KR102467776B1 - Display Device - Google Patents

Abstract

The present invention relates to a display device including a polarizing plate, which includes a display panel displaying an image through a display area, a polarizing plate on the display panel, a cover window on the polarizing plate, and adhesion between the polarizing plate and the cover window. The adhesive member includes a first adhesive layer in contact with the polarizing plate and a second adhesive layer covering upper and side surfaces of the first adhesive layer, wherein the moisture vapor transmission rate of the first adhesive layer is greater than that of the second adhesive layer. , The first adhesive layer and the second adhesive layer have the same refractive index. Accordingly, in a high-temperature environment, moisture inside the polarizing plate moves to the first adhesive layer to prevent reddening of the polarizing film and deterioration of image quality of the display device.

Description

Display Device {Display Device}

The present invention relates to a display device, and more particularly, to a display device including a polarizing plate.

As society entered the information age in earnest, the display field, which processes and displays large amounts of information, has developed rapidly. Various flat panel display devices such as display device (ELD) have been developed and are in the spotlight.

Among these flat panel display devices, the liquid crystal display device includes as essential components a liquid crystal panel including an upper substrate and a lower substrate bonded with a liquid crystal layer including liquid crystal molecules therebetween, and an electric field formed between a pixel electrode and a common electrode. As a result, the liquid crystal layer is driven to display an image.

In addition, the electroluminescent display device includes as an essential component a light emitting diode including an anode and a cathode facing each other with a light emitting layer interposed therebetween, and holes and electrons injected from the anode and cathode are combined in the light emitting layer to emit light, thereby displaying an image. will display

Such a liquid crystal display device or an electroluminescent display device includes a display panel for displaying an image, and selectively transmits light by attaching a polarizing plate to one or both sides of the display panel as necessary.

The polarizing plate includes a polarizing film, and the polarizing film is formed by stretching poly-vinyl alcohol (PVA) dyed with iodine (I), and an absorption axis is formed in the stretching direction and is parallel to the absorption axis. Light vibrating in one direction is absorbed, and only light vibrating in a direction perpendicular to the absorption axis is selectively transmitted.

Meanwhile, a cover window is attached to an upper portion of the polarizing plate, and an adhesive is positioned between the polarizing plate and the cover window.

However, in a display device including such a polarizing plate, redness of the polarizing film occurs in a high-temperature environment.

More specifically, the polarizing film contains about 5% of moisture, and when placed at a high temperature of about 95 degrees Celsius or higher, the moisture is trapped in the polarizing film, and iodine is decomposed to yellowish and reddish. (reddish) and reddish phenomenon occurs. This reddening phenomenon occurs in the central portion of the display device, and gradually expands toward the edge as time passes, increasing the reddening area.

The polarizing film once reducible does not return to its original state, and the image of the display device is implemented in a brown color due to the reddened polarizing film, thereby deteriorating the image quality.

The present invention is intended to solve the problem of reddening of a polarizing film of a conventional display device in a high-temperature environment.

In addition, the present invention is to solve the problem of deterioration of image quality of a display device including a polarizing plate.

In order to achieve the above object, the display device of the present invention includes a display panel for displaying an image through a display area, a polarizing plate on the display panel, a cover window on the polarizing plate, and an adhesive member between the polarizing plate and the cover window, The adhesive member includes a first adhesive layer in contact with the polarizing plate and a second adhesive layer covering the top and side surfaces of the first adhesive layer, the moisture vapor transmission rate of the first adhesive layer is greater than the moisture vapor transmission rate of the second adhesive layer, and the first adhesive layer and The second adhesive layer has the same refractive index.

The first adhesive layer may have the same area as the display area or may have a smaller area than the display area.

Also, the first adhesive layer may have a first opening at a corner and may have a second opening at a display area.

In the display device of the present invention, by using an adhesive member in which the moisture transmittance of the first adhesive layer in contact with the polarizing plate is greater than the moisture transmittance of the second adhesive layer surrounding the first adhesive layer, moisture in the polarizing film of the polarizing plate in a high-temperature environment is first By moving to the adhesive layer, it is possible to prevent decomposition of iodine and reddening of the polarizing film. Accordingly, deterioration of the image quality of the display device can be prevented.

In addition, the second adhesive layer has a relatively low water permeability, so that moisture from the outside can be prevented from being introduced.

In addition, since the second adhesive layer is relatively hard and has strong adhesive properties, it is possible to prevent a thickness step from occurring in the adhesive member.

