WO2008026862A1

WO2008026862A1 - Upper substrate, liquid crystal panel using the same and manufacturing method thereof

Info

Publication number: WO2008026862A1
Application number: PCT/KR2007/004122
Authority: WO
Inventors: Yung Il Bang; Ki Soo Park; Soon Mok Kwon; Su Eun Lee
Original assignee: Iljin Display Co Ltd
Current assignee: Iljin Display Co Ltd
Priority date: 2006-08-28
Filing date: 2007-08-28
Publication date: 2008-03-06
Anticipated expiration: 2009-02-28
Also published as: KR20080019464A

Abstract

The present invention relates to an upper substrate for a liquid crystal panel, the liquid crystal panel using the same, and a manufacturing method thereof, comprising: a transparent substrate; a plurality of micro lenses having a higher refractive index than the transparent substrate, and being repeatedly and regularly accumulated in lens shape on an upper part of the transparent substrate; a space layer accumulated on upper parts of the transparent substrate and the micro lenses, and being formed in resin series; and a transparent electrode deposited on the space layer. According to the liquid crystal panel attached with a micro lens array and a manufacturing method thereof in accordance with the present invention, the micro lens array is directly etched on the upper substrate of the liquid crystal panel, thereby removing a separate bonding process as increasing brightness of the liquid crystal panel by enabling light projected on a light blocking area to be refracted to a pixel area.

Description

UPPER SUBSTRATE, LIQUID CRYSTAL PANEL USING THE SAME AND MANUFACTURING METHOD THEREOF

Technical Field

[1] The present invention generally relates to an upper substrate for a thin film transistor liquid crystal panel attached with a micro lens array, the liquid crystal panel using the same, and a manufacturing method thereof, and more specifically, to an upper substrate for a thin film transistor liquid crystal panel, the liquid crystal panel using the same, and a manufacturing method thereof capable of easily aligning the micro lens array by etching the micro lens array which concentrates light on pixels to the upper substrate of the liquid crystal panel. Background Art

[2] A liquid crystal display device displays images by transmitting or blocking light on pixels with the use of optical anisotropy of a liquid crystal. A liquid crystal panel consisting of a lot of pixels is disposed in such a liquid crystal display device, In case of an XGA-grade liquid crystal panel, it has the number of pixels of 1024x768 columns and rows. And, thin film transistors which are switching elements are connected to each pixel, and wires to which scanning signals and data signals for displaying images are inputted are vertically crossed. The thin film transistors are located at cross points of the wires to block or transmit light by applying or intercepting electric fields to liquid crystals according to switching actions of the thin film transistors.

[3] The liquid crystal panel can be divided into a light blocking area and a light transmission area. The light blocking area is an area where thin film transistors which are switching elements for switching liquid crystals are formed, meaning an area where incident light is blocked, while the light transmission area can be defined as an area except the light blocking area. The light transmission area can be commonly called a pixel area.

[4] In the liquid crystal panel, a ratio between an area occupied by one pixel and an area occupied by the light transmission area of the area occupied by the corresponding pixel refers to an opening ratio. A liquid crystal panel of a high opening ratio can provide a screen of more improved brightness with the same power.

[5] As a method for increasing brightness even without substantially changing the opening ratio, a method for attaching a micro lens array to an upper part of a liquid crystal panel has been suggested. This method refracts light incident on a light blocking area to the micro lens array, so that the light can be irradiated on a light transmission area. Thus, in case the same light source is used, much light can be transmitted in the light transmission area, thereby displaying images in a more bright way.

[6]

[7] Fig. 1 is a diagram illustrating a sectional view in accordance with a manufacturing process of a micro lens array by prior art. Referring to Fig. 1, photoresists(30) are patterned on a transparent substrate(10)(a), and are reflowed so that the pho- toresists(30) are formed as convex curved surfaces on the transparent substrate(10)(b). Then, when dry etching is applied to an upper part of the transparent substrate, a plurality of convex lens-shaped curves are formed on the upper part of the transparent substrate(10)(c). A synthetic resin(l 12) is evenly coated on an upper part of the transparent substrate(lθ) where a micro lens array is formed(d).

[8] A micro lens array consisting of a plurality of micro lenses is formed on the upper part of the transparent substrate by a difference between refractive indexes of the transparent substrate(lθ) and the synthetic resin(l 12), which is caused by curved parts of the transparent substrate and the synthetic resin. Then, a dustproof substrate(120) is attached to the upper part of the transparent substrate where the micro lens array is formed(e).

