KR20070028631A - Retardation film and the fabricationi method, liquid crystal display device thereof - Google Patents

Abstract

A retardation compensating film, a method for manufacturing the same, and an LCD using the same are provided to satisfactorily realize black state and white state in a transmissive part and a reflective part, thereby improving the picture quality, by uniformly forming the retardation film in cell without phase difference using an alignment layer partially aligned through ion beam and a photo-reactive liquid crystal material. A retardation compensating film comprises an alignment layer and a photo-reactive liquid crystal material formed on the alignment layer. The alignment layer has a plurality of first regions(E) aligned vertically, and a plurality of second regions(F) aligned horizontally. A portion of the photo-reactive liquid crystal material, which is formed on the second region, has a retardation value. The photo-reactive liquid crystal material is photo-cured.

Description

Retardation film and its manufacturing method, and a liquid crystal display device using the same

1 is an exploded perspective view showing a typical transflective color liquid crystal display device.

2 is a cross-sectional view showing a general reflective transmissive liquid crystal display device.

3a to 3c is a process flow chart showing a method for producing a multi-domain retardation compensation film according to the present invention.

4 is a photograph showing the characteristics of a multi-domain retardation compensation film according to the present invention.

5 is a cross-sectional view showing a schematic configuration of a reflection type liquid crystal display device to which a retardation compensation film according to the present invention is applied.

<Code Description of Main Parts of Drawing>

213: common electrode 214: liquid crystal layer

215: upper substrate 221: lower substrate

230: alignment film 231: retardation compensation film

249: reflector 251: first polarizer

252: second polarizing plate 261: transparent electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to an in-cell retardation compensation film, a manufacturing method thereof, and a liquid crystal display device.

In general, a liquid crystal display device may be classified into a transmissive liquid crystal display device using a backlight as a light source and a reflective liquid crystal display device using natural light and artificial light without using the backlight as a light source.

In this case, the transmissive liquid crystal display uses a backlight as a light source to realize a bright image even in a dark external environment. However, there is a problem that can not be used in bright places, the power consumption is large.

On the other hand, since the reflective liquid crystal display does not use a backlight, power consumption can be reduced, but there is a limitation that it cannot be used when the external natural light is dark.

As an alternative to overcome these limitations, a reflective liquid crystal display device is provided.

Such a transflective liquid crystal display device has a function of a transmissive liquid crystal display device and a reflective liquid crystal display device by simultaneously providing a reflection unit and a transmissive unit in a unit pixel area, and includes backlight light and external natural light or artificial light. Since all light sources can be used, there is an advantage in that power consumption is reduced without being restricted by the surrounding environment.

FIG. 1 is an exploded perspective view illustrating a general reflective transmissive color liquid crystal display device.

As shown in the drawing, a general reflective transmissive liquid crystal display device 11 includes an upper substrate 15 having a transparent common electrode 13 formed on a black matrix 16 and a sub color filter 17 and a pixel region P. As shown in FIG. And a lower substrate 21 having a switching element T and array wirings 25 and 39 formed thereon.

The pixel area includes a reflective electrode (49 in FIG. 2) and a transparent electrode (61 in FIG. 2) including the transmission hole A, and is defined as a transmission part B and a reflection part D.

In addition, the liquid crystal 14 is filled between the upper substrate 15 and the lower substrate 21.

2 is a cross-sectional view showing a general reflective transmissive liquid crystal display device.

As shown, the reflective liquid crystal display 11 includes a pixel electrode including an upper substrate 15 having a common electrode 13 formed thereon, a reflective electrode 49 including a transmission hole A, and a transparent electrode 61. The lower substrate 21 includes a liquid crystal 14 filled between the upper substrate 15 and the lower substrate 21, and a backlight 41 positioned below the lower substrate 21.

When the reflective liquid crystal display device 11 having such a configuration is used in a reflective mode, most of the light is used as an external natural light or an artificial light source.