1 is a schematic cross-sectional view of a display device according to an exemplary embodiment of the present invention.
2A and 2B are schematic cross-sectional views illustrating examples of a display panel of a display device according to an exemplary embodiment of the present invention.
3 is a schematic cross-sectional view of an adhesive member according to a first embodiment of the present invention.
4 is a plan view schematically illustrating an adhesive member according to a first embodiment of the present invention.
5 is a schematic cross-sectional view of an adhesive member according to a second embodiment of the present invention.
6 is a plan view schematically illustrating an adhesive member according to a second embodiment of the present invention.
7 is a plan view schematically illustrating an adhesive member according to a third embodiment of the present invention.
8 is a plan view schematically illustrating an adhesive member according to a fourth embodiment of the present invention.
9 is a plan view schematically illustrating an adhesive member according to a fifth embodiment of the present invention.
10 is a plan view schematically illustrating an adhesive member according to a sixth embodiment of the present invention.
11 is a plan view schematically illustrating an adhesive member according to a seventh embodiment of the present invention.
12 is a plan view schematically illustrating an adhesive member according to an eighth embodiment of the present invention.

A display device according to an embodiment of the present invention includes a display panel displaying an image through a display area; a polarizing plate above the display panel; a cover window above the polarizer; An adhesive member between the polarizing plate and the cover window, wherein the adhesive member includes a first adhesive layer contacting the polarizing plate and a second adhesive layer covering top and side surfaces of the first adhesive layer, wherein the first adhesive layer includes moisture The water vapor transmission rate is greater than the water vapor transmission rate of the second adhesive layer.

The first adhesive layer and the second adhesive layer have the same refractive index.

The first adhesive layer has a smaller storage modulus and hardness than the second adhesive layer.

The first adhesive layer may have the same area as the display area.

The second adhesive layer may contact the polarizing plate in a non-display area surrounding the display area, and a width of the second adhesive layer contacting the polarizing plate in the non-display area may be greater than or equal to 0.5 mm.

Alternatively, the first adhesive layer may have a smaller area than the display area.

At this time, the second adhesive layer contacts the polarizing plate in the display area, and the total length of the second adhesive layer contacting the polarizing plate in the display area along the first direction is less than 1/3 of the length of the first adhesive layer. can be less than or equal to

Alternatively, the first adhesive layer may have an area corresponding to the display area and may have a first opening at a corner.

Also, the first adhesive layer may have a second opening in the display area.

Meanwhile, the length of the first adhesive layer in the first direction may be smaller than that of the display area, and the length in the second direction may be equal to that of the display area.

Hereinafter, a display device according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 is a schematic cross-sectional view of a display device according to an exemplary embodiment, and FIGS. 2A and 2B are schematic cross-sectional views illustrating examples of a display panel of the display device according to an exemplary embodiment.

As shown in FIGS. 1, 2A, and 2B, the display device according to the exemplary embodiment of the present invention includes a display panel 100, a polarizer 110 positioned above the display panel 100, and the polarizer 110. ) includes a cover window 120 located on the upper side, and an adhesive member 130 between the polarizer 110 and the cover window 120. Here, the display device is divided into a display area AA where an image is displayed and a non-display area NAA surrounding the display area AA.

The display panel 100 displays an image through the display area AA.

As shown in FIG. 2A , the display panel 100 may be a light emitting diode display panel.

That is, the display panel 100 includes a substrate 150, a thin film transistor Tr positioned on the display area AA of the substrate 150, and a light emitting diode D connected to the thin film transistor Tr. and an encapsulation film 190 covering the light emitting diode (D).

More specifically, a semiconductor layer 154 is formed on the substrate 150 . A buffer layer (not shown) may be formed between the substrate 150 and the semiconductor layer 154 . The buffer layer may be made of an inorganic insulating material such as silicon oxide or silicon nitride, and may have a single-layer structure or a multi-layer structure.

The substrate 150 may be made of glass or plastic having relatively high thermal stability. As an example, the plastic may be polyimide, but is not limited thereto.

Meanwhile, the semiconductor layer 154 may be formed of an oxide semiconductor material or polycrystalline silicon.

When the semiconductor layer 154 is made of an oxide semiconductor material, a light blocking pattern (not shown) may be formed under the semiconductor layer 154, and the light blocking pattern prevents light from entering the semiconductor layer 154. Thus, the semiconductor layer 154 is prevented from being deteriorated by light. Alternatively, the semiconductor layer 154 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 154 may be doped with impurities.

A gate insulating layer 156 made of an insulating material is formed on the semiconductor layer 154 . The gate insulating layer 156 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

A gate electrode 160 made of a conductive material such as metal is formed on the gate insulating layer 156 to correspond to the center of the semiconductor layer 154 .

In FIG. 2A , the gate insulating film 156 is formed on the entire surface of the substrate 150 , but the gate insulating film 156 may be patterned in the same shape as the gate electrode 160 .

An interlayer insulating film 162 made of an insulating material is formed on the gate electrode 160 . The interlayer insulating layer 162 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating layer 162 has first and second contact holes 164 and 166 exposing both sides of the semiconductor layer 154 . The first and second contact holes 164 and 166 are spaced apart from the gate electrode 160 on both sides of the gate electrode 160 .

