KR100744390B1 - Liquid crystal display device - Google Patents

Abstract

An LCD is provided to prevent the hardening failure of a sealant, by using a total reflection plate with a plurality of slits so that an inside portion of the sealant is exposed to UV through total reflection during UV irradiation. TN(Twisted Nematic) mode LCD comprises an upper substrate(51), a lower substrate(52) facing the upper substrate, and a liquid crystal layer interposed between the upper substrate and the lower substrate. The upper substrate includes a resin black matrix(42), an overcoat layer(43), and a common electrode sequentially formed in an outer region of an active area of an upper glass substrate(41). A sealant is formed in the outer region of the active area. The lower substrate includes a slit type metal layer(47) formed in an outer region of an active area of a lower glass substrate(46). A total reflection plate(45) is formed on the common electrode, wherein the total reflection plate has a plurality of slits.

Description

Liquid crystal display device

1A and 1B are cross-sectional views illustrating a liquid crystal display device in which a conventional UV irradiation is performed.

2A is a cross-sectional view for describing a TN mode driving liquid crystal display device according to an exemplary embodiment of the present invention.

FIG. 2B is a top view illustrating an outer side of an active area of a TN mode driving liquid crystal display device according to an exemplary embodiment of the present invention. FIG.

3 is a cross-sectional view illustrating a liquid crystal display device of a transverse electric field mode driving method according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

21,41: upper glass substrate 22,42: resin black matrix

23,43: overcoating layer 24: common electrode

25: total reflection plate 26, 46: lower glass substrate

27,47: metal layer 28,48: sealing material

31,51: upper substrate 32, 52: lower substrate

44: first total reflector 45: second total reflector

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device provided with a total reflection plate in order to improve the curing rate of the sealing material.

In general, a liquid crystal display device is an electronic device that changes and transmits various electrical information generated by various devices into visual information by using a change in transmittance of a liquid crystal according to an applied voltage. An information display window of a portable terminal, a screen display of a notebook computer, etc. It is used as an information display window.

The liquid crystal display includes an upper substrate provided with a color filter layer, a lower substrate opposing the upper substrate, and a liquid crystal layer interposed between the upper substrate and the lower substrate provided with the thin film transistor.

Here, the upper substrate and the lower substrate are bonded through the hardening of a sealant applied to the outside of the active region. In other words, the bonding between the substrates is performed by thermocompression bonding between the substrates with a sealant applied to an edge of one of the substrates, for example, a lower substrate, and curing the sealant. Is done. At this time, the curing of the sealing material is mainly carried out using a method of irradiating UV to the sealing material. In particular, the method of curing the seal material using the UV irradiation is indispensably used in the manufacture of the liquid crystal display device using the recent liquid crystal drop injection (One Drop Fill).

On the other hand, in the upper substrate, it is common to form a black matrix (hereinafter referred to as BM) for isolation between sub-pixels. The BM has been generally formed of a metal of Cr material, but recently, the use of BM of the resin component is increasing, and depending on the driving mode, in particular, the upper substrate such as the IPS (In Plane Switching) mode or the FFS (Fringe Field Switching) mode In a liquid crystal display device having a configuration in which there is no liquid crystal driving electrode, that is, a counter electrode, the use of resin BM becomes essential.

In general, in the case of forming the sealing material 70,700 on the portion of the BM (20,200) outside the active area for bonding the lower substrate (40,400) and the upper substrate (10,100), as shown in Figure 1a, 70) If the lower BM 20 is made of metal, that is, Cr (chromium), the reflectance of incident light is high, so there is no problem, as shown in Figure 1b, the BM ( When 200) is made of a resin, the resin absorbs the light irradiated, the reflectance of the light incident on the BM 200 decreases, and causes a failure in curing of the sealing material, thereby causing a phenomenon of bursting of the sealing material or liquid crystal by the sealing material. There is a problem that causes contamination of the layer 600 and the like.

