KR20080047023A - Liquid crystal panel and method of making the same - Google Patents

Abstract

An LCD(Liquid Crystal Display) panel and a manufacturing method thereof are provided to insert a glass substrate between the upper and lower substrates and to adhere polarizing panels between the glass substrate and the upper and lower substrates. The upper and lower substrates(111,113) are arranged oppositely to each other. A liquid crystal layer is formed between the upper substrate and the lower substrate. The first glass substrate(120) and the second glass substrate(122) are formed at the upper and lower surfaces of the upper and lower substrates. The first polarizing panel(130) and the second polarizing panel(132) are attached on the upper and lower surfaces of the first and second glass substrates. The first glass substrate and the first polarizing panel are formed by the same size and the second glass substrate and the second polarizing panel are formed by the same size.

Description

Liquid crystal panel and its manufacturing method {LIQUID CRYSTAL PANEL AND METHOD OF MAKING THE SAME}

1 is a view schematically illustrating a general liquid crystal display.

2 is a schematic cross-sectional view of a liquid crystal panel having a conventional flat plate.

3 is a diagram illustrating a problem that warpage occurs in a conventional liquid crystal panel having a flat plate.

4 is a perspective view schematically illustrating a liquid crystal panel according to an exemplary embodiment of the present invention.

5 is a cross-sectional view showing the structure of a general polarizing plate.

6 is a schematic cross-sectional view of a liquid crystal panel according to an exemplary embodiment of the present invention.

7 is a schematic cross-sectional view of a liquid crystal panel according to another exemplary embodiment of the present invention.

8 is a flowchart schematically illustrating a method of manufacturing a liquid crystal panel according to an exemplary embodiment of the present invention.

9 is a flowchart for explaining the manufacturing method of FIG. 8 in detail.

10 is a flowchart illustrating a method of manufacturing a liquid crystal panel according to another exemplary embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

110: liquid crystal cells 111, 611, 711: upper substrate

113, 613, 713: lower substrate 120, 620, 720: first glass substrate

122, 622, 722: second glass substrate 130, 630, 730: first polarizing plate

132, 632, and 732: second polarizing plate 500: polarizing plate

510: adhesive layer 520, 540: first and second TAC

530: PVA 550: release film

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal panel and a manufacturing method thereof.

In general, a liquid crystal display device arranges two substrates on which electrodes are formed so as to face each other, forms a liquid crystal between the two substrates, and then moves the liquid crystal molecules by an electric field generated by applying a voltage to the two electrodes. It is a device that expresses the image by adjusting the transmittance.

1 is a view schematically showing a liquid crystal panel for a general liquid crystal display device.

As illustrated, a general liquid crystal display device is largely composed of an upper substrate 10 and a lower substrate 20, and a liquid crystal layer 40 between the upper substrate 10 and the lower substrate 20.

The upper substrate 10 includes a black matrix 12 between the color filter 14 and the color filter 14 on the transparent insulating substrate, and the common electrode 18 under the color filter 14 and the black matrix 12. ) Is deposited.

The lower substrate 20 is defined as a pixel region P and a non-pixel region, and the pixel electrode 36, the thin film transistor Tr, and the array wirings 22 and 24 are formed on the pixel region P. FIG.

The lower substrate 20 is also called an array substrate, and the thin film transistor Tr, which is a switching element, is disposed in a matrix type. The gate wiring 22 and the data wiring 24 are formed to cross the plurality of thin film transistors Tr.

In addition, upper and lower polarizing plates (72 and 70 in FIG. 2) are respectively positioned on the upper and lower surfaces of the liquid crystal panel, and a backlight unit having a lamp and light scattering means is disposed below the lower polarizing plate, an exterior case, and the like. By providing this, a liquid crystal display device is comprised.

FIG. 2 is a schematic cross-sectional view of a liquid crystal panel having a conventional flat plate, and FIG. 3 is a view for explaining a problem in which warpage occurs in the liquid crystal panel having a conventional flat plate.

Referring to FIG. 2, the liquid crystal panel according to the related art has a lower substrate 50 having a thin film transistor and a pixel electrode formed on an insulating substrate, an upper substrate 60 having a color filter formed on the insulating substrate, a lower substrate 50, and an upper substrate. Two polarizing plates 70 and 72 are provided on the upper and lower surfaces of the substrate 60, respectively.

