CN1707318A - Liquid crystal display device and driving method thereof - Google Patents

Abstract

The invention discloses a liquid crystal display device, which comprises: a liquid crystal panel, having a plurality of gate lines and a plurality of data lines respectively arranged in rows and columns and intersecting each other, connected to the plurality of gate lines and a plurality of data lines A plurality of control elements, and a plurality of pixels connected to the plurality of control elements; a gate driver, used to provide gate signals to the gate lines; a timing controller, used to receive external image signals and form different gamma The first data signal and the second data signal of the Ma constant; and the data driver, which is used to respectively provide the grayscale voltage corresponding to the first data and the second data signal generated by the timing controller to the pixels having a plurality of pixels through the data lines. A first pixel group having a plurality of pixels and a second pixel group having a plurality of pixels.

Description

Liquid crystal display device and driving method thereof

This application claims priority from Korean Patent Applications No. 10-2004-0042302 and No. 10-2005-0033249 filed on June 9, 2004 and April 21, 2005, respectively, the disclosures of which are incorporated herein by reference .

technical field

The present invention relates to a liquid crystal display device (LCD) and a driving method thereof, and more particularly, to a liquid crystal display device and a driving method thereof with improved visibility in which gamma characteristics are reduced when viewed from the front and side difference.

Background technique

The demand for large-screen TVs has promoted the development of flat panel display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), or organic electroluminescent display devices (OELD) to replace common cathode ray tubes (CRT) . In particular, small and light liquid crystal display devices are attracting attention.

The LCD includes an upper panel with common electrodes and color filters and a lower panel with thin film transistors and pixel electrodes. A liquid crystal substance having dielectric anisotropy is injected between the upper panel and the lower panel. The transmission of light through the panel is controlled by varying the strength of the electric field provided to the upper and lower bases, thereby controlling the orientation of the liquid crystal display material and displaying a desired image.

Thin film transistor liquid crystal display (TFT LCD) using thin film transistors as switching elements is a mainstream technology in the LCD industry.

In a vertical alignment (VA) mode LCD, in which the longer axes of liquid crystal (LC) molecules are vertically aligned with the upper and lower panels or substrates in a state where no electric field is applied, and since the vertical alignment (VA) mode LCD has a relatively The high contrast ratio and wide viewing angle have attracted much attention. As shown in Figure 1, VA mode LCDs have different gamma characteristics between frontal viewing and side viewing. Front view and side view correspond to on-axis gamma properties and off-axis (upward, rightward or diagonal) gamma properties. In VA mode LCDs, these characteristics are different from each other, which causes poor side visibility. In order to improve side visibility, a plurality of sub-pixels are formed in each pixel, and a coupling capacitor is formed between the plurality of sub-pixels to apply a gray-scale voltage to one sub-pixel and apply a gray-scale voltage to the other sub-pixels. The method is called half-tone gray method (half-tone gray).

The VA mode LCD includes an independent liquid crystal panel with a plurality of pixels, and each pixel has a plurality of sub-pixels, which inevitably reduces the aspect ratio and causes a decrease in the overall brightness of the liquid crystal panel. In particular, when a liquid crystal panel is formed of an organic insulating layer, it is impossible to form a coupling capacitor having a large capacitance, and this makes it difficult to improve visibility.

Contents of the invention

It is an object of the present invention to provide a liquid crystal display that can effectively improve visibility by minimizing the difference in gamma characteristics between the front and side surfaces without forming a plurality of auxiliary pixels for each pixel.

Another object of the present invention is to provide a driving method for the above-mentioned liquid crystal display.

According to an embodiment of the present invention, a liquid crystal display device (LCD) includes: a liquid crystal panel having a plurality of gate lines and a plurality of data lines respectively arranged in rows and columns and intersecting each other. The liquid crystal panel also includes a plurality of control elements connected to the plurality of gate lines and the plurality of data lines, and a plurality of pixels connected to the plurality of control elements. The LCD also includes a gate driver, which is used to provide a gate signal to the gate line; a timing controller, which is used to receive an external image signal and provide a first data signal and a second data signal with different gamma constants; and a data signal The driver is used for providing the grayscale voltage corresponding to the first data and the second data signal generated by the timing controller to the plurality of pixels of the first pixel group and the plurality of pixels of the second pixel group through the data lines.

According to another embodiment of the present invention, a liquid crystal display device (LCD) includes: a liquid crystal panel, which has a plurality of gate lines and a plurality of data lines respectively arranged in rows and columns and crossing each other, connected to the plurality of gate lines and Multiple control elements on multiple data lines, and multiple pixels connected to the multiple control elements. The LCD further includes a gate driver for supplying a gate signal to the gate line; a timing controller for receiving an external image signal and selectively providing first data having a different gamma constant or the same gamma constant signal and the second data signal; and a data driver, which is used to provide the grayscale voltage corresponding to the first data and the second data signal generated by the timing controller to the first pixel group and the second pixel group respectively through the data lines. group of pixels.