[9] The reason why the dustproof substrate is attached to the micro lens array is because an image emitted from a liquid crystal panel is displayed on a screen after being expanded through an optical lens in case of the liquid crystal panel used for a liquid crystal projector, and at this time, a focus of the optical lens is adjusted to a liquid crystal display panel. So, once foreign substance such as dust is attached to a surface of the liquid crystal display panel owing to the thin liquid crystal display panel, the foreign substance is expanded by the optical lens, and the dust is displayed on the screen together with the image. To solve such a problem, the dustproof substrate is attached to both sides of the liquid crystal display panel to make the liquid crystal panel thicker, in order that foreign substance is separated from a focus of a lens in more than a certain distance though the foreign substance such as dust is attached to the surface of the liquid crystal display panel, thereby preventing the foreign substance such as dust from being displayed.

[10] Besides, when light is irradiated on the liquid crystal display panel, the liquid crystal display panel is heated. If excessive heat is generated, a problem occurs while the image is displayed on the liquid crystal display panel. Therefore, the dustproof substrate is attached to distribute the heat generated on the liquid crystal display panel, so that the panel can tolerate the heat.

[H]

[12] However, the prior micro lens array uses an adhesive formed as a synthetic resin during cohesion with an upper substrate, and the corresponding adhesive has a property of melting at relatively low temperature. The upper substrate of a liquid crystal panel used for a TFT liquid crystal display device is processed at high temperature during an ITO(Indium Tin Oxide) deposition process, an ITO thermal treatment process, and an alignment layer processing step. Particularly, after an ITO electrode is deposited, a thermal treatment process(alloy) is conducted for about 30 minutes at 25O⁰C approximately so as to obtain electric and optical properties of an ITO film, then an about 30-minute imide process is carried out at 25O⁰C to process an alignment layer. A prior upper substrate manufacturing method for bonding an MLA with an upper substrate has produced problems of bubble formation owing to boiling phenomenon and transmissivity deterioration caused by discoloration as a result of a thermal shock test at 25O⁰C by a used adhesive.

[13] Also, the prior micro lens array which employs a synthetic resin adhesive has difficulty in cutting. During the cutting of the micro lens array, a scribe-breaking method is generally used, which is a cutting method by applying vertical power to an upper part of a scribe in a direction vertical to an upper side of glass(or quartz) after the scribe is made by scratching the upper side of the glass to be cut. But, though the vertical power is delivered in the direction vertical to the upper side of the glass (or quartz), a direction of the power is distributed in an area of the synthetic resin(12), resulting in disadvantage that a section is not formed in a vertical way. Accordingly, when the prior micro lens array is used, it is hard to apply a manufacturing method of cutting the micro lens array during an after-process after attaching the micro lens array to a liquid crystal panel equipped with TFT elements.

[14] Since the dustproof substrate is attached to the transparent substrate by using an adhesive formed as a synthetic resin, thermal expansion coefficients of the transparent substrate, the dustproof substrate, and the adhesive may differ once heat is applied, thereby causing a risk of cell gap changes of the liquid crystal display panel. Furthermore, an additional operation such as a process of attaching the dustproof substrate is necessary, resulting in a complex process of manufacturing the liquid crystal panel and a lot of costs.

[15] In addition, there is a problem that light transmissivity of the liquid crystal display panel deteriorates owing to the adhesive, and that foreign substance may be attached while the dustproof substrate is attached to the liquid crystal display panel. As a result, there exist a lot of disadvantages such as management difficulty in preventing foreign substance, the increase of expenses, and generation/elimination of bubbles and rumples. Disclosure of Invention Technical Problem

[16] It is therefore an object of the present invention to provide a thin film transistor liquid crystal panel and a manufacturing method thereof for realizing high brightness without alignment by directly forming a micro lens array on an upper substrate. Technical Solution

[17] In order to accomplish the above object of the present invention, an upper substrate for a liquid crystal panel comprises: a transparent substrate; a plurality of micro lenses having a higher refractive index than the transparent substrate, and being repeatedly and regularly accumulated in lens shape on an upper part of the transparent substrate; a space layer accumulated on upper parts of the transparent substrate and the micro lenses, and being formed in resin series; and a transparent electrode deposited on the space layer.

