KR101972489B1 - Stereoscopic image display and gamma compensation method thereof - Google Patents

Abstract

The present invention relates to a stereoscopic image display apparatus and a gamma correction method thereof, and more particularly, to a stereoscopic image display apparatus and a gamma correction method therefor. More particularly, the present invention relates to a stereoscopic image display apparatus and a gamma correction method, Modulated data and second modulated data for modulating a maximum gradation of the current frame data when the gradation of the previous frame data is the minimum gradation and the gradation of the current frame data is the maximum gradation. The brightness when the first modulated data is displayed on the pixels of the liquid crystal display panel and the brightness when the second modulated data is displayed on the pixels of the liquid crystal display panel are substantially the same, And is displayed every set frame period.

Description

TECHNICAL FIELD [0001] The present invention relates to a stereoscopic image display apparatus and a gamma correction method,

The present invention relates to a stereoscopic image display apparatus and a gamma correction method thereof.

Liquid crystal displays are rapidly replacing the existing CRT (cathode ray tube) market due to advantages such as light weight, thinness, low power driving and recent progress of process technology and circuit technology. The liquid crystal display displays an image by adjusting the phase delay value of the liquid crystal layer according to the data voltage applied to the liquid crystal layer.

2. Description of the Related Art In recent years, a demand for a stereoscopic image display device using a liquid crystal display device is increasing rapidly. Such a stereoscopic image display device can implement a 2D image in a 2D mode and a stereoscopic image in a 3D mode. However, when a display panel in which the gamma characteristic is optimized to 2.2 gamma on the basis of the 2D mode is driven in the 3D mode, distortion of the gamma curve occurs, and image quality deteriorates when the stereoscopic image is displayed. In a conventional display panel, a gamma curve is set in a static state in which the same gradation is continued. On the other hand, in the stereoscopic image, since the left eye image and the right eye image are alternated every frame in order to realize the binocular parallax, the gradation of data is very changed, and the liquid crystal does not respond quickly to such a gradation change, . This will be described by way of example in Fig.

FIG. 1 shows a change in brightness of a pixel when the gray level of stereoscopic image data applied to the same pixel is changed to 0, 255, 100, and 255 in a four-frame period in a stereoscopic image display device using a liquid crystal display device.

Referring to FIG. 1, the left eye image data is written to the pixel at gradation '0' for the Nth (N is a natural number) frame period, and the right eye image data is written to the pixel at the gradation '255' for the (N + 1) . Then, the left eye image data is written to the pixel with gradation '100' for the (N + 2) -th frame period and the right eye image data is written to the pixel with the gradation '255' for the (N + 3) -th frame period. When a data voltage changing from gradation '0' to gradation '255' is applied to the pixel, the luminance of the pixel arriving within the (N + 1) -th frame period due to the liquid crystal response delay of the pixel is shifted to the gradation '253' And is recognized as a corresponding luminance. On the other hand, if a data voltage changing from the gradation '100' to the gradation '255' is applied to the pixel, the luminance of the pixel arriving in the (N + 3) -th frame period due to the liquid crystal response delay of the pixel corresponds to the gradation '255' The target brightness can be recognized. Therefore, when the luminance of the pixel arriving within the (N + 1) -th frame period changes from the gradation '0' to the gradation '255' and the luminance of the pixel arriving within the The luminance of the pixel is different by? L and it may cause flicker in severe cases. Because of the gray-to-gray distortion between the left eye image and the right eye image as shown in FIG. 1, the viewer can feel a 3D crosstalk in which the left eye image and the right eye image overlap each other.

The present invention provides a stereoscopic image display device and a gamma correction method thereof that can optimize the gamma characteristic of the stereoscopic image to the same level as the 2D image and improve the image quality of the stereoscopic image.

A stereoscopic image display apparatus includes: a liquid crystal display panel for displaying left-eye image data and right-eye image data in a time-division manner; A gamma correcting unit for modifying the left eye image data and the right eye image data; A data driving circuit for converting data modulated by the gamma correction unit into data voltages and supplying the data voltages to the data lines of the liquid crystal display panel; A gate driving circuit sequentially supplying a gate pulse synchronized with the data voltage to the gate lines of the liquid crystal display panel; And a timing controller for inputting the input image data to the gamma correction unit and transmitting the data modulated by the gamma correction unit to the data driving circuit for every predetermined frame period and controlling the operation timing of the data driving circuit and the gate driving circuit Controller.

