KR100666237B1 - Transflective lcd device - Google Patents

Abstract

A semi-transmissive type LCD is provided to use no phase compensation film, thereby reducing the entire thickness and weight of the LCD, by preparing a polarizing plate within a cell. An upper substrate(110) has a color filter layer, an overcoat layer, and an upper alignment layer sequentially formed on one side thereof. A polarizing plate(140) is formed on the other side of the upper substrate. A lower substrate(120) has a counter electrode, a passivation layer, a pixel electrode, a lower alignment layer sequentially formed thereon. An inner polarizing plate(124) is formed between the pixel electrode and the lower alignment layer. A liquid crystal layer(130) is interposed between the upper substrate and the lower substrate.

Description

Transflective LCD device

1 is a cross-sectional view showing a conventional transflective liquid crystal display device;

2 is a cross-sectional view showing a transflective liquid crystal display device according to an embodiment of the present invention;

3 is a cross-sectional view showing a state in which a viewing angle compensation film is inserted into the transflective liquid crystal display of FIG. 2;

4 is a cross-sectional view of a transflective liquid crystal display device according to still another embodiment of the present invention;

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

100 ... LCD 110. Upper substrate

120 ... lower substrate 121 ... counter electrode

123 ... pixel electrode 124 ... internal polarizer

125 ... lower alignment layer 130 ... liquid crystal layer

140 ... Polarizer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transflective liquid crystal display, and more particularly, to a transflective liquid crystal display for a change in arrangement of a polarizer for converting polarization components of light.

In general, a transflective liquid crystal display device has a transmissive area and a reflective area coexisting in one pixel area, and in a dark environment, the transmissive area is used as a transmissive type by using an internal light source built in the transflective liquid crystal display device. The transflective liquid crystal display device refers to a liquid crystal display device that is used as a reflection type by utilizing ambient light outside.

As such a transflective liquid crystal display, a structure as shown in FIG. 1 is generally employed.

Referring to the drawings, the transflective liquid crystal display device 30 includes an upper substrate 10 and a lower substrate 20 facing the upper substrate 10 and between the upper substrate 10 and the lower substrate 20. The liquid crystal layer LC is interposed, and upper and lower polarizers 11 and 21 are disposed on one side of the upper substrate 10 and the other side of the lower substrate 20, respectively, between the upper substrate 10 and the upper polarizer 11 and the lower substrate. Compensation film is provided between the 20 and the lower polarizer 21 to control the on / off of the light in the reflection mode, which is λ / 2 which twists the linearly polarized light through the upper polarizer by 90 °. Compensation films 12 and 22 and λ / 4 compensation films 13 and 23 for converting linearly polarized light into circularly polarized light are provided.

The other side of the upper substrate 10 is provided with a color filter layer (not shown), a black matrix (not shown), an overcoating layer (not shown), and an upper alignment layer (not shown), and one side of the lower substrate 20 is made of an opaque metal. Reflecting portion 20a, transmissive portion 20b, and a lower alignment layer (not shown) are provided thereon.

However, the transflective liquid crystal display device having such a structure uses a phase compensation film to convert the linearly polarized light component of incident light into circularly polarized light and to control on / off of the liquid crystal, which increases the thickness and weight of the liquid crystal display device. Since the manufacturing process is complicated by attaching the phase compensation film and the polarization axis of the polarizing plate, the manufacturing process is complicated and there is a problem of causing an increase in manufacturing cost.

The present invention has been made to solve the above problems, and an object thereof is to provide an improved semi-transmissive liquid crystal display device, which can simplify the light and small size of the transflective liquid crystal display device and simplify its manufacturing process.

A semi-transmissive liquid crystal display device according to an embodiment of the present invention for achieving the above object comprises an upper substrate in which a color filter layer, an overcoating layer and an upper alignment layer are sequentially stacked on one side; A polarizing plate provided on the other side of the upper substrate; A lower substrate on which a counter electrode, a passivation layer, a pixel electrode, and a lower alignment layer having an antiparallel anisotropy axis and an antiparallel anisotropy axis are sequentially stacked on a surface of the upper substrate; An internal polarizer disposed between the pixel electrode and the lower alignment layer; And a liquid crystal layer interposed between the upper substrate and the lower substrate.

Here, it is preferable that the polarization axis of the internal polarizing plate is within -5 to 5 degrees.

Moreover, it is preferable that the polarization axis of the said polarizing plate and the polarization axis of the said internal polarizing plate mutually orthogonally cross.

In addition, the anisotropic axis of the lower alignment layer and the polarization axis of the internal polarizing plate are preferably parallel to each other.

In addition, a viewing angle compensation film is further provided between the polarizing plate and the upper substrate.

In another embodiment, the transflective liquid crystal display includes: an upper substrate in which a color filter layer, an overcoating layer, and an upper alignment layer are sequentially stacked on one side; An upper polarizing plate provided between the overcoat layer and the upper alignment layer; A lower substrate on which a counter electrode, a passivation layer, a pixel electrode, and a lower alignment layer having an antiparallel anisotropy axis and an antiparallel anisotropy axis are sequentially stacked on a surface of the upper substrate; A lower polarizer provided between the pixel electrode and the lower alignment layer and having a polarization axis orthogonal to the polarization axis of the upper polarizer; And a liquid crystal layer interposed between the upper substrate and the lower substrate.

Here, the polarization axis of the lower polarizing plate is preferably within -5 ° ~ 5 °.

