KR980010507A - Display device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a manufacturing method for reducing the damage of an alignment film due to a rubbing process by dividing each color filter having an optimum thickness in consideration of the amount of light transmission in manufacturing a liquid crystal display substrate into an upper plate and a lower plate while maintaining a predetermined thickness . In the case of the simple matrix type liquid crystal display device, the common manufacturing method of the apparatus includes a step of forming a common electrode in the longitudinal direction on the lower plate at first, a step of alternately forming the blue filter, the green filter and the red filter on the transparent electrode, Forming a protective film on the transparent electrode so that at least one or more color filters correspond to colors and positions of the filters of the lower plate; A step of forming an alignment film, a step of rubbing the alignment film formed on the upper and lower substrates, and a step of sealing the liquid crystal between the two substrates.

Description

Display device and manufacturing method thereof

1 to 3 are sectional views of a conventional liquid crystal display device.

FIG. 4 is a cross-sectional view of a simple matrix liquid crystal display device according to an embodiment of the present invention.

FIGS. 5 and 6 are cross-sectional views of an active matrix liquid crystal display device according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

2: lower plate 4: upper plate

6a, 6b: transparent electrode 7a: common electrode

7b: pixel electrode 8:

10, 10a, 10b, 12, 12a, 12b, 14, 14a, 14b:

16a, 16b: protective films 18a, 18b:

20: liquid crystal layer 22: switching element

The present invention relates to a display device and a method of manufacturing the same, and more particularly, to a liquid crystal display device capable of preventing breakage of an alignment film caused by rubbing by dividing a color filter into upper and lower substrates, .

In general, a display device is divided into a light emitting type that can emit light itself and a light receiving type that is not. Typical examples of the light emitting type are a cathode ray tube (CRT), a plasma display panel (POD), a visual fluorescent display (VFD), a light emitting diode (LED) (EL: electro luminescent display). In the light-receiving type, a liquid crystal display (LCD) is a typical example, which is divided into a simple matrix type and an active matrix type.

A liquid crystal display substrate is roughly divided into two substrates and a liquid crystal material therebetween. A color filter is formed on one of the substrates, an electrode layer and an orientation film cover the electrodes, and an electrode layer and an orientation film are formed on the other substrate. Both substrates are attached via a sealing material.

Hereinafter, the liquid crystal display and its manufacturing method will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a conventional simple matrix liquid crystal display device. In the case of the simple matrix type, pixels of the vertical and horizontal intersections are driven by being turned on when electrical signals are transmitted by positioning the longitudinal and transverse electrodes on the upper and lower plates respectively.

A longitudinal transparent electrode 6a is formed in a stripe form in the lower plate 2 and color filters 10, 12 and 14 of the three primary colors are formed at the same height thereon. And an acrylic protective film (16a) and a polyimide alignment film (18a) are sequentially coated thereon.

Next, a transverse transparent electrode 6b is formed in a stripe shape on the upper plate 4, and a protective film 16b and an orientation film 18b are coated on the transverse transparent electrode 6b.

The upper plate 4 and the lower plate 2 are adhered to each other with a sealing material 8, and a liquid crystal layer 20 is formed between the two substrates.

In such a conventional liquid crystal display device, since light having different wavelengths passed through the color filters 10, 12, and 14 of the red, green, and blue rays emitted from the backlight passes through the liquid crystal layer 20 of the same thickness, There is a problem that the optimum value of the light transmission amount varies depending on the wavelength.

The liquid crystal display of FIGS. 2 and 3 improves this problem. When the transmission amount of each light having different wavelengths when no external voltage is applied is in a normally white mode, And a thickness of the liquid crystal layer, which is one of the parameters for determining the transmission amount so as to exhibit the minimum amount of light transmission in the normally black mode.

FIG. 2 is a cross-sectional view showing another conventional simple matrix type liquid crystal display device. Here, a color filter is formed only on the lower plate, and the blue filter 14 is the thickest among the color filters, and the green filter 12 and the red filter 10 are in the order.