Wherein the lookup table of the gamma correction unit includes a first modulation data setting unit for modulating the current frame data when the gray level value of the previous frame data is the same as the gray level value of the current frame data, A second modulation data setting section for modulating the current frame data when the gray level value of the data is lower than the gray level value of the previous frame data and a second modulation data setting section for modulating the current frame data when the gray level value of the current frame data is higher than the gray level value of the previous frame data And a third modulated data setting unit.

The first modulation data setting unit includes first modulation data for modulating the maximum gradation of the current frame data to a low level when the gradation of the previous frame data is the maximum gradation and the gradation of the current frame data is the maximum gradation. And the third modulated data setting unit includes second modulated data for modulating a maximum gradation of the current frame data when the gradation of the previous frame data is the minimum gradation and the gradation of the current frame data is the maximum gradation.

The brightness when the first modulated data is displayed on the pixels of the liquid crystal display panel and the brightness when the second modulated data is displayed on the pixels of the liquid crystal display panel are substantially the same.

A left eye filter that transmits only the light of the left eye image displayed on the liquid crystal display panel and a right eye filter that transmits only the light of the right eye image displayed on the liquid crystal display panel.

Wherein the stereoscopic image display device comprises: an active retarder adhered to a display surface of the liquid crystal display panel to convert light of the left eye image and light of the right eye image into different polarized lights; And a polarizing glasses having a left eye filter for transmitting only polarized light of the left eye image and a right eye filter for transmitting only polarized light of the right eye image.

Wherein the stereoscopic image display apparatus inputs input image data to the gamma correction unit, transmits data modulated by the gamma correction unit to the data drive circuit, and controls an operation timing of the data drive circuit and the gate drive circuit And a timing controller.

The timing controller transmits data modulated by the gamma correction unit to the data driving circuit every frame period.

The timing controller transmits data modulated by the gamma correction unit to the data driving circuit only during a frame period in which the left eye image and the right eye image alternate.

The gamma correction method of the stereoscopic image display apparatus modulates the current frame data with the modulation data preset in the first modulation data setting unit of the gamma correction unit when the gray level value of the previous frame data is equal to the gray level value of the current frame data Modulating; Modulating the current frame data with the modulation data preset in the second modulation data setting unit of the gamma correction unit when the gray level value of the current frame data is lower than the gray level value of the previous frame data; Modulating the current frame data with the modulation data preset in the second modulation data setting unit of the gamma correction unit when the gray level value of the current frame data is higher than the gray level value of the previous frame data; And displaying the data modulated by the gamma correction unit on the liquid crystal display panel every predetermined frame period.

The present invention relates to a stereoscopic image display apparatus for displaying a left-eye image and a right-eye image in a time-division manner, the method comprising the steps of modulating a left eye image and a right eye image data with gray level values satisfying a 2.2 gamma curve, Level. ≪ / RTI > As a result, the present invention can improve stereoscopic image quality by preventing flicker and 3D crosstalk in the 3D mode.

FIG. 1 is a diagram illustrating an example in which gradation change distortion occurs in a conventional stereoscopic image display apparatus.
2 is a block diagram illustrating a stereoscopic image display apparatus according to an exemplary embodiment of the present invention.
FIG. 3 is a detailed block diagram of the 3D gamma correction lookup table of the gamma correction unit shown in FIG. 2. Referring to FIG.
4 is a diagram illustrating an example of a gamma correction method according to the present invention.
5 is a timing chart showing stereoscopic image data driven at a frame frequency of 120 Hz.
6 is a timing chart showing stereoscopic image data driven at a frame frequency of 240 Hz.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The present invention is applied to a stereoscopic image display device having any structure in which a left eye image and a right eye image are displayed in a time division manner in a 3D mode. For example, the stereoscopic image display apparatus of the present invention may include a display panel for displaying the left eye image and the right eye image in a time-division manner, and a shutter eyeglass alternately opening the left eye image and the right eye image so as to be synchronized with the left eye image and the right eye image have. In addition, the stereoscopic image display apparatus of the present invention is a display panel in which a left eye image and a right eye image are displayed in a time-division manner, an active retarder that is attached to the display panel and converts polarization characteristics of the left eye image and the right eye image differently through an electric control method (Active retarder), and polarizing glasses for passing the polarized light of the left eye image passing through the active retarder to the left eye filter and passing the polarized light of the right eye image to the right eye filter. The display panel of the present invention can be implemented as a display panel of a liquid crystal display device.