Here, the first and second contact holes 164 and 166 are also formed in the gate insulating layer 156 . Alternatively, when the gate insulating layer 156 is patterned in the same shape as the gate electrode 160 , the first and second contact holes 164 and 166 may be formed only in the interlayer insulating layer 162 .

A source electrode 170 and a drain electrode 172 made of a conductive material such as metal are formed on the interlayer insulating film 162 .

The source electrode 170 and the drain electrode 172 are spaced apart from each other with respect to the gate electrode 160, and both sides of the semiconductor layer 154 through the first and second contact holes 164 and 166, respectively. come into contact with

The semiconductor layer 154, the gate electrode 160, the source electrode 170, and the drain electrode 172 constitute the thin film transistor Tr, and the thin film transistor Tr is a driving element. function as an element.

Here, the thin film transistor Tr has a coplanar structure in which the gate electrode 160, the source electrode 170, and the drain electrode 172 are positioned on the semiconductor layer 154.

Alternatively, the thin film transistor Tr may have an inverted staggered structure in which a gate electrode is positioned below the semiconductor layer and a source electrode and a drain electrode are positioned above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

Although not shown, a gate line and a data line cross each other to define a pixel area, and a switching element connected to the gate line and the data line is further formed. The switching element is connected to the thin film transistor Tr, which is a driving element, and may have the same structure as the thin film transistor Tr.

In addition, a power line is formed to be spaced apart in parallel with the gate line or the data line, and a storage capacitor for maintaining a constant voltage of the gate electrode of the thin film transistor (Tr), which is a driving element, for one frame is further provided. can be configured.

A protective layer 174 having a drain contact hole 176 exposing the drain electrode 172 of the thin film transistor Tr is formed to cover the thin film transistor Tr.

On the protective layer 174, a first electrode 180 connected to the drain electrode 172 of the thin film transistor Tr through the drain contact hole 176 is formed separately for each pixel area. The first electrode 180 may be an anode and may be made of a conductive material having a relatively high work function value. For example, the first electrode 180 may be made of a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO). .

The display panel 100 of the present invention may be a top-emission type light emitting diode display panel, and a reflective electrode or a reflective layer may be further formed below the first electrode 180 . For example, the reflective electrode or the reflective layer may be made of an aluminum-palladium-copper (APC) alloy or silver (Ag).

In addition, a bank layer 186 covering an edge of the first electrode 180 is formed on the passivation layer 174 . The bank layer 186 exposes the center of the first electrode 180 corresponding to the pixel area.

An emission layer 182 is formed on the first electrode 180 . The light-emitting layer 182 may have a single-layer structure of a light-emitting material layer made of a light-emitting material. On the other hand, in order to increase the luminous efficiency, the light emitting layer 182 includes a hole injection layer, a hole transporting layer, a light emitting material layer, and an electron transporting layer sequentially stacked on the first electrode 180. It may have a multilayer structure of an electron transporting layer and an electron injection layer.

Here, the light emitting material of the light emitting material layer may be an organic light emitting material or an inorganic light emitting material such as a quantum dot.

A second electrode 184 is formed on the substrate 150 on which the light emitting layer 182 is formed. The second electrode 184 is located on the front surface of the display area and is made of a conductive material having a relatively low work function value and can be used as a cathode. For example, the second electrode 184 may be formed of any one of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (AlMg).

The first electrode 180, the light emitting layer 182, and the second electrode 184 form a light emitting diode (D).

An encapsulation film 190 is formed on the second electrode 184 to prevent penetration of external moisture into the light emitting diode D. The encapsulation film 190 may have a stacked structure of a first inorganic insulating layer 192 , an organic insulating layer 194 , and a second inorganic insulating layer 196 , but is not limited thereto.

Meanwhile, as shown in FIG. 2B , the display panel 100 of the present invention may be a liquid crystal display panel.

That is, the display panel 100 includes first and second substrates 210 and 250 facing each other and a liquid crystal interposed between the first and second substrates 210 and 250 and including liquid crystal molecules 262 . Layer 260 may be included.

Here, the first and second substrates 210 and 250 may be made of glass or plastic having relatively high thermal stability. In one example, the plastic may be polyimide, but is not limited thereto.

A thin film transistor Tr is formed on the first substrate 210 . That is, a gate electrode 222 is formed on the first substrate 210 , and a gate insulating layer 224 is formed covering the gate electrode 222 . In addition, a gate wire (not shown) connected to the gate electrode 222 is formed on the first substrate 210 .

Although not shown, a buffer layer may be formed between the first substrate 210 and the gate electrode 222 . The buffer layer may be made of an inorganic insulating material such as silicon oxide or silicon nitride, and may have a single-layer structure or a multi-layer structure.

