KR20070079617A - Liquid crystal display panel and manufacturing method thereof and liquid crystal display including the same - Google Patents

Abstract

An LCD(Liquid Crystal Display) panel, a manufacturing method thereof and an LCD including the same are provided to differently form the thickness of a color filter at high and low gradation regions. A sub pixel is divided into the first and second gradation areas(40,42). The thickness of a color filter(32) at the first and second gradation areas differs. The low gradation voltage is applied to the first gradation area and the high gradation voltage is applied to the second gradation area. The thickness of the first gradation area is thicker than that of the second gradation area. When manufacturing the LCD panel, a color photo resist is formed on an insulating layer. The color photo resist is exposed so that the color filter with different thickness is formed at the first and second gradation areas of each sub pixel. When exposing the color photo resist, a partial transmission mask is used. A data driving member supplies the different data to the first and second gradation areas of each sub pixel.

Description

Liquid crystal panel, its manufacturing method, and the liquid crystal display device including the same TECHNICAL FIELD

1 is a plan view illustrating one sub-pixel of a liquid crystal panel according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of a sub pixel along the line II ′ of FIG. 1.

3A through 3D are cross-sectional views illustrating a driving process of one sub-pixel illustrated in FIG. 2 for each gray level.

4 is a cross-sectional view illustrating a method of manufacturing the color filter shown in FIG. 2.

FIG. 5 is a block diagram illustrating the liquid crystal display shown in FIG. 1.

<Explanation of symbols for the main parts of the drawings>

10: timing controller 12: data driver

14 Analog Switch 16 High Gradation Gamma Voltage Section

18: low gray gamma voltage unit 20: gamma voltage unit

22: gate driver 24: liquid crystal panel

26 subpixel 27 pixel electrode of high gradation region

28 pixel electrode in low gradation region 30 insulating substrate

32: color filter 34: common electrode

36 liquid crystal molecule 38 thin film transistor substrate

40: low gradation region 42: high gradation region

44: blocking part 45: full penetration part

46 partially transmissive portion 47 mask substrate

48: mask

The present invention relates to a liquid crystal panel capable of improving color reproducibility by varying the thickness of color filters in the low gradation region and the high gradation region, a manufacturing method thereof, and a liquid crystal display device using the same.

The liquid crystal display displays an image by driving liquid crystal molecules according to an electric field to adjust light transmittance. To this end, the liquid crystal display includes a liquid crystal display panel (hereinafter, referred to as a liquid crystal panel) for displaying an image through a liquid crystal cell matrix, and a driving circuit for driving the liquid crystal panel. The liquid crystal display is developing with a wide viewing angle technology in order to overcome a viewing angle limitation point in which an image is distorted depending on a position of a screen.

As a representative wide viewing angle technology of the liquid crystal display, a multi-domain VA (Multi-domain Vertical Alignment) mode is used. In particular, the multi-domain VA mode divides each sub-pixel into multi-domains and symmetrically arranges the liquid crystal molecules so that a change in transmittance occurs symmetrically to obtain a wide viewing angle.

As the multi-domain VA mode, a patterned vertical alignment (PVA) mode in which a multi-domain is formed by using a fringe field generated by slits formed in the common electrode and the pixel electrodes of the upper and lower plates is mainly used. However, the PVA mode has a problem in that the side visibility is poor due to the Lateral Filed generated at the edge of the sub-pixel.

In order to solve this problem, a method of dividing each sub-pixel having a multi-domain into a high gradation region and a low gradation region and improving visibility by gradation mixing of the two gradation regions has recently been proposed. However, since low gradation is implemented, only a relatively small high gradation region is driven, thereby causing poor color reproducibility.

Accordingly, the technical problem of the present invention is to provide a liquid crystal panel, a method of manufacturing the same, and a liquid crystal display device including the same, which can improve color reproducibility by varying the thickness of the color filters in the low gray region and the high gray region.

To this end, the liquid crystal panel according to the present invention comprises: a sub-pixel divided into first and second gray level regions; The thickness of the color filters of the first and second gray scale regions is different.

The low gray voltage is supplied to the first gray area, and the high gray voltage is supplied to the second gray area, and the color filter of the second gray area is thicker than the first gray area.

And a method of manufacturing a liquid crystal panel according to the present invention comprises the steps of forming a color photoresist on an insulating substrate; Exposing the color photoresist to form color filters having different thicknesses in the first and second gray level regions of each sub-pixel.

A partial transmissive mask is used when exposing the color photoresist.

In addition, the liquid crystal display according to the present invention comprises: a liquid crystal panel for displaying an image with each sub pixel combination divided into first and second gray level regions having different color filter thicknesses; And a data driver for supplying different data to the first and second gray level regions of each sub-pixel.

Other objects and features of the present invention in addition to the above technical problem will become apparent from the description of the embodiments with reference to the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a plan view illustrating one sub-pixel according to an exemplary embodiment of the present invention.

