KR100705618B1 - Liquid crystal display and method for fabricating the same - Google Patents

Abstract

The present invention discloses a transflective liquid crystal display and a method of manufacturing the same. The disclosed invention, the upper and lower substrates; A reflection part and a transmission part having an embossing pattern formed on the lower substrate; A first high pretilt alignment film and a first low pretilt alignment film formed on the reflective electrode and the transmissive electrode formed on the surface of the embossed pattern of the reflective part, respectively; An RGB resin layer and a transparent electrode formed under the upper substrate; A second high pretilt alignment layer and a second low pretilt alignment layer formed under the transparent electrode and respectively corresponding to the first high pretilt alignment layer and the first low pretilt alignment layer; And a liquid crystal layer arranged between the upper and lower substrates. The liquid crystal layer is configured to reduce the refractive index anisotropy value of the liquid crystal without reducing the existing cell gap so that the phase delay value of the reflector is half of the transmissive part.

Description

Semi-transmissive liquid crystal display device and manufacturing method therefor {Liquid crystal display and method for fabricating the same}

1 is a conceptual diagram of a semi-transmissive optical design according to the prior art,

2 is a schematic diagram of a transflective liquid crystal display device according to a first embodiment of the present invention;

3 is a view showing a refractive index of a liquid crystal of a reflector in the transflective liquid crystal display device according to the first embodiment of the present invention;

4A to 4H are cross-sectional views illustrating a method of manufacturing a transflective liquid crystal display device according to a first embodiment of the present invention;

5 is a schematic diagram of a transflective liquid crystal display device according to a second embodiment of the present invention;

6 is an equivalent circuit diagram of a transflective liquid crystal display device according to a second embodiment of the present invention;

7 is a view showing transmission characteristics according to voltages of a transmission part and a reflection part in the second embodiment of the present invention;

[Description of Drawing Reference]

31: lower substrate 33: transparent electrode transparent part

35: polymer resin layer 37: reflective electrode

39a, 57: high pretilt alignment film 43a, 59: low pretilt alignment film

51: upper substrate 53: RGB resin layer

55: upper transparent electrode

The present invention relates to a method of manufacturing a semi-transmissive liquid crystal display device, and more particularly, a semi-transmissive liquid crystal display device in which the phase delay value of the reflecting part is made to be half of the transmissive part by reducing the refractive index anisotropy value of the liquid crystal without reducing the existing cell gap. It relates to a manufacturing method of.

Referring to the manufacturing method of the transflective liquid crystal display device according to the prior art as follows.

1 is a cross-sectional view of a transflective liquid crystal display device according to the prior art.

As shown in FIG. 1, the transflective liquid crystal display device according to the related art has a structure in which a lower substrate 11 and an upper substrate 21 are disposed and a liquid crystal (not shown) is inserted between these substrates.

Here, the transparent transparent electrode 13 is formed on the lower substrate 11, and the polymer resin layer 15 is formed on a predetermined portion thereon, and is reflected on the surface of the polymer resin layer 15. The electrode 17 is formed.

In addition, an RGB resin layer 23 is formed on the upper substrate 23 surface, and an upper transparent electrode 25 is formed on the RGB resin layer 23.

In the above configuration, part of the light is reflected through the reflective electrode 17 and the other part is transmitted through the upper substrate 21.

As in the above configuration, in general, in order to increase the light efficiency, the transmissive part is designed with a phase delay (Δnd) value of 0.48 μm, which is the maximum transmission condition, and the reflecting part is a liquid crystal cell because the optical path passes through the liquid crystal layer twice. Δnd is designed to be 1/2 of the transmission portion.

Moreover, it is common to design optically so that Δn (refractive anisotropy) of the liquid crystal is fixed and the cell gap d is 1/2 of the transmission portion.

However, the transmissive part and the reflecting part should be formed in one unit pixel, and in this case, rubbing unevenness occurs due to a large step in one unit pixel, resulting in a problem of degrading the screen quality.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and a semi-transmissive liquid crystal display device which reduces the refractive index anisotropy value of the liquid crystal so that the phase delay value of the reflector is half the transmissive part without reducing the existing cell gap; The purpose is to provide a method for producing the same.