A semiconductor layer 226 is formed on the gate insulating layer 224 to correspond to the gate electrode 222 . The semiconductor layer 226 may be made of an oxide semiconductor material. Alternatively, the semiconductor layer 226 may be made of silicon. In this case, the semiconductor layer 226 may include an active layer of intrinsic amorphous silicon and an ohmic contact layer of impurity amorphous silicon.

A source electrode 230 and a drain electrode 232 spaced apart from each other are formed on the semiconductor layer 226 . In addition, a data line (not shown) connected to the source electrode 230 intersects the gate line to define a pixel area.

The gate electrode 222, the semiconductor layer 226, the source electrode 230, and the drain electrode 232 constitute a thin film transistor Tr.

A protective layer 234 having a drain contact hole 236 exposing the drain electrode 232 is formed on the thin film transistor Tr.

On the protective layer 234, a pixel electrode 240 connected to the drain electrode 232 through the drain contact hole 236 and a common electrode 242 alternately arranged with the pixel electrode 240 are formed. is formed

A black matrix 254 is formed on the second substrate 250 to cover non-pixel areas such as the thin film transistor Tr, the gate wiring, and the data wiring. In addition, a color filter layer 256 is formed corresponding to the pixel area. The black matrix 254 may be omitted.

Although not shown, a buffer layer may be formed between the second substrate 250 and the black matrix 254 . The buffer layer may be made of an inorganic insulating material such as silicon oxide or silicon nitride, and may have a single-layer structure or a multi-layer structure.

The first and second substrates 210 and 250 are bonded with the liquid crystal layer 260 therebetween, and the liquid crystal layer 260 is formed by an electric field generated between the pixel electrode 240 and the common electrode 242. ) of the liquid crystal molecules 262 are driven. The pixel electrode 240, the common electrode 242, and the liquid crystal layer 260 form a liquid crystal capacitor, and the liquid crystal capacitor is connected to the thin film transistor Tr.

Although not shown, an alignment layer may be formed on each of the first and second substrates 210 and 250 in contact with the liquid crystal layer 260 .

Here, the common electrodes 242 are alternately arranged with the pixel electrodes 240 on the first substrate 210. Unlike this, the common electrodes are formed on the entire surface of the second substrate 250, and the The pixel electrode 240 may be formed in a plate shape in the pixel area.

Referring back to FIG. 1 , a polarizer 110 is attached to an upper portion of the display panel 100 . In this case, the polarizer 110 may be attached to the display panel 100 through an adhesive layer (not shown). For example, the adhesive layer may be a pressure sensitive adhesive (PSA), but is not limited thereto.

Although not shown, the polarizing plate 110 may include a polarizing film and first and second supporting films. The polarizing film may be formed by stretching poly-vinyl alcohol (PVA) dyed with iodine (I). Vibrating light is absorbed, and only light vibrating in a direction perpendicular to the absorption axis is selectively transmitted.

The first and second supporting films are attached to the upper and lower surfaces of the polarizing film, respectively, to protect the polarizing film. The first and second support films may be made of tri-acetyl cellulose (TAC) or cyclic olefin polymer (COP), but are not limited thereto.

The polarizing plate 110 may have a larger area than the display area AA and may have a smaller area than the display panel 100 . Alternatively, the polarizer 110 may have the same area as the display panel 100 .

Meanwhile, although not shown, one side of the display panel 100 is connected to a printed circuit board to form a pad portion to which a signal is applied. That is, the substrate 150 of the electroluminescent display panel and the first substrate 210 of the liquid crystal display panel have a larger area than the insulation film 190 and the second substrate 250, respectively, so that one side is exposed, and the exposed substrate A pad part is formed on the 150 and the first substrate 210 . The pad portion is covered with a protective resin, and the protective resin is also formed on the upper surface of the display panel 100, that is, on the outer surface of the insulation film 190 or the second substrate 250. At this time, the protective resin should be spaced apart from the polarizer 110 attached to the upper surface of the display panel 100 without overlapping with it. When the protective resin overlaps the polarizer 110, the protective resin applies stress to the polarizer 110 in a high-temperature environment, and thus delamination or yellow mura may occur.

Therefore, it is preferable that one end of the polarizer 110 on one side of the display panel 100 including the pad unit is located on the display area AA side compared to one end of the display panel 100 . On the other hand, one end of the polarizer 110 on a side other than the display panel 100 including the pad unit may coincide with one end of the display panel 100 .

When the display panel 100 is an electroluminescent display panel, the polarizer 110 may be a circular polarizer that further includes a quarter wave plate adjacent to the display panel 100 . The circular polarizing plate may serve to reduce reflection of external light.

Unlike this, when the display panel 100 is a liquid crystal display panel, a polarizer may be further attached to the lower portion of the display panel 100 . In this case, the light transmission axis of the polarizer under the display panel 100 may be disposed perpendicular to the light transmission axis of the polarizer 110 above the display panel 100 .