The sub-pixel 26 shown in FIG. 1 is divided into a high gradation region 42 and a low gradation region 40 to which different data signals are applied to improve visibility. In other words, the pixel electrode of the sub pixel 26 is divided into a high gradation region 42 and a low gradation region 40 to which different data signals are applied. The pixel electrode of the high gradation region 42 and the pixel electrode of the low gradation region 40 are independently driven by different thin film transistors TFTs to receive data signals according to different gamma curves.

In contrast, the pixel electrode of the high gradation region 42 receives a data signal through the thin film transistor TFT, and the pixel electrode of the low gradation region 40 has a coupling capacitance with the pixel electrode of the high gradation region 42. And a lower data signal than the pixel electrode of the high gradation region 42.

Hereinafter, for convenience of description, only the sub-pixel 26 driving the high gradation region 42 and the low gradation region 40 by using two transistors TFT will be described as an example.

The pixel electrodes of the high gradation region 42 and the low gradation 40 region are formed on the lower plate together with the thin film transistor TFT, and the common electrode and the electric field formed on the upper plate according to the data signal supplied through the thin film transistor TFT are formed. It forms and drives the vertically aligned liquid crystal molecules between the upper and lower plates.

Each of the two thin film transistors TFT supplies a data signal of the data line DL to each of the high gray region 42 and the low gray region 40 pixel electrode in response to a scan signal of the gate line GL. The thin film transistor TFT connected to each of the sub-pixel high gradation region 42 and the low gradation region 40 is connected to different gate lines or to different data lines. Accordingly, each sub-pixel expresses a desired gray scale by combining the high gray region 42 and the low gray region 40 driven according to different data.

FIG. 2 is a cross-sectional view of a sub pixel along the line II ′ of FIG. 1.

The color filter substrate shown in FIG. 2 includes a color filter 32 formed on the insulating substrate 30 and a common electrode 34 stacked on the color filter 32. This color filter substrate includes liquid crystal between the thin film transistor substrate 38. Here, the color filter 32 has different thicknesses of the high gradation region 42 and the low gradation region 40. In particular, the color filter 32 of the high gradation region 42 is formed thicker than the color filter 32 of the low gradation region 40. Accordingly, only the high gradation region 42 is driven to improve color reproducibility when implementing low gradation.

3A through 3D are cross-sectional views illustrating a driving process of one sub-pixel illustrated in FIG. 2 for each gray level.

Referring to FIG. 3A, a black data voltage is applied to each of the pixel electrodes 27 and 28 of the high gradation region 42 and the low gradation region 40 of the liquid crystal panel 24 during black driving to apply the black data voltage to the common electrode 34. There is no voltage difference from the applied common voltage. Therefore, since the liquid crystal molecules 36 oriented perpendicular to the high gradation region 42 and the low gradation region 40 are not driven, black luminance is displayed.

Referring to FIG. 3B, a black voltage is applied to the pixel electrode 28 of the low gradation region 40, and a low voltage data voltage is applied to the pixel electrode 27 of the high gradation region 42. As a result, a black voltage is applied to the pixel electrode 28 of the low gradation region 40 so that there is no voltage difference from the common voltage, so that the liquid crystal is not driven. Only the liquid crystal molecules 36 of the high gradation region 42 are rotated at a predetermined angle by a difference voltage between the predetermined data voltage and the common voltage applied to the pixel electrode 27 of the high gradation region 42. When the low gray scale is implemented, color reproducibility is improved because only the liquid crystals of the high gray scale region 42 are driven by the color filter 32 by the data signal.

Referring to FIG. 3C. During the half grayscale driving, respective data voltages are applied to the pixel electrode 27 of the high gradation region 42 of the liquid crystal panel 24 and the pixel electrode 28 of the low gradation region 40 to be common with the common electrode 34. The voltage difference between the voltages is different, and the liquid crystal molecules 36 are also rotated at respective predetermined angles. Intermediate gradation is realized by the combination of the high gradation region 42 and the low gradation region 40.

Referring to FIG. 3D, a white data signal is applied to the pixel electrode 27 of the high gradation region 42 of the liquid crystal panel 24 and the pixel electrode 28 of the low gradation region 40 during white driving. 34 and the common voltage have a voltage difference, and the liquid crystal molecules 36 of the high gradation region 42 and the low gradation region 40 are rotated at predetermined angles different from each other. Both the high gradation region 42 and the low gradation region 40 are displayed with white luminance.

4 is a cross-sectional view illustrating a method of manufacturing the color filter shown in FIG. 2.

Referring to FIG. 4, the color filter 32 is formed by applying a colored photoresist colored with one of R, G, and B on the insulating substrate 30 and patterning the photoresist using a mask 48. The mask 48 for forming the color filter 32 has a blocking portion 44 having a blocking pattern formed on the substrate 47 to block ultraviolet rays, and a blocking pattern is not formed on the substrate 47 to prevent ultraviolet rays. It is divided into a full transmissive portion 45 that transmits through and a partial transmissive portion 46 in which a blocking pattern is partially formed on the substrate 47.

