KR20040016570A - Fringe field switching mode liquid crystal display device - Google Patents

Abstract

PURPOSE: A fringe field switching mode LCD is provided to dispose a conductive black matrix to an outer surface of an upper substrate for improving the ununiform rubbing and preventing the static electricity without using an overcoating layer and an ITO film, thereby reducing the fabricating cost. CONSTITUTION: A fringe field switching mode LCD includes a conductive black matrix(460) formed with opaque metal such as single-layered or multi-layered chromium at positions corresponding to signal transmission lines(200) on an outer surface of an upper substrate, wherein the conductive black matrix blocks the light leakage and prevents the static electricity. The upper substrate is formed with an upper orientation film(500) but not any structure which requires stepped differences, so that an overcoating layer for flattening such a structure is not required any more and uniform rubbing of the orientation film is realized.

Description

Fringe field switching mode liquid crystal display device {FRINGE FIELD SWITCHING MODE LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fringe field switched mode liquid crystal display device, and more particularly, to a fringe field switched mode liquid crystal display device having high quality characteristics due to uniform rubbing and having high brightness characteristics by removing the outer surface ITO.

Among various liquid crystal display devices, a liquid crystal display device which is used for medical purposes does not have an RGB color layer, unlike a general display including an RGB color layer, and blocks upper and lower substrates, electrodes capable of driving liquid crystals, and light leakage from the electrode part. A black matrix (BM), an analyzer, and a polarizing plate attached to the outer surface of each of the upper and lower substrates are used as basic configurations.

Such a medical display device requires various characteristics for accurate diagnosis, review, analysis, and the like. Some of them, for example, for resolutions of general shooting and digital film reading, require 2048 × 2560 pixels or more for 14 ”× 17” in width × length, brightness of 65 fL or more and size of 20 "More products are required.

Therefore, the panel of the medical liquid crystal display device requires a wide viewing angle characteristics, high brightness characteristics due to high transmission, high quality characteristics by orientation uniformity for precise analysis, and low-cost characteristics for product competitiveness.

In the fringe field switching mode liquid crystal display device according to the related art, as shown in FIG. 1, the lower substrate 10 and the upper substrate 40 are bonded to each other with the liquid crystal layer 30 interposed therebetween.

Predetermined lines 20 are disposed on the lower substrate 10 to transmit electrical signals, and are patterned in a box shape to form a fringe field for driving the liquid crystal molecules 32 in the liquid crystal layer 30. The pixel electrode 18 patterned by the slit with the electrode 14 and the insulating layer 16 interposed therebetween is arrange | positioned.

The upper substrate 40 is formed with a resin black matrix 46 to prevent field distortion and an overcoating layer 48 to planarize the stepped portion, and an outer surface for preventing static electricity on the outer surface of the upper substrate 40. ITO 44 is disposed.

The uppermost layer of each of the lower substrate 10 and the upper substrate 40 is coated with alignment layers 22 and 50 for orienting liquid crystal molecules 32, and in order to maintain a constant cell gap, the lower substrate 10 and A spacer 60 is formed between the upper substrate 40, and a polarizing plate 12 and an analyzer plate 42 are disposed on each of the outer surfaces of the lower substrate 10 and the upper substrate 40.

However, the fringe field switching mode liquid crystal display device according to the prior art has the following problems.

In the prior art, a black matrix must be provided in order to prevent light leakage occurring at the stepped portion of the gate line or the data line, and in the liquid crystal display mode using a transverse electric field such as a fringe field, the electric field distortion between the counter electrode and the pixel electrode is prevented. To prevent this, a resin black matrix having a high resistance should be employed. In this case, since the thickness of the resin black matrix is 1.2 µm or more, the occurrence of rubbing nonuniformity in the resin black matrix step portion is inevitable, and an overcoating layer is necessarily required to solve this problem. Accordingly, there is a disadvantage of price increase.

In addition, unlike the TN mode, since there is no electrode on the upper substrate, there is a disadvantage that is vulnerable to static electricity due to various causes such as external contact. In order to solve this problem, an anti-static ITO should be placed on the outer surface of the upper substrate, and thus there is a problem of price increase and transmittance decrease.