A cover window 130 is positioned above the polarizing plate 110 , and the polarizing plate 110 and the cover window 130 are attached through an adhesive member 130 .

The adhesive member 130 includes a first adhesive layer 132 and a second adhesive layer 134 . The first adhesive layer 132 contacts the entire surface of the polarizer 110 , and the second adhesive layer 134 partially contacts the polarizer 110 and also contacts the cover window 130 . Here, the water vapor transmission rate (WVTR) of the first adhesive layer 132 is greater than that of the second adhesive layer 134, which will be described in detail later.

The cover window 120 may be made of transparent glass or plastic, but is not limited thereto. The cover window 130 may include a black matrix corresponding to the non-display area NAA. In this case, the black matrix may be formed on one surface of the cover window 130 , that is, on a surface facing the polarizer 110 .

As mentioned above, in the adhesive member 130 of the present invention, the moisture transmittance of the first adhesive layer 132 in full contact with the polarizing plate 110 is the moisture of the second adhesive layer 134 in partial contact with the polarizing plate 110. It is greater than the transmittance, and thus, moisture in the polarizing film of the polarizing plate 110 moves to the first adhesive layer 132 in a high-temperature environment, thereby preventing reddening of the polarizing film.

An adhesive member according to an embodiment of the present invention will be described in detail with reference to the drawings.

3 is a cross-sectional view schematically showing an adhesive member according to a first embodiment of the present invention, and FIG. 4 is a plan view schematically showing an adhesive member according to a first embodiment of the present invention, and for convenience of explanation, a cover Show the windows together.

3 and 4, the adhesive member 130 according to the first embodiment of the present invention includes a first adhesive layer 132 and a second adhesive layer 134, the second adhesive layer 134 It is located between the first adhesive layer 132 and the cover window 120 .

More specifically, the first adhesive layer 132 is in front contact with the polarizer (110 in FIG. 1 ), and the second adhesive layer 134 covers the side and upper surfaces of the first adhesive layer 132 and the polarizer (110 in FIG. 1 ). partially in contact with Also, the second adhesive layer 134 contacts the cover window 130 .

Here, the first adhesive layer 132 corresponds to the display area AA, and an area of the first adhesive layer 132 may be substantially the same as that of the display area AA. Accordingly, the portion of the second adhesive layer 134 that partially contacts the polarizer ( 110 in FIG. 1 ) corresponds to the non-display area NAA.

At this time, each width (w1, w2, w3, w4) of the portion of the second adhesive layer 134 contacting the polarizer (110 in FIG. 1) in the non-display area NAA is preferably 0.5 mm or more. The second adhesive layer 134 is formed by coating an adhesive material on the top of the first adhesive layer 132 and then bringing the cover window 120 into contact with the adhesive material to press and harden the adhesive material. However, when each width (w1, w2, w3, w4) of the portion of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) in the non-display area NAA is less than 0.5 mm, in the process of pressing and curing Delamination may occur at the interface between the second adhesive layer 134 and the polarizer ( 110 in FIG. 1 ) and/or between the second adhesive layer 134 and the cover window 120 to generate bubbles. Therefore, by setting the widths (w1, w2, w3, w4) of the portion of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) in the non-display area NAA to be 0.5 mm or more, the generation of bubbles due to peeling is prevented. prevent. Here, the widths w1 , w2 , w3 , and w4 of portions of the second adhesive layer 134 contacting the polarizer ( 110 in FIG. 1 ) in the non-display area NAA may be the same. Alternatively, the widths w1 , w2 , w3 , and w4 of portions of the second adhesive layer 134 contacting the polarizer ( 110 in FIG. 1 ) in the non-display area NAA may be different from each other.

The adhesive member 130 including the first and second adhesive layers 132 and 134 may have substantially the same area as the polarizer ( 110 in FIG. 1 ). Alternatively, the area of the adhesive member 130 may be smaller than the area of the polarizing plate (110 in FIG. 1 ). In this case, one end of the adhesive member 130 on one side of the display panel (100 in FIG. 1 ) configured with the pad unit is the polarizing plate. Compared to one end of (110 in FIG. 1), it may be located on the side of the display area AA.

On the other hand, one end of the polarizer 110 and the adhesive member 130 on the other side of the display panel (100 in FIG. 1) configured with the pad portion may extend to the edge of the non-display area NAA, but are pressed at the four corners ( push) One end of the polarizing plate 110 and the adhesive member 130 on the side other than the display panel (100 in FIG. 1) configured with the pad portion has the same adhesive force as on one side of the display panel (100 in FIG. 1) configured with the pad portion so that the adhesive strength is the same. It is preferable to be configured identically.