Advantageous Effects

[18] According to a liquid crystal panel attached with a micro lens array and a manufacturing method thereof in accordance with the present invention, it is possible to increase brightness of the liquid crystal panel by directly forming the micro lens array on an upper substrate of the liquid crystal panel, so that light projected on a light blocking area can be refracted to a pixel area.

[19] According to a liquid crystal panel equipped with a micro lens array and a manufacturing method thereof in accordance with the present invention, it is available to carry out an ITO alloy process and alignment layer processing at high temperature since an adhesive such as a synthetic resin type is not used when the micro lens array is manufactured.

[20] Moreover, because a synthetic resin adhesive is not used, the micro lens array can be easily cut. Thus, it is possible to apply a manufacturing method of cutting the micro lens array during an after-process after attaching the micro lens array to a liquid crystal panel equipped with TFT elements.

[21] In case thickness of a space layer or a high refractive index layer is adjusted, a separate dustproof substrate does not have to be attached. So, a process of attaching the dustproof substrate is omitted, thereby simplifying a manufacturing process of a micro lens array as solving a problem that transmissivity deteriorates due to an adhesive.

[22] Finally, when design of an optical system part including a focus lens is changed, thickenss of a space layer or a high refractive index layer can be adjusted in the present invention, therefore the design can be easily changed.

[23]

[24] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. Brief Description of the Drawings

[25] The advantages of the invention wil become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings, in which:

[26] Fig. 1 is a sectional view in accordance with a manufacturing process of a micro lens array by prior art;

[27] Fig. 2 through Fig. 9 illustrate one embodiment of a manufacturing process of a liquid crystal panel upper substrate in accordance with the present invention;

[28] Fig. 10 through Fig. 17 illustrate one embodiment of a manufacturing process of a liquid crystal panel upper substrate in accordance with the present invention; and

[29] Fig. 18 and Fig. 19 illustrate one embodiment of a liquid crystal panel in accordance with the present invention.

[30]

[31] ***** Reference List *****

[32] 10: transparent substrate 20: high refractive index layer

[33] 30: photoresist 50: space layer

[34] 60: transparent electrode layer 100: upper substrate

[35] 200: lower substrate 300: liquid crystal layer

[36]

Best Mode for Carrying Out the Invention

[37] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.

[38] Fig. 2 through Fig. 9 illustrate one embodiment of a manufacturing process of a liquid crystal panel upper substrate in accordance with the present invention. A high refractive index layer is deposited on an upper substrate(lθ) of a transparent substrate such as a glass or quartz substrate(Fig. 2 and Fig. 3). A refractive index of the deposited high refractive index layer(20) is in a range between 1.47 and 2.0. When the quartz substrate is used as the transparent substrate, a refractive index of the quartz substrate is 1.46, thus a refractive index of the high refractive index layer(20) should at least have a larger value than a refractive index of the transparent substrate. That is, the purpose of using the high refractive index layer(20) is for condensation. Basically, a difference(Delta n) between refractive indexes of the high refractive index layer(20) and the transparent substrate(lθ) determines a condensing rate together with a lens shape. In other words, a larger value than a refractive index of the common quartz substrate should be at least set. Likewise, if the refractive index gets bigger than 2.0, a final area where light passing through the high refractive index layer(20) should pass can be out of an upper BM area. And, an angle compared to a progressing direction of the light gets too bigger after the light passes through a lens, deteriorating efficiency in a projection system part. If a refractive index difference with the transparent substrate(lθ) gets bigger owing to a high refractive index of the high refractive index layer(20), based on Snell's Law, the angle of the light is increased after the light passes through the lens even though effective focal length is reduced, thereby producing problems that condensation is limited in the projection system part. It is more desirable to maintain the refractive index of the high refractive index layer(20) in a range of between 1.5 and 1.9, and thickness of the deposited high refractive index layer(20) should be at least more than 3um to form a lens shape.

