KR100296873B1 - Liquid crystal display and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A liquid crystal display and a method for manufacturing the same are provided to increase the transmissivity with respect to respective driving cells by re-reflecting light, the light not passing through a polarization plate but being reflected. CONSTITUTION: A liquid crystal display includes a viewing angle expansion layer(20) formed between a top glass substrate(2) and a polarization plate(10) for expanding a viewing angle and improving discrimination and the viewing angle expansion layer includes top and bottom surfaces(201,202) having different size from each other and inclined side surface parts(203) formed in the shape of sawtooth and extended to the periphery of the top and bottom surfaces.

Description

LCD and its manufacturing method

1 is a cross-sectional view showing an embodiment of a liquid crystal display device provided with a viewing angle expanding layer according to the present invention.

2 is a plan view showing a viewing angle expanding layer according to the present invention.

3 is a side cross-sectional view showing a method of manufacturing a liquid crystal display device according to an embodiment of the present invention.

4 is a cross-sectional view showing an operation state of the viewing angle magnification layer according to an embodiment of the present invention.

Figure 5 is a cross-sectional view showing a viewing angle magnification layer action state of another embodiment according to the present invention.

6 is a cross-sectional view showing an example of a conventional liquid crystal display device.

* Explanation of symbols for main parts of the drawings

DESCRIPTION OF SYMBOLS 1: Upper surface glass substrate 20: Viewing angle expansion layer

40: metal film

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD) and a method of manufacturing the same, and more particularly, by providing a viewing angle enlargement layer made of a metal film on an upper glass substrate of an LCD, The present invention relates to an LCD manufacturing apparatus and a method of manufacturing the same, which not only enlarge the narrow viewing angle of the LCD due to birefringence but also improve the visibility of the product.

[Prior art]

In general, LCD, which is one type of flat panel display, usually has two conductive plate materials arranged in parallel, injects a liquid crystal having dielectric anisotropy therebetween, It is known to display predetermined letters, numbers, or any other image by using light reflecting properties different from each other.

In addition, the LCD has low power consumption, low voltage driving, thinness, and lightness in terms of its characteristics, and is used for vehicle loading, color TV image, etc. in addition to the display of a laptop computer or a pocket computer. Its use is rapidly expanding.

The LCD has a structure in which two glass substrates face each other, a spacer is inserted to maintain a predetermined gap therebetween to form an internal space, and then the liquid crystal is injected into the space. The bar will be made in more detail with reference to the accompanying drawings as follows.

FIG. 6 is a cross-sectional view showing the structure of a known LCD, and as shown in FIG. 6, a common electrode or a segment electrode is formed on the inner facing surfaces of two transparent upper and lower glass substrates 30 and 31 arranged in parallel. ITO (Induim Tin Oxide) transparent conductive films 32 and 33 are formed, and an alignment film 34 for limiting the dielectric anisotropy of the liquid crystal is deposited.

On the other hand, the two glass substrates 30 and 31 described above are coated and sintered to the peripheral portion of the sealant 35, which is a conventional sealing material, except for the injection hole (not shown) of the liquid crystal, thereby forming a liquid crystal cell.

Inside the liquid crystal cell, spacers 36 are inherent to maintain a constant cell gap between the upper and lower glass substrates 30 and 31.

Thus, after the liquid crystal is injected into the liquid crystal cell through the injection hole, the liquid crystal injection hole is sealed, and the polarizing plate 37 is attached to the outer surfaces of the upper and lower glass substrates 30 and 31.

In addition, a retardation film 38 is interposed between the upper glass substrate 30 and the polarizing plate 37 to compensate for the display color coloring problem occurring in the LCD.

The operation of the conventional LCD made in this way, first, when a current is applied to the transparent conductive film (32, 33) formed on the inner facing surface of the upper and lower glass substrates (30, 31), an electric field is formed therebetween, The liquid crystal contained therein is distorted in the direction in which the alignment layer 34 is set by dielectric anisotropy, thereby refracting external light in the direction of molecular arrangement.

As a result, a portion in which the distorted liquid crystal exists in the display area of the liquid crystal, that is, a cell formed by the intersection of the common electrode and the segment electrode, transmits light to other cells, thereby displaying a predetermined image.

Such a method of manufacturing the LCD will be briefly described through each process as follows.

First, an image process of coating and exposing a photoresist to a glass substrate to form a desired transparent conductive film on the glass substrate, and through this image process, an alignment layer is applied on the glass substrate on which the transparent conductive film is formed and the liquid crystals can be arranged. An alignment film treatment step of treating the film is performed.

