KR20160049466A - Display Device - Google Patents

Abstract

According to the present invention, a display device comprises: a display panel including a plurality of pixels and outputting an image through a first surface; and a first polarizing plate attached to a first surface of the display panel and configured to transmit linear polarization light of a first direction and reflect linear polarization light of a second direction vertical to the first direction. When a voltage is not applied, the display device is used in a mirror mode by reflecting external light by the first polarizing plate. When a voltage is applied, the display device is used in an image mode which outputs the image from the display panel through the first polarizing plate. A mirror function is assigned to the display device by a reflective polarizing plate to increase brightness of the display device and slim the display device so as to save costs.

Description

[0001]

The present invention relates to a display device, and more particularly to a display device having a mirror function.

In view of the information age, the display field has also been rapidly developed. As a flat panel display device (FPD) having the advantages of thinning, light weight, and low power consumption in response to the information age, ) And an organic light emitting diode (OLED) display device (OLED) have been developed and widely used.

In recent years, a display device has been proposed in which such a flat panel display device is provided with a mirror function in addition to a video display function. That is, a display device having a mirror function has been researched and developed such that when the display device is on, the display device displays an image, and when the display device is off, the display device has a mirror function.

Such a display device includes a half mirror glass on the side where an image is displayed so as to have a mirror function.

Half-mirror glass is made by depositing a metal oxide on one side of a glass substrate to have a mirror surface effect, reflecting part of light and transmitting part of it. However, since the half mirror glass has a transmittance of about 40%, the brightness of the display device is reduced.

In particular, when the display device is a liquid crystal display device, the transmissivity of the upper polarizer of the liquid crystal display device is about 43%, so that the total transmissivity of the upper polarizer and the half mirror glass is about 17.2%, which is very low.

Further, since the thickness of the half mirror glass is about 3 mm, which is much thicker than the thickness of the display panel, the thickness of the display device is increased by the half mirror glass.

In addition, since such a half mirror glass is mechanically fixed to the upper portion of the display device, the thickness of the display device is further increased, the manufacturing process is complicated, and processing equipment and materials are added to increase the cost. At this time, an air gap is generated between the half mirror glass and the display device, and light is scattered, so that image quality deteriorates as a number of images are formed.

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 provide a display device having a mirror function capable of enhancing brightness, thinner thickness and improving image quality.

Another object of the present invention is to provide a display device having a mirror function in which the manufacturing process is simple and the cost can be reduced.

According to an aspect of the present invention, there is provided a display panel comprising: a display panel including a plurality of pixels and outputting an image through a first surface; And a first polarizer which reflects linearly polarized light in a second direction perpendicular to the first direction. When no voltage is applied, external light is reflected by the first polarizer to be used in a mirror mode, The display panel is used as a video display mode in which an image from the display panel is output through the first polarizer.

The first polarizing plate includes a first film that transmits linearly polarized light in the first direction and reflects linearly polarized light in the second direction and a second film that transmits linearly polarized light in the first direction and absorbs linearly polarized light in the second direction do.

The first polarizing plate has a structure in which the first film and the second film are alternately laminated.

The first film has a structure in which a first layer having a first refractive index and a second layer having a second refractive index different from the first refractive index are alternately stacked.

The second film includes a dichroic dye, and the major axis direction of the dichroic dye is parallel to the second direction.

The display device of the present invention further includes a touch panel positioned above the first polarizer.

The display device of the present invention further includes a second polarizer attached to a second surface of the display panel and absorbing linearly polarized light in the first direction and transmitting linearly polarized light in the second direction and a second polarizer attached to the outside of the second polarizer And the display panel includes a liquid crystal layer between the first and second substrates and the first and second substrates.

At this time, the first substrate includes a gate wiring, a data line, a thin film transistor, a pixel electrode and a common electrode, and the first polarizer is attached to the first substrate.

At least one of the gate wiring and the data wiring includes aluminum or a silver-palladium-copper alloy.

Alternatively, at least one of the gate wiring and the data wiring has a double-layer structure including a first metal layer and a second metal layer, the reflectance of the first metal layer is larger than that of the second metal layer, 1 metal layer.

The first metal layer may be made of aluminum or silver-palladium-copper alloy, and the second metal layer may be made of copper.

The pixel electrode and the common electrode may include a first electrode layer made of aluminum or a silver-palladium-copper alloy.