2 is a block diagram illustrating a stereoscopic image display apparatus according to an exemplary embodiment of the present invention.

2, the stereoscopic image display apparatus of the present invention includes a liquid crystal display panel 200, a data formatter 112, a gamma correction unit 100, a timing controller 101, a data driving circuit 102, (103) and the like.

In the liquid crystal display panel 200, a liquid crystal layer is formed between two glass substrates. The liquid crystal display panel 200 includes liquid crystal cells (or pixels) arranged in a matrix form by an intersection structure of the data lines 105 and the gate lines 106. On the lower glass substrate of the liquid crystal display panel 200, a TFT array is formed. The TFT array includes TFTs (Thin Film Transistors) formed at intersections of data lines 105, gate lines 106, data lines 105 and gate lines 106, pixel electrodes , A storage capacitor (Cst), and the like. The liquid crystal is driven by an electric field between the pixel electrodes and the common electrode. A color filter array is formed on the upper glass substrate of the liquid crystal display panel 200. The color filter array includes a black matrix, a color filter, a common electrode, and the like. An alignment film is formed on each of the upper glass substrate and the lower glass substrate to attach a polarizing film and to set a pre-tilt angle of the liquid crystal. The common electrode is formed on the upper glass substrate in a vertical electric field driving method such as a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode, and a horizontal electric field such as IPS (In Plane Switching) mode and FFS (Fringe Field Switching) It can be formed on the lower glass substrate together with the pixel electrode in the driving method. A column spacer for maintaining a cell gap of the liquid crystal layer may be formed between the glass substrates.

The liquid crystal display panel 200 may be implemented in any liquid crystal mode as well as a TN mode, a VA mode, an IPS mode, and an FFS mode. The liquid crystal display device can be implemented in any form such as a transmissive liquid crystal display device, a transflective liquid crystal display device, and a reflective liquid crystal display device. In the transmissive liquid crystal display device and the transflective liquid crystal display device, the backlight unit 210 and the backlight driving circuit 211 are required. The backlight unit 210 may be implemented as a direct type backlight unit or an edge type backlight unit. The backlight driving circuit 211 adjusts the light source brightness, the duty ratio, etc. of the backlight unit 210 in response to the dimming signal DIM input from the timing controller 101.

The data formatter 112 may be embedded in the timing controller 101. The data formatter 112 separates the stereoscopic image data input from the host system 110 in the 3D mode into left eye image data LEFT and right eye image data RIGHT as shown in FIG. And outputs the stereoscopic image data in the frequency format. 6, the data formatter 112 converts the stereoscopic image data input from the host system 110 in the 3D mode into first left eye image data L1, second left eye image data L2, (Or 200 Hz) frame frequency format separated by the first right eye image data R1 and the second right eye image data R2. The data formatter 112 separates the 2D image data input from the host system 110 into left / right eye image data reflecting depth information using the 2D-3D conversion module to generate stereoscopic image data, The stereoscopic image data can be converted into stereoscopic image data in a 120 Hz (or 100 Hz) frame frequency format or a 240 Hz (or 200 Hz) frame frequency format. The data formatter 112 may multiply the frame frequency of the input image by two or four times to transmit the left eye image and the right eye image data to the timing controller 101. [ When the input frame frequency is 50 Hz, the data formatter 112 can transmit the stereoscopic image data to the timing controller 101 at a frame frequency of 100 Hz by multiplying the frame frequency by 2, and multiply the frame frequency by 4 times The stereoscopic image data can be transmitted at a frame frequency of 200 Hz. When the input frame frequency is 60 Hz, the data formatter 112 can transmit the stereoscopic image data to the timing controller 101 at a frame frequency of 120 Hz by multiplying the frame frequency by twice, and multiply the frame frequency by 4 times The stereoscopic image data can be transmitted at a frame frequency of 240 Hz. Here, the input frame frequency is 50 Hz in the PAL (Phase Alternate Line) method and 60 Hz in the NTSC (National Television Standards Committee) method.

The data formatter 112 inserts one or two frame data between the n-th frame data and the (n + 1) -th frame data of the 2D image data using a data frame interpolation method such as MEMC (Motion Estimation Motion Compensation) do. Accordingly, the data formatter 112 can transmit the 2D input image data to the timing controller 101 at a frame frequency multiplied by 2 or 4 times the input frame frequency in the 2D mode.