According to still another embodiment of the present invention, the method for driving a liquid crystal display (LCD), wherein the liquid crystal display includes a liquid crystal panel, which has a plurality of gate lines and a plurality of data lines arranged in rows and columns and intersecting each other, A plurality of control elements connected to a plurality of gate lines and a plurality of data lines, a plurality of pixels connected to a plurality of control elements, the method includes the following steps: providing gate signals to the gate lines; receiving external image signals and generating first data signals and second data signals corresponding to different gamma constants; and providing grayscale voltages corresponding to the first data signals and the second data signals to the first pixel group and the second pixel group respectively through the data lines .

According to yet another embodiment of the present invention, a method for driving a liquid crystal display (LCD), wherein the liquid crystal display includes a liquid crystal panel, and the liquid crystal panel has a plurality of gate lines and a plurality of data lines respectively arranged in rows and columns and intersecting each other. lines, a plurality of control elements connected to a plurality of gate lines and a plurality of data lines, and a plurality of pixels connected to a plurality of control elements, wherein the method includes the steps of: applying a gate signal to the gate line; receiving external image signal and generate a first data signal and a second data signal corresponding to different gamma constants or corresponding to the same gamma constant; Voltages are provided to the first pixel group and the second pixel group respectively.

Description of drawings

The present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a gamma characteristic curve diagram of a liquid crystal display device in a common vertical alignment mode;

2A is a block diagram of a liquid crystal display device according to an embodiment of the present invention;

2B is a block diagram of a liquid crystal display device according to another embodiment of the present invention;

3A is a front gamma curve of a liquid crystal display device according to an embodiment of the present invention;

3B is a side gamma curve of a liquid crystal display device according to an embodiment of the present invention;

4 is a graph showing the relationship between the visual range of the user and the effective PPI (pixels per inch) of the liquid crystal display device;

5 and 6 show graphs of data signals with different gamma constants applied to each pixel group of a frame-independent liquid crystal display device;

7A to 8B illustrate liquid crystal panels that provide data signals having different gamma constants for each predetermined frame;

9A to 10B show inversion drive signals according to embodiments of the present invention;

FIG. 11A and FIG. 11B are graphs showing the dependence of chromaticity on viewing angle in a liquid crystal display according to an embodiment of the present invention and a liquid crystal display device in a common VA mode; and

FIG. 12 is a block diagram of a liquid crystal display device according to another embodiment of the present invention.

Detailed ways

A more in-depth understanding of the present invention can be obtained through the following detailed description with reference to the accompanying drawings and preferred embodiments. The invention may be embodied in many different forms and the invention should not be limited to the specific embodiments described herein. In addition, the specific embodiments described here are for a complete and thorough understanding of the present invention, and for those skilled in the art to fully appreciate the gist of the present invention. Like reference numerals denote like elements throughout the specification.

Referring to FIG. 2A , the liquid crystal display includes a liquid crystal panel 100 , a gate driver 200 , a data driver 300 , and a timing controller 400 .

The liquid crystal panel 100 includes a plurality of gate lines G1˜Gn and a plurality of data lines D1˜Dn respectively arranged in rows and columns and intersecting each other, and a control panel connected to the plurality of gate lines G1˜Gn and the plurality of data lines D1˜Dn. element M, and a plurality of pixels connected to the plurality of control elements M. The plurality of pixels may include a first pixel group and a second pixel group. The first pixel groups and the second pixel groups are arranged alternately to form a matrix pattern, and their arrangement can be changed according to the more detailed description below. Either one or the other of the first pixel group and the second pixel group includes one or three pixels. For example, when a pixel is used as the basic unit of the matrix mode of the first pixel group or the second pixel group, the first pixel group is a group of pixels in which the sum of the row and column of the pixel row and column is an even number, and the second pixel group is a pixel A group of pixels whose row and column sum is an odd number. Optionally, it is also possible that the first pixel group is a group of pixels in which the sum of rows and columns of pixel rows and columns is an odd number, and the second pixel group is a group of pixels in which the sum of rows and columns of pixel rows and columns is an even number.

Each pixel includes a control element M connected to a plurality of gate lines G1Gn and a plurality of data lines D1Dn, a liquid crystal capacitor Clc connected to the control element M, and a storage capacitor Cst.

A plurality of gate lines G1 to Gn arranged in a row transmit gate signals to the control element M, and a plurality of data lines D1 to Dm transmit gray voltages corresponding to the data signals to the control element M. Each control element M is a three-terminal element, its control end is connected to the gate lines G1-Gn, its input end is connected to the data lines D1-Dm, and its output end is connected to the liquid crystal capacitor Clc or the storage capacitor Cst. The control element M may be a metal oxide semiconductor transistor, in which amorphous silicon or polycrystalline silicon is used as a channel layer to realize a thin film transistor. A liquid crystal capacitor Clc may be connected between the output terminal of the control element M and a common electrode (not shown), and a storage capacitor Cst may be connected (in an independent wiring manner) between the output terminal of the control element M and the common electrode, or may be connected between Between the output terminal of each control element M and one of the gate lines G1-Gn.

The gate driver 200 is connected to a plurality of gate lines G1˜Gn, and provides gate signals to the plurality of gate lines G1˜Gn. The gate signal includes a combination of a gate-on voltage Von and a gate-off voltage Voff provided by the driving voltage controller 500 . The data driver 300 is connected to the plurality of data lines D1-Dm, and generates gray voltages to supply the first data signal Data1 and the second control signal Data2 generated by the timing controller 400 to the plurality of data lines D1-Dm.

