the data lines DL1 to DLm. At this time, the data driver 4 selects a positive or negative gamma voltage having a predetermined level according to the gray value of the image data VData, and supplies the selected gamma voltage to each data line DL1 to DLm as an image signal. do.

The gate driver 6 includes a gate control signal GCS from the timing controller 8, for example, a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable (GSC). Scan pulses are sequentially generated in response to a GOE (Gate Output Enable) signal, and are sequentially supplied to the gate lines GL1 to GLn. In other words, the gate driver 6 shifts the GSP from the timing controller 8 according to GSC to sequentially supply scan pulses, for example, gate-on voltages, to the gate lines GL1 to GLn. The gate-off voltage is supplied to the gate lines GL1 to GLn during the period when the gate-on voltage is not supplied. Here, the gate driver 6 controls the pulse width of the scan pulse in accordance with the GOE signal.

The timing controller 8 arranges the image data RGB input from the outside to be suitable for driving the liquid crystal panel 2 and supplies the image data RGB to the data driver 4. The data driver 4 and the gate driver 6 are controlled by generating a gate control signal GCS and a data control signal DCS using the external synchronization signals DCLK, DE, Hsync, and Vsync. . In addition, a plurality of control signals for driving the light amount detection circuit 12 of the present invention included in the liquid crystal panel 2 of the timing controller 8, that is, the first to third detection control signals VG1 to VG3 and the reset are performed. The control signal Rst is generated and supplied to the light quantity detecting circuit 12.

The light amount detection circuit 12 has the same configuration as the light amount detection circuit according to the embodiments of the present invention described with reference to FIGS. 1 to 3. Accordingly, the detailed description of the light quantity detecting circuit 12 will be replaced with the above description.

The light quantity detecting circuit 12 is attached to the periphery of the liquid crystal panel 2 to generate a light quantity signal Lout corresponding to the external brightness of the liquid crystal panel 2, and thus, a plurality of driving circuits using the light quantity signal Lout. For example, it is supplied to the timing controller 8, the data driver 4, the backlight drive part 14, etc.

The light quantity detecting circuit 12 of the present invention is formed in the liquid crystal panel 2 together with the formation of the thin film transistor TFT of each liquid crystal cell, thereby generating a light quantity signal Lout corresponding to the external brightness of the liquid crystal panel 2. can do. In this case, the light amount detection circuit 12 illustrated in FIGS. 1 and 2 may be formed in the liquid crystal panel 2, or only the detection sensor unit DS may be formed in the liquid crystal panel 2.

The backlight driver 14 includes a backlight driving voltage generator for generating a backlight driving voltage VL for driving the backlight 10 according to the light quantity signal Lout from the light quantity detecting circuit 12.

The backlight 10 generates light according to the backlight driving voltage VL supplied from the backlight driver 14 and irradiates the liquid crystal panel 2. To this end, the backlight 10 includes at least one lamp that is turned on by the backlight driving voltage VL and generates light, or at least that emits light by emitting light by the backlight driving voltage VL. It consists of one light emitting diode.

As described above, the liquid crystal display according to the exemplary embodiment of the present invention drives the backlight 10 according to the external brightness of the liquid crystal panel 2 to adjust the luminance of the liquid crystal panel 2 to thereby consume power of the backlight 10. May be reduced.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a block diagram showing a light amount detection circuit according to an embodiment of the present invention.

2 is a block diagram showing a light amount detecting circuit according to another embodiment of the present invention.

FIG. 3 is a waveform diagram illustrating control signals for driving the light amount detection circuit shown in FIG.

FIG. 4 is a configuration diagram illustrating a liquid crystal display device having the light amount detection circuit shown in FIG. 1 or 2.

* Brief description of symbols for the main parts of the drawings *

2: liquid crystal panel 4: data driver

6: gate driver 8: timing controller

10: backlight 12: light amount detection circuit

14: backlight drive unit GVM: light amount detection correction unit

DS: Detection sensor part RS: I / V conversion part

GMS: Light quantity signal corrector

Claims (10)