As mentioned above, the moisture permeability of the first adhesive layer 132 is greater than that of the second adhesive layer 134 . For example, the moisture permeability of the first adhesive layer 132 may be 100 to 300 g/m ² ·day, but is not limited thereto. When the moisture transmittance of the first adhesive layer 132 is less than 100 g/m ² day, it is difficult to prevent reddening because moisture inside the polarizing film of the polarizing plate (110 in FIG. 1) cannot move in a high temperature environment, and the first adhesive layer ( 132), when the water permeability is greater than 300 g/m ² ·day, the curing density is low and the shape is not maintained, making it difficult to form. Meanwhile, the moisture permeability of the second adhesive layer 134 may be 30 to 100 g/m ² ·day, but is not limited thereto. The second adhesive layer 134 has a relatively low moisture permeability and prevents moisture from entering from the outside.

In addition, the storage modulus of the first adhesive layer 132 is smaller than that of the second adhesive layer 134, and the hardness of the first adhesive layer 132 is lower than that of the second adhesive layer 134. That is, since the second adhesive layer 134 is harder than the first adhesive layer 132, the adhesive strength is greater. The adhesive strength of the second adhesive layer 134 may be about twice that of the first adhesive layer 132 . For example, the adhesive force of the second adhesive layer 134 may be about 4.4 to about 4.7 kgf, and the adhesive force of the first adhesive layer 132 may be about 2.1 to about 2.7 kgf, but is not limited thereto.

For example, the storage modulus of the first adhesive layer 132 may be 1.0×10 ⁴ to 1.0×10 ⁵ Pa, and the hardness may be Shore OO 10 to Shore A 50, but is not limited thereto. If the storage modulus of the first adhesive layer 132 is less than 1.0×10 ⁴ Pa, it flows down in a high temperature environment and cannot form a film, and if the storage modulus of the first adhesive layer 132 is greater than 1.0×10 ⁵ Pa, the curing density is The higher it is, the more difficult it is to move water. In addition, if the hardness of the first adhesive layer 132 is less than Shore OO 10, it flows down in a high temperature environment and cannot form a film. It gets difficult.

The second adhesive layer 134 may have a storage modulus of 1.0×10 ⁵ to 1.0×10 ⁶ Pa, and a hardness of Shore A 50 or greater, but is not limited thereto. If the storage modulus of the second adhesive layer 134 is less than 1.0×10 ⁵ Pa, the adhesive strength is poor, and if the storage modulus of the second adhesive layer 134 is greater than 1.0×10 ⁶ Pa, it is very hard to hold the substrate in contact with it. will pull Accordingly, when the display panel ( 110 in FIG. 1 ) is a liquid crystal display panel, a cell gap may change or yellowing may occur. In addition, when the hardness of the second adhesive layer 134 is less than Shore A 50, it is very soft and the adhesive strength is poor.

Meanwhile, in order to prevent deterioration in visibility, the first and second adhesive layers 132 and 134 preferably have the same refractive index.

The first and second adhesive layers 132 and 134 may include an acrylic material, a silicone material, or a mixture thereof.

As such, in the adhesive member 130 according to the first embodiment of the present invention, the moisture transmittance of the first adhesive layer 132 in full contact with the polarizing plate (110 in FIG. 1 ) partially contacts the polarizing plate (110 in FIG. 1 ). It is greater than the moisture permeability of the second adhesive layer 134 to be. Accordingly, moisture in the polarizing film of the polarizing plate ( 110 in FIG. 1 ) moves to the first adhesive layer 132 in a high-temperature environment, thereby preventing decomposition of iodine and reddening of the polarizing film.

In addition, the second adhesive layer 134 has a relatively low water permeability, so that moisture from the outside can be prevented from entering.

In addition, the second adhesive layer 134 is relatively hard and has strong adhesive strength, so that it is possible to prevent a thickness step from occurring in the adhesive member 130 .

5 is a cross-sectional view schematically showing an adhesive member according to a second embodiment of the present invention, and FIG. 6 is a plan view schematically showing an adhesive member according to a second embodiment of the present invention, and for convenience of explanation, a cover Show the windows together. The adhesive member according to the second embodiment of the present invention has the same characteristics as the first embodiment except for the structure of the first and second adhesive layers, and the same reference numerals are given to the same parts, and the description thereof is omitted or simplified. .

5 and 6, the adhesive member 130 according to the second embodiment of the present invention includes a first adhesive layer 132 and a second adhesive layer 134, the second adhesive layer 134 It is located between the first adhesive layer 132 and the cover window 120 .

More specifically, the first adhesive layer 132 is in front contact with the polarizer (110 in FIG. 1 ), and the second adhesive layer 134 covers the side and upper surfaces of the first adhesive layer 132 and the polarizer (110 in FIG. 1 ). partially in contact with Also, the second adhesive layer 134 contacts the cover window 130 .