3 is a cross-sectional view of a conventional active matrix type liquid crystal display device. In the active matrix type, two or three terminal switching elements are attached to each pixel to turn on or off the target pixel, and the vertical and horizontal electrodes are formed on one substrate, and a common electrode is formed on the other substrate together with the color filter have.

Here again, the color filters 10, 12 and 14 are formed only in the lower plate 2, the blue filter 14 in the color filter is the thickest, and the order of the green filter 12 and the red filter 10 is in this order. A common electrode 7a is formed on the color filters 10, 12 and 14 and a protective film 16a and an alignment film 18a are sequentially formed thereon.

A pixel electrode 7b is formed on the upper plate 4 so as to correspond to the color filters 10, 12 and 14 of the lower plate 2, a switching element 22 is formed therebetween, and a protective film 16b is formed thereon. And an orientation film 18b.

In such a liquid crystal display device, the height of the color filters 10, 12, and 14 is varied according to the color, and the thickness of the liquid crystal layer 20 is appropriately adjusted to make the viewing angle and contrast ratio Can be improved.

However, such a conventional manufacturing method has a problem in that the step between the highest blue filter 14 and the lowest red filter 10 is so significant that the alignment film 18a is damaged during rubbing of the alignment film 18a.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to prevent the alignment layer on a specific color filter from being damaged, thereby increasing the yield and reducing display defects. In the case of a simple matrix type liquid crystal display device, the liquid crystal display device according to the present invention for solving such problems includes a transparent electrode formed in a longitudinal direction on a lower plate, a color filter of blue, green, and red formed on the transparent electrode, At least one transparent electrode formed in a transverse direction and a transparent electrode on the lower plate so as to correspond to the color and position of the filter in the lower plate, and the sum of the thickness formed by the upper plate and the lower plate is a color having a relationship of blue> green> red filter It includes a filter.

In this method of manufacturing a liquid crystal display device, a transparent electrode is formed in the longitudinal direction of the lower plate, a blue filter, a green filter and a red filter are formed on the transparent electrode, a transparent electrode is formed in the transverse direction, A step of forming at least one or more color filters on the electrode so as to correspond to colors and positions of the filters of the lower plate and forming a relationship of blue, green, and red filters with the sum of the thicknesses of the color filters formed on the upper plate and the lower plate .

In the case of an active matrix type liquid crystal display device, a color filter of blue, green, and red filters formed on a lower plate, a thin film transistor formed between the electrodes formed on the upper plate to correspond to the color filter of the lower plate, The color filter includes at least one or more of a blue filter, a green filter, and a red filter. The filter has a relationship of blue filter, green filter, and red filter.

Forming a blue filter, a green filter, and a red filter on the lower plate, forming electrodes and a switching device on the upper plate, arranging at least one or more color filters on the lower plate, And the sum of the thicknesses of the color filters formed on the upper plate and the lower plate so as to have a relation of blue> green> red filter.

In the liquid crystal display device according to the present invention, the color filter is divided into the upper plate and the lower plate so as to reduce the step between the adjacent filters, thereby maintaining the thickness of the predetermined liquid crystal layer so as to increase the contrast ratio, .

Hereinafter, with reference to the accompanying drawings, a method of manufacturing a liquid crystal display device according to an embodiment of the present invention will be described in detail so as to be easily carried out by a person having ordinary skill in the art to which the present invention belongs.

FIG. 4 is a cross-sectional view of a simple matrix type liquid crystal display panel according to the first embodiment of the present invention.

A longitudinal transparent electrode 6a is formed in a stripe shape on the lower plate 2 and color filters 10a, 12a and 14a of three primary colors are formed thereon. And an acrylic protective film (16a) and a polyimide alignment film (18a) are sequentially coated thereon.