Next, a printing process of printing an epoxy-based adhesive to form a gasket to inject liquid crystal, and a spacer coating process of forming a spacer to maintain a constant cell gap between the upper and lower glass substrates. Run

Next, an assembly process of joining two printed glass substrates together to prevent misalignment, a cutting process of cutting the glass substrate after the assembly and separating the plurality of glass substrates into a plurality of liquid crystal cells, and a cut and separated liquid crystal cell. After injecting the liquid crystal, the liquid crystal injection process for sealing the inlet, the inspection process for visual inspection and electrical property inspection to examine the properties of the finished product, and the polarizing plate and phase difference on the front and back of the finished product. The product is completed by a module process of attaching a film and attaching a printed circuit board (PCB) to an electrode pad.

[Problem trying to solve the invention]

As described above, the LCD made through the above-described configuration and method has a light-receiving type that can be displayed by receiving light through a constant light source, while the element itself of other flat panel displays is light-emitting.

Therefore, the LCD is relatively easy to recognize the display when the user is viewed from the front, but when viewed at the left and right sides or at a predetermined angle, the LCD has a narrower viewing angle due to its birefringence, which is a characteristic of the liquid crystal. It has a chronic difficulty of inferior visibility.

In order to improve this problem, there has been proposed a method of providing a flat panel for viewing angle magnification in the LCD along with the continuous study of the LCD according to the birefringence of the liquid crystal, but the price is too high and the effect is not so great. There is a fundamental difficulty in solving the problem.

Accordingly, the present invention is to solve the problems of the conventional LCD as described above, and to improve the display quality by increasing the visibility and narrow viewing angle of the LCD due to the birefringence of the liquid crystal display device and Its purpose is to provide a method of manufacturing the same.

[Means to solve the problem]

Accordingly, in order to realize the above object, the present invention provides an ITO electrode and an alignment film which are formed to be stacked in the upper and lower glass substrates arranged in parallel to each other, a spacer disposed between the glass substrates, and a liquid crystal cell. A liquid crystal display comprising a liquid crystal injected into a glass, a polarizing plate attached to an outer surface of the glass substrate, and a retardation film, wherein an enlarged viewing angle of the liquid crystal display device is provided between the upper glass substrate and the corresponding polarizing plate. The present invention provides a liquid crystal display device having a viewing angle enlargement layer capable of improving visibility.

In this case, the viewing angle expanding layer is formed of a metal film formed by dot arrangement.

In addition, the viewing angle magnification layer is characterized in that it is formed of a trapezoidal quadrangular column provided with an upper and lower surfaces and different inclined side portions extending around the upper and lower surfaces.

On the other hand, in the viewing angle enlargement layer is made as described above, characterized in that the inclined side portion is formed in the sawtooth shape.

The metal film is made of one of Cr, Ni or Al.

In addition, the present invention comprises the steps of coating a metal film on the outer surface of the glass substrate on which the ITO electrode is formed; Applying a photosensitive agent onto said metal film and exposing through a predetermined mask; Developing the photosensitive agent to form and harden a predetermined pattern; It provides a method for manufacturing a liquid crystal display device comprising a strip process of etching the metal film and peeling off the photosensitive agent.

At this time, the photosensitive agent is coated and characterized in that the exposure process is carried out twice.

The coating of the metal film is characterized in that it is made of 600 ~ 2,000Å thickness.

[Action]

The LCD of the present invention thus made allows the viewing angle magnification layer to better reflect and scatter incident light administered from a light source such as a back light to reproduce high quality images.

That is, some incident light reflected by the retardation film and not passing through the polarizing plate after passing through the upper surface glass substrate is reflected back from the side portion of the viewing angle expanding layer and introduced into the polarizing plate, thereby making the viewing angle wider than before.

EXAMPLE

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

1 is a cross-sectional view showing a state in which the LCD according to the present invention is provided with a viewing angle expanding layer according to the present invention.

As illustrated, the LCD of the present invention has the ITO transparent electrodes 3 and 4 and the alignment films 5 and 6 stacked in the upper and lower glass substrates 1 and 2 formed in parallel and interposed therebetween. In the upper and lower glass substrates 1 and 2, the spacers 7 are scattered so as to maintain a constant distance, and the upper and lower glass substrates 1 and 2 are coated with a sealing material 8 and Sintered to form a liquid crystal cell.

In addition, liquid crystal is injected into the space between the upper and lower glass substrates 1 and 2, and respective polarizing plates 9 and 10 are attached to the outer surfaces of the upper and lower glass substrates 1 and 2. The phase difference film 11 is provided between the upper surface glass substrate 1 and the upper polarizing plate 10.

Here, the viewing angle magnification layer 20 is formed at the upper end of the upper surface glass substrate 1 so that the viewing angle of the LCD can be enlarged. As shown in the drawing, the viewing angle magnification layer 20 has a trapezoidal cross section. It is provided with a metal film made of a mold.

In other words, the viewing angle expanding layer 20 includes upper and lower surfaces 201 and 202 having different sizes and inclined side portions 203 extending around the upper and lower surfaces 201 and 202.

On the other hand, the viewing angle expanding layer 20 according to the present invention in another embodiment, as shown in Figure 5 may be provided in the shape of the inclined side surface portion 203 having a sawtooth shape.