The gamma correction unit 100 includes a lookup table for 2D gamma correction for modulating 2D image data in the 2D mode and a lookup table for 3D gamma correction for modulating the stereoscopic image data in the 3D mode. The gamma correction unit 100 modulates the data inputted from the timing controller 101 into preset lookup table data and supplies the modulated data to the timing control unit 101. [ The look-up table for 2D gamma correction is substantially the same as the conventional one, and a detailed description thereof will be omitted. In the look-up table for 3D gamma correction, the modulation data (FIG. 3) set to the gradation conversion value of the luminance satisfying the 2.2 gamma curve is stored through the luminance measurement result according to the gradation change of the left eye image and the right eye image. The gamma correction unit 100 may be incorporated in the timing controller 101. [

The timing controller 101 supplies the digital video data RGB of the 2D image input from the data formatter 112 in the 2D mode to a 2D gamma correction lookup table (not shown) of the gamma correction unit 100, And transmits the 2D image data modulated by the lookup table for gamma correction to the data driving circuit 102. The timing controller 101 supplies the left / right eye image data input from the data formatter 112 in the 3D mode to a lookup table for 3D gamma correction as shown in FIG. 3, and outputs the left / right eye image data, which is hyperdriven modulated from the 3D gamma correction lookup table And transmits the video data to the data driving circuit 102. When the data modulated by the gamma correction unit 100 includes a decimal value of less than 1 as shown in FIG. 3, the timing controller 101 controls the timing controller 101 so as to express a fine gradation value of 0.25, 0.5, 0.75, The fine gradation value is dispersed temporally and spatially in the pixels of the liquid crystal display panel 200 by a frame rate control method using a dither pattern.

When the stereoscopic image data of the 120 Hz (or 100 Hz) frame frequency format as shown in FIG. 5 is inputted from the data formatter 112 in the 3D mode, the timing controller 101 alternates the left eye image and the right eye image every frame, And transmits the data modulated by the 3D gamma correction lookup table of the gamma correction unit 100 to the data driving circuit 102. [ On the other hand, when the stereoscopic image data of the 240 Hz (or 200 Hz) frame frequency format as shown in FIG. 6 is input from the data formatter 112 in the 3D mode, the timing controller 101 outputs the stereoscopic image data, The data modulated by the 3D gamma correction lookup table of the gamma correction unit 100 is transmitted to the data driving circuit 102 only during the (N + 1) th and (N + 2) do. When the stereoscopic image data of the 240 Hz (or 200 Hz) frame frequency format as shown in FIG. 6 is input from the data formatter 112 in the 3D mode, the timing controller 101 outputs the stereoscopic image data of the same left eye image (or right eye image) To the data driving circuit 102 without modulating the data input from the data formatter 112 during the second frame period (the (N + 1) th frame period, the (N + 3)

The timing controller 101 receives a timing signal such as a vertical synchronizing signal, a horizontal synchronizing signal, a data enable signal and a dot clock input from the host system 110 through the data formatter 112 and supplies the timing signal to the data driving circuit 102 And generates control signals for controlling the operation timing of the gate driving circuit 103. The control signals include a gate timing control signal for controlling the operation timing of the gate drive circuit 103, a data timing control signal for controlling the operation timing of the data drive circuit 102 and the polarity of the data voltage. The gate timing control signal includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), and the like. The gate start pulse GSP is applied to a gate drive IC (Integrated Circuit) generating a first gate pulse to control the gate drive IC so that a first gate pulse is generated. The gate shift clock GSC is a clock signal commonly input to the gate drive ICs, and is a clock signal for shifting the gate start pulse GSP. The gate output enable signal GOE controls the output of the gate drive ICs. The data timing control signal includes a source start pulse (SSP), a source sampling clock (SSC), a polarity control signal (POL), and a source output enable signal (SOE) . The source start pulse SSP controls the data sampling start timing of the data driving circuit. The source sampling clock SSC is a clock signal for controlling the sampling timing of data in the data driving circuit 102 on the basis of the rising or falling edge. The polarity control signal POL controls the polarity of the data voltage output from the data driving circuit 102. [ The source output enable signal SOE controls the output timing of the data driving circuit 102. The source start pulse SSP and the source sampling clock SSC may be omitted if the digital video data to be input to the data driving circuit 102 is transmitted in the mini LVDS (Low Voltage Differential Signaling) interface standard.