[39] The high refractive index layer(20) can use a mixture of silicon dioxide(SiO ) and one material selected from metal oxide series or a material of organic series. There are representative materials of the metal oxide series such as TiO , Al O , and Ta O . Since the above metal oxide series have relatively large refractive indexes like TiO 2

(refractive index: 2.3), Al O (refractive index: 1.63), and Ta O (refractive index: 2.1), the refractive indexes are adjusted by mixing silicon dioxide in order to accomplish a refractive index within the range used for the upper substrate for the liquid crystal panel. The high refractive index layer(20) can be formed with the material of the organic series, and as a representative example, there is T-27 of Honeywell. Such a high refractive index layer(20) is accumulated on an upper part of the transparent substrate by using a deposition method like a chemical vapor deposition method.

[40] A photoresist material(30) is applied to an upper part of a high refractive index layer(20)(Fig. 4). Then, the applied photoresist material is exposed and developed by a gray scale lithography method to form convex or concave lenses(Fig. 5 and Fig. 6). The gray scale lithography method can realize a micro lens array shape by using gray level differences within a mask(90) during exposure.

[41] From now on, in reference to Fig. 6 through Fig. 9, a diagram(a) where convex lenses are formed on a high refractive index layer(20) and a diagram(b) where concave lenses are formed will be divisively explained. A lens center of the convex lenses illustrated in the diagram(a) should be located on top of a central part(center of pixels, approximately) of an area where light of a lower substrate passes through, and a lens center of the concave lenses illustrated in the diagram(b) should be located on top of a central part(that is, an area where light is blocked by switching elements) of an area where the light of the lower substrate is blocked.

[42] The photoresist(30) formed in lens shape is dry-etched to a high refractive index layer(20), so that the lens shape can be formed on the high refractive index layer(20)(Fig. 7). Next, a space layer(50) is coated(Fig. 8). A material for forming the space layer(50) is a resin type having a refractive index in a range between 1.3 and 1.6 while Tg(Glass Transition Temperature) should be at more than 25O⁰C, and a material having high-compression and crack-free physical properties is selected. Besides, so that the space layer can be used for a liquid crystal panel, the higher transmissivity is better as possible. The thickness of the applied space layer(50) is between 15 and 70um, and the space layer is formed in multi-structure. The thickness of the space layer(50) is designed by thickness and the refractive index of the high refractive index layer(20).

[43] It is desirable that the refractive index of the space layer is lower than the refractive index of the high refractive index layer (20), and it is more desirable that the refractive index is between 1.4 and 1.5 approximately because heat resistance deteriorates as the refractive index gets higher.

[44] Also, since temperature rises up to about 25O⁰C in a future transparent(ITO) alloy step or alignment layer processing step, it is desirable for the space material to have high curing temperature as possible. In the present invention, the space material of about 25O⁰C curing temperature has been used. It is more desirable that the glass transition temperature of the space layer(50) is over 300⁰C so as to obtain sufficient ITO properties.

[45] Cyclotene of Dow Chemical of BCB(Bisbenzocyclobutene) series and OCE-1010 of Samyang EMS have been used as representative materials for the space layer(50). The two kinds of the above materials are insulators used between metal wires and ITO electrodes to improve an opening ratio by general a-Si TFT companies, and normally, they are called overcoat materials.

[46] A step of spreading the space material will be described as follows.

[47] As a first step, pretreatment is conducted with rinse and, when necessary, a suitable activator on a substrate to realize good coating power. As a second step, with the use of materials of viscosity designed to be suitable for target thickness, BSR(Back-Side Rinse) and EBR(Edge-Bead Removal) processes are progressed after a sping-coating process by dispensing the materials on a substrate which rotates in hundreds of or thousands of RPM according to a preset program. As a third step, through a baking process for about 20 to 300 seconds(changed by temperature) on a hot plate of 60 to 200⁰C, a process of removing a slight solvent to prevent movement of the space layer(50) is progressed during the processing step. As a fourth step, a soft curing process is executed in an inert atmosphere(N2 atmosphere) when necessary for 20 to 60 minutes at 150 to 25O⁰C. As a fifth step, if multi-coating is required, the above second to fourth steps are repeated.

[48] Next, an ITO electrode is deposited in an upper part of a space layer(50)(Fig. 9). Since the space layer(50) is formed with a resin series melting at more than 25O⁰C in the present invention, a deposition process at room temperature(low temperature process) is applied to ITO. According to the measured results, it is known that the ITO electrode deposited through the LT process does not show a big difference from the existing high-temperature ITO deposition process in terms of electric resistance and transmissivity. In case of the rest of the ITO ally process and the alignment layer processing, the space material did not show any problems of bubble formation or discoloration shown on the existing synthetic resin-type adhesive even though the space material was treated as it was at high temperature. It is because the space of the present invention forms a melting point at 25O⁰C while an adhesive used for bonding the existing MLA lens with an upper substrate has a low melting point. Thus, it is analyzed that there is no material limit to progress a baking process of an alignment layer or an ITO alloy process which is a future high-temperature process.