On the upper panel 4, a transversal transparent electrode 6b is formed in the form of a stripe, on which color filters 10b, 12b and 14b of three primary colors are connected to the color filters 10a, 12a and 14a of the lower panel 2 And is patterned to have the same color and thickness as the position. At this time, the sum of the thicknesses of the color filters formed on the two substrates 2 and 4 is equal to the thickness of the color filters 10, 12, and 14 formed on the lower substrate 2 shown in FIG. 2 . The protective film 16b and the alignment film 18b are coated. On the other hand, the transparent electrodes formed on the upper plate may be formed in a rectangular dot shape.

The upper plate 4 and the lower plate 2 are adhered to each other with a sealing material 8, and a liquid crystal layer 20 is formed between the two substrates.

A manufacturing method of such a liquid crystal display device is as follows.

First, longitudinal transparent electrodes 6a are formed in a stripe form on the lower substrate 2, and color filters 10a, 12a, and 14a of three primary colors are formed thereon. At this time, the blue filter 14a is formed thickest and then the green filter 12a and the red filter 910a are arranged in this order.

Next, the acrylic protective film 16a is formed to have a thickness of 1.3 占 퐉. An alignment film 18a is formed to a thickness of 0.1 mu m on the protective film 16a. The alignment film 18a is an organic polymer film that serves to align the liquid crystal molecules after the rubbing process, and usually a polyimide resin is used and formed by a flexo printing method. It is preferable that the alignment layer exhibits good alignment and insulative properties, so that the liquid crystal layer is less likely to be stained and exhibits high charge retention.

Next, a transverse transparent electrode 6b in the form of a stripe is formed on the upper plate 4. The color filters 10b, 12b, and 14b are patterned so that their thickness, color, and position are the same as those of the color filters 10a, 12a, and 14a of the substrate 2 opposed to the transparent electrodes 6b. In this case, the sum of the thicknesses of the color filters formed on the two substrates 2 and 4 is a value calculated considering the optimum value of the transmittance when the back light is irradiated with light.

Optical properties of the liquid crystal substrate depend on the electro-optic properties of the liquid crystal substrate. The parameters for determining the electro-optical characteristics of the liquid crystal substrate include the wavelength of incident light, the thickness of the liquid crystal layer, the thickness of the orientation film, the conductivity / resistivity, There are many other factors besides the inherent pitch.

The light source of the backlight is EL (electroluminescence) and fluorescent lamp, and the fluorescent lamp is the mainstream. The fluorescent lamp is manufactured by using the material having high efficiency, and the blue, green, and red phosphors are mixed Three types of white-based wavelengths are used. By varying the mixing ratio of these phosphors, the color is expressed.

The acrylic protective film 16b is covered with a thickness of 1.3 탆.

An alignment film 18b is formed on the protective film to a thickness of 0.1 mu m.

The alignment films 18a and 18b formed on the upper plate 4 and the lower plate 2 are rubbed and the liquid crystal 20 is injected between the two substrates 2 and 4 through the assembling process.

Problems that occur during rubbing include not only a step difference but also a charging phenomenon caused by friction and dust generation.

In order to prevent the charging phenomenon, a method of adjusting the intensity of the rubbing or increasing the humidity in the rubbing device is used. The dust is generated by rinsing the engine after the rubbing treatment.

FIG. 5 is a cross-sectional view of an active matrix liquid crystal display device according to a second embodiment of the present invention.

The lower plate 2 is provided with blue, green and red color filters 10a, 12a and 14a and the thicknesses of the green filter 122a and the red filter 10a are the same as the thicknesses of the green and red filters 12 , 10), and the blue filter 14a and the green filter 12a have the same height. A protective film 16a, a common electrode 7a, and an alignment film 18a are formed thereon. A pixel electrode 7b is formed on the upper plate 4 so as to correspond to the color filters 10a, 12a and 14a of the lower plate 2 and a switching element 22 is formed between the pixel electrodes 7b. A blue filter 14b is formed on the pixel electrode 7b at a position corresponding to the blue filter 14a of the lower plate 2. This blue filter 14b is equal in thickness to the thickness of the blue filter 14 formed on the lower plate 2 shown in FIG. 3 by the sum of the thickness formed by the upper plate 4 and the lower plate 2 in a divided manner. Next, a protective film 16b and an orientation 18b are coated.