Therefore, the present invention has been made to solve the above-mentioned problems in the prior art, an object of the present invention is to place a conductive black matrix on the outer surface of the upper substrate to solve the problem of rubbing unevenness and prevent the static electricity fringe field switching mode The present invention provides a liquid crystal display device.

1 is a cross-sectional view showing a fringe field switching mode liquid crystal display device according to the prior art.

2 is a cross-sectional view showing a fringe field switching mode liquid crystal display device according to Embodiment 1 of the present invention;

3 is a perspective view showing a conductive black matrix in the fringe field switched mode liquid crystal display device according to the first embodiment of the present invention.

4 is a cross-sectional view showing a fringe field switching mode liquid crystal display device according to Embodiment 2 of the present invention.

FIG. 5 is a perspective view illustrating a conductive black matrix in the fringe field switched mode liquid crystal display device according to Embodiment 2. FIG.

Explanation of symbols on the main parts of the drawings

100,105; Lower substrates 120 and 125; Polarizer

140,145; Counter electrode 160,165; Insulation layer

180,185; Pixel electrodes 200 and 205; Signal transmission line

220,225; Lower alignment layers 300 and 305; Liquid crystal layer

320,335; Liquid crystal molecules 400,405; Upper substrate

420,425; Analyzer plates 460,465; Conductive Black Matrix

500,505; Upper alignment layer 600; Spherical spacer

605; Holding spacer

A fringe field switching mode liquid crystal display device according to the present invention for achieving the above object is a fringe field switching mode liquid crystal display device in which a lower substrate and an upper substrate are bonded to each other with a liquid crystal layer including a spacer interposed therebetween. In order to drive the liquid crystal molecules in the liquid crystal layer, the counter electrode and the pixel electrode which form the fringe field are sequentially formed on the inner surface of the substrate with the insulating layer interposed therebetween, and the liquid crystal molecules are aligned in the predetermined direction on the insulating layer. A lower alignment layer is formed, a predetermined signal transmission line for transmitting an electrical signal is formed on the same layer as the pixel electrode, and an upper alignment layer having the same function as the lower alignment layer is formed on an inner surface of the upper substrate. External incident on the outer surface of the lower substrate A polarizer for changing a polarized outgoing light is formed, and a, is characterized in that the outer surface of the upper substrate, the conductive black matrix at a position corresponding to an analyzer plate and the signal transmission line are formed.

According to the present invention, since the conductive black matrix is disposed on the outer surface of the upper substrate, the overcoating layer is unnecessary and the antistatic ITO is unnecessary. As a result, the price competitiveness can be improved and the high quality and high brightness characteristics due to uniform rubbing can be improved.

Hereinafter, a fringe field switching mode liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of a fringe field switched mode liquid crystal display device according to a first embodiment of the present invention, and FIG. 3 is a diagram showing a conductive black matrix in a fringe field switched mode liquid crystal display device according to a first embodiment of the present invention. Perspective view. 4 is a cross-sectional view illustrating a fringe field switched mode liquid crystal display device according to a second embodiment of the present invention, and FIG. 5 is a cross-sectional view illustrating a conductive black matrix in the fringe field switched mode liquid crystal display device according to a second embodiment of the present invention. It is a perspective view shown.

In the fringe field switching mode liquid crystal display device according to the first embodiment of the present invention, as shown in FIG. 2, a lower portion of the liquid crystal layer 300 including the spherical spacer 600 is formed of a transparent insulator such as glass. It is a basic structure that the substrate 100 and the upper substrate 400 are bonded while maintaining a constant cell gap.

The spherical spacer 600 plays a role of maintaining a constant gap, that is, a cell gap between the lower substrate 100 and the upper substrate 400. The liquid crystal layer 300 is filled with several liquid crystal molecules 320 having a positive dielectric constant or a negative dielectric anisotropy.

Here, the inner and outer surfaces of each of the lower substrate 100 and the upper substrate 400 include various components as follows.

First, look at what is formed on the inner surface of each of the lower substrate 100 and the upper substrate 400 as follows.

On the inner surface of the lower substrate 100, a counter electrode 140 and a pixel electrode 180 forming a fringe field, which is a parabolic transverse electric field, to drive the liquid crystal molecules 320 in the liquid crystal layer 300. ) Are sequentially formed with the insulating layer 160 therebetween.