[49] Fig. 6 through Fig. 9 illustrate the present invention by dividing into the diagram(a) and the diagram(b) to separately illustrate the formed lens shape according to a convex or concave shape. So, a substantially applied process can be performed in the same way or in a very similar way.

[50]

[51] Fig. 10 through Fig. 17 illustrate one embodiment of a manufacturing process of a liquid crystal panel upper substrate in accordance with the present invention. A photoresist material(30) is applied to an upper substrate(lθ) of a transparent substrate such as a glass or quartz substrate(Fig. 10 and Fig. 11). Then, the applied photoresist material(30) is exposed and developed through a gray scale photo etching method by using a gray scale mask(90) to form convex or concave lenses(Fig. 12 and Fig. 13). The gray scale photo etching method realizes a desired lens shape by differentiating a degree of development by using gradation of light during exposure.

[52] From now on, in reference to Fig. 13 through Fig. 17, a diagram(a) where convex lenses are formed on an upper substrate(lθ) and a diagram(b) where concave lenses are formed will be divisively explained. A lens center of the convex lenses illustrated in the diagram(a) should be located on top of a central part(that is, an area where light is blocked by switching elements) of an area where light of a lower substrate is blocked, and a lens center of the concave lenses illustrated in the diagram(b) should be located on top of a central part(center of pixels, approximately) of an area where the light of the lower substrate passes through.

[53]

[54] A photoresist(30) formed in lens shape is dry-etched to a transparent substrate(lθ), so that the lens shape can be formed on the transparent substrate(10)(Fig. 14). Next, a high refractive index layer(20) is deposited(Fig. 15). A refractive index of the deposited high refractive index layer(20) is in a range between 1.47 and 2.0. When a quartz substrate is used as the transparent substrate, the refractive index of the high refractive index layer(20) should be at least larger than a refractive index of the transparent substrate since a refractive index of the quartz substrate is 1.46. That is, the purpose of using the high refractive index layer(20) is for condensation. Basically, a difference(Delta n) between refractive indexes of the high refractive index layer(20) and the transparent substrate(lθ) determines a condensing rate together with a lens shape. In other words, a larger value than a refractive index of the common quartz substrate should be at least set. Likewise, if the refractive index gets bigger than 2.0, a final area where light passing through the high refractive index layer(20) should pass can be out of an upper BM area. And, an angle compared to a progressing direction of the light gets too bigger after the light passes through a lens, deteriorating efficiency in a projection system part. If a refractive index difference with the transparent substrate(lθ) gets bigger owing to a high refractive index of the high refractive index layer(20), based on Snell's Law, the angle of the light is increased after the light passes through the lens even though effective focal length is reduced, thereby producing problems that condensation is limited in the projection system part. It is more desirable to maintain the refractive index of the high refractive index layer(20) in a range of between 1.5 and 1.9, and thickness of the deposited high refractive index layer(20) should be at least more than 3um to form a lens shape.

[55] The high refractive index layer(20) can use a mixture of silicon dioxide(SiO ) and one material selected from metal oxide series or a material of organic series. There are representative materials of the metal oxide series such as TiO , Al O , and Ta O . Since the above metal oxide series have relatively large refractive indexes like TiO (refractive index: 2.3), Al O (refractive index: 1.63), and Ta O (refractive index: 2.1), the refractive indexes are adjusted by mixing silicon dioxide in order to accomplish a refractive index within the range used for the upper substrate for the liquid crystal panel. The high refractive index layer(20) can be formed with the material of the organic series, and as a representative example, there is T-27 of Honeywell. Such a high refractive index layer(20) is accumulated on an upper part of the transparent substrate by using a deposition method like a chemical vapor deposition method.