A liquid crystal layer 20 is formed between the two substrates 2 and 4.

A manufacturing procedure of a liquid crystal display device having such a structure is as follows.

First, the three primary color filters 10a, 12a, and 14a are patterned on the lower substrate 2. The green filter 12a and the blue filter 14a have similar heights and the thicknesses of the green and red filters 12a and 10a are the same as the thicknesses of the green filter 12 and the red filter 12b of the lower plate 2 shown in FIG. 10).

Next, the acrylic protective film 16a is formed to have a thickness of 1.3 탆, and then the common electrode 7a is deposited.

A polyimide alignment film 18a is formed on the common electrode layer 7a to a thickness of 0.1 占 퐉 by a printing method.

The pixel electrode 7b is formed in the upper plate 4 so as to correspond to the color filters 10a, 12a and 14a formed in the next lower substrate 2 and the switching element 22 is formed between the pixel electrodes 7b.

A blue filter 14b is formed on the pixel electrode 7b so as to correspond to the blue filter 114a of the opposing substrate 2. [ At this time, the sum of the thicknesses of the blue filters 14a and 14b formed in the upper plate 4 and the lower plate 2 is equal to the thickness of the blue filter 14 formed in the lower plate 2 in FIG.

Next, the acrylic protective film 16b is formed to have a thickness of 1.3 탆.

On the protective film 16b, a polyimide-based alignment film 18b having a thickness of 0.1 탆 is formed by a printing method.

The alignment film 18b is rubbed and liquid crystal is injected between the two substrates 2 and 4 through the assembling process to form the liquid crystal layer 20. [

FIG. 6 is a cross-sectional view of an active matrix liquid crystal display device according to a third embodiment of the present invention.

In this case, the height of the red filter 10a and the green filter 12a are similarly formed in the lower plate 2, and the blue filter 14a is formed slightly higher than the two filters 10a and 12a. At this time, the thickness of the red filter 10a is the same as that of the red filter 10 formed on the lower plate 2 shown in FIG.

A green filter 12b and a blue filter 14b are formed in the upper plate 4 in correspondence with the green and blue filters 12a and 14a of the lower plate 2, respectively. The thicknesses of the two filters 12a, 12b, 14a and 14b formed in the upper plate 2 and the lower plate 4 in this way are the same as the thicknesses of the two filters 12, 13, respectively.

A manufacturing method of a liquid crystal display device having such a structure is as follows.

First, color filters 10a, 12a, and 14a of three primary colors are formed on the lower plate 2. The red filter 10a and the green filter 12a are formed to have a thickness similar to each other and the blue filter 14a is formed slightly higher than the two filters 10a and 12a. And the thickness of the red filter 10 formed on the substrate 2 is the same.

The acrylic protective film 16a covering the next color filters 10a, 12a, and 14a is formed to have a thickness of 1.3 占 퐉.

A common electrode 7a is deposited on the protective film 16a.

On the common electrode 7a, a polyimide alignment film 18a having a thickness of 0.1 占 퐉 is formed by a printing method.

The pixel electrodes 7b are formed so as to correspond to the color filters 10a, 12a and 14a formed on the upper plate 4 and the switching elements 22 are formed between the pixel electrodes 7b.

The blue and green filters 14b and 12b are formed on the pixel electrode 7b so as to correspond to the blue filter 14a and the green filter 12a of the opposing substrate 2. The sum of the thicknesses of the blue and green filters 14a, 14b, 12a and 12b formed in the upper plate 4 and the lower plate 2 is equal to the sum of the thicknesses of the blue and green filters 14, 12).

Next, the acrylic protective film 16b is formed to have a thickness of 1.3 탆. The polyimide-based alignment layer 18b is formed to a thickness of 0.1 占 퐉 by using the printing method.

The alignment film 18b is rubbed and liquid crystal is sealed between the two substrates 2 and 4 through an assembling process.