The pixel electrode and the common electrode may further include a second electrode layer made of indium-tin-oxide or indium-zinc-oxide.

According to the present invention, the display device is provided with a mirror function by using the reflection type polarizing plate, whereby the brightness of the display device can be increased.

Since the reflection type polarizing plate is a film type and its thickness is as thin as several tens of micrometers, the display device can be made thinner and can be attached to the upper surface of the display panel by the laminating method, so that the attaching process is simple and additional equipment and materials are required Doing so can save money.

Further, since an air layer is not formed between the reflective polarizer and the display panel, scattering of light can be prevented and image quality can be improved.

On the other hand, by attaching the reflection type polarizing plate to the array substrate including the signal wiring, it is possible to enhance the reflectivity by the light reflected from the signal wiring and to provide a better mirror function.

At this time, the signal wiring may be formed of a metal material having a high reflectance to further increase the reflectance, and a metal material having a relatively low specific resistance may be added to prevent a deterioration in image quality due to signal delay.

1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention.
2 is a cross-sectional view schematically showing a display panel of a display device according to a first embodiment of the present invention.
3A and 3B are cross-sectional views schematically showing an operation mode of the display device according to the first embodiment of the present invention.
4 is a cross-sectional view schematically showing a first polarizing plate of a display device according to an embodiment of the present invention.
5 is a cross-sectional view schematically showing a first film of a first polarizing plate according to an embodiment of the present invention.
6 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention.
7 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention.
8 is a cross-sectional view schematically showing a display panel of a display device according to a third embodiment of the present invention.
9A and 9B are cross-sectional views schematically showing the operation mode of the display device according to the third embodiment of the present invention.
10 is a cross-sectional view schematically showing a display panel of a display device according to a fourth embodiment of the present invention.

Hereinafter, embodiments of the present invention capable of solving the above problems will be described with reference to the drawings.

First Embodiment

FIG. 1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view schematically showing a display panel of a display device according to a first embodiment of the present invention, Respectively. Here, the liquid crystal panel will be described as an example of the display panel.

1, a display device 100 according to a first embodiment of the present invention includes a liquid crystal panel 110 as a display panel, a first polarizer plate 160 disposed on a first side of the liquid crystal panel 110, And a second polarizing plate 170 positioned on the second side of the liquid crystal panel 110. [ In addition, the display apparatus 100 of the present invention further includes a backlight unit 190 located under the second polarizer 170. [

Referring to FIG. 2, the liquid crystal panel 110 includes a first substrate 120, a second substrate 140, and a liquid crystal layer 150 between the first and second substrates 120 and 140.

A gate wiring (not shown) and a gate electrode 122 are formed on the inner surface of the first substrate 120. The gate wiring extends along one direction, and the gate electrode 122 is connected to the gate wiring. The gate electrode 122 may extend from the gate wiring or may be part of the gate wiring.

A gate insulating film 124 is formed on the gate wiring and the gate electrode 122. A gate insulating film 124 can be formed of an inorganic insulating material of silicon nitride (SiNx) or silicon oxide (SiO _2).

A semiconductor layer 126 is formed on the gate insulating layer 124 in correspondence with the gate electrode 122. The semiconductor layer 126 includes an active layer 126a of intrinsic amorphous silicon and an ohmic contact layer 126b of impurity-doped amorphous silicon.

Source and drain electrodes 128 and 129 are formed on the semiconductor layer 126. The source and drain electrodes 128 and 129 are spaced apart from the semiconductor layer 126. The ohmic contact layer 126b is a source And the drain electrodes 128 and 129, respectively. The active layer 126a is exposed between the source and drain electrodes 128 and 129 and the active layer 126a is formed in the same way as the source and drain electrodes 128 and 129 except between the source and drain electrodes 128 and 129. [ Shape. Alternatively, the source and drain electrodes 128 and 129 may partially cover the sides of the ohmic contact layer 126b and the active layer 126a.

The gate electrode 122 and the semiconductor layer 126, the source electrode 128 and the drain electrode 129 constitute a thin film transistor T and the active layer 126a exposed between the source and drain electrodes 128 and 129 Is a channel of the thin film transistor T.

The thin film transistor T has an inverted staggered structure in which the gate electrode 122 is positioned below the semiconductor layer 126 and the source and drain electrodes 128 and 129 are located above the semiconductor layer 126. [ ) Structure.