Although not shown in FIG. 2, a liquid crystal layer (not shown) is further included between the lower substrate 50 and the upper substrate 60.

The two polarizing plates 70 and 72 provided on the upper and lower surfaces of the liquid crystal panel each include polarizers, and serve to polarize light passing through the polarizing plate in only one direction.

However, the conventional polarizing plates 70 and 72 are contracted in the stretching direction in response to a change in temperature or humidity, as shown in FIG. 3, such that the polarizing plates 70 and 72 are bent in a predetermined direction. In addition, as the temperature generated from the lamp becomes very high, the liquid crystal panel positioned on the upper part of the lamp is also bent in a predetermined direction by being affected by the temperature, wherein the bending directions of the polarizing plates 70 and 72 and the bending direction of the liquid crystal panel are In the same case, the degree of warpage of the liquid crystal panel becomes more severe.

Accordingly, there is a problem that a screen defect such as black luminance nonuniformity occurs.

Accordingly, an object of the present invention is to provide a liquid crystal panel capable of maintaining a uniform screen quality over the entire area of the liquid crystal panel by improving the warpage phenomenon of the liquid crystal panel by the polarizing plate.

Another object of the present invention is to provide a method for manufacturing a liquid crystal panel for improving the warpage of the liquid crystal panel.

Further technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above are clearly understood by those skilled in the art from the following description. It can be understood.

According to an embodiment of the present invention, a liquid crystal panel includes an upper substrate and a lower substrate disposed to face each other, a liquid crystal layer formed between the upper substrate and the lower substrate, and upper and lower surfaces of the upper substrate and the lower substrate. And a first polarizing plate and a second polarizing plate respectively attached to upper and lower surfaces of the first and second glass substrates, respectively.

In the method of manufacturing a liquid crystal panel according to the present invention, (a) manufacturing a liquid crystal cell composed of an upper substrate, a lower substrate, and a liquid crystal layer, (b) a first glass substrate and a second on the upper and lower surfaces of the liquid crystal cell; Forming a glass substrate, respectively, and (c) forming a first polarizing plate and a second polarization on the upper and lower surfaces of the first glass substrate and the second glass substrate, respectively.

In another aspect, the method of manufacturing a liquid crystal panel according to the present invention comprises the steps of (a) manufacturing a liquid crystal cell composed of an upper substrate, a lower substrate, and a liquid crystal layer, (b) a top and bottom surfaces of the first and second glass substrates. Forming a first polarizing plate and a second polarizing plate, respectively, and (c) forming the first and second glass substrates on the upper and lower surfaces of the upper and lower substrates, respectively.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

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

4 is a perspective view schematically illustrating a liquid crystal panel according to an exemplary embodiment of the present invention.

Referring to FIG. 4, a liquid crystal panel according to an exemplary embodiment of the present invention includes a liquid crystal formed between the upper substrate 111 and the lower substrate 113 and the upper substrate 111 and the lower substrate 113 disposed to face each other. A first glass substrate 120, a second glass substrate 122, and a first glass substrate 120 formed on the upper and lower surfaces of the layer (not shown), the upper substrate 111, and the lower substrate 113, respectively. The first polarizing plate 130 and the second polarizing plate 132 are formed on the upper and lower surfaces of the second glass substrate 122, respectively.

The upper substrate 111 includes a black matrix for blocking light leakage on a transparent insulating substrate, and a color filter layer including color filters of red (R), green (G), and blue (B). In addition, an overcoat layer may be further included to planarize the color filter layer.

In the lower substrate 113, a plurality of gate lines and data lines are arranged to cross each other, and a unit pixel region P is defined by crossing, and a pixel electrode and a thin film transistor are formed in the defined pixel region P.

The liquid crystal layer (not shown) varies the alignment of the liquid crystal molecules according to a vertical electric field between the upper substrate 111 and the lower substrate 113, or a horizontal electric field inside the lower substrate 113. By varying the amount of light transmitted, various image information is displayed.

Reference numeral 110 denotes a liquid crystal cell, in which the upper substrate 111 and the lower substrate 113 are cut in cell units.