[56] A space layer(50) is coated on an upper part of a high refractive index layer(20)(Fig. 16). A material for forming the space layer(50) is a resin type having a refractive index in a range between 1.3 and 1.6 while Tg(Glass Transition Temperature) should be at more than 25O⁰C, and a material having high-compression and crack-free physical properties is selected. Besides, so that the space layer can be used for a liquid crystal panel, the higher transmissivity is better as possible. The thickness of the applied space layer(50) is between 15 and 70um, and the space layer is formed in multi-structure. The thickness of the space layer(50) is designed by thickness and the refractive index of the high refractive index layer (20).

[57] It is desirable that the refractive index of the space layer is lower than the refractive index of the high refractive index layer (20), and it is more desirable that the refractive index is between 1.4 and 1.5 approximately because heat resistance deteriorates as the refractive index gets higher.

[58] Also, since temperature rises up to about 25O⁰C in a future transparent(ITO) alloy step or alignment layer processing step, it is desirable for the space material to have high curing temperature as possible. In the present invention, the space material of about 25O⁰C curing temperature has been used. It is more desirable that the glass transition temperature of the space layer(50) is over 300⁰C so as to obtain sufficient ITO properties.

[59] Cyclotene of Dow Chemical of BCB(Bisbenzocyclobutene) series and OCE-1010 of Samyang EMS have been used as representative materials for the space layer(50). The two kinds of the above materials are insulators used between metal wires and ITO electrodes to improve an opening ratio by general a-Si TFT companies, and normally, they are called overcoat materials.

[60] A step of spreading the space material will be described as follows.

[61] As a first step, pretreatment is conducted with rinse and, when necessary, a suitable activator on a substrate to realize good coating power. As a second step, with the use of materials of viscosity designed to be suitable for target thickness, BSR(Back-Side Rinse) and EBR(Edge-Bead Removal) processes are progressed after a sping-coating process by dispensing the materials on a substrate which rotates in hundreds of or thousands of RPM according to a preset program. As a third step, through a baking process for about 20 to 300 seconds(changed by temperature) on a hot plate of 60 to 200⁰C, a process of removing a slight solvent to prevent movement of the space layer(50) is progressed during the processing step. As a fourth step, a soft curing process is executed in an inert atmosphere(N2 atmosphere) when necessary for 20 to 60 minutes at 150 to 25O⁰C. As a fifth step, if multi-coating is required, the above second to fourth steps are repeated.

[62]

[63] Next, an ITO electrode is deposited in an upper part of a space layer(50)(Fig. 17).

Since the space layer(50) is formed with a resin series melting at more than 25O⁰C in the present invention, a deposition process at room temperature(low temperature process) is applied to ITO. According to the measured results, it is known that the ITO electrode deposited through the LT process does not show a big difference from the existing high-temperature ITO deposition process in terms of electric resistance and transmissivity. In case of the rest of the ITO ally process and the alignment layer processing, the space material did not show any problems of bubble formation or discoloration shown on the existing synthetic resin-type adhesive even though the space material was treated as it was at high temperature. It is because the space of the present invention forms a melting point at 25O⁰C while an adhesive used for bonding the existing MLA lens with an upper substrate has a low melting point. Thus, it is analyzed that there is no material limit to progress a baking process of an alignment layer or an ITO alloy process which is a future high-temperature process.

[64] Fig. 10 through Fig. 17 illustrate the present invention by dividing into a diagram(a) and a diagram(b) to separately illustrate the formed lens shape according to a convex or concave shape. So, a substantially applied process can be performed in the same way or in a very similar way.

[65]

[66] Fig. 18 and Fig. 19 illustrate one embodiment of a liquid crystal panel in accordance with the present invention. The liquid crystal panel is composed of liquid crystal materials (300) injected between an upper substrate(lOO) and a lower substrate(200). The aforementioned micro lens shape is integratedly formed on the upper substrate(lOO), and ITO electrodes and alignment layers are equipped thereon. Switching elements, storage capacitors, and alignment layers are equipped on the lower substrate(200). The upper substrate(lOO) and the lower substrate(200) whose alignment layer processing is completed are bonded together, and the liquid crystals are injected therebetween to complete the liquid crystal panel. Fig. 18 shows the liquid crystal panel comprising micro lenses having a convex lens shape formed according to the processes of Fig. 2 through Fig. 9, while Fig. 19 shows the liquid crystal panel comprising micro lenses having a convex lens shape formed according to the processes of Fig. 10 through Fig. 17.