Here, the first adhesive layer 132 corresponds to the display area AA, and the area of the first adhesive layer 132 is smaller than that of the display area AA. Accordingly, the portion of the second adhesive layer 134 that partially contacts the polarizer ( 110 in FIG. 1 ) corresponds to the display area AA and the non-display area NAA.

The total length (d1+d2) of the second adhesive layer 134 contacting the polarizer (110 in FIG. 1) along one direction, for example, the vertical direction, in the display area AA is the length of the first adhesive layer 132 ( It is preferably less than or equal to 1/3 of d3). When the total length (d1 + d2) of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) is greater than 1/3 of the length (d3) of the first adhesive layer 132, the polarizer (Fig. Reddening of the polarizing film of 110) may occur.

In addition, the total length of the second adhesive layer 134 contacting the polarizer (110 in FIG. 1 ) along the horizontal direction in the display area AA is preferably equal to or less than 1/3 of the length of the first adhesive layer 132 . do.

At this time, each width (w1, w2, w3, w4) of the portion of the second adhesive layer 134 contacting the polarizer (110 in FIG. 1) in the non-display area NAA is preferably 0.5 mm or more. Therefore, each width of the portion of the second adhesive layer 134 contacting the polarizer ( 110 in FIG. 1 ) in the display area AA and the non-display area NAA is greater than 0.5 mm.

The adhesive member 130 according to the second embodiment increases the area of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) compared to the first embodiment, thereby increasing the adhesive strength with the polarizer (110 in FIG. 1). favorable for improvement

Hereinafter, various structures of the adhesive member of the present invention will be described in detail with reference to FIGS. 7 to 12 .

7 to 12 are plan views schematically illustrating adhesive members according to third to eighth embodiments of the present invention, and a cover window is also shown for convenience of explanation. Here, the adhesive members according to the third to eighth embodiments of the present invention have the same characteristics as those of the first embodiment except for the structure of the first and second adhesive layers, and the same reference numerals are assigned to the same parts and description thereof are omitted or abbreviated.

First, as shown in FIGS. 7 and 8, the adhesive member 130 according to the third and fourth embodiments of the present invention has four corners of the first adhesive layer 132 partially compared to the first embodiment. is removed with At this time, four corners of the first adhesive layer 132 may be removed in a triangular shape as shown in FIG. 7 or removed in a quadrangular shape as shown in FIG. 8 . The portions removed from the four corners of the first adhesive layer 132 form the opening 132a.

Here, the second adhesive layer 134 not only contacts the polarizer ( 110 in FIG. 1 ) in the non-display area NAA, but also contacts the polarizer ( 110 in FIG. 1 ) in the display area AA through the opening 132a. do.

The adhesive member 130 according to the third and fourth embodiments increases the area of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) compared to the first embodiment, thereby forming the polarizer (110 in FIG. 1) It is advantageous to improve adhesion with

In addition, the adhesive member 130 according to the third and fourth embodiments of the present invention is advantageous in a reliability test. That is, in the reliability test at high temperature, air bubbles are generated at the corner of the first adhesive layer 132 to affect the display area AA, and the adhesive member according to the third and fourth embodiments of the present invention ( 130) can prevent the influence of air bubbles by removing the edge of the first adhesive layer 132.

Next, as shown in FIG. 9, in the adhesive member 130 according to the fifth embodiment of the present invention, compared to the first embodiment, four corners and four side surfaces of the first adhesive layer 132 are partially removed. . At this time, four corners and four side surfaces of the first adhesive layer 132 may be removed in a rectangular shape. The portions removed from the four corners and four side surfaces of the first adhesive layer 132 form the first opening 132b.

In addition, the adhesive member 130 according to the fifth embodiment of the present invention has a plurality of second openings 132c adjacent to at least one side surface of the display area AA. The second openings 132c may be spaced apart from the first openings 132b and may be arranged in a zigzag shape.

Here, the second adhesive layer 134 not only contacts the polarizer ( 110 in FIG. 1 ) in the non-display area NAA, but also contacts the polarizer (110 in FIG. 1 ) through the first and second openings 132b and 132c in the display area AA. 110 in Fig. 1).

In the adhesive member 130 according to the fifth embodiment having the first and second openings 132b and 132c, compared to the first embodiment, the second adhesive layer 134 in contact with the polarizer ( 110 in FIG. 1 ) While increasing the area to improve adhesion with the polarizing plate (110 in FIG. 1), it has a structure that is advantageous for the movement of moisture inside the polarizing film of the polarizing plate (110 in FIG. 1).

Also, in the adhesive member 130 according to the fifth embodiment of the present invention, since the corner of the first adhesive layer 132 is removed, the effect of air bubbles in a reliability test can be prevented.