In the above-described liquid crystal display device, at least one or more color filters are formed by dividing the lower plate 2 and the upper plate 4, and the value obtained by adding the thicknesses of the divided filters is equal to a value that takes into account the optimum value of the transmittance with respect to incident light .

The liquid crystal display device according to the present invention has an effect of improving the yield and manufacturing a high quality display device by controlling the transmission amount in consideration of the wavelength of the incident light and reducing the damage of the alignment film during the process.

Claims (28)

A transparent electrode formed in a longitudinal direction on the lower plate, a color filter formed on the transparent electrode, an upper plate, a transparent electrode formed in a lateral direction on the upper plate, and a transparent electrode formed on the transparent electrode in correspondence with the filter of the lower plate And at least one color filter formed on the substrate. The display device according to claim 1, wherein the transparent electrodes of the upper plate are formed in a stripe shape. The display device according to claim 1, wherein the transparent electrode of the upper plate is formed in a rectangular dot shape. The display device according to claim 1, wherein the color filter is formed of three colors of red, green, and blue. The display device according to claim 4, wherein the sum of the thicknesses of the color filters dividedly formed between the upper plate and the lower plate has a relationship of blue filter> green filter> red filter. The display device according to claim 1, further comprising a protective film formed on the upper plate and the lower plate, respectively. The display device according to claim 1, further comprising an alignment film formed on the upper plate and the lower plate, respectively. Forming a color filter on the transparent electrode, forming a transparent electrode in a transverse direction on the upper plate, forming at least one color filter on the transparent electrode in a color filter And the second electrode is formed so as to correspond to the first electrode and the second electrode. 9. The manufacturing method of a display device according to claim 8, wherein the color filter is formed of three colors of red, green, and blue. The manufacturing method of a display device according to claim 9, wherein the sum of the thicknesses of the color filters dividedly formed in the upper plate and the lower plate has a relationship of blue filter> green filter> red filter. The manufacturing method of a display device according to claim 8, further comprising forming a protective film on each of the upper plate and the lower plate. 9. The method of manufacturing a display device according to claim 8, further comprising the step of forming an alignment film on each of the upper plate and the lower plate. 13. The manufacturing method of a display device according to claim 12, wherein the orientation film is formed by a printing method. The manufacturing method of a display device according to claim 12, further comprising rubbing the alignment film. A color filter formed on the lower plate, an upper plate, electrodes formed on the upper plate, a switching element switching signals applied to the electrodes, and at least one or more color filters formed on the electrodes corresponding to the color filters of the lower plate An active matrix type display device comprising a color filter. 16. The display device according to claim 15, wherein the color filter is formed of three colors of red, green, and blue. 17. The display device according to claim 16, wherein the sum of the thicknesses of the curled filters divided into the upper plate and the lower plate has a relation of blue filter> green filter> red filter. The display device according to claim 15, wherein the color filter formed on the upper plate is blue. The display device according to claim 15, wherein the color filter formed on the upper plate is blue and green. The display device according to claim 15, further comprising a protective film formed on the upper plate and the lower plate, respectively. The display device according to claim 15, further comprising an alignment film formed on the upper plate and the lower plate, respectively. Forming an electrode and a switching element on the upper plate; and forming at least one or more color filters on the electrode so that the color and the position of the color filter correspond to the filter of the lower plate, ≪ / RTI > The method of manufacturing a display device according to claim 22, wherein the color filter is formed of three colors of red, green, and blue. The manufacturing method of a display device according to claim 23, wherein the sum of the thicknesses of the color filters dividedly formed on the two substrates has a relationship of blue filter> green filter> red filter. The method of manufacturing a display device according to claim 22, further comprising forming a protective film on the upper plate and the lower plate, respectively. The method of manufacturing a display device according to claim 22, further comprising the step of forming an alignment film on each of the upper plate and the lower plate. 27. The manufacturing method of a display device according to claim 26, wherein the orientation film is formed by a printing method. 27. The manufacturing method of a display device according to claim 26, further comprising rubbing the alignment film. ※ Note: It is disclosed by the contents of the first application.