A semi-transmissive liquid crystal display device according to a first embodiment of the present invention for achieving the above object, the upper and lower substrates;

A transmissive electrode formed of a transparent electrode on the lower substrate;

A reflection portion having an embossed pattern formed on the transmission electrode on the lower substrate and a transmission portion having no resin layer;

A first high pretilt alignment film and a first low pretilt alignment film formed on the reflective electrode and the transmissive electrode formed on the surface of the embossed pattern of the reflective part, respectively;

An RGB resin layer and a transparent electrode formed under the upper substrate;

A second high pretilt alignment layer and a second low pretilt alignment layer formed under the transparent electrode and respectively corresponding to the first high pretilt alignment layer and the first low pretilt alignment layer;

A liquid crystal layer arranged between the upper and lower substrates;

Respective polarizing plates attached to an outer side of the upper and lower substrates;

Characterized in that it comprises a phase compensation film contained in the polarizing plate of the upper substrate.

In addition, a semi-transmissive liquid crystal display device according to a second embodiment of the present invention,

Upper and lower substrates;

A transmissive electrode formed on the lower substrate;

A transmissive part formed on the transmissive electrode part and having a reflecting part composed of a polymer resin layer having an embossing pattern and a flat polymer resin layer remaining;

A reflection electrode formed on the embossing pattern of the reflection part;

An RGB resin layer and an upper transparent electrode formed on the upper substrate;

Respective alignment layers formed on the reflective and transmissive portions of the lower substrate and the transparent electrodes on the upper substrate; And

It comprises a liquid crystal layer arranged between the upper and lower substrates,

A polarizing plate attached to an outer surface of the upper and lower substrates;

The polarizing plate of the upper substrate is characterized in that it comprises a phase compensation plate.

In addition, the manufacturing method of the transflective liquid crystal display device according to the first embodiment of the present invention,

Providing an upper and lower substrate;

Forming a transparent electrode formed of a transparent electrode on the lower substrate;

Forming a reflective part having an embossed pattern and a transparent part having no resin layer on the transparent electrode on the lower substrate;

Forming a first high pretilt alignment layer and a first low pretilt alignment layer on the reflective electrode and the transmissive electrode formed on the surface of the embossing pattern of the reflecting unit;

Forming an RGB resin layer and a transparent electrode under the upper substrate;

Forming a second high pretilt alignment layer and a second low pretilt alignment layer respectively corresponding to the first high pretilt alignment layer and the first low pretilt alignment layer under the transparent electrode;

Arranging a liquid crystal layer between the upper and lower substrates;

Attaching a polarizing plate to an outer side of the upper and lower substrates; And

It characterized in that it comprises a step of including a phase compensation film on the polarizing plate of the upper substrate.

Furthermore, a method of manufacturing a transflective liquid crystal display device according to a second embodiment of the present invention,

Providing an upper and lower substrate;

Forming a transmissive electrode on the lower substrate;

A high difference layer formed on the transmissive electrode portion, wherein a portion of the polymer layer forms an embossed pattern to become a reflecting position, and a portion of the polymer layer remains as a flat polymer layer without the embossing pattern to form a transmissive portion;

Forming a reflective electrode on the embossed pattern of the reflective part;

Forming an RGB resin layer and an upper transparent electrode on the upper substrate;

Forming an alignment layer on the reflective and transmissive portions of the lower substrate and the transparent electrode of the upper substrate; And

It comprises a step of arranging the liquid crystal layer between the upper and lower substrates,

Each polarizer attached to an outer surface of the upper and lower substrates;

The polarizing plate of the upper substrate is characterized in that it comprises a trauma compensation plate.

(Example)

Hereinafter, a transflective liquid crystal display according to an exemplary embodiment of the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of a transflective liquid crystal display device according to a first embodiment of the present invention, and FIG. 3 is a method of manufacturing a transflective liquid crystal display device according to a first embodiment of the present invention. 4A to 4H are cross-sectional views illustrating a method of manufacturing a transflective liquid crystal display device according to a first embodiment of the present invention.

Referring to the transflective liquid crystal display device according to the first embodiment of the present invention, as shown in FIG. 2, the lower substrate 31 and the upper substrate 51 are arranged with a predetermined space therebetween. The liquid crystal layer 71 is arranged in a structure.