The operation of the liquid crystal display device in the reflection mode and the transmission mode will be described with reference to the above-described configuration.

In the reflective mode, the liquid crystal display uses an external natural or artificial light source, and the light F2 incident on the upper substrate 15 of the liquid crystal display is reflected on the reflective electrode 49 to reflect the reflection. Passes through the liquid crystal 14 arranged by the electric field of the electrode and the common electrode 13, the amount of light (F2) passing through the liquid crystal is adjusted according to the arrangement of the liquid crystal 14 to display the image (Image) Will be implemented.

On the contrary, when operating in the transmission mode, the light source uses the light F1 of the backlight 41 positioned under the lower substrate 21. Light emitted from the backlight 41 is incident on the liquid crystal 14 through the transparent electrode 61, and is arranged by an electric field of the transparent electrode 61 and the common electrode 13 below the transmission hole. By adjusting the amount of light incident from the lower backlight 41 by the liquid crystal 14, an image is realized.

However, since the optical paths of the reflecting portion and the transmitting portion are different from each other in the reflection-transmitting liquid crystal display device configured as described above, the retardation conditions of the reflecting portion and the transmitting portion are different from each other, thereby compensating the phase difference using various optical films. Needs to be.

To this end, a phase difference compensation film is formed on the outside or inside of the liquid crystal panel, which includes a step of laminating at least one layer or two layers, including at least four to seven layers including a step of applying an interlayer adhesive. It goes through a complicated process that requires stacking.

Therefore, with the disadvantage that the process is long, there is a great possibility that a defect occurs in the film itself in several bonding processes.

 Therefore, there is a limit in configuring the liquid crystal panel compactly.

An object of the present invention is to provide a compact liquid crystal display device in which a retardation compensation film is applied in an in-cell structure in a liquid crystal display device.

In addition, another object of the present invention is to provide a retardation compensation film without a step using an alignment layer and a photoreactive liquid crystal material subjected to alignment treatment by irradiating an ion beam, and a method of manufacturing the same.

The retardation compensation film according to the present invention includes an alignment film defined by a plurality of vertically aligned first regions and a plurality of second regions horizontally aligned; And a photoreactive liquid crystal material formed on the alignment layer.

In addition, a method of manufacturing a phase difference compensation film according to the present invention includes the steps of applying an alignment film on a substrate defined by a plurality of first regions and second regions; Masking a first region on the alignment layer; Irradiating an ion beam on the alignment layer; Forming a photoreactive liquid crystal material on the alignment layer; And curing the photoreactive liquid crystal material.

In addition, the liquid crystal display according to the present invention comprises: a substrate in which a reflecting portion and a transmitting portion are defined in a pixel region; Gate wiring and data wiring intersecting on said substrate to define a pixel region; A thin film transistor formed at an intersection point of the gate line and the data line; A transparent electrode formed in the pixel region; A reflection electrode formed on the reflection portion; And a phase difference compensation film formed on the entire surface of the substrate and having a region having a phase delay value and a region having no phase delay value.

Hereinafter, the retardation compensation film and the manufacturing method thereof according to the present invention will be described in detail.

3A to 3C are process flowcharts showing a method of manufacturing a multi-domain retardation compensation film according to the present invention.

As shown in FIG. 3A, an alignment material is coated on the substrate 100 to form the alignment layer 130.

At this time, a vertical alignment material is used as the alignment material.

As shown in FIG. 3B, a shadow mask 151 is formed in the first region E of the alignment layer 130, and the second region F of the alignment layer 130 is exposed. .

In addition, an ion beam is irradiated onto the substrate 100 to align the exposed alignment layer 130 of the second region F.

The ion beam 141 is irradiated with a predetermined irradiation angle θ.

In this case, the irradiation angle θ of the ion beam 141 refers to the angle between the ion beam 141 irradiated obliquely from the substrate.

The irradiation angle θ is determined between 0 degrees and 90 degrees.