The timing controller 400 receives R, G, B signals from an external image source (not shown) and transmits a first data signal Data1 and a second data signal Data2 having different gamma constants to the data driver 300 . Here, the first data signal Data1 is transmitted to the pixels belonging to the first pixel group, and the second data signal Data2 is transmitted to the pixels belonging to the second pixel group. Also, the timing controller 400 generates a gate selection signal Gate CLK or CPV for controlling the gate on/off voltage Von/Voff, a vertical synchronization start signal STV, an output enable signal OE, and other signals, and supplies them to the gate Drive 200.

The process of outputting the first data signal Data1 and the second data signal Data2 corresponding to different gamma constants from the timing controller 400 will be described in detail below.

The timing controller 400 receives an external image signal of the first pixel group from an image source and outputs a first data signal Data1 to the data driver 300 . The first data signal Data1 is obtained by changing the gamma characteristic of the external image signal so that its gamma curve matches the gamma curve of the first gamma constant γ1. The timing controller 400 also receives an external image signal of the second pixel group from the image source and outputs the second data signal Data2 to the data driver 300 . The second data signal Data2 is obtained by changing the gamma characteristic of the external image signal so that its gamma curve conforms to the second gamma constant γ2 gamma curve. Here, the first gamma constant γ1 and the second gamma constant γ2 are different, and correspond to the first data signal Data1 and the second data signal Data2, respectively. Keeping the first data signal Data1 and the second data signal Data2 constant is independent of the first gamma constant γ1 and the second gamma constant γ2 from the predetermined period. Also, the first data signal Data1 is transmitted to the pixels belonging to the first pixel group, and the second data signal Data2 is transmitted to the pixels belonging to the second pixel group.

Also, when the timing controller 400 outputs the first data signal Data1 and the second data signal Data2 corresponding to different gamma constants, the gamma constants may be exchanged with each other every predetermined period to provide the first data signal Data1 and the second data signal Data1 provides the same cycle. For example, in the first period, the timing controller 400 receives the external image signal for the first pixel group, transforms its gamma characteristic to conform to the gamma curve of the first gamma constant γ1, and then uses it as the first data signal Data1 output. In the same cycle, the timing controller 400 receives an external image signal for an image group of a second pixel group, transforms its gamma characteristic to conform to a gamma curve of a second gamma constant γ2, and then uses it as the second data Signal Data2 output. Then, in the second cycle, the timing controller 400 receives the external image signal for the first pixel group and transforms its gamma characteristic to conform to the gamma curve of the second gamma constant γ2 and then uses it as the first data signal Data1 output, and the timing controller 400 receives the external image signal for the second pixel group and transforms its gamma characteristic to conform to the gamma curve of the first gamma constant γ1 and then outputs it as the second data signal Data2. Here, the first cycle and the second cycle may be the same. For example, the first period and the second period may be one frame.

Using a look-up table (Look-Up Table; LUT) or calculation operation, the timing controller 400 can output the first data signal Data1 and the second data signal Data2 alternately having the first gamma constant γ1 and the second gamma constant γ2. This lookup table is stored in the memory of the timing controller 400, for example, may be stored in a nonvolatile storage device such as ROM (Read Only Memory). In this case, the gamma constant can also be adjusted without changing the structure of the liquid crystal panel 100 .

FIG. 2B is a block diagram of a liquid crystal display device according to an embodiment of the present invention. As shown in FIG. 2B, a separate storage device 450 is connected to the timing controller 400 storing the look-up table. At this time, since the storage device 450 can be changed or replaced, various look-up tables can be used according to user needs. Furthermore, when a new liquid crystal panel is used, the new liquid crystal panel can be adopted by using only the optimum look-up table. Here, the storage device 450 may use various memory storage devices; for example, the storage device 450 may use ROM, EEPROM (Electrically Erasable Read Only Memory), or the like.

Referring to FIG. 3A and FIG. 3B , it shows in detail the front and side gamma characteristics of a liquid crystal display device according to an embodiment of the present invention. FIG. 3A is a front gamma curve of a liquid crystal display device, and FIG. 3B is a side gamma curve of a liquid crystal display device. Although the gamma characteristic curves shown in FIG. 3A and FIG. 3B are described with the 256 gray levels listed in the figures, the present invention is not limited thereto, and can also be applied to use 64 gray levels and 1024 gray levels. A liquid crystal display device with flat or other gray levels.

The following relationship is established between the luminance and the gray level of the liquid crystal display device.

Among them, γ is the gamma constant,

Likewise, normalized luminance is proportional to the gamma power of the gray level. Therefore, the gamma curves shown in FIGS. 3A and 3B represent an exponential function relationship between brightness and gray level.

Shown with reference to Fig. 3 A, this figure has shown the gamma curve of front side, and gamma curve F4 has shown the gamma constant (for example, 2.2, 2.4 or 2.6 etc., hereinafter referred to as standard gamma) that uses in the liquid crystal display device Constant (γnormal)) relationship between gray level and brightness. Referring to FIG. 3B , which shows the side gamma curve, the gamma curve S4 shows the relationship between the gray level and the brightness using the standard gamma constant γ. Comparing the gamma curve F4 and the gamma curve S4 shown in FIG. 3A and FIG. 3B, when observing the liquid crystal display device from the side, in the case of using the ordinary standard gamma constant (γnormal) in the middle gray scale level, it can be seen that to a substantial increase in brightness. While a general liquid crystal display device has good frontal visibility, a large increase in side brightness results in reduced visibility.