Here, a transparent transparent electrode 33 is arranged on the lower substrate 31, and a polymer resin layer 35 having a plurality of embossing 35a is formed on a portion of the transparent transparent electrode 33. The reflective electrode 37 is formed on the surface of the polymer resin layer 35.

Further, an alignment film having a large pretilt angle is formed on the reflective electrode 37, and an alignment film having a small pretilt angle on a portion of the transparent transparent electrode 33 in which the reflective electrode 37 is not formed. 43a is formed.

On the other hand, an RGB resin layer 53 is formed on the upper substrate 51, an upper transparent electrode 55 is formed on the RGB resin layer 53, and the large transparent electrode 55 is formed on the surface of the upper transparent electrode 55. An alignment film 39a having a pretilt angle, an alignment film 43a having a small pretilt angle, an alignment film 57 having a large pretilt angle corresponding to each other, and an alignment film 59 having a small pretilt angle are formed. .

Through this configuration, it is reflected through the portion of the alignment film 39a having the large pretilt angle, and the remaining part is transmitted through the portion of the alignment film 59 having the small protilt angle arranged on the upper substrate 51.

A method of manufacturing a semi-transmissive liquid crystal display device having such a configuration will be described below with reference to the accompanying drawings.

4A to 4H are cross-sectional views illustrating a method of manufacturing a transflective liquid crystal display device according to a first embodiment of the present invention.

In the method of manufacturing a transflective liquid crystal display according to the first embodiment of the present invention, as shown in FIG. 4A, the transparent transparent electrode 33 is arranged on the translucent substrate 31, and the transparent transparent electrode 33 is transparent. A polymer resin layer 35 having a plurality of embossing 35a is formed on a portion of the. At this time, the thickness of the polymer layer is formed to be the minimum in consideration of the step with the removed resin layer of the transmission portion, and then the reflective electrode 37 is formed on the surface of the polymer resin layer (35).

Then, as shown in Figure 4b, a high pretilt alignment agent 39 is coated on the upper surface of the entire structure.

Subsequently, as shown in FIG. 4C, the portion of the high pretilt alignment agent 39 corresponding to the transmissive portion is blocked by the first exposure mask 41, and then the exposure process is performed.

Next, as shown in FIG. 4D, the high pretilt alignment agent 39 in the region where the light is blocked is removed through the developing process after the exposure process is performed.

Subsequently, as shown in FIG. 4E, the low pretilt alignment agent 43 is coated on the upper surface of the entire structure including the portion of the high pretilt alignment agent pattern 39a positioned in the reflecting portion.

Next, as shown in FIG. 4F, the exposure process is performed in a state where the second exposure mask 43 is disposed above the high pretilt alignment agent pattern 39a corresponding to the reflecting area. Light is irradiated to the said low pretilt aligning part 43 part.

Subsequently, as shown in FIG. 4G, the development process is performed to remove the portion of the low pretilt aligning agent 43 in the reflecting region where the light is not irradiated to remove the low pretilt aligning agent in the transmissive region ( 43a).

Next, as shown in FIG. 4H, the upper and lower substrates on which the high pretilt alignment agent pattern 39a and the low pretilt alignment agent pattern 43a are formed are cured and rubbed to form a unit pixel. A substrate having different pretilt angles is obtained in the inside.

In the liquid crystal cell having the above structure, the liquid crystal molecules are aligned with high pretilt in the reflection part, and the transmission part is aligned with low pretilt. Here, high pretilt means a pretilt angle of 8 degrees or more, more preferably 10 degrees or more, and a low pretilt angle of pretilt angle of 6 degrees or less, more preferably 5 degrees or less.

An example of forming a high pretilt angle and a low pretilt angle in the pixel, and another method is to coat the same alignment agent and then to change the orientation conditions of the photo-alignment high and high pretilt angle region and low pretilt Each region may be formed. Alternatively, a high pretilt region and a low pretilt region may be formed in one pixel by depositing a DLC (diamond like carbon) alignment layer and adjusting ion beam conditions.