When the color filter 32 is the negative type, the color photoresist of the region exposed to the ultraviolet rays remains through the full transmission portion 45 of the mask to become the color filter 32 of the high gradation region 42, and the partial transmission portion 46 ), The color filter 32 of the low gradation region 40 is formed so that the exposure amount is less than that of the full transmission part 45 and the thickness of the color filter 32 is smaller than that of the full transmission part 45.

FIG. 5 is a block diagram illustrating the liquid crystal display shown in FIG. 1.

The liquid crystal display shown in FIG. 5 includes a gate driver 22 driving the liquid crystal panel 24, a gate line GL of the liquid crystal panel 24, and a data line DL of the liquid crystal panel 24. A timing controller 10 for controlling the data driver 12, the gate driver 22, and the data driver 12, and a gamma voltage unit for selectively supplying high and low gray gamma voltages to the data driver 12 ( 20).

The timing controller 10 generates a gate control signal for controlling the gate driver 22 and a data control signal for controlling the data driver 12 by using a synchronization signal and a clock signal input from the outside. In addition, the timing controller 10 realigns the R, G, and B data signals input from the outside and supplies them to the data driver 12.

The gate driver 22 sequentially drives the gate line GL of the liquid crystal panel 24 in response to the gate control signal from the timing controller 10.

The data driver 12 converts the data signal from the timing controller 10 into an analog data signal. In this case, the data driver 12 converts the data signal into a high gray data signal and a low gray data signal by using the high gray gamma voltage and the low gray gamma voltage generated by the gamma voltage unit 20 to convert the data signal into a liquid crystal panel 24. To be supplied.

Specifically, the gamma voltage unit 20 includes a high gray gamma voltage unit 16 for generating a plurality of high gray gamma voltages, a low gray gamma voltage unit 18 for generating a plurality of low gray gamma voltages, and a high gray level. An analog switch 14 for switching the output of the gamma voltage section 16 and the low gradation gamma voltage section 18 is provided.

The analog switch 14 stores the high gray gamma voltages from the high gray gamma voltage unit 16 in one horizontal synchronizing period and the low gray gamma voltages from the low gray gamma voltage unit 18 in the next horizontal synchronizing period. 12), and this switching operation is repeated every horizontal period. At this time, the analog switch 14 may be built in the data driver 12.

Accordingly, the data driver 12 converts the R, G, and B data signals from the timing controller 10 into high gray data signals using the high gray gamma voltage in one horizontal period and supplies them to the liquid crystal panel 24. In the next horizontal period, the low gray gamma voltage is converted into a low gray data signal and supplied to the liquid crystal panel 24.

The liquid crystal panel 24 includes a plurality of sub pixels including the high gradation region 42 and the low gradation region 40 having different thicknesses of the color filters. It is driven by each thin film transistor TFT. In particular, the high gradation region 42 and the low gradation region 40 of the R, G, and B sub-pixels are provided in the horizontal period and the low gradation data signal by the analog method using the gamma voltage unit 20. Driven by a horizontal period in which is supplied. For example, the thin film transistor TFT connected to the first gate line GL is connected to the high gradation region 42 of the sub-pixel, and the thin film transistor TFT connected to the second gate line GL is It is connected to the low gradation region 40.

Accordingly, the high gradation data signal supplied from the data driver 12 to the data line DL is charged in the high gradation region 42 in the 1H period during which the first gate line GL is driven. Subsequently, a low gradation data signal supplied from the data driver 12 to the data line DL is charged in the low gradation region 40 in the 2H period during which the second gate line GL is driven.

As described above, the liquid crystal panel according to the present invention, a method for manufacturing the same, and a liquid crystal display including the same improve color reproducibility by dividing the subpixels into high and low gradation regions and then varying thicknesses of the color filters in the two regions. do. In other words, the thicker the color filter is, the closer to the primary color is, thereby increasing color reproducibility.

Although the detailed description of the present invention described above has been described with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art, those skilled in the art, described in the claims below It will be understood that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

A sub pixel divided into first and second gray level regions; The thickness of the color filter of the first and second gradation region is different. The method of claim 1, The low gray voltage is supplied to the first gray area, and the high gray voltage is supplied to the second gray area, and the color filter of the second gray area is thicker than the first gray area. Forming a color photoresist on the insulating substrate; Exposing the color photoresist to form color filters having different thicknesses in the first and second gray level regions of each sub-pixel. The method of claim 3, Each of the sub-pixels may include the first gray area to which the low gray voltage is applied and the second gray area to which the high gray voltage is applied, and the color filter of the second gray area is thicker than the first gray area. The manufacturing method of the liquid crystal panel. The method of claim 4, wherein A partial transmission mask is used when exposing the said color photoresist. The manufacturing method of the liquid crystal panel characterized by the above-mentioned. A liquid crystal panel which displays an image with each sub pixel combination divided into first and second gray level regions having different color filter thicknesses; And a data driver for supplying different data to the first and second gray level regions of each sub-pixel. The method of claim 6, The low gray voltage is supplied to the first gray area, and the high gray voltage is supplied to the second gray area, and the color filter of the second gray area is thicker than the gray area.

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