In general, as shown in the liquid crystal panel, the lower substrate 113 is formed larger than the upper substrate 111. This is to form a data pad part (not shown) and a gate pad part (not shown) on the lower substrate 113 to be connected to an external driving circuit.

The first glass substrate 120 and the second glass substrate 122 are transparent insulating substrates, and are substrates having no influence by passing the incident light as they are. This may be referred to as an auxiliary substrate for preventing bending of the polarizing plate.

For convenience of description, the glass substrate formed on the upper surface of the upper substrate 111 is referred to as the first glass substrate 120, and the glass substrate formed on the lower surface of the lower substrate 113 is referred to as the second glass substrate 122.

As illustrated, the first polarizer 130 and the second polarizer 132 are formed on the upper and lower surfaces of the first glass substrate 120 and the second glass substrate 122, respectively.

The first polarizing plate 130 formed on the upper surface of the first glass substrate 120 and the second polarizing plate 132 formed on the lower surface of the second glass substrate 122 may have the same properties, or may be attached to each other. Depending on the characteristics of the device, polarizing plates having different characteristics may be attached.

For example, a liquid crystal display having a wide viewing angle may attach a polarizing plate having a compensation film for the wide viewing angle internally to an upper surface of the upper substrate 111, and attach a general polarizing plate to a lower surface of the lower substrate 113. Done. In this case, the two polarizing plates vary in the direction of the polarizer, the strength of the pressure-sensitive adhesive layer, the degree of stretching when the polarizer is formed, and the number of laminated layers.

In addition, the first glass substrate 120, the first polarizing plate 130, the second glass substrate 122, and the second polarizing plate 132 should be provided with the same size.

5 is a cross-sectional view illustrating a structure of a general polarizer, and a structure thereof will be described.

The polarizer 500 generally includes an adhesive layer 510, a first triacetylcellulose (TAC) film 520, a polyvinylalcohol (PVA) film 530, a second TAC film 540, and a release film 550 in this order. Has a structure.

The PVA film 530 is stretched in a predetermined direction and dyed with a dye having a second color. Since the PVA film 530 is a stretched film, the PVA film 530 is easily contracted or expanded according to a change in temperature or humidity.

The first and second TAC films 520 and 540 are attached to both surfaces of the PVA film 530, and the adhesive layer 510 is formed of a polymer material having adhesive force, such that the polarizer 500 is the first glass substrate 120. ) And the second glass substrate 122.

The adhesive layer 510 has the same adhesive force to both the first glass substrate 120 and the second glass substrate 122.

When the first polarizing plate 130 and the second polarizing plate 132 configured as described above are formed on the first glass substrate 120 and the second glass substrate 122 as shown in FIG. 4, the first glass substrate 120 is formed. ) And the inner adhesive layer 510 facing each other on the outside of the second glass substrate 122 and then the respective adhesive layers 510 are disposed on the first glass substrate 120 and the second glass substrate 122. It is attached to each of the first glass substrate 120 and the second glass substrate 122 by contacting the.

6 is a cross-sectional view schematically showing a liquid crystal panel according to an embodiment of the present invention, and FIG. 7 is a cross-sectional view schematically showing a liquid crystal panel according to another embodiment of the present invention.

The first and second polarizers of the liquid crystal panel according to the exemplary embodiment of the present invention are designed in consideration of only the active region in which an image is displayed, regardless of their characteristics, and are generally larger than the active region.

Referring to FIG. 6, a liquid crystal panel according to an exemplary embodiment of the present invention may include a first polarizer 630 positioned on an upper surface of an upper substrate 611 and a second polarizer 632 positioned on a lower surface of a lower substrate 613. Is larger than the active region, but is formed in the same size.

However, the maximum size of the first and second polarizers 630 and 632 is limited to be smaller than the overall size of the liquid crystal panel.

Reference numerals 620 and 622 denote first and second glass substrates.

Referring to FIG. 7, the liquid crystal panel according to another exemplary embodiment of the present invention has a second polarizing plate 732 positioned on the bottom surface of the lower substrate 713 as compared to the first polarizing plate 730 located on the upper surface of the upper substrate 711. ) Has a larger size.