As described above, in the multi-domain divided into a plurality of regions such as the first region E and the second region F, the alignment layer 130a of the first region E is the ion beam 141. This irradiation does not irradiate and has a vertical alignment characteristic, and the alignment layer 130b of the second region F has a horizontal alignment characteristic by irradiating the ion beam 141 inclinedly.

Thereafter, as shown in FIG. 3C, a photoreactive liquid crystal material is formed on the alignment layer 130.

The photoreactive liquid crystal material is formed by mixing a liquid crystal (LC), a binder, a photoreactive curing material (UV reactor), or the like.

The photoreactive liquid crystal material is vertically aligned in the first region E so as to have no phase delay value, and is horizontally aligned in the second region F so as to have a predetermined phase delay value.

Finally, the photoreactive liquid crystal material formed on the alignment layer 130 is photocured.

As such, when the alignment layer 130 that is vertically or horizontally processed by the ion beam 141 is formed on the substrate 100, and the liquid crystal material is coated and cured on the alignment layer 130, the horizontal alignment treatment is performed. The liquid crystal material formed on the alignment layer 130 has a phase delay value to form the phase difference compensation film 131.

The retardation compensation film 131 as described above may be formed in one layer at the same time, including the portion 131b and the portion 131a that do not require phase delay, and the step difference does not occur between regions.

In general, the phase retardation value of the retardation compensation film 131 is often influenced by the thickness thereof, and when the thickness is formed thicker or thinner than the intended retardation compensation film 131, the risk of defects may be increased. However, the present invention can form an in-cell type retardation compensation film of uniform thickness by irradiating an ion beam to align the alignment layer and coating and curing the liquid crystal material.

4 is a photograph showing the characteristics of the multi-domain retardation compensation film according to the present invention.

As shown in FIG. 4, when the black state is implemented using the phase difference compensation film according to the present invention and the upper and lower polarizers that cross each other by 90 degrees, the portion expressed in gray has a predetermined phase delay value. Is a second region F having, and a portion represented in black is a first region E having no phase delay value.

In the retardation compensation film 131a of the first region E, the alignment layer 130a has a vertical alignment characteristic and vertical alignment of the photoreactive liquid crystal material formed on the alignment layer 130a does not have a phase delay value.

In addition, the phase difference compensation film 131b of the second region F may have a horizontal alignment characteristic of the alignment layer 130b, and horizontally align the photoreactive liquid crystal material formed on the alignment layer 130b with pretilt to provide a predetermined value. Have a phase delay value.

Accordingly, since the second region F has no phase delay, a complete black state is realized, and the first region E implements a gray state by a predetermined phase delay value. The difference in optical efficiency of the transmission part can be compensated for.

In addition, when the alignment layer is oriented using an ion beam, the process may be simplified.

5 is a cross-sectional view illustrating a schematic configuration of a reflective liquid crystal display device to which a retardation compensation film according to the present invention is applied.

As shown in FIG. 5, the reflective liquid crystal display according to the present invention includes an upper substrate 215 on which the common electrode 213 is formed, a reflective electrode 249 including transparent holes, and a transparent electrode 261. A lower substrate 221 on which an electrode is formed, an in-cell type retardation compensation film 231 formed on the lower substrate 221, and a liquid crystal 214 filled between the upper substrate 215 and the lower substrate 221. ) And a backlight 241 positioned below the lower substrate 221.

First and second polarizing plates 251 and 252 are attached to outer surfaces of the lower substrate 221 and the upper substrate 215.

When a reflective liquid crystal display having such a configuration is used in a reflective mode, most of the light is used as an external natural light or an artificial light source.

The in-cell type retardation compensation film 231 is formed in the form of a multi-domain divided into a plurality of regions, and has a portion having a phase delay value (second region) and a portion having no phase delay value (first region). .

The retardation compensation film 231 is formed by coating and curing a photoreactive liquid crystal material on the alignment layer 230. In this case, the first region E of the alignment layer 230 is formed by applying a vertical alignment material. The second region F is formed by inclining an ion beam to the vertical alignment material and performing horizontal alignment.