The counter electrode 140 is patterned in a box shape, and the pixel electrode 180 is patterned in a slit shape having a cramp (<) shape for the purpose of preventing color blur. Specifically, the slit width W1 of the pixel electrode 180 is about 4 μm, and the gap W2 between the slits is about 5 μm.

A lower alignment layer 220 is formed on the insulating layer 160 to align the liquid crystal molecules 320 in a predetermined direction, and a predetermined signal transmission line 200 for transmitting an electrical signal such as a gate line or a data line is formed. It is formed on the same layer as the pixel electrode 180.

An upper alignment layer 500 having the same function as the lower alignment layer 220 is formed on an inner surface of the upper substrate 400. On the other hand, since there is no structure to form a step in the upper alignment layer 500 on the inner surface of the upper substrate 400, uniform rubbing is possible, and a film for planarization such as an overcoating layer is not required.

The outer surface of each of the lower substrate 100 and the upper substrate 400 includes the following components.

A polarizing plate 120 is formed on the outer surface of the lower substrate 100 to convert external incident light into polarized outgoing light, and a counter plate 420 is formed on the outer surface of the upper substrate 400.

In addition, a conductive black matrix 460 formed of a conductor such as an opaque metal such as single layer chromium (Cr) or multilayer chrome is formed on the outer surface of the upper substrate 400 at a position corresponding to the signal transmission line 200. It is. Accordingly, the conductive black matrix 460 serves to block leakage light and to prevent static electricity.

In addition, if the low reflection treatment is applied to the conductive black matrix 460, the reflection of ambient light may be blocked.

As shown in FIG. 3, the conductive black matrix 460 formed on the outer surface of the upper substrate 400 includes an assembly key for aligning with the lower substrate 100 and the upper alignment layer. 500) a variety of keys such as a key for forming, an alignment key for cutting, a monitoring key for cutting, and a micro vernier for checking the degree of adhesion between the upper substrate and the lower substrate. The keys A are located.

Although not shown in the figure, the conductive black matrix 460 is connected to ground such as a bezel of a module or a printed circuit board (PCB) through a conductive tape or a conductive cue.

The fringe field switching mode liquid crystal display device according to the second embodiment of the present invention is composed of a transparent insulator such as glass with a liquid crystal layer 305 including a holding spacer 605 therebetween, as shown in FIG. 4. The lower substrate 105 and the upper substrate 405 are bonded to each other while maintaining a constant cell gap.

The holding spacer 605 plays a role of maintaining a constant gap, that is, a cell gap between the lower substrate 105 and the upper substrate 405. The liquid crystal layer 305 is filled with several liquid crystal molecules 325 having positive dielectric constant or negative dielectric anisotropy.

Here, the inner and outer surfaces of each of the lower substrate 105 and the upper substrate 405 include the following components.

First, looking at the inner surface of each of the lower substrate 105 and the upper substrate 405 as follows.

A counter electrode 145 and a pixel electrode 185 are formed on an inner side surface of the lower substrate 105 to form a fringe field, which is a parabolic transverse electric field, for driving the liquid crystal molecules 325 in the liquid crystal layer 305. ) Is sequentially formed with the insulating layer 165 therebetween.

The counter electrode 145 is patterned in a box shape, and the pixel electrode 185 is patterned in a slit shape having a cramp (<) shape for the purpose of preventing color spurs. Specifically, the slit width W1 of the pixel electrode 185 is about 4 μm, and the interval W2 between the slits is about 5 μm.

A lower alignment layer 225 is formed on the insulating layer 165 to align the liquid crystal molecules 325 in a predetermined direction, and a predetermined signal transmission line 205 for transmitting an electrical signal such as a gate line or a data line is formed. It is formed on the same layer as the pixel electrode 185.

An upper alignment layer 505 having the same function as the lower alignment layer 225 is formed on an inner surface of the upper substrate 405. On the other hand, since there is no structure to form a step on the upper alignment layer 505 on the inner surface of the upper substrate 405, uniform rubbing is possible, and a film for planarization such as an overcoating layer is not required.

The outer surface of each of the lower substrate 105 and the upper substrate 405 includes the following components.

The polarizing plate 125 for converting external incident light into polarized outgoing light is formed on an outer surface of the lower substrate 105, and an analyzer 425 is formed on an outer surface of the upper substrate 405.