[67]

Claims

[I] An upper substrate for a liquid crystal panel, comprising: a transparent substrate; a plurality of micro lenses having a higher refractive index than the transparent substrate, and being repeatedly and regularly accumulated in lens shape on an upper part of the transparent substrate; a space layer accumulated on upper parts of the transparent substrate and the micro lenses, and being formed in resin series; and a transparent electrode deposited on the space layer. [2] The upper substrate for a liquid crystal panel of claim 1, wherein the space layer has glass transition temperature over 25O⁰C. [3] The upper substrate for the liquid crystal panel of claim 1, wherein the micro lenses have a refractive index between 1.47 and 2.0. [4] The upper substrate for the liquid crystal panel of claim 1, wherein the space layer has a refractive index between 1.3 and 1.6. [5] The upper substrate for the liquid crystal panel of claim 4, wherein the space layer is formed in 15 to 70um thickness. [6] The upper substrate for the liquid crystal panel of claim 1, wherein the micro lenses consist of a mixture of silicon dioxide and one material selected from metal oxides. [7] The upper substrate for the liquid crystal panel of claim 1, wherein the micro lenses consist of organic materials. [8] An upper substrate for a liquid crystal panel, comprising: a transparent substrate equipped with micro lenses repeatedly and regularly formed on one side; a high refractive index layer having a higher refractive index than the transparent substrate, and being accumulated on the one side where the micro lenses are formed; a space layer accumulated on an upper part of the high refractive index layer, and being formed as a resin series; and a transparent electrode deposited on the space layer. [9] The upper substrate for the liquid crystal panel of claim 8, wherein the space layer has glass transition temperature over 25O⁰C. [10] The upper substrate for the liquid crystal panel of claim 8, wherein the micro lenses have a refractive index between 1.47 and 2.0.

[I I] The upper substrate for the liquid crystal panel of claim 8, wherein the space layer has a refractive index between 1.3 and 1.6. [12] The upper substrate for the liquid crystal panel of claim 11, wherein the space layer is formed in 15 to 70um thickness. [13] The upper substrate for the liquid crystal panel of claim 8, wherein the micro lenses consist of a mixture of silicon oxide and one material selected from metal oxides. [14] The upper substrate for the liquid crystal panel of claim 8, wherein the micro lenses consist of organic materials. [15] A liquid crystal panel comprises the upper substrate of one claim selected from the first to fourteenth claims. [16] A method for manufacturing an upper substrate for a liquid crystal panel, comprising the steps of: a 1st step of preparing a transparent substrate; a 2nd step of accumulating a high refractive index layer having a higher refractive index than a refractive index of the transparent substrate on an upper part of the transparent substrate; a 3rd step of applying a photoresist to an upper part of the high refractive index layer; a 4th step of forming a plurality of micro lenses by using a gray scale etching method for the photoresist; a 5th step of etching the plurality of the micro lenses on the high refractive index layer by dry-etching even the high refractive index layer with the use of the plurality of the formed micro lenses; a 6th step of forming a space layer formed as a resin on the upper part of the high refractive index layer where the plurality of the micro lens shapes are etched; and a 7th step of forming a transparent electrode layer on an upper part of the space layer. [17] The manufacturing method of claim 16, wherein the high refractive index layer consists of a mixture of silicon oxide and one material selected from metal oxides. [18] The manufacturing method of claim 16, wherein the high refractive index layer consists of an organic material. [19] A method for manufacturing an upper substrate for a liquid crystal panel, comprising the steps of: a 1st step of preparing a transparent substrate; a 2nd- 1 step of applying a photoresist to an upper part of the transparent substrate; a 3rd-l step of forming a plurality of micro lenses by using a gray scale etching method for the photoresist; a 4th- 1 step of etching the plurality of the micro lenses on the transparent substrate by dry-etching even the transparent substrate with the use of the plurality of the formed micro lenses; a 5th- 1 step of accumulating a high refractive index layer having a higher refractive index than a refractive index of the transparent substrate on the upper part of the transparent substrate where the plurality of the micro lenses are etched; a 6th- 1 step of forming a space layer on an upper part of the high refractive index layer; and a 7th- 1 step of forming a transparent electrode layer on an upper part of the space layer. [20] The manufacturing method of claim 19, wherein the high refractive index layer consists of a mixture of silicon oxide and one material selected from metal oxides. [21] The manufacturing method of claim 19, wherein the high refractive index layer consists of an organic material.