In FIG. 1A and FIG. 1B, reference numeral 60 denotes a liquid crystal layer, 30,300 represents an overcoating layer, and 50,500 represents a metal line, respectively.

On the other hand, since the use of resin BM is essential in the liquid crystal display of the IPS or FFS mode driving method, the problem caused by poor curing of the sealing material generated when the resin BM is applied is used to secure the screen quality of the liquid crystal display. In addition, the problem must be solved in order to improve the manufacturing yield.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide an improved liquid crystal display device capable of preventing a curing failure of a sealing material.

In order to achieve the above object, the present invention provides a resin black matrix, an overcoating layer, and a common electrode sequentially disposed on an upper glass substrate outside the active region to which the sealing material is applied, and spaced apart from the upper substrate. In the liquid crystal display of the TN mode driving method including a lower substrate provided with a slit metal layer on the lower glass substrate outside the active region and a liquid crystal layer interposed between the upper substrate and the lower substrate, on the common electrode Provided is a liquid crystal display device characterized in that a total reflection plate having a plurality of slits is provided.

Here, the slit width of the total reflection plate is larger toward the active region side.

The total reflection plate is characterized in that made by a resin having a refractive index of 1.50 ~ 1.55.

In addition, in order to achieve the above object, the present invention, the upper substrate and the resin substrate is provided with a black matrix and the over coating layer sequentially on the upper glass substrate outside the active region to which the seal material is applied, spaced apart from the upper substrate, In the liquid crystal display device of the transverse electric field mode driving method including a lower substrate provided with a slit-shaped metal layer on the lower glass substrate outside the active area and a liquid crystal layer interposed between the upper substrate and the lower substrate, the resin black A plate-shaped first reflecting plate is provided between the matrix and the overcoating layer, and a second slit-shaped reflecting plate is provided on the overcoating layer.

Here, the first and second total reflection plate is characterized in that the refractive index is lower than the overcoat layer.

The overcoating layer and the first and second total reflection plates are made of acrylic resin, and the acrylic resin constituting the first and second reflection plates has longer side chains attached to the main chain than the acrylic resin forming the overcoating layer. It features.

The slit width of the second reflector may be larger toward the active area.

(Example)

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the liquid crystal display of the TN mode driving method according to the present invention will be briefly described. The liquid crystal display of the present invention includes a resin black matrix, an overcoating layer, and a common electrode on an upper glass substrate outside the active region to which the sealing material is applied. A plurality of slits are formed on the upper substrate and the common electrode which are sequentially provided. The lower substrate may be spaced apart from the upper substrate, and may include a lower substrate provided with a slit metal layer on a lower glass substrate outside the active region, and a liquid crystal layer interposed between the upper substrate and the lower substrate.

In this way, exposure to the inside of the sealing material through total reflection during UV irradiation for curing of the sealing material may prevent the sealing material from bursting and contamination of the liquid crystal.

In addition, the liquid crystal display device of the transverse electric field mode driving method of the present invention will be briefly described. An upper substrate having a resin black matrix and an overcoating layer sequentially formed on an upper glass substrate outside the active region to which a sealing material is applied, and the resin black A plate-shaped first reflecting plate is provided between the matrix and the overcoating layer, and a slit-shaped second reflecting plate is provided on the overcoating layer. The lower substrate may be spaced apart from the upper substrate, and may include a lower substrate provided with a slit metal layer on a lower glass substrate outside the active region, and a liquid crystal layer interposed between the upper substrate and the lower substrate.

In this case, when UV irradiation for curing the sealing material advances the light to the lower portion of the sealing material UV can be irradiated in both the up and down direction, it is possible to increase the exposure efficiency.

Therefore, the liquid crystal display of the present invention can solve the problem of UV curing failure of the sealant, which is a problem in applying the ODF technology, so that the screen quality can be improved as well as reliability and manufacturing yield.