The timing controller 101 analyzes the input image and generates a dimming signal (DIM) for global / local dimming based on the analysis result to control the backlight driving circuit 211. The timing controller 101 generates a mode signal (not shown) input from the host system 110 through the data formatter 112 or a data signal supplied from the data driving circuit 102, The 2D mode and the 3D mode operation of the driving circuit 103 and the backlight driving circuit 211 can be switched.

The data driving circuit 102 latches the 2D / 3D digital video data (RGB) under the control of the timing controller 101. The data driving circuit 102 converts the latched data into a positive / negative gamma compensation voltage and outputs it to the data lines 105. The gate driving circuit 103 sequentially supplies gate pulses to the gate lines 106 in response to gate timing control signals.

The host system 110 includes an external video source 300 such as a set-top box, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system (Home Theater Sytem). The host system 110 may include a system on chip (SoC) including a scaler and may include 2D / 3D suitable for displaying graphic data from an external video source 300 on the liquid crystal display panel 200. [ Converts it into a video data format, and transmits it to the data formatter 112.

The host system 110 transmits the 2D / 3D image data and the timing signals Vsync, Hsync, DE, and CLK to a timing controller (not shown) through an interface such as a Low Voltage Differential Signaling (LVDS) interface or a Transition Minimized Differential Signaling 101). The host system 110 supplies the 2D image in the 2D mode to the timing controller 101 while supplying the left / right eye image data or 2D image data of the 3D image to the data formatter 112 in the 3D mode.

The host system 110 switches the 2D mode operation and the 3D mode operation in response to the user data input through the user input device 111. [ The user input device 111 includes a keypad, a keyboard, a mouse, an on screen display (OSD), a remote controller, a touch screen, and the like. The user can select the 2D mode and the 3D mode through the user input device 111, and select the 2D-3D image conversion in the 3D mode.

The host system 110 may switch the operation of the 2D mode and the operation of the 3D mode through the 2D / 3D identification code encoded in the data of the input image. In addition, the host system 110 may generate a mode signal that can identify whether the current drive mode is the 2D mode or the 3D mode, and may transmit the mode signal to the data formatter 112.

Host system 110 then transmits the shutter control signal from the shutter control signal transmission unit 120, in order to open and close alternately the left eye filter (ST _L) and right-eye filter (ST _R) of the shutter glasses 130 from the 3D mode . The shutter control signal transmitting unit 120 transmits a shutter control signal to the shutter control signal receiving unit 121 via the wired / wireless interface. The shutter control signal receiving unit 121 may be built in the shutter glasses 130 or may be manufactured as a separate module and attached to the shutter glasses 130.

The shutter glasses 130 include an electronically controlled left eye filter ST _L and a right eye filter ST _R. Each of the left eye filter ST _L and the right eye filter ST _R includes a first transparent substrate, a first transparent electrode formed on the first transparent substrate, a second transparent substrate, a second transparent electrode formed on the second transparent substrate, And a liquid crystal layer sandwiched between the first transparent substrate and the second transparent substrate. A reference voltage is supplied to the first transparent electrode and an ON / OFF voltage is supplied to the second transparent electrode. Each of the left eye filter ST _L and the right eye filter ST _R transmits the light from the liquid crystal display panel 200 when the ON voltage is supplied to the second transparent electrode while the OFF voltage is supplied to the second transparent electrode The light from the liquid crystal display panel 200 is blocked.

Shutter control signal reception section 121 is opened and closed by the organic / receiving a shutter control signal over the air interface, and the left eye filter (ST _L) and right-eye filter (ST _R) of the shutter glasses 130 in accordance with a shutter control signal alternately . The left eye filter _(L ST) is opened in synchronization with left-eye image displayed on the liquid crystal display panel 200, the right eye filter (ST _R) is opened in synchronization with the right-eye image displayed on the liquid crystal display panel 200. Shutter control signal is the second of the first when the logical value to be inputted to the shutter control signal receiving section 121, whereas the ON voltage is applied to the second transparent electrode of the left eye filter (ST _L), right-eye filter (ST _R) OFF voltage is supplied to the transparent electrode. When the shutter control signal is input to the shutter control signal reception section 121 in the second logic value, whereas the second is OFF, the voltage supplied to the second transparent electrode of the left eye filter (ST _L), the second right-eye filter (ST _R) ON voltage is supplied to the transparent electrode. Thus, the left eye filter (ST _L) of the shutter glasses 130, the shutter control signal is the second logical right-eye filter (ST _R), the shutter control signal of the opened when generating a first logic value, the shutter glasses 130 Value. ≪ / RTI >

As another embodiment of the present invention, the active retarder may be attached to the display surface of the liquid crystal display panel 200, and the shutter glasses 130 may be replaced with polarizing glasses.