The retardation compensation film 231 does not generate a step between the first region E and the second region F because the alignment layer 230 is horizontally aligned using an ion beam.

The reflective liquid crystal display device configured as described above has a phase difference compensating film formed to have a uniform thickness without a step inside the cell to compensate for the phase difference generated in the transmissive portion and the reflective portion, and has a portion having a phase difference and a portion having no phase difference. By forming a multi-domain retardation compensation film, it is possible to satisfactorily implement a black state and a white state in the transmissive part and the reflecting part, thereby improving image quality.

In addition, when the retardation compensation film is formed by the in-cell method, since the cell design of the liquid crystal display may be independently performed without considering the relationship between the reflecting unit and the transmitting unit, the design and the process may be easily performed.

As described above, the retardation compensation film according to the present invention, a method for manufacturing the same, a liquid crystal display using the same, and a method for manufacturing the same are not limited to the above-mentioned embodiments, and the technical features of the present invention are well known in the art. Modified or improved embodiments by those skilled in the art will also be included within the scope of the present invention.

Reflective type liquid crystal display device according to the present invention by forming a multi-domain retardation compensation film in a uniform thickness without a step inside the cell to implement a good black state and white state in the transmissive portion and the reflective portion has an effect that the image quality is improved. .

In addition, the present invention simplifies the process by forming an alignment layer by forming an alignment layer using an ion beam and coating and curing the alignment layer using an ion beam when forming a retardation compensation film in an in-cell manner, It can be designed without considering the phase difference, there is an effect that becomes easy to manufacture.

In addition, the present invention has the effect of implementing a compact transflective liquid crystal display by forming a retardation compensation film in an in-cell method.

Claims (15)

An alignment film defined by a plurality of vertically oriented first regions and a plurality of horizontally oriented second regions; And a photoreactive liquid crystal material formed on the alignment layer. The method of claim 1, And the photoreactive liquid crystal material formed on the second region has a phase retardation value. The method of claim 1, And the photoreactive liquid crystal material is photocured. The method of claim 1, The photoreactive liquid crystal material is a phase difference compensation film, characterized in that consisting of a liquid crystal (LC), a binder (binder) and a photocurable material. The method of claim 1, The alignment layer is a phase difference compensation film, characterized in that the coating of the vertical alignment material. Applying an alignment layer on a substrate defined by a plurality of first and second regions; Masking a first region on the alignment layer; Irradiating an ion beam on the alignment layer; Forming a photoreactive liquid crystal material on the alignment layer; And curing the photoreactive liquid crystal material. The method of claim 6, The alignment film is a method of manufacturing a phase difference compensation film, characterized in that made of a vertical alignment material. The method of claim 6, Irradiating an ion beam on the alignment layer, The ion beam is characterized by irradiating obliquely retardation film. The method of claim 6, And the photoreactive liquid crystal material has a phase retardation value in the second region. A substrate in which a reflecting unit and a transmitting unit are defined in the pixel region; Gate wiring and data wiring intersecting on said substrate to define a pixel region; A thin film transistor formed at an intersection point of the gate line and the data line; A transparent electrode formed in the pixel region; A reflection electrode formed on the reflection portion; And a phase difference compensation film formed on the entire surface of the substrate and having a phase delay value and a region having no phase delay value. The method of claim 10, And the retardation compensation film comprises an alignment film defined by a plurality of vertically aligned first regions and a plurality of horizontally aligned second regions, and a photoreactive liquid crystal material formed on the alignment layer. The method of claim 11, The photoreactive liquid crystal material formed on the second region has a phase retardation value. The method of claim 11, And the photoreactive liquid crystal material is photocured. The method of claim 11, And the photoreactive liquid crystal material is formed of liquid crystal (LC), a binder, and a photocurable material. The method of claim 11, And the alignment layer is coated with a vertical alignment material.

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