In Fig. 3A and Fig. 3B, the gamma curve F1 and the gamma curve S1 use the first gamma constant γ1 for the front view and the side view, and the gamma curve F2 and the gamma curve S2 use the second gamma constant for the front view and the side view. Horse constant γ2. The first gamma constant γ1 and the second gamma constant γ2 can be defined, so that the gamma curve F3 representing the average brightness of the gamma curve F1 and the gamma curve F2 observed from the front is actually the same as the gamma curve using the standard gamma constant γnormal F4 is the same. Gamma curve S3 represents the average brightness of gamma curve S1 and gamma curve S2 viewed from the side, and the brightness difference between gamma curve S3 and gamma curve F3 may be smaller than that between gamma curve S4 and gamma curve F3 The brightness is poor.

The method for defining the first gamma constant γ1 and the second gamma constant γ2 will be described in detail below. When the second gamma constant γ2 is smaller than the first gamma constant γ1 , as shown in FIG. 3A and FIG. 3B , the gamma curves F1 and S1 are located below the gamma curves F2 and S2 . In the gamma curves F4 , S4 to which the standard gamma constant γnormal is applied, there is a significant difference between the gamma curves of the front view and the side view at a low gray level. In order to prevent an increase in luminance viewed on the side of a low gray level, the first gamma constant γ1 may be set to various values according to the gray level. That is, in a low gray level, the first gamma constant γ1 is set to a low value, and the luminance difference in this interval is approximately zero.

Assuming that in the gamma curve F1 or S1, the maximum gray level at which the luminance is about zero is set as the critical gray level gray C, the first gamma constant γ1 may be changed according to the critical gray level. Preferably, the first gamma constant γ1 has a larger value in the first cycle than in the second cycle. Here, the first period is lower than the critical gray level gray C and the second period is higher than the critical gray level gray C. If the first gamma constant γ1 is not greater than the critical gray level gray level C, it may be greater than 3.

As described above, the first gamma constant γ1 and the second gamma constant γ2 are set so that the average of the luminance according to the first gamma γ1 and the luminance according to the second gamma constant γ2 is substantially the same as the luminance according to the standard gamma constant γnormal same, thereby minimizing the difference in gamma properties between frontal and side view. Therefore, each pixel does not need to form a plurality of sub-pixels.

FIG. 4 is a graph showing a relationship between a user's visual range and an effective PPI (pixels per inch) of a liquid crystal display device. Here, PPI represents the resolving power of the liquid crystal display device; in particular, represents the number of pixels formed per one inch. Generally, the closer an object is to the viewer's eye, the clearer the object will be seen because more information reaches the retina of the viewer's eye. The closest distance at which the eye can focus is referred to as the near point or point of clear vision and at which maximum resolving power occurs. For most people, the near point is about 30cm, and the angular resolution at the near point is 1/60° (≈0.0167°). The human eye has maximum resolving power at the near point. When objects are closer or farther away from the near point, the ability of the eyes to distinguish is reduced. For an object at 1.5 meters from the eye, the angular resolution of the eye is at a distance of 436 μm. A pixel interval of 436 μm corresponds to a resolution of a liquid crystal display device of about 58 PPI.

When the timing controller 400 provides the first data signal Data1 and the second data signal Data2 respectively corresponding to the first gamma constant γ1 and the second gamma constant γ2 irrespective of the predetermined frame, when the liquid crystal panel 100 passes through the adjacent When the pixel groups display data signals with different gamma constants, an image with improved side visibility can be realized when human eyes cannot perceive it in a high-definition liquid crystal display device of about 58PPI.

Embodiments of the present invention can be applied to any liquid crystal display device. For a high-precision liquid crystal display device, in addition to improving side visibility, image roughness can be prevented by alternately changing gamma constants corresponding to respective data signals every predetermined period. For example, the timing controller 400 transmits frames of the first data signal Data1 and the second data signal Data2 to the data driver 300 . Odd frames of the first data signal Data1 have a first gamma constant γ1 and even frames thereof have a second gamma constant γ2. The odd frames of the second data signal Data2 have the second gamma constant γ2 and the even frames thereof have the first gamma constant γ1. In this way, it is possible to effectively suppress the generation of the flickering phenomenon or streaks, and to improve the contrast. While the liquid crystal display device according to the embodiment of the present invention is described as having frames having different gamma constants, the present invention is not limited thereto, and the period for gamma constant variation may be changed in various ways. If the period is multiple frames, flickering or streaking may occur. Therefore, as long as this unfavorable phenomenon can be prevented, the change period of the gamma constant can be changed in various ways. For convenience, an embodiment of the present invention using a data signal of frames having different gamma constants alternately will be described below.