In detail, the liquid crystal display of the TN mode driving method according to an embodiment of the present invention will be described with reference to FIGS. 2A and 2B. FIG. 2A is a cross-sectional view illustrating a liquid crystal display of a TN mode driving method, and FIG. 2B is a top view illustrating the outside of an active region.

Referring to FIG. 2A, first, in order to generally manufacture the upper substrate 31, the resin black matrix 22, the overcoating layer 23, and the common electrode 24 are formed on the upper glass substrate 21. Are produced sequentially. Then, a total reflection plate 25 having a plurality of slits is formed on the common electrode 24 outside the active region to which the seal member 28 is to be applied. Here, the total reflection plate 25 is made of a resin (resin) having a refractive index of 1.50 ~ 1.55.

In addition, a lower substrate 32 facing the upper substrate 31 and spaced apart from each other and having a slit-shaped metal layer 27 formed on the lower glass substrate 26 outside the active region is provided. After dropping a predetermined amount of liquid crystal (not shown) into the lower substrate 32 according to a drop fill (hereinafter referred to as ODF), the lower portion is formed through the sealing material 28 formed on the upper substrate 31. The substrate 32 is bonded to the upper substrate 31 to manufacture a TN mode driving liquid crystal display device according to an exemplary embodiment of the present invention.

As described above, in order to apply the ODF technology in the liquid crystal display device of the TN mode driving method, the UV curing process of the sealing material 28 is essential during the panel assembly process.

Therefore, in the present invention, by forming the total reflection plate 25 on the upper substrate 31, the total reflection plate 25 formed in this way can totally reflect the incoming light during UV irradiation to cure the sealing material (28).

In other words, the total reflection can be performed when the refractive index of the light propagation portion is higher than the refractive index of the outer layer during UV irradiation. The refractive index of the upper substrate common electrode 24 is about 1.85 to 1.87, and the total reflection plate made of the resin Since the refractive index of (25) is about 1.50-1.55, total reflection is possible.

Referring to FIG. 2B, the slit width of the total reflection plate 25 may be larger toward the active region, and thus the amount of UV emitted totally reflected may be similar to the outside and the inside.

Accordingly, the present invention forms a total reflection plate having a plurality of slits formed on the substrate, and is exposed to the inside of the sealing material through the total reflection plate during UV irradiation to cure the sealing material, thereby preventing the sealing material from bursting and contamination of the liquid crystal. Can be.

As a result, it is possible to increase the exposure efficiency of the sealing material when manufacturing the liquid crystal display device of the TN mode driving method, thereby minimizing productivity degradation due to the bursting of the sealing material and defects caused by liquid crystal contamination, and exposure time as the exposure efficiency increases. It can reduce the production rate and increase the output.

3 is a diagram illustrating a liquid crystal display device of a transverse electric field mode driving method according to another embodiment of the present invention.

Referring to FIG. 3, first, in order to generally manufacture the upper substrate 51, a common electrode (not shown) is formed on an inner surface of the upper glass substrate 41, and the outside of the upper glass substrate 41 is formed. A resin black matrix 42 is formed on the side surface, and a plate-shaped first total reflection plate 44 is formed on the resin black matrix 42. The overcoating layer 43 is formed on the first transfer reflecting plate 44, and the second transfer plate 45 having a slit shape is formed on the overcoating layer 43.

Here, the first and second reflecting plates 44 and 45 have a lower refractive index than the overcoating layer 43, and the overcoating layer 43 and the first and second reflecting plates 44 and 45 are made of acrylic resin. The acryl-based resin has a longer side chain attached to the main chain than the acryl-based resin forming the overcoating layer 43.

Although not shown, the slit width of the second reflector plate 45 is increased toward the active region.