Alternatively, the thin film transistor may have a coplanar structure in which the gate electrode and the source and drain electrodes are located on one side of the semiconductor layer, that is, on the upper side of the semiconductor layer. In this case, the semiconductor layer may be made of polycrystalline silicon, and impurities may be doped on both sides of the semiconductor layer.

On the other hand, the semiconductor layer may be made of an oxide semiconductor, and in the case of an inversely staggered structure, the ohmic contact layer may be omitted.

Further, a data line (not shown) is formed of the same material in the same layer as the source and drain electrodes 128 and 129. The data wiring crosses the gate wiring to define the pixel region. At this time, the data line may cross the gate line at right angles, or alternatively at an angle. The data line may be connected to the source electrode 128, and a dummy semiconductor pattern having the same layer structure may be formed under the data line with the same material as the semiconductor layer 126. Alternatively, the data line may be formed in direct contact with the gate insulating film 124. [

The first passivation layer 130 is formed on the source and drain electrodes 128 and 129 and on the data line. The first passivation layer 130 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x).

A second passivation layer 132 is formed on the first passivation layer 130. The second passivation layer 132 has a flat surface and has a drain contact hole 132a exposing the drain electrode 129 together with the first passivation layer 130. The second passivation layer 132 may be formed of an organic insulating material such as benzocyclobutene (BCB) or photo acryl.

Here, one of the first passivation layer 130 and the second passivation layer 132 may be omitted.

A pixel electrode 134 and a common electrode 136 are formed in a pixel region above the second passivation layer 132. The pixel electrode 134 is in contact with the drain electrode 129 through the drain contact hole 132a and the common electrode 136 is arranged alternately away from the pixel electrode 134. [ The pixel electrode 134 and the common electrode 136 may be formed of a transparent conductive material such as indium tin oxide or indium zinc oxide.

(Not shown) parallel to the gate wiring may be formed on the same layer as the gate wiring, and the second passivation layer 132 and the first passivation layer 130 may be formed on the gate insulating layer 124 And a common contact hole (not shown) for exposing the common wiring, and the common electrode 136 can be in contact with the common wiring through the common contact hole.

Alternatively, the pixel electrode 134 and the common electrode 136 may overlap each other corresponding to the pixel region, and the electrode located above the pixel electrode 134 and the common electrode 136 may have a plurality of openings .

Such a first substrate 120 is referred to as an array substrate.

On the other hand, a black matrix 142 is formed on the inner surface of the second substrate 140. The black matrix 142 has an opening corresponding to the pixel region and may be formed corresponding to a gate wiring (not shown), a data wiring (not shown) and a thin film transistor T. [

A color filter layer 144 is formed under the black matrix 142 in correspondence with the openings of the black matrix 142. The color filter layer 144 includes red, green, and blue color filters, and one color filter corresponds to one pixel area, and is sequentially and repeatedly arranged.

Here, the structure in which the color filter layer 144 is formed on the second substrate 140 has been described. However, the color filter layer may be formed on the first substrate 120. That is, the liquid crystal panel 110 according to the embodiment of the present invention may have a color filter on array structure in which a color filter layer is formed on the top or bottom of the thin film transistor T on the first substrate 120 have.

Such a color filter-on-array structure can increase the aperture ratio by reducing the cohesion margin of the first and second substrates 120 and 140. At this time, the black matrix may be formed or omitted on the first substrate 120 or the second substrate 140, in which case the aperture ratio can be further increased.

An overcoat layer (not shown) may be formed under the color filter layer 144 to protect and planarize the color filter layer 144.

This second substrate 140 is referred to as a color filter substrate.

A first alignment layer is formed on the pixel electrode 134 and the common electrode 136 of the first substrate 120 and a second alignment layer is formed on the lower portion of the color filter layer 144 of the second substrate 140, . The first alignment layer and the second alignment layer are rubbed or optically aligned in a predetermined direction, and the surfaces of the first alignment layer and the second alignment layer have an orientation.

A liquid crystal layer 150 is positioned between the first alignment layer and the second alignment layer. The liquid crystal molecules of the liquid crystal layer 150 have an initial alignment state according to the alignment directions of the first and second alignment films.