Since the lower substrate 713 is provided with a larger size than the upper substrate 711 by the pad portion connected to the external circuit, the size of the second polarizing plate 732 is largely formed in accordance with the lower substrate 713. to be.

Reference numerals 720 and 722 denote first and second glass substrates.

As described above, the liquid crystal panel according to the present invention does not directly adhere the polarizing plate to the existing upper substrate and the lower substrate, but indirectly attaches the glass substrate therebetween, thereby improving the bending phenomenon of the liquid crystal panel generated by the polarizing plate. can do.

In addition, since the polarizer is not directly attached to the liquid crystal cell, it may be easily repaired or replaced when a defect occurs in the polarizer.

Hereinafter, a process of manufacturing a liquid crystal panel according to an embodiment of the present invention will be described.

For reference, a method of manufacturing a liquid crystal panel according to an embodiment of the present invention will be described by dividing into two embodiments.

FIG. 8 is a flowchart illustrating a manufacturing method of a liquid crystal panel according to an exemplary embodiment of the present invention, and FIG. 9 is a flowchart illustrating the manufacturing method of FIG. 8 in detail.

In one embodiment of the present invention, the glass substrate forming process and the polarizing plate forming process are sequentially performed after the liquid crystal cell process.

First, referring to FIG. 8 in conjunction with FIG. 4, as a first step, a liquid crystal cell including an upper substrate 111, a lower substrate 113, and a liquid crystal layer (not shown) is manufactured (S10).

Next, two glass substrates 120 and 122 are formed on the upper and lower surfaces of the liquid crystal cell (S20).

The first glass substrate 120 is formed on the upper surface of the upper substrate 111 among the liquid crystal cells, and the second glass substrate 122 is formed on the lower surface of the lower substrate 113.

The first glass substrate 120 and the second glass substrate 122 have the same size as that of the first polarizing plate 130 and the second polarizing plate 132 to be formed in the following process.

Next, two first and second polarizing plates 130 and 132 are formed on the upper and lower surfaces of the first and second glass substrates 120 and 122, respectively, and then the manufacturing process of the liquid crystal panel is completed ( S30).

At this time, the first polarizing plate 130 and the second polarizing plate 132 are disposed so that the adhesive layers inside thereof face each other, and then contact the upper and lower surfaces of the first glass substrate 120 and the second glass substrate 122, respectively. By doing so, each polarizing plate 130, 132 is attached to the first glass substrate 120 and the second glass substrate 122, respectively.

In the above-described liquid crystal cell process, as illustrated in FIG. 9, first, a manufacturing process S11 of an upper substrate and a manufacturing process S12 of a lower substrate are separately performed.

The manufacturing process S11 of the upper substrate basically includes a process of forming a black matrix to block light leakage on the transparent insulating substrate, and a process of forming a color filter of red, green, and blue between the black matrix.

In the manufacturing process S12 of the lower substrate, a process of arranging a plurality of gate wirings and data wirings on a transparent insulating substrate, a process of forming a pixel electrode in a region where the plurality of gate wirings and data wirings intersect, and a plurality of Forming a thin film transistor at a point where the gate line and the data line cross each other.

Thereafter, the upper substrate 111 and the lower substrate 113 manufactured through the manufacturing process S11 of the upper substrate and the manufacturing process S12 of the lower substrate are bonded to each other (S13).

After bonding, the upper substrate 111 and the lower substrate 113 are cut in units of cells (S14).

Next, a liquid crystal layer is formed between the upper substrate 111 and the lower substrate 113 cut in units of cells through the liquid crystal (S15).

The liquid crystal cell has a gap of several μm in an area of several hundred cm 2. Therefore, as a method of forming a liquid crystal layer in the cell of such a structure, there exist an injection system using the pressure difference inside and outside a cell, the dropping system, etc.

10 is a flowchart illustrating a method of manufacturing a liquid crystal panel according to another exemplary embodiment of the present invention.

In another embodiment of the present invention, unlike the embodiment, after the liquid crystal cell process and the process of forming the polarizing plate on the glass substrate are separately performed, the process proceeds to the process of forming the glass substrate in the liquid crystal cell.

Referring to FIG. 4 in detail, as a first step, a liquid crystal cell including an upper substrate 111, a lower substrate 113, and a liquid crystal layer (not shown) is manufactured (S110).