3 is a schematic diagram of the refractive index of the liquid crystal of the reflecting unit, in which case the refractive index anisotropy (Δn) of the liquid crystal of the reflecting unit corresponds to Δn 'corresponding to the shadow of the inclined array liquid crystal. In other words, the liquid crystal having the same refractive index can control the liquid crystal array inclination angle of the reflecting portion to reduce the refractive index anisotropy (Δn) of the liquid crystal. Can design at 2 levels.

In this case, the rubbing unevenness in the unit pixels is prevented by uniform rubbing by flattening the unit pixels while increasing the light efficiency, thereby improving the screen quality.

Meanwhile, the transflective liquid crystal display according to the second embodiment of the present invention will be described.

5 is a cross-sectional view for describing a transflective liquid crystal display device according to a second embodiment of the present invention, and FIG. 6 is an equivalent circuit diagram of a transflective liquid crystal display device according to a second embodiment of the present invention.

Referring to the transflective liquid crystal display according to the second embodiment of the present invention, as shown in FIG. 5, the lower substrate 81 and the upper substrate 91 are arranged with a predetermined space therebetween. The liquid crystal layer 101 is arranged in between.

Here, the reflecting portion A and the transmissive portion B are defined in the unit pixel of the lower substrate 81 so that the transmissive portion transparent electrode 83 is arranged in these areas, that is, a part of the transmissive portion transparent electrode 83, A polymer resin layer 85 having a plurality of embossing 85a is formed on the reflective portion A, and a reflective electrode 87 is formed on the surface of the polymer resin layer 85, while the transmissive portion B is formed. ) Is a transparent polymer resin layer 85 is formed without embossing.

In addition, a reflective electrode 87 made of an opaque metal having a good reflectance of aluminum series or silver series is formed on the polymer embossing 85a on the reflection portion A side.

The transmissive electrode 83 and the reflective electrode 87, which are pixel electrodes formed on the lower substrate 81, are connected to a source electrode.

In addition, a patterned BM layer (not shown) and an RGB resin layer 93 are formed on the upper substrate 91, and a transparent electrode 95 serving as a counter electrode is formed thereon.

On the other hand, the upper and lower substrates 81 and 91 are coated with alignment films 89 and 99, and the surfaces of these alignment films 89 and 97 are rubbed.

After the process of injecting the liquid crystal between the upper and lower substrates 81 and 91 manufactured as described above to complete the liquid crystal cell, the upper and lower substrates 81 and 91 are not shown in the drawings, but the respective polarizing plates and the upper Compensation film is attached to the substrate to complete the transflective liquid crystal cell.

FIG. 6 is an equivalent circuit according to a second embodiment of the present invention of FIG. 5, wherein the reflecting portion and the transmitting portion have different capacitances formed between the pixel electrode and the counter electrode.

The total potential difference V _reflection connected in series with the _reflector is expressed as follows.

V _reflection = V _PI + V _LC + V _PI , and q = CV can be expressed as V _reflection = q (1 / C _PI + 1 / C _LC + 1 / C _PI ).

Similarly, the series connected total potential difference V _transmission of the _transmission is as follows.

V _transmission = V _PI + V _LC + V _PI + V _resin , and q = CV can be expressed as V _transmission = q (1 / C _PI + 1 / C _LC + 1 / C _PI + 1 / C _resin ). .

Here, in the transmission region, a polymer resin layer having a high dielectric constant and a thick film thickness is inserted between the pixel electrode and the counter electrode, and thus requires more voltage. On the contrary, when the voltage is constant, voltage loss occurs.

FIG. 7 is a graph showing transmission characteristics according to voltages of the transmission part and the reflection part according to the second embodiment. As can be seen from FIG. 7, when the same voltage is applied, a higher voltage is applied to the liquid crystal due to less voltage loss than the transmission part. As a result, when the vicinity of the transmittance inflection point of the transmission part is set to the white voltage, the reflection part A is inclined to the liquid crystal molecules.

As described above, according to the semi-transmissive liquid crystal display according to the present invention and a method of manufacturing the same, the liquid crystal having the same refractive index can be adjusted to reduce the refractive index anisotropy (Δn) of the liquid crystal by adjusting the inclination angle of the liquid crystal array of the reflector As a result, the phase delay value (Δnd) of the reflector can be lowered to design the half level of the transmissive part. In this case, the rubbing unevenness in the unit pixels is prevented by uniform rubbing by flattening the unit pixels while increasing the light efficiency, thereby improving the screen quality.