In a general liquid crystal display device in which a coupling capacitor is used to improve side visibility between pixels and sub-pixels, since an organic insulating layer as a dielectric material occupies a large area, its aspect ratio decreases. On the contrary, in the liquid crystal display device according to the embodiment of the present invention, since the coupling capacitor is not used, the aspect ratio can be improved. In addition, in the liquid crystal display device according to the embodiment of the present invention, there is no need to form individual sub-pixels within one pixel, thereby enhancing the overall brightness of the liquid crystal display device 100, and compensating for variations in gamma characteristics of the liquid crystal display device 100 according to process variations. .

A frame may be represented by two-dimensional planes X and Y. Here, X represents the horizontal axis and Y represents the vertical axis. The Z axis represents time and the Z values are in frames. Pixels are represented by X, Y, Z values. At this time, a duty rate is defined by fixing the X and Y values and dividing the number of times the pixel is turned on while a predetermined frame is repeated a predetermined number of times. For example, if the grayscale voltage level duty factor of the data signal at (1, 1) is 1/2, the pixels are turned on in one frame in 2 frames. Therefore, in order to apply a liquid crystal display device to express a variety of gray voltage levels, a frame rate control (FRC) type liquid crystal display device can be used; a load factor for each gray voltage level is set in the frame rate control type liquid crystal display device and Frames of on/off pixels based on these load factors. In addition to providing data signals with different gamma constants, the dithering of the pixels helps to produce images with improved lateral visibility.

The data signals of the pixel groups of the liquid crystal panel of the disclosed liquid crystal display device according to the embodiment of the present invention will be described below with reference to FIGS. 5 to 8B .

5 and 6 are graphs showing data signals having different gamma constants applied to respective pixel groups of a liquid crystal display device irrespective of a frame.

Specifically, FIG. 5 shows a first pixel group and a second pixel group that are alternately arranged with each other in a matrix pattern and are composed of R, G, and B pixels. As shown in FIG. 5, the first data signal Data1 having the first gamma constant γ1 is provided to the pixels of the first pixel group, and the second data signal Data2 having the second gamma constant γ2 is provided to the pixels of the second pixel group. Pixels, here, the positions of the first pixel group and the second pixel group can be interchanged.

FIG. 6 shows a first pixel group and a second pixel group each having one pixel as a basic unit of a matrix pattern arranged alternately with each other to form a matrix pattern. As shown in FIG. 6 , the first pixel group is a group of pixels in which the sum of pixel rows and columns is an odd number, and the second pixel group is a group of pixels in which the sum of pixel rows and columns is an even number. Pixels belonging to the first pixel group (for example, odd-numbered columns C1, C3, C5, C7, C9 pixels of odd-numbered rows R1, R3 and even-numbered columns C2, C4 of even-numbered rows R2, R4 , C6, C8 pixels) provide the first data signal Data1 with the first gamma constant γ1. In addition, pixels belonging to the second pixel group (for example, odd-numbered columns C2, C4, C6, C8 pixels of odd-numbered rows RI, R3 and even-numbered columns C1, C3 of even-numbered rows R2, R4 , C5, C7 pixels) provide a second data signal Data2 having a second gamma constant γ2. Here, the positions of the first pixel group and the second pixel group may be interchanged.

7A to 8B illustrate liquid crystal panels supplied with data signals having different gamma constants for each predetermined frame.

Specifically, FIG. 7A and FIG. 7B show a liquid crystal panel supplied with a data signal at a period of one frame. FIG. 7A shows data signals supplied to odd-numbered frames and FIG. 7B shows data signals supplied to even-numbered frames. The first pixel group and the second pixel group are alternately arranged to form a matrix pattern and consist of R, G, and B pixels.

In the odd-numbered frame, as shown in FIG. 7A , the first data signal Data1 is provided to the pixels belonging to the first pixel group, and the second data signal Data2 is provided to the pixels belonging to the second pixel group.

In the even-numbered frame, as shown in FIG. 7B , the second data signal Data2 corresponding to the second gamma constant γ2 is applied to the pixels belonging to the first pixel group, and the second data signal Data2 corresponding to the first gamma constant γ2 is applied to the pixels belonging to the second pixel group. The first data signal Data1 of horse constant γ1.

Here, data signals can be converted.

8A and 8B show a liquid crystal panel supplied with a data signal at a period of one frame. FIG. 8A shows data signals supplied to odd-numbered frames, and FIG. 8B shows data signals supplied to even-numbered frames.

Here, the first pixel group and the second pixel group are alternately arranged to form a matrix pattern and consist of one pixel.

As shown in FIG. 8A , in the odd-numbered frame, the pixels belonging to the first pixel group (for example, the odd-numbered columns C1, C3, C5, C7, C9 pixels of the odd-numbered rows R1, R3 and the even-numbered pixels Even-numbered columns C2 , C4 , C6 , and C8 pixels of rows R2 , R4 provide the first data signal Data1 . In addition, to the pixels belonging to the second pixel group (the odd-numbered columns C2, C4, C6, and C8 pixels of the odd-numbered rows R1, R3 and the even-numbered columns C1, C3, C5, C5, and C7 pixel) provides the second data signal Data2.