1, a first polarizing plate 160, which is an upper polarizing plate, is disposed on a first surface of the liquid crystal panel 110, that is, an upper surface on which an image generated by the liquid crystal panel 110 is output, Lt; / RTI > That is, one side of the first polarizer 160 is adhered to the second substrate 140 (FIG. 2) of the liquid crystal panel 110 through the first adhesive layer 182. The first adhesive layer 182 may be a pressure sensitive adhesive, that is, a pressure sensitive adhesive (PSA).

The first polarizing plate 160 is a reflection type polarizing plate and transmits linearly polarized light in the first direction and linearly polarized linearly polarized light in the second direction. Since the first polarizing plate 160 is a film type and its thickness is as thin as a few tens of micrometers, the display device 100 can be manufactured in a thin shape, and the transmittance is higher than that of the conventional upper polarizer plate and half mirror glass structure. . The structure of the first polarizing plate 160 will be described later in detail.

On the other hand, a second polarizing plate 170, which is a lower polarizing plate, is attached to the second surface of the liquid crystal panel 110, that is, the first surface, through the second adhesive layer 184. That is, one side of the second polarizing plate 170 is bonded to the first substrate (120 in FIG. 2) of the liquid crystal panel 110 through the second adhesive layer 184. The second adhesive layer 184 may be a pressure-sensitive adhesive, that is, a pressure-sensitive adhesive.

The second polarizing plate 170 is an absorption type polarizing plate, and the absorption axis of the second polarizing plate 170 is parallel to the transmission axis of the first polarizing plate 160. Therefore, the second polarizing plate 170 absorbs the linearly polarized light in the first direction and transmits the linearly polarized light in the second direction.

The second polarizing plate 170 includes a polarizing layer 172 and first and second protective films 174 and 176. The polarizing layer 172 is disposed between the first and second protective films 174 and 176 and is provided with a first protective film 174 and a polarizing layer 172 from the lower surface of the liquid crystal panel 110, (176).

The polarizing layer 172 may be made of polyvinyl alcohol (PVA), and each of the first and second protective films 174 and 176 may be formed of triacetyl cellulose (TAC) or a cyclic olefin polymer cyclic olefin polymer (COP). Here, the first and second protective films 174 and 176 may be referred to as a support film.

The second polarizing plate 170 may be formed by stretching polyvinyl alcohol in which iodine ions or dichroic dyes are dyed to form a polarizing layer 172 having an absorption axis in the stretching direction, And attaching the first and second protective films 174 and 176 to both sides of the polarizing layer 172 to prevent the polarizing layer 172 from shrinking.

The second polarizing plate 170 has a second adhesive layer 184 attached to the outside of the first protective film 174 and a second adhesive layer 184 attached to the outside of the second adhesive layer 184 and the second protective film 176, (release film or separatable protection film). The release film is detached and the second adhesive layer 184 is attached to the outside of the first substrate 120.

A backlight unit 190 is disposed below the second polarizer 170 to supply light to the liquid crystal panel 110.

The display device 100 according to the first embodiment of the present invention is used in a mirror mode and a video display mode depending on whether a voltage is applied or not. That is, when no voltage is applied, the external light is reflected by the first polarizer 160 to have a mirror function. When a voltage is applied, light from the backlight unit 190 is reflected by the second polarizer 170, Through the panel 110 and the first polarizer 160, and has an image display function.

FIGS. 3A and 3B are cross-sectional views schematically showing an operation mode of a display apparatus according to the first embodiment of the present invention, wherein FIG. 3A shows a mirror mode and FIG. 3B shows an image display mode.

3A, of the external light incident on the display device 100 when the display device 100 is off, that is, when no voltage is applied, the linearly polarized light L1 in the first direction, Passes through the first polarizing plate 160 and then passes through the liquid crystal panel 110 as it is and reaches the second polarizing plate 170. At this time, the linearly polarized light L1 in the first direction reaching the second polarizing plate 170 coincides with the absorption axis direction of the second polarizing plate 170, so that it is absorbed by the second polarizing plate 170.

On the other hand, when the display device 100 is in the off state, the linearly polarized light L2 in the second direction perpendicular to the first direction of the external light incident on the display device 100 is reflected by the first polarizing plate 160, Allowing device 100 to have a mirror function.