The inventor of the present application measured the luminance value measured from the liquid crystal display panel while changing the gradation in the previous frame period and the current frame period and measured the gradation of the input image so that the luminance value change measured at each gradation change satisfies the 2.2 gamma curve And converts the brightness measurement value satisfying the 2.2 gamma curve into a gray level value to set modulation data satisfying the 2.2 gamma curve in all gray level changes and outputs the modulation data to the 3D gamma correction lookup table shown in FIG. Respectively.

FIG. 3 is a detailed block diagram of the gamma correction look-up table of FIG. 1 for 3D gamma correction.

Referring to FIG. 3, the 3D gamma correction lookup table receives previous frame data (Previous Data) and current frame data (Current Data) as input addresses, and outputs modulated data previously stored in the input addresses.

The lookup table for 3D gamma correction includes a first modulation data setting unit 30, a second data setting unit 31, and a third data setting unit 31 in which preset modulation data is stored through an experiment to realize a 2.2 gamma characteristic in a stereoscopic image. (32).

The first modulation data setting unit 30 is allocated to the diagonal area in the memory area of the 3D gamma correction lookup table. The first modulation data setting unit 30 registers the modulation data for modulating the current frame data to a tone value lower than the maximum tone value when the tone value of the previous frame data is the same as the tone value of the current frame data. Here, the maximum gradation depends on the color depth of the input image data or the number of bits. When the pixel data of the input image is 8 bits, the maximum gradation is 2 ⁸ (= 255).

In the first modulation data setting unit 30, the modulation data '0' at the position where the gradation of the previous frame data is the highest gradation '255' and the gradation of the current frame data is the lowest gradation '255' 233.25 'indicates that the modulation data set in the third modulation data setting unit 32 is a modulation signal indicating that the gradation of the previous frame data is the minimum gradation' 0 'and the gradation of the current frame data is the intersection of the low gradation' 255 ' Data '255' are values obtained by converting the luminance measured at the same luminance value into the gray value through the above-described experiment. In the first modulation data setting unit 30, the column data having the gradation of '255' of the previous frame data and the data other than the modulated data '233.25' listed at the intersection of the row line having the gradation of '255' Other modulation data are grayscale conversion values of luminance satisfying the 2.2 gamma curve.

The second modulation data setting unit 31 is a memory area allocated above the first modulation data setting unit 30. [ The second modulation data setting unit 31 registers the modulation data for modulating the current frame data to a tone value or less of the current frame data when the tone value of the current frame data is lower than the tone value of the previous frame data. The modulation data of the second modulation data setting section 31 is set to the gray level values satisfying the 2.2 gamma curve based on the modulation data of the first modulation data setting section 30. [

The third modulation data setting unit 32 is a memory area allocated to the lower side of the first modulation data setting unit 30. [ The third modulation data setting unit 32 sets the modulation data for modulating the current frame data to a gray level value that is higher than or lower than the gray level value of the current frame data when the gray level value of the current frame data is higher than the gray level value of the previous frame data The data are listed. The modulation data of the third modulation data setting section 32 is set to the gray level values satisfying the 2.2 gamma curve based on the modulation data of the first modulation data setting section 31. [

In the look-up table for 3D gamma correction, the modulation data registered in the same row line, that is, the modulation data 33 whose previous frame data changes from 0 to 255 and the current frame data has the same gray level, Tone conversion value.

On the other hand, the look-up table for 3D gamma correction is not limited to Fig. For example, according to the panel characteristics of the liquid crystal display panel 200, the modulation data of the look-up table for 3D gamma correction may be set to a different value.

4 is a diagram illustrating an example of a gamma correction method according to the present invention.

4, the present invention modulates the data of the left eye image and the right eye image of the stereoscopic image using the modulation data as shown in FIG. 3 to determine the luminance when the gray level changes from 0 to 255 and the luminance when the gray level changes from 0 to 255 Can be made the same.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the present invention should not be limited to the details described in the detailed description, but should be defined by the claims.