In the even-numbered frame, to the pixels belonging to the first pixel group (that is, the odd-numbered columns C1, C3, C5, C7, C9 pixels of the odd-numbered rows R1, R3 and the pixels of the even-numbered rows R2, R4 Even-numbered columns C2, C4, C6, C8 pixels) provide the first data signal Data1. In addition, to the pixels belonging to the second pixel group (that is, the odd-numbered columns C2, C4, C6, and C8 pixels of the odd-numbered rows R1, R3 and the even-numbered columns C1, C3, C8 of the even-numbered rows R2, R4 C5, C7 pixels) provide the second data signal Data2.

A data signal corresponding to the gamma constant shown in FIG. 8A need not be supplied to the odd-numbered frame, and a data signal corresponding to the gamma constant shown in FIG. 8B need not be supplied to the even-numbered frame. A data signal corresponding to the gamma constant shown in FIG. 8B may be supplied to the odd-numbered frame, and a data signal corresponding to the gamma constant shown in FIG. 8A may be supplied to the even-numbered frame.

When changing the gamma constant at a cycle of one frame, embodiments of the present invention are not limited thereto, and the cycle may be changed in various ways as long as flicker or streaks are prevented from occurring.

The data signal inversion driving applicable to the liquid crystal display device according to the embodiment of the present invention will be described below with reference to FIGS. 9A to 10B . For convenience, the data signal inversion driving will be described using the liquid crystal panel shown in FIGS. 8A and 8B . Embodiments of the present invention can be applied to various liquid crystal panels having the first pixel group and the second pixel group arranged in various ways as described above.

9A and 9B show dot inversion drive signals. 10A and 10B show (1+2) dot inversion drive signals. In FIGS. 9A to 10B , symbols (+), (-) indicate the polarity of each pixel.

The data signal provided to each pixel of the liquid crystal display device according to the embodiment of the present invention is not limited to the dot inversion signal or the (1+2) dot inversion signal, and various inversion driving forms can be used. Preferably, when the data signal is a dot inversion driving signal, generation of flicker phenomenon can be suppressed and contrast can be improved.

11A and 11B are views of the amount of change (hereinafter referred to as chromaticity) in the color coordinates with respect to the change in viewing angle according to an embodiment of the present invention; 11B shows the chromaticity dependence of viewing angle in a liquid crystal display device according to an embodiment of the present invention. Here, curve A represents the chromaticity of an RGB color with gray levels (192, 128, 64), curve B represents the chromaticity of an RGB color with gray levels (64, 192, 128), and curve C represents Chroma of RGB colors with grayscale levels (217, 172, 144).

As shown in FIG. 11A and FIG. 11B , in the liquid crystal display device according to the embodiment of the present invention, first data corresponding to different gamma constants are provided to the first pixel group and the second pixel group alternately arranged with each other to form a matrix pattern. signal and the second data signal, thereby substantially reducing the side chroma.

The above-mentioned liquid crystal display device is driven by the first data signal Data1 and the second data signal Data2 having different gamma constants.

FIG. 12 is a block diagram of a liquid crystal display device according to an embodiment of the present invention. The user can control the image quality of the liquid crystal display device. That is, the image quality of the liquid crystal display device is controlled by making the gamma constants of the first data signal Data1 and the second data signal Data2 the same or different.

When only frontal visibility (hereinafter referred to as a general mode) is considered, a selection signal SS that will cause the first data signal and the second data signal to correspond to the same gamma constant may be supplied to the timing controller 440 . When only side visibility is considered (hereinafter referred to as a side emphasis mode), a selection signal for making the first data signal Data1 and the second data signal Data2 correspond to different gamma constants is supplied to the timing controller 400 .

As described above, when the timing controller 400 receives a user-initiated selection signal SS, it may provide the first data signal Data1 and the second data signal Data2 having the same gamma constant. For example, when the user uses a remote controller or similar device to send a selection signal SS to the timing controller 400, the timing controller 400 provides the first data signal Data1 and the second data signal Data2 suitable for the normal mode or the side enhancement mode, thereby adjusting Image quality of liquid crystal display devices.

As mentioned above, the normal mode or the side enhancement mode is selected by the selection signal SS from the outside; other methods can be applied to realize the selection. For example, normal mode or side enhancement mode is automatically selected according to the type of external image signal (RGB) from an external graphics source. In general, moving images consider side visibility and in still images it is less of a consideration. Likewise, if a still image is displayed, the timing controller 400 applies the general mode. However, the timing controller 400 applies the side-enhanced mode if a moving image is displayed.

The above-mentioned liquid crystal display device according to an embodiment of the present invention is applicable not only to a vertical alignment mode, but also to a TN (twisted nematic) mode in which side visibility needs to be enhanced.

As described above, the liquid crystal display device according to the present invention can effectively improve the reliability by supplying data signals having different gamma constants to adjacent pixels and by supplying data signals having different gamma constants to one pixel in units of predetermined frames. visibility.

Also, in the liquid crystal display device according to the embodiment of the present invention, separate groups of sub-pixels are not required, and the aspect ratio is improved, thereby increasing the overall brightness of the liquid crystal panel 100 and compensating for variations in gamma characteristics of the liquid crystal panel 100 . In particular, when a liquid crystal panel is formed using an organic insulating layer, the brightness of the liquid crystal panel can be effectively increased.