3B, the linearly polarized light L3 in the first direction among the lights supplied from the backlight unit 190 when the display device 100 is in the ON state, that is, when the voltage is applied, Reaches the second polarizing plate 170. Since the linearly polarized light L3 in the first direction coincides with the absorption axis direction of the second polarizing plate 170, the linearly polarized light L3 is absorbed by the second polarizing plate 170. [

On the other hand, when the display apparatus 100 is on, the linearly polarized light L4 in the second direction of the light supplied from the backlight unit 190 passes through the second polarizing plate 170, passes through the liquid crystal panel 110 The polarizing direction is changed to reach the first polarizing plate 160 and transmitted through the first polarizing plate 160. Therefore, the display apparatus 100 displays an image.

In the conventional display device, linearly polarized light in the second direction, for example, of the light supplied from the backlight unit when in the ON state passes through the lower polarizer plate, the liquid crystal panel, and the upper polarizer plate and then passes through the half mirror glass, Only a part of the linearly polarized light in the second direction passing through the upper polarizer is output to the outside.

On the contrary, in the display apparatus 100 of the present invention, most of the linearly polarized light L4 in the second direction passing through the first polarizer 160 is output to the outside, so that the display apparatus 100 of the present invention is applied to a conventional display apparatus Respectively.

On the other hand, even when the display apparatus 100 is in the ON state, some of the external light is reflected by the first polarizer 160, but since the light supplied from the backlight unit 190 has a higher luminance than the external light, Reflection by the first polarizer 160 does not matter.

As described above, the display device 100 according to the first embodiment of the present invention can be used in a mirror mode and an image display mode depending on whether a voltage is applied or not.

FIG. 4 is a cross-sectional view schematically showing a first polarizer of a display device according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view schematically showing a first film of a first polarizer plate according to an embodiment of the present invention .

4 and 5, the first polarizer 160 of the display device according to the embodiment of the present invention has a structure in which the first film 162 and the second film 164 are alternately stacked to increase the degree of polarization .

The first film 162 has a structure in which a first layer 162a having a first refractive index n1 and a second layer 162b having a second refractive index n2 are alternately stacked, And the linearly polarized light in the second direction perpendicular thereto is reflected.

Further, the second film 164 includes a dichroic dye, and transmits linearly polarized light in the first direction and linearly polarized light in the second direction. At this time, the long axis direction of the dichroic dye may be parallel to the second direction. The second film 164 may be a structure in which layers having different refractive indices are laminated.

A first adhesive layer 182 is attached to one side of the first polarizing plate 160. For example, the first adhesive layer 182 may be attached to the outside of the second film 164 of the first polarizing plate 160, and the first polarizing plate 160 may be attached to the first adhesive layer 182 and the first film 164, (Release film or separatable protection film) may be respectively attached to the outer side of the first electrode 162. The release film is detached and the first adhesive layer 182 is attached to the outside of the second substrate (140 in Fig. 2).

The first polarizing plate 160 can be attached to the upper surface of the liquid crystal panel 110 (FIG. 1) by a laminating method, so that the attaching process is simple, and additional equipment and materials are not required, thereby reducing the cost. Further, no air layer is formed between the liquid crystal panel (110 in Fig. 1) and the image quality can be increased.

Second Embodiment

6 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention. The structure except for the touch panel is the same as that of the display device of the first embodiment, and a description of the same structure will be simplified.

As shown in FIG. 6, the display device 100 according to the second embodiment of the present invention includes a liquid crystal panel 110 which is a display panel. The liquid crystal panel 110 may have the structure shown in FIG.

The first polarizer 160, which is an upper polarizer, is attached to the first surface of the liquid crystal panel 110, that is, the upper surface of the liquid crystal panel 110 where the image is output, through the first adhesive layer 182. The first polarizing plate 160 is a reflection type polarizing plate and transmits linearly polarized light in the first direction and linearly polarized linearly polarized light in the second direction. The first polarizing plate 160 may have the structure shown in Figs. 4 and 5.

The touch panel 200 is positioned above the first polarizer 160. Various types of position information detection methods can be applied to the touch panel 200. For example, the touch panel 200 may be of a capacitive type. The touch panel 200 may be manufactured as a separate film and attached to the first polarizer 160. Alternatively, the touch panel 200 may be manufactured by forming a touch electrode (not shown) on the first polarizer 160 and integrating the same.

On the other hand, a second polarizing plate 170, which is a lower polarizing plate, is attached to the second surface of the liquid crystal panel 110, that is, the first surface, through the second adhesive layer 184. The second polarizing plate 170 is an absorption type polarizing plate, and the absorption axis of the second polarizing plate 170 is parallel to the transmission axis of the first polarizing plate 160. Therefore, the second polarizing plate 170 absorbs the linearly polarized light in the first direction and transmits the linearly polarized light in the second direction.