Next, as shown in FIG. 10, in the adhesive member 130 according to the sixth embodiment of the present invention, four corners of the first adhesive layer 132 are partially removed compared to the first embodiment. In this case, four corners of the first adhesive layer 132 may be removed in a rectangular shape. The portions removed from the four corners of the first adhesive layer 132 form the first opening 132d.

In addition, the adhesive member 130 according to the sixth embodiment of the present invention has a second opening 132e in the display area AA. The second opening 132e may have a rectangular frame shape.

Here, the second adhesive layer 134 not only contacts the polarizer ( 110 in FIG. 1 ) in the non-display area NAA, but also contacts the polarizer ( 110 in the display area AA) through the first and second openings 132d and 132e. 110 in Fig. 1).

The adhesive member 130 according to the sixth embodiment having the first and second openings 132d and 132e has a portion of the second adhesive layer 134 in contact with the polarizer ( 110 in FIG. 1 ) compared to the first embodiment. Adhesion with the polarizing plate (110 in FIG. 1) may be improved by increasing the area.

Also, in the adhesive member 130 according to the sixth embodiment of the present invention, since the corner of the first adhesive layer 132 is removed, the influence of air bubbles in a reliability test can be prevented.

Next, as shown in FIG. 11, in the adhesive member 130 according to the seventh embodiment of the present invention, the length of the first adhesive layer 132 in the vertical direction is greater than the display area AA compared to the first embodiment. is less than the length of

Accordingly, the second adhesive layer 134 not only contacts the polarizing plate ( 110 in FIG. 1 ) in the non-display area NAA, but also contacts the polarizing plate ( 110 in FIG. 1 ) in the upper and lower sides of the display area AA.

The adhesive member 130 according to the seventh embodiment increases the area of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1 ) compared to the first embodiment, thereby increasing the contact with the polarizer (110 in FIG. 1 ). While improving adhesion, it is advantageous to prevent stress of a display device having a curvature in the horizontal direction.

Next, as shown in FIG. 12, in the adhesive member 130 according to the eighth embodiment of the present invention, the length of the first adhesive layer 132 in the horizontal direction is greater than the display area AA compared to the first embodiment. is less than the length of

Accordingly, the second adhesive layer 134 not only contacts the polarizing plate ( 110 in FIG. 1 ) in the non-display area NAA, but also contacts the polarizing plate ( 110 in FIG. 1 ) in the left and right sides of the display area AA.

The adhesive member 130 according to the eighth embodiment increases the area of the second adhesive layer 134 in contact with the polarizer (110 in FIG. 1) compared to the first embodiment, thereby increasing the contact with the polarizer (110 in FIG. While improving adhesion, it is advantageous to prevent stress of a display device having a curvature in the vertical direction.

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art may variously modify the present invention within the scope not departing from the technical spirit and scope of the present invention described in the claims below. And it will be understood that it can be changed.

100: display panel 110: polarizer
120: cover window 130: adhesive member
132: first adhesive layer 134: second adhesive layer

Claims (11)

a display panel displaying an image through the display area;
a polarizing plate above the display panel;
a cover window above the polarizer;
Adhesive member between the polarizer and the cover window
including,
The adhesive member includes a first adhesive layer in contact with the polarizing plate and a second adhesive layer covering upper and side surfaces of the first adhesive layer, wherein the first adhesive layer has a moisture transmittance greater than that of the second adhesive layer,
The second adhesive layer is in contact with the polarizing plate,
A contact area between the first adhesive layer and the polarizing plate is greater than a contact area between the second adhesive layer and the polarizing plate.
According to claim 1,
The first adhesive layer and the second adhesive layer have the same refractive index.
According to claim 1,
The first adhesive layer has a smaller storage modulus and hardness than the second adhesive layer.
According to claim 1,
The first adhesive layer has the same area as the display area.
According to claim 4,
The second adhesive layer contacts the polarizing plate in a non-display area surrounding the display area, and a width of the second adhesive layer contacting the polarizing plate in the non-display area is 0.5 mm or more.
According to claim 1,
The display device of claim 1 , wherein the first adhesive layer has an area smaller than the display area.
According to claim 6,
The second adhesive layer is in contact with the polarizing plate in the display area, and the total length of the second adhesive layer in contact with the polarizing plate in the display area along the first direction is less than 1/3 of the length of the first adhesive layer; same display.
According to claim 1,
The first adhesive layer has an area corresponding to the display area and has a first opening at a corner of the display device.
According to claim 8,
The first adhesive layer has a second opening in the display area.
According to claim 1,
The display device of claim 1 , wherein a length of the first adhesive layer in a first direction is smaller than that of the display area, and a length in a second direction is equal to that of the display area. According to claim 1,
The moisture transmittance of the first adhesive layer is 100 to 300 g/m ² ·day, and the moisture transmittance of the second adhesive layer is 30 to 100 g/m ² ·day.

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