As mentioned above, these are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (47)

1. liquid crystal indicator comprises:

Liquid crystal panel comprises being arranged in rows and columns respectively and many gate lines intersected with each other and many data lines, being connected a plurality of control elements on described many gate lines and described many data lines and being connected a plurality of pixels on described a plurality of control element;

Gate drivers is used for providing signal to described gate line;

Timing controller is used to receive external image signal and produces first data-signal and second data-signal with different gamma constants; And

Data driver is used for and will offers first pixel groups with a plurality of pixels and second pixel groups with a plurality of pixels by described data line corresponding to described first data that produced by described timing controller and the grayscale voltage of described second data-signal.

2. liquid crystal indicator according to claim 1, wherein, described first pixel groups and second pixel groups formation matrix pattern that is alternately arranged with each other.

3. liquid crystal indicator according to claim 2, wherein, each in each described first pixel groups and described second pixel groups includes single pixel.

4. liquid crystal indicator according to claim 2, wherein, each in described first pixel groups and described second pixel groups includes redness, green and blue pixel.

5. liquid crystal indicator according to claim 1, wherein, described first data-signal is corresponding to the first gamma constant (γ 1), and described second data-signal is corresponding to the second gamma constant (γ 2).

6. liquid crystal indicator according to claim 5, wherein, the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

7. liquid crystal indicator according to claim 5, wherein, the described first gamma constant (γ 1) changes according to critical grey level, and described critical grey level is changed to maximum grey level, zero luminance herein.

8. liquid crystal indicator according to claim 7, wherein, than having bigger value when described critical grey level is following, and the described first gamma constant (γ 1) is more than or equal to 3 when described critical grey level is above for the described first gamma constant (γ 1).

9. liquid crystal indicator according to claim 5, wherein, described liquid crystal indicator resolution is about 58 PPI or higher.

10. liquid crystal indicator according to claim 1, wherein, described first data-signal the period 1 corresponding to the described first gamma constant (γ 1), second round corresponding to the second gamma constant (γ 2) littler than the described first gamma constant (γ 1), and described second data-signal in the described period 1 corresponding to the described second gamma constant (γ 2), in described second round corresponding to the first gamma constant (γ 1).

11. liquid crystal indicator according to claim 10, wherein, locate to locate average corresponding between the brightness of described predetermined grey level at the described first gamma constant (γ 1) to similar corresponding to the brightness of described predetermined grey level at standard gamma constant (γ normal) corresponding to the brightness of predetermined grey level with at the described second gamma constant (γ 2).

12. liquid crystal indicator according to claim 10, wherein, the described period 1 is identical with described second round.

13. liquid crystal indicator according to claim 12, wherein, described period 1 and described second round all are a frame.

14. liquid crystal indicator according to claim 10, wherein, the described first gamma constant (γ 1) changes according to critical grey level, and described critical grey level is changed to maximum grey level, zero luminance herein.

15. liquid crystal indicator according to claim 14, wherein, than having bigger value when described critical grey level is following, and the described first gamma constant (γ 1) is more than or equal to 3 when described critical level is above for the described first gamma constant (γ 1).

16. liquid crystal indicator according to claim 1, wherein, described timing controller comprises external image signal is transformed to corresponding to first question blank of described first data-signal of the described first gamma constant (γ 1) with described external image signal and is transformed to second question blank corresponding to described second data-signal of the second gamma constant (γ 2).

17. liquid crystal indicator according to claim 1, wherein, also comprise memory storage, described memory storage comprises described external image signal is transformed to corresponding to first question blank of described first data-signal of the described first gamma constant (γ 1) with described external image signal and is transformed to second question blank corresponding to described second data-signal of the second gamma constant (γ 2), and provides described first question blank and described second question blank to described timing controller.

18. a liquid crystal indicator comprises:

Liquid crystal panel comprises being arranged in rows and columns respectively and many gate lines intersected with each other and many data lines, being connected a plurality of control elements on described many gate lines and described many data lines and being connected a plurality of pixels on described a plurality of control element;

Gate drivers is used for providing signal to described gate line;

Timing controller is used to receive outside picture signal and optionally produces first data-signal and second data-signal with different gamma constants or identical gamma constant; And

Data driver is used for and will offers first pixel groups with a plurality of pixels and second pixel groups with a plurality of pixels by described data line corresponding to described first data that produced by described timing controller and the grayscale voltage of described second data-signal.

19. liquid crystal indicator according to claim 18, wherein, described first pixel groups and described second pixel groups formation matrix pattern that is alternately arranged with each other.

20. liquid crystal indicator according to claim 19, wherein, each in described first pixel groups and described second pixel groups includes single pixel.

21. liquid crystal indicator according to claim 18, wherein, each in described first pixel groups and described second pixel groups includes redness, green and blue pixel.

22. want 18 described liquid crystal indicators according to right, wherein, whether described first data-signal of selection signal deciding that described timing controller produces according to the outside is identical with the gamma constant of described second data-signal.

23. liquid crystal indicator according to claim 18, wherein, described first data-signal is corresponding to the described first gamma constant (γ 1), described second data-signal is corresponding to the described second gamma constant (γ 2), and the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

24. liquid crystal indicator according to claim 18, wherein, described first data-signal the period 1 corresponding to the first gamma constant (γ 1), second round corresponding to the second gamma constant (γ 2) littler than the described first gamma constant (γ 1), and described second data-signal the described period 1 corresponding to the described second gamma constant (γ 2), described second round corresponding to the described first gamma constant (γ 1).