In addition, it is preferable that antiparallel anisotropic axes are formed on the upper alignment layer and the lower alignment layer, and the anisotropic formation axis is parallel to the polarization axis of the lower polarizing plate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the transflective liquid crystal display device of the present invention is formed with a single cell gap, and the dΔn of the liquid crystal layer is within 0.4056 to 0.4656 μm.

2 is a schematic cross-sectional view of a transflective liquid crystal display device according to a first embodiment of the present invention.

Referring to the drawings, the transflective liquid crystal display device 100 includes an upper substrate 110, a lower substrate 120 facing the upper substrate 110, and a gap between the upper substrate 110 and the lower substrate 120. The liquid crystal layer 130 is interposed, and the polarizer 140 is provided on the upper substrate 110.

A color filter layer (not shown), an overcoating layer (not shown), and an upper alignment layer (not shown) are sequentially stacked below the upper substrate 110, that is, on a surface facing the lower substrate.

The counter electrode 121, the passivation layer 122, the pixel electrode 123, the internal polarizer 124, and the lower alignment layer 125 are disposed on the upper surface of the lower substrate 120, that is, the surface facing the upper substrate 110. These are stacked sequentially. Here, the counter electrode 121 is a transparent electrode, and the pixel electrode 123 is an opaque electrode made of an opaque metal and serves as a reflector.

Here, the polarization axis of the internal polarizing plate 124 is formed at -5 to 5 degrees, and is orthogonal to the polarization axis of the polarizing plate 140 provided on the upper substrate 110.

The anisotropic axes of the upper alignment layer and the lower alignment layer 125 are antiparallel to each other, and are formed parallel to the angle of the polarization axis of the internal polarizer 124.

Meanwhile, a viewing angle compensation film 150 for compensating the viewing angle may be further inserted between the polarizer 140 and the upper substrate 110 as shown in FIG. 3.

4 is a cross-sectional view of a transflective liquid crystal display according to another exemplary embodiment of the present invention.

Referring to the drawings, the transflective liquid crystal display 200 may include an upper substrate 210, a lower substrate 220 facing the upper substrate 210, and a gap between the upper substrate 210 and the lower substrate 220. The interposed liquid crystal layer 230 is included.

The color filter layer 211, the overcoating layer 212, the upper polarizing plate 213, and the upper alignment layer 214 are sequentially stacked on a surface of the upper substrate 210 that faces the lower substrate 220.

The counter electrode 221, the passivation layer 222, the pixel electrode 223, the lower polarizer 224, and the lower alignment layer 225 are sequentially disposed on the surface of the lower substrate 220 that faces the upper substrate 210. Are stacked.

Here, the polarization axis of the upper polarizing plate 213 and the polarization axis of the lower polarizing plate 224 are orthogonal to each other, and the polarization axes of the lower polarizing plate 224 are formed at -5 to 5.

In addition, the upper alignment layer 214 and the lower alignment layer 225 have an anisotropic axis parallel to the polarization axis of the lower polarizing plate 224, and the anisotropic axis of the upper alignment layer 214 and the anisotropic axis of the lower alignment layer 225 are formed antiparallel.

According to the transflective liquid crystal display device having such a structure, a phase compensation film for controlling on / off by converting incident light into a circular polarization state in a reflection mode is omitted, and the incident light is linearly formed by a polarizing plate provided inside the cell. Incident and reflection can be performed in a polarized state.

As described above, according to the semi-transmissive liquid crystal display device of the present invention, by providing a polarizing plate inside the cell, it is possible to remove the phase compensation film required for on / off control of light in the reflection mode, It offers the effect of simplifying the overall thickness, weight and manufacturing process.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

Claims (8)

An upper substrate on which one side of the color filter layer, the overcoating layer, and the upper alignment layer are sequentially stacked; A polarizing plate provided on the other side of the upper substrate; A lower substrate on which a counter electrode, a passivation layer, a pixel electrode, and a lower alignment layer having an antiparallel anisotropy axis and an antiparallel anisotropy axis are sequentially stacked on a surface of the upper substrate; An internal polarizer disposed between the pixel electrode and the lower alignment layer; And A transflective liquid crystal display device comprising a liquid crystal layer interposed between the upper substrate and the lower substrate. The method of claim 1, A transflective liquid crystal display device, wherein the polarization axis of the internal polarizing plate is within -5 to 5 degrees. The method of claim 1, And a polarization axis of the polarizing plate and the polarization axis of the internal polarizing plate are perpendicular to each other. The method of claim 1, And a polarization axis of the lower alignment layer and a polarization axis of the internal polarizing plate are parallel to each other. The method of claim 1, The transflective liquid crystal display device further comprising a viewing angle compensation film provided between the polarizing plate and the upper substrate. An upper substrate on which one side of the color filter layer, the overcoating layer, and the upper alignment layer are sequentially stacked; An upper polarizing plate provided between the overcoat layer and the upper alignment layer; A lower substrate on which a counter electrode, a passivation layer, a pixel electrode, and a lower alignment layer having an antiparallel anisotropy axis and an antiparallel anisotropy axis are sequentially stacked on a surface of the upper substrate; A lower polarizer provided between the pixel electrode and the lower alignment layer and having a polarization axis orthogonal to the polarization axis of the upper polarizer; And A transflective liquid crystal display device comprising a liquid crystal layer interposed between the upper substrate and the lower substrate. The method of claim 6, And a polarization axis of the lower polarizer is within a range of -5 ° to 5 °. The method of claim 6, The anti-parallel anisotropy axis is formed on the upper alignment layer and the lower alignment layer, and the anisotropic formation axis is parallel to the polarization axis of the lower polarizing plate.

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