100: gamma correction unit 101: timing controller
102: Data driving circuit 103: Gate driving circuit
110: host system 112: data formatter
130: Shutter glasses

Claims (9)

A liquid crystal display panel for time-divisionally displaying left eye image data and right eye image data;
A gamma correcting unit for modifying the left eye image data and the right eye image data;
A data driving circuit for converting data modulated by the gamma correction unit into data voltages and supplying the data voltages to the data lines of the liquid crystal display panel;
A gate driving circuit sequentially supplying a gate pulse synchronized with the data voltage to the gate lines of the liquid crystal display panel; And
A timing controller for inputting the input image data to the gamma correction unit and transmitting the data modulated by the gamma correction unit to the data driving circuit for every predetermined frame period and controlling the operation timing of the data driving circuit and the gate driving circuit, Lt; / RTI >
Wherein the lookup table of the gamma correction unit includes a first modulation data setting unit for modulating the current frame data when the gray level value of the previous frame data is equal to the gray level value of the current frame data, A second modulation data setting unit configured to modulate the current frame data when the gray level value of the frame data is lower than the gray level value of the previous frame data and to output the current frame data when the gray level value of the current frame data is higher than the gray level value of the previous frame data Wherein the first modulation data setting section modifies the maximum gradation of the current frame data to a low level when the gradation of the previous frame data is the maximum gradation and the gradation of the current frame data is the maximum gradation Wherein the first modulated data comprises first modulated data, Wherein the first modulation data includes second modulation data for modulating a maximum gradation of the current frame data when the gradation of the previous frame data is the minimum gradation and the gradation of the current frame data is the maximum gradation, Wherein the brightness when the first modulated data is displayed on the pixels of the display panel and the brightness when the second modulated data is displayed on the pixels of the liquid crystal display panel are substantially the same.
The method according to claim 1,
Further comprising: a left eye filter that transmits only the light of the left eye image displayed on the liquid crystal display panel; and a right eye filter that transmits only light of the right eye image displayed on the liquid crystal display panel. . The method according to claim 1,
An active retarder adhered to a display surface of the liquid crystal display panel to convert light of the left eye image and light of the right eye image into different polarized lights; And
Further comprising: a left eye filter that transmits only the polarized light of the left eye image; and a right eye filter that transmits only the polarized light of the right eye image. delete The method according to claim 1,
The timing controller includes:
And transmits the data modulated by the gamma correction unit to the data driving circuit every frame period. The method according to claim 1,
The timing controller includes:
And transmits the data modulated by the gamma correction unit to the data driving circuit only during a frame period in which the left eye image and the right eye image alternate. A gamma correction method of a stereoscopic image display apparatus including a liquid crystal display panel for displaying left-eye image data and right-eye image data in a time-division manner, and a gamma correction unit for modulating the left-
Modulating the current frame data with the modulation data preset in the first modulation data setting unit of the gamma correction unit when the gray level value of the previous frame data is the same as the gray level value of the current frame data;
Modulating the current frame data with the modulation data preset in the second modulation data setting unit of the gamma correction unit when the gray level value of the current frame data is lower than the gray level value of the previous frame data;
Modulating the current frame data with the modulation data preset in the third modulation data setting unit of the gamma correction unit when the gray level value of the current frame data is higher than the gray level value of the previous frame data; And
And displaying data modulated by the gamma correction section on the liquid crystal display panel every predetermined frame period,
Wherein the first modulation data setting unit includes first modulation data for modulating the maximum gradation of the current frame data to a low level when the gradation of the previous frame data is the maximum gradation and the gradation of the current frame data is the maximum gradation,
Wherein the third modulation data setting unit includes second modulation data for modulating a maximum gradation of the current frame data when the gradation of the previous frame data is the minimum gradation and the gradation of the current frame data is the maximum gradation,
Wherein the brightness when the first modulated data is displayed on the pixels of the liquid crystal display panel and the brightness when the second modulated data is displayed on the pixels of the liquid crystal display panel are substantially the same, / RTI > 8. The method of claim 7,
Wherein the step of displaying the data modulated by the gamma correction unit on the liquid crystal display panel every predetermined frame period comprises:
And displaying the modulated data on the liquid crystal display panel in every frame period. ≪ Desc / Clms Page number 19 >
8. The method of claim 7,
Wherein the step of displaying the data modulated by the gamma correction unit on the liquid crystal display panel every predetermined frame period comprises:
And displaying the modulated data on the liquid crystal display panel only in a frame period in which the left eye image and the right eye image alternate.

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