25. liquid crystal indicator according to claim 24, wherein, the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

26. liquid crystal indicator according to claim 24, wherein, described period 1 and second round all are frames.

27. liquid crystal indicator according to claim 18, wherein, described timing controller comprises described external image signal is transformed to corresponding to first question blank of described first data-signal of the described first gamma constant (γ 1) with described external image signal and is transformed to second question blank corresponding to described second data-signal of the described second gamma constant (γ 2).

28. liquid crystal indicator according to claim 18, wherein, also comprise memory storage, described memory storage comprises described external image signal is transformed to corresponding to first question blank of described first data-signal of the described first gamma constant (γ 1) with described external image signal and is transformed to second question blank corresponding to described second data-signal of the described second gamma constant (γ 2), and provides described first question blank and described second question blank to described timing controller.

29. the driving method of a liquid crystal indicator, described liquid crystal indicator comprises liquid crystal panel, described liquid crystal panel has and is arranged in rows and columns respectively and many gate lines intersected with each other and many data lines, is connected a plurality of control elements on described many gate lines and described many data lines and is connected a plurality of pixels on described a plurality of control element, and described method comprises the steps:

Provide signal to described gate line;

Receive external image signal and produce first data-signal and second data-signal of corresponding different gamma constants; And

To offer first pixel groups and second pixel groups corresponding to the grayscale voltage of described first data-signal and second data-signal respectively by described data line.

30. method according to claim 29, wherein, described first pixel groups and described second pixel groups formation matrix pattern that is alternately arranged with each other.

31. method according to claim 30, wherein, each in described first pixel groups and described second pixel groups includes single pixel.

32. method according to claim 30, wherein, each in described first pixel groups and described second pixel groups includes redness, green and blue pixel.

33. method according to claim 29, wherein, produce described first and second data-signal and comprise and respectively described external image signal being transformed to corresponding to described first data-signal of the described first gamma constant (γ 1) and corresponding to described second data-signal of the second gamma constant (γ 2), the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

34. method according to claim 29, wherein, produce described first and second data-signal comprise with described external image signal be transformed in the period 1 corresponding to the described first gamma constant (γ 1) and in second round corresponding to first data-signal of the second gamma constant (γ 2) littler than the described first gamma constant (γ 1), and with described external image signal be transformed in the described period 1 corresponding to the described second gamma constant (γ 2) and in described second round corresponding to second data-signal of the described first gamma constant (γ 1).

35. method according to claim 34, wherein, the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level with locate at the described second gamma constant (γ 2) corresponding to the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

36. method according to claim 34, wherein, the described period 1 is identical with described second round.

37. method according to claim 36, wherein, described period 1 and second round all are frames.

38. the driving method of a liquid crystal indicator, described liquid crystal indicator comprises liquid crystal panel, described liquid crystal panel has and is arranged in rows and columns respectively and many gate lines intersected with each other and many data lines, is connected a plurality of control elements on described many gate lines and described many data lines and is connected a plurality of pixels on described a plurality of control element, and described method comprises the steps:

Provide signal to described gate line;

Receive external image signal, and optionally produce corresponding to different gamma constants or corresponding to first data-signal and second data-signal of identical gamma constant;

And

To offer first pixel groups that comprises a plurality of pixels and second pixel groups that comprises a plurality of pixels corresponding to the grayscale voltage of described first data-signal and second data-signal respectively by described data line.

39. according to the described method of claim 38, wherein, described first pixel groups and described second pixel groups formation matrix pattern that is alternately arranged with each other.

40. according to the described method of claim 39, wherein, each in described first pixel groups and described second pixel groups includes single pixel.

41. according to the described method of claim 39, each in described first pixel groups and described second pixel groups comprises redness, green and blue pixel.

42., wherein, produce described first and second data-signal and comprise according to the described method of claim 38:

Receive the outside selection signal that produces; And

Generation has described first and second data-signal of identical gamma constant.

43. according to the described method of claim 38, wherein, when described first and second data-signal has different gamma constant, produce described first and second data-signal and comprise described external image signal is transformed to corresponding to first data-signal of the described first gamma constant (γ 1) and corresponding to second data-signal of the described second gamma constant (γ 2), and the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

44. according to the described method of claim 38, wherein, when described first and second data-signal has different gamma constants, produce described first and second data-signal comprise with described external image signal be transformed to the period 1 corresponding to the described first gamma constant (γ 1) and in second round first data-signal corresponding to the second gamma constant (γ 2) littler than the described first gamma constant (γ 1), and with described external image signal be transformed to the described period 1 corresponding to the second gamma constant (γ 2) and in described second round second data-signal corresponding to the described first gamma constant (γ 1).

45. according to the described method of claim 44, wherein, the described first gamma constant (γ 1) locate corresponding to the brightness of predetermined grey level and the described second gamma constant (γ 2) locate corresponding between the brightness of described predetermined grey level on average to locate corresponding to the brightness of described predetermined grey level similar at standard gamma constant (γ normal).

46. according to the described method of claim 44, wherein, the described period 1 is identical with described second round.

47. according to the described method of claim 46, wherein, described period 1 and described second round all are frames.

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