Further, a backlight unit 190 located below the second polarizer 170 of the display device 100 according to the second embodiment of the present invention is located.

The display device 100 according to the second embodiment of the present invention can be used in a mirror mode and an image display mode depending on whether a voltage is applied using the first polarizer 160 which is a reflective polarizer, Transmittance and luminance are high. At this time, the display device 100 according to the second embodiment of the present invention further includes a touch function, so that it is easy to operate.

In the above embodiment, the display panel is a liquid crystal panel, but the present invention is not limited thereto. That is, the display panel may be a display panel using an organic light emitting diode or a display panel using a quantum rod. In this case, the second lower polarizing plate and / or the backlight unit may be omitted.

Third Embodiment

FIG. 7 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention, and FIG. 8 is a cross-sectional view schematically showing a display panel of a display device according to a third embodiment of the present invention, Respectively.

7, the display device 300 according to the third embodiment of the present invention includes a liquid crystal panel 310 as a display panel, and the liquid crystal panel 310 includes a first substrate 320, 2 substrate 340, and a liquid crystal layer 350 between the first and second substrates 320, 340. The image generated in the liquid crystal panel 310 is output to the outside through the first substrate 320.

The display device 300 of the present invention further includes a first polarizer 360 positioned on the first side of the liquid crystal panel 310, that is, the outer surface of the first substrate 320, A second polarizing plate 370 located on the outer surface of the second substrate 340 and a backlight unit 390 located below the second polarizing plate 370.

Referring to FIG. 8, a gate wiring 321 and a gate electrode 322 made of a metal material are formed on the inner surface of the first substrate 320 of the liquid crystal panel 310. For example, the gate wiring 321 and the gate electrode 322 may be made of copper (Cu) having a relatively low resistivity. The gate wiring 321 extends along one direction, and the gate electrode 322 is connected to the gate wiring 321. The gate electrode 322 may extend from the gate wiring 321 or may be part of the gate wiring 321.

A gate insulating film 324 is formed under the gate wiring 321 and the gate electrode 322. A gate insulating film 324 may be formed of an inorganic insulating material of silicon nitride (SiNx) or silicon oxide (SiO _2).

A semiconductor layer 326 is formed under the gate insulating film 324 to correspond to the gate electrode 322. The semiconductor layer 326 includes an active layer 326a of intrinsic amorphous silicon and an ohmic contact layer 326b of impurity-doped amorphous silicon.

Source and drain electrodes 328 and 329 made of a metal material are formed under the semiconductor layer 326. The source and drain electrodes 328 and 329 are spaced apart from the bottom of the semiconductor layer 326, 326b have the same shape as the source and drain electrodes 328, 329. The active layer 326a is exposed between the source and drain electrodes 328 and 329 and the active layer 326a is formed in the same way as the source and drain electrodes 328 and 329 except between the source and drain electrodes 328 and 329 Shape. Alternatively, the source and drain electrodes 328 and 329 may partially cover the sides of the ohmic contact layer 326b and the active layer 326a.

The gate electrode 322 and the semiconductor layer 326, the source electrode 328 and the drain electrode 329 constitute the thin film transistor T and the active layer 326a exposed between the source and drain electrodes 328 and 329 Is a channel of the thin film transistor T.

Here, the thin film transistor T has a structure in which a gate electrode 322 is disposed on the semiconductor layer 326 and a source electrode 328 and a source electrode 328 are disposed on the lower side of the semiconductor layer 326, inverted staggered structure.

Alternatively, the thin film transistor may have a coplanar structure in which the gate electrode and the source and drain electrodes are located on one side of the semiconductor layer, that is, substantially below the semiconductor layer. In this case, the semiconductor layer may be made of polycrystalline silicon, and impurities may be doped on both sides of the semiconductor layer.

On the other hand, the semiconductor layer may be made of an oxide semiconductor, and in the case of an inversely staggered structure, the ohmic contact layer may be omitted.

Further, the data line 327 is formed of the same material in the same layer as the source and drain electrodes 328 and 329. In one example, the data line 327 and the source and drain electrodes 328 and 329 may be made of copper with relatively low resistivity. Although not shown in the drawing