In addition, a conductive black matrix 465 formed of a conductor such as an opaque metal such as single layer chromium (Cr) or multilayer chromium is formed on the outer surface of the upper substrate 405 at a position corresponding to the signal transmission line 205. It is. Therefore, the conductive black matrix 465 plays a role of blocking leakage light and also prevents static electricity.

In addition, if the conductive black matrix 465 is subjected to a low reflection treatment, the reflection of ambient light may be blocked.

Here, the post spacer 605 is formed at a position corresponding to the conductive black matrix 465, more specifically at a position corresponding to the signal transmission line 205 such as a gate line. Thus, the conductive black matrix 465, the post spacer 605, and the signal transmission line 205 lie on the same vertical line.

Meanwhile, as shown in FIG. 5, the conductive black matrix 465 formed on the outer surface of the upper substrate 405 has an assembly key for aligning with the lower substrate 105 and the upper alignment layer ( 505) a variety of keys such as a key for forming, an alignment key for cutting, a monitoring key for cutting, and a micro vernier for checking the bonding degree of the upper substrate and the lower substrate. The keys B are located.

Although not shown in the figure, the conductive black matrix 465 is connected to ground such as a bezel of a module or a printed circuit board (PCB) through a conductive tape or a conductive cue.

Various embodiments can be easily implemented as well as self-explanatory to those skilled in the art without departing from the principles and spirit of the invention. Accordingly, the claims appended hereto are not limited to those already described above, and the following claims are intended to cover all of the novel and patented matters inherent in the invention, and are also common in the art to which the invention pertains. Includes all features that are processed evenly by the knowledgeable.

As described above, the fringe field switching mode liquid crystal display device according to the present invention has the following effects.

In the present invention, since the conductive black matrix is disposed on the outer surface of the upper substrate, the overcoating layer is unnecessary and the antistatic ITO is unnecessary. As a result, the price competitiveness can be improved and the high quality and high brightness characteristics can be improved by uniform rubbing. There is.

Claims (10)

In a fringe field switching mode liquid crystal display device in which a lower substrate and an upper substrate are bonded to each other with a liquid crystal layer including a spacer therebetween, A counter electrode and a pixel electrode forming a fringe field are sequentially formed on an inner surface of the lower substrate with an insulating layer interposed therebetween to drive the liquid crystal molecules in the liquid crystal layer, and the liquid crystal molecules are disposed in a predetermined direction on the insulating layer. A lower alignment layer for aligning is formed, a predetermined signal transmission line for transmitting an electrical signal is formed on the same layer as the pixel electrode, An upper alignment layer having the same function as the lower alignment layer is formed on an inner surface of the upper substrate. On the outer surface of the lower substrate is formed a polarizing plate for changing the external incident light into polarized outgoing light, A fringe field switching mode liquid crystal display device, characterized in that a conductive black matrix is formed at a position corresponding to the detector plate and the signal transmission line on an outer surface of the upper substrate. The method of claim 1, The counter electrode is patterned in a box shape, fringe field switching mode liquid crystal display device. The method of claim 1, The pixel electrode is patterned in a slit shape, fringe field switching mode liquid crystal display device. The method of claim 3, The slit has a width of 4㎛, the interval between the slits fringe field switching mode liquid crystal display device. The method of claim 1, The conductive black matrix is a fringe field switching mode liquid crystal display device, characterized in that made of an opaque metal. The method of claim 5, The opaque metal is single layer chromium or multilayer chromium fringe field switching mode liquid crystal display device. The method of claim 1, The conductive black matrix is a fringe field switching mode liquid crystal display device characterized in that the low reflection treatment to block the reflection of the ambient light. The method of claim 1, The conductive black matrix is a fringe field switching mode liquid crystal display device comprising at least one alignment key. The method of claim 8, The alignment key may be an assembly key for aligning with the lower substrate, a key for forming the upper alignment layer, a cutting alignment key, a cutting degree monitoring key, a micro vernier for checking the bonding degree of the upper substrate and the lower substrate, and their Fringe field switching mode liquid crystal display device, characterized in that any one of the combination. The method of claim 1, The conductive black matrix is a fringe field switching mode liquid crystal display device, characterized in that connected to the cut or the printed circuit board of the module by a predetermined conductive connection means.