The viewing angle magnification layer 20 is made of Cr, Ni, Al, etc., and appears to be in a lattice form on the upper surface glass substrate 1, but in fact, the lower portion of the viewing angle magnification layer 20 is described above. The side surface 202 is attached to the upper surface glass substrate 1, which corresponds to a portion having no pattern by crossing the ITO transparent electrodes 3 and 4, that is, the segment electrode and the common electrode, and forms a point disposed state. (See Figure 2)

Referring to Figure 3 (a) to (e) of the accompanying drawings the LCD manufacturing method of the present invention made as described above are as follows.

First, as shown in FIG. 3 (a), on the glass substrates 1 and 2 on which the ITO transparent electrodes 3 and 4 are formed in a predetermined pattern, for installing the viewing angle enlargement layer 20 of the present invention. The metal film 40 (for example, Cr, Ni, Al, etc.) is coated.

At this time, the metal film 40 is coated to a thickness of 600 ~ 2,000Å by a known sputtering method, E-beam evaporating method or the like.

Subsequently, the metal film 40 is patterned by the same method as the method for patterning the ITO transparent electrodes 3 and 4 by photolithography.

Photoresist P is coated on the upper surface of the metal film 40, and a predetermined pattern is formed by exposing and developing a predetermined mask (not shown). After that, the curing process proceeds. (See Figures 3 (b) and (c).)

Subsequently, as shown in FIG. 3 (d), the portion of the metal film 40 corresponding to the portion from which the photoresist P has been removed is selectively etched to form a viewing angle enlarged layer as described above. 20 is patterned.

Next, the viewing angle expanding layer 20 is formed as shown in FIG. 3E through a stripping process and a rinsing and cleaning process to strip off the remaining portion of the photoresist P. Referring to FIG.

Thereafter, the remaining steps of manufacturing the LCD of the present invention, that is, the assembly process, the liquid crystal injection process, the polarizing plate and the retardation film attaching process, and the like are performed as before.

On the other hand, the formation of the viewing angle magnification layer 20 according to another embodiment of the present invention, in the above-described manufacturing method, if the other parts are the same, after the photoresist (P) is coated, the exposure energy during exposure 30mJ If the exposure is performed twice at / cm 2 or less, selective patterning as shown in FIG. 5 becomes possible.

In the LCD of the present invention manufactured as described above, when the image is reproduced on the working surface thereof, as shown in FIG. 4, light emitted from a predetermined light source and polarized light passes through the upper surface glass substrate 1 and the phase difference. Passing through the upper polarizing plate 9 through the film 11, some of the light hit the retardation film 11 is reflected.

The reflected light is reflected back from the inclined side surface portion 203 of the viewing angle expanding layer 20 to be re-introduced into the upper surface of the LCD.

Therefore, for each drive cell displaying an image, more light is transmitted, so that the viewing angle for the entire image can be widened.

In addition, when forming the viewing angle enlargement layer 20 provided with the serrated inclined side portion 203 shown in FIG. 5 and using it in the LCD of the present invention, it is possible to send the reflected light more widely, thereby further expanding the viewing angle. Will perform.

[Effects of the Invention]

As described above, the LCD according to the present invention has a viewing angle enlargement layer capable of re-reflecting and reflecting some of the light that is not passed through the polarizing plate and is reflected by the driving cell when the LCD is driven to reproduce the image. By providing the LCD on the LCD, the transmittance of each driving cell may be increased to realize a clearer image.

For this reason, the viewing angle with respect to a display image is expanded, and the visibility of LCD is improved, and the product which is excellent in display quality is attained.

Claims (6)

An ITO electrode and an alignment film which are formed to be stacked in the upper and lower glass substrates arranged in parallel to each other; A spacer disposed between the glass substrate; A liquid crystal injected into such a liquid crystal cell; In the liquid crystal display device comprising a polarizing plate and a retardation film attached to the outer surface of the glass substrate, between the upper surface glass substrate and the corresponding polarizing plate, it is possible to increase the viewing angle and improve visibility of the liquid crystal display device A viewing angle magnification layer is provided, wherein the viewing angle magnification layer is formed of a metal film having an upper and lower surfaces formed of different sizes and an inclined side portion that extends around the upper and lower surfaces. The liquid crystal display device according to claim 1, wherein the inclined side portions of the viewing angle enlargement layer are serrated. The liquid crystal display device according to claim 1, wherein the metal film is made of one of Cr, Ni, and Al. Coating a metal film on the outer surface of the glass substrate on which the ITO electrode is formed; Applying a photosensitive agent onto said metal film and exposing through a predetermined mask; Developing the photosensitive agent to form and harden a predetermined pattern; And a stripping process of etching the metal film and peeling off the photosensitive agent. The method of manufacturing a liquid crystal display device according to claim 4, wherein the exposure step is performed twice. The method of claim 4, wherein the metal film is coated with a thickness of 600 to 2,000 μm.