In addition, a lower substrate 52 facing the upper substrate 51 and spaced apart from each other and having a slit-shaped metal layer 47 formed inside the lower glass substrate 46 outside the active region is provided. After dropping a predetermined amount of liquid crystal (not shown) inside the substrate 52, the lower substrate 52 is connected to the upper substrate 51 by the sealing material 48 formed on the upper substrate 51. Bonding to manufacture a liquid crystal display device of the transverse electric field mode driving method according to another embodiment of the present invention.

As described above, in order to apply the ODF technology among the liquid crystal display device of the transverse electric field mode driving method, the UV curing process of the sealing material is essential during the panel assembly process.

Accordingly, in the present invention, a plate-shaped first reflecting plate 44 is formed between the resin black mattress 42 and the overcoating layer 43, and a slit-shaped second reflecting plate 45 is formed on the overcoating layer 43. By forming a, the total reflection plates 44 and 45 formed in this way may advance light to the lower part of the sealing material during UV irradiation to cure the sealing material 48 so that UV can be irradiated in both the up and down directions to increase the exposure efficiency. Can be.

In other words, a plate-shaped first reflecting plate 44 having a lower refractive index than the overcoating layer is formed between the resin black matrix 42 and the overcoating layer 43, and the refractive index of the overcoating layer 43 is higher than that of the overcoating layer 43. The second reflecting plate 45 having a low slit shape may be formed to allow the UV to be totally reflected during UV irradiation to be irradiated toward the sealing material, thereby increasing the exposure efficiency.

In addition, the slit width of the second reflector plate 45 is made larger toward the active region, so that the amount of UV that is totally reflected may come out from the outside and the inside.

As a result, it is possible to increase the exposure efficiency of the sealing material when manufacturing the transverse electric field mode driving type liquid crystal display device, thereby minimizing productivity degradation due to the bursting of the sealing material and defects due to liquid crystal contamination. This can save time and increase production.

As described above, the present invention forms a total reflection plate capable of total reflection, and forms a pattern in the middle to expose the inside of the sealing material through total reflection during UV irradiation, thereby increasing the efficiency of exposure.

Therefore, problems caused by bursting of the sealing material and contamination of the liquid crystal during UV irradiation for curing the sealing material can be solved, and the exposure time can be reduced as the exposure efficiency is increased, thereby increasing production.

It is to be understood that the invention is not limited to that described above and illustrated in the drawings, and that more modifications and variations are possible within the scope of the following claims.

Claims (7)

A resin black matrix on the upper glass substrate outside the active region to which the seal material is applied, an upper substrate on which the overcoating layer and the common electrode are sequentially provided, and are spaced apart from the upper substrate, and slit on the lower glass substrate outside the active region. In the liquid crystal display device of the TN mode driving method including a lower substrate provided with a metal layer of the form and a liquid crystal layer interposed between the upper substrate and the lower substrate, And a total reflection plate having a plurality of slits formed on the common electrode. The method of claim 1, And a slit width of the total reflection plate becomes larger toward the active region. The method of claim 1, The total reflection plate is made of a resin having a refractive index of 1.50 ~ 1.55. The upper substrate on which the resin black matrix and the overcoating layer are sequentially provided on the upper glass substrate outside the active region to which the seal material is applied, and the upper substrate is spaced apart from the upper substrate, and a slit metal layer is disposed on the lower glass substrate outside the active region. In the liquid crystal display device of the transverse electric field mode driving method including the lower substrate and the liquid crystal layer interposed between the upper substrate and the lower substrate, A plate-shaped first total reflection plate is provided between the resin black matrix and the overcoating layer, and a slit-shaped second reflection plate is provided on the overcoating layer. The method of claim 4, wherein The first and second total reflection plates have a lower refractive index than the overcoating layer. The method of claim 4, wherein The overcoating layer and the first and second total reflection plates are made of an acrylic resin, The acrylic resin constituting the first and second total reflection plates has a longer side chain attached to the main chain than the acrylic resin constituting the overcoating layer. The method of claim 4, wherein And a slit width of the second reflecting plate increases toward the active area.

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