In addition, another method approach of the semi-transmissive optical design can solve the problem of rubbing nonuniformity due to the step in the unit pixel while maximizing the light efficiency of the transmissive part and the reflecting part.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (14)

Upper and lower substrates; A transmissive electrode formed of a transparent electrode on the lower substrate; A reflection portion having an embossed pattern formed on the transmission electrode on the lower substrate and a transmission portion having no resin layer; A first high pretilt alignment film and a first low pretilt alignment film formed on the reflective electrode and the transmissive electrode formed on the surface of the embossed pattern of the reflective part, respectively; An RGB resin layer and a transparent electrode formed under the upper substrate; A second high pretilt alignment layer and a second low pretilt alignment layer formed under the transparent electrode and respectively corresponding to the first high pretilt alignment layer and the first low pretilt alignment layer; A liquid crystal layer arranged between the upper and lower substrates; Semi-transmissive liquid crystal display device comprising a. The transflective liquid crystal display device according to claim 1, wherein the embossing pattern of the reflecting portion is made of a polymer resin. The transflective liquid crystal display device according to claim 1, wherein a compensation film is attached to the upper and lower substrates on the polarizer and the upper substrate. The transflective liquid crystal display of claim 1, wherein the pretilt angle of the reflector is greater than the pretilt angle of the transmissive part. The semi-transmissive liquid crystal display device according to claim 1, wherein the pretilt angle of the high pretilt alignment layer is 10 degrees or more and the pretilt angle of the low pretilt alignment layer is 5 degrees or less. Upper and lower substrates; A transmissive electrode formed on the lower substrate; A transmissive part formed on the transmissive electrode part and having a reflecting part composed of a polymer resin layer having an embossing pattern and a flat polymer resin layer remaining; A reflection electrode formed on the embossing pattern of the reflection part; An RGB resin layer and an upper transparent electrode formed on the upper substrate; An alignment layer formed on the reflective part of the lower substrate and the transparent electrode formed on the upper substrate; And And a liquid crystal layer arranged between the upper and lower substrates. The transflective liquid crystal display device according to claim 6, wherein a phase compensation film is attached to the upper and lower substrates on the polarizer and the upper substrate. Providing an upper and lower substrate; Forming a transparent electrode formed of a transparent electrode on the lower substrate; Forming a reflective part having an embossed pattern and a transparent part having no resin layer on the transparent electrode on the lower substrate; Forming a first high pretilt alignment layer and a first low pretilt alignment layer on the reflective electrode and the transmissive electrode formed on the surface of the embossing pattern of the reflecting unit; Forming an RGB resin layer and a transparent electrode under the upper substrate; Forming a second high pretilt alignment layer and a second low pretilt alignment layer respectively corresponding to the first high pretilt alignment layer and the first low pretilt alignment layer under the transparent electrode; And Arranging the liquid crystal layer between the upper and lower substrates; semi-transmissive liquid crystal display device manufacturing method comprising a. The method of claim 8, wherein the embossing pattern of the reflector is formed of a polymer resin. 10. The method of claim 8, further comprising attaching a compensation film to the upper and lower polarizers and the upper substrate. The method of claim 8, wherein the pretilt angle of the reflector is greater than the pretilt angle of the transmissive part. The method of claim 8, wherein the pretilt angle of the high pretilt alignment layer is 10 degrees or more and the pretilt angle of the low pretilt alignment layer is 5 degrees or less. Providing an upper and lower substrate; Forming a transmissive electrode on the lower substrate; A high difference layer formed on the transmissive electrode portion, wherein a portion of the polymer layer forms an embossed pattern to be a reflecting portion position, and a portion of the polymer layer remains as a flat polymer layer without the embossing pattern to form a transmissive portion; Forming a reflective electrode on the embossed pattern of the reflective part; Forming an RGB resin layer and an upper transparent electrode on the upper substrate; Forming an alignment layer on the reflecting portion, the transmitting portion, and the upper transparent electrode of the lower substrate; And And arranging a liquid crystal layer between the upper and lower substrates. 15. The method of claim 13, further comprising attaching a phase compensation film to the upper and lower substrates to the polarizer and the upper substrate.

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