An optical sensor for outputting a light detection signal corresponding to the amount of light incident according to the first power signal and the first detection control signal from the outside; A dark sensor connected in parallel with the optical sensor and outputting an element characteristic signal corresponding to a characteristic of an element provided in accordance with a second power signal and a second detection control signal from the outside; And Connected to the output terminals of the optical sensor and the dark sensor connected in parallel to detect a difference current between the light detection signal and the device characteristic signal as a light quantity current signal, and correct the detected light quantity current signal according to a reference voltage source from the outside. And a light quantity detection correction section for generating and outputting a light quantity signal. A detection sensor unit for detecting and outputting a light detection signal corresponding to an amount of light incident from the outside and an element characteristic signal corresponding to a characteristic of an element provided in itself; An I / V conversion unit for performing self reset according to a reset control signal from the outside and converting each current into a voltage when the photo detection signal and the device characteristic signal are respectively input from the detection sensor unit; And A light quantity signal is generated and output by detecting a difference voltage between a light quantity detection voltage and a device characteristic voltage converted into a voltage through the I / V converter, and correcting the detected level of the difference voltage according to a gain value set by a user. A light quantity detection circuit comprising a light quantity signal corrector. The method of claim 2, The detection sensor unit includes an optical sensor for generating and outputting a light detection signal corresponding to an amount of light incident according to the first power signal and the first detection control signal from the outside, and a second power signal and the second detection control signal from the outside. According to the device having a dark sensor for outputting a device characteristic signal corresponding to the characteristics of the device itself, The I / V converter is a first converter for converting the current of the light detection signal input from the optical sensor into a voltage using a reference voltage source from the outside, a second capacitor connected in parallel to the first converter input terminal and the output terminal, the second converter A first reset switching element connected in parallel with a first converter input terminal and an output terminal to reset the first converter according to a reset control signal from the outside, and an amount of light output through the first converter in response to a third detection control signal from the outside; A first detection switching element for detecting and outputting a detection voltage, a second converter for converting a current of an element characteristic signal input from the dark sensor into a voltage using the reference voltage source, and connected in parallel with the second converter input terminal and output terminal A second capacitor is connected in parallel with the second converter input terminal and the output terminal according to the reset control signal. A second reset switching element for resetting the second converter, a second detection switching element for detecting and outputting a device characteristic voltage output through the second converter in response to the third detection control signal; The light quantity signal correcting unit detects the difference voltage between the light quantity detection voltage and the device characteristic voltage, and then corrects the level of the difference voltage detected according to a gain value set by the user and outputs a light quantity signal. Light quantity detection circuit comprising a. The method of claim 3, wherein The gain value is The correction voltage value may be a preset correction voltage value from the user, and the correction voltage value is used to compensate for deviations of at least one of the process deviation of the light quantity detection circuits, the environmental deviation in which the light quantity detection circuits are configured, and the driving deviation of the light quantity detection circuits. The light quantity detecting circuit is set to have a continuous value since it is used to correct the slope of the deviations as a preset value. A liquid crystal panel having a plurality of pixel regions; A gate and data driver driving gate and data lines of the liquid crystal panel; A light quantity detecting circuit according to any one of claims 1 to 4, which generates and outputs a light quantity signal corresponding to an external brightness of the liquid crystal panel; And a timing controller for generating data and gate control signals to control the data and gate drivers, and generating a plurality of control signals for controlling the light quantity detection circuits to control the light quantity detection circuits. Positive display. Outputting a light detection signal corresponding to an amount of light incident according to a first power signal and a first detection control signal from the outside using an optical sensor; Outputting an element characteristic signal corresponding to a characteristic of an element provided in accordance with a second power signal and a second detection control signal from the outside by using a dark sensor connected in parallel with the optical sensor; And The output current of the optical sensor and the dark sensor connected in parallel detects the difference current between the light detection signal and the device characteristic signal as a light quantity current signal and corrects the detected light quantity current signal according to a reference voltage source from the outside to correct the light quantity signal. And generating and outputting the light quantity detecting circuit. Detecting and outputting a light detection signal corresponding to an amount of light incident from the outside and a device characteristic signal corresponding to a characteristic of a device provided by the detection sensor unit; Performing self reset according to a reset control signal from the outside using an I / V converter, and converting each current into a voltage when the photodetection signal and the device characteristic signal are respectively input; And And generating and outputting a light quantity signal by detecting a difference voltage between the light quantity detection voltage and the device characteristic voltage converted into the voltage and correcting the level of the detected difference voltage according to a gain value set by a user. A method of driving a light quantity detection circuit. The method of claim 7, wherein Generating the light detection signal and the device characteristic signal Generating and outputting the light detection signal corresponding to the amount of light incident according to the first power signal and the first detection control signal from the outside using an optical sensor; and a second power signal from the outside using the dark sensor And outputting the device characteristic signal corresponding to the property of the device itself provided according to the second detection control signal. The step of converting the current of the light detection signal and the device characteristic signal into a voltage may include converting a current of the light detection signal input from the optical sensor into a voltage according to a reference voltage source from the outside using a first converter. Resetting the first converter according to a reset control signal of the detector; detecting and outputting a light quantity detection voltage output through the first converter in response to a third detection control signal from an external device; Converting a current of an element characteristic signal input from the dark sensor into a voltage according to the reference voltage source, resetting the second converter according to the reset control signal, and in response to the third detection control signal; Detecting and outputting a device characteristic voltage output through the second converter, The outputting of the light quantity signal may include detecting a difference voltage between the light quantity detection voltage and the device characteristic voltage, and correcting the level of the difference voltage detected according to a gain value set and input by the user to output a light quantity signal. A driving method of a light quantity detection circuit comprising the step of. The method of claim 8, The gain value is The correction voltage value may be a preset correction voltage value from the user, and the correction voltage value is used to compensate for deviations of at least one of the process deviation of the light quantity detection circuits, the environmental deviation in which the light quantity detection circuits are configured, and the driving deviation of the light quantity detection circuits. A method of driving a light quantity detection circuit, characterized in that it is preset to have a continuous value because it is used to correct the slope of the deviations as a preset value. A method of driving a liquid crystal display device having a liquid crystal panel having a plurality of pixel regions and a gate and data driver for driving gate and data lines of the liquid crystal panel, Displaying an image by adjusting the transmittance of light; And A driving method of a liquid crystal display device comprising the driving method of any one of claims 6 to 9 to generate and output a light quantity signal corresponding to an external brightness of the liquid crystal panel.

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