The process for producing the liquid crystal cell has already been described and will be omitted.

Next, two polarizing plates 130 and 132 are formed on the two glass substrates 120 and 122, respectively.

As shown in FIG. 4, the first polarizing plate 130 is formed on the first glass substrate 120, and the second polarizing plate 132 is formed on the second glass substrate 122.

At this time, the size of the first glass substrate 120 and the second glass substrate 122 is determined according to the size of the first polarizing plate 130 and the second polarizing plate 132, and generally the first polarizing plate 130 and It is provided in the same manner as the size of the second polarizing plate 132.

In addition, as a method of forming two polarizing plates 130 and 132 on the first glass substrate 120 and the second glass substrate 122, as described above, adhesives formed in the two polarizing plates 130 and 132 may be used. After the layers face each other, the polarizing plates 130 and 132 are made of the first glass substrate 120 and the first glass substrate 120 by contacting the upper and lower surfaces of the first glass substrate 120 and the second glass substrate 122, respectively. 2 to be attached to the glass substrate (122).

Next, the liquid crystal panel is completed by forming the first glass substrate 120 and the second glass substrate 122 having the polarizing plates 130 and 132 attached to the upper and lower surfaces of the liquid crystal cell, respectively (S130).

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that.

Therefore, since the embodiments described above are provided to completely inform the scope of the invention to those skilled in the art, it should be understood that they are exemplary in all respects and not limited. The invention is only defined by the scope of the claims.

The liquid crystal panel according to the present invention made as described above, by indirectly attaching a glass substrate therebetween without directly adhering the polarizing plate to the existing upper substrate and the lower substrate, the liquid crystal panel according to the shrinkage and expansion of the polarizing plate There is an effect that can prevent the warpage phenomenon.

In addition, it is possible to prevent screen defects due to black luminance unevenness, thereby providing an excellent product capable of maintaining a uniform screen quality over the entire liquid crystal panel area.

In addition, since the polarizer is not directly attached to the liquid crystal cell, when a defect occurs in the polarizer, there is an effect that can be easily repaired or replaced.

Claims (11)

An upper substrate and a lower substrate disposed to face each other; A liquid crystal layer formed between the upper substrate and the lower substrate; First and second glass substrates formed on upper and lower surfaces of the upper substrate and the lower substrate, respectively; And First and second polarizers attached to upper and lower surfaces of the first and second glass substrates, respectively. Liquid crystal panel comprising a. The method of claim 1, The first glass substrate and the first polarizing plate, the second glass substrate and the second polarizing plate is a liquid crystal panel, characterized in that formed in the same size. The method of claim 1, The first polarizing plate and the second polarizing plate is formed with the same size to each other liquid crystal panel. The method of claim 1, The first polarizing plate and the second polarizing plate is a liquid crystal panel, characterized in that formed in different sizes. The method of claim 4, wherein And a polarizing plate having a larger size among the first polarizing plate and the second polarizing plate is located on a lower surface of the lower substrate. (a) manufacturing a liquid crystal cell composed of an upper substrate, a lower substrate, and a liquid crystal layer; (b) forming first and second glass substrates on the upper and lower surfaces of the liquid crystal cell, respectively; And (c) forming a first polarizing plate and a second polarization on the upper and lower surfaces of the first and second glass substrates, respectively; Method for producing a liquid crystal panel comprising a. The method of claim 6, In the step (b), each of the first glass substrate and the second glass substrate is provided to have the same size as that of the first polarizing plate and the second polarizing plate. The method of claim 6, In the step (c), the first polarizing plate and the second polarizing plate are attached to each other. (a) manufacturing a liquid crystal cell composed of an upper substrate, a lower substrate, and a liquid crystal layer; (b) forming a first polarizing plate and a second polarizing plate, respectively, on upper and lower surfaces of the first and second glass substrates; And (c) forming the first and second glass substrates on the upper and lower surfaces of the upper and lower substrates, respectively. Method for producing a liquid crystal panel comprising a. The method of claim 9, In the step (b), the first polarizing plate and the second polarizing plate are attached. The method of claim 9, In the step (b), each of the first glass substrate and the second glass substrate is provided to have the same size as that of the first polarizing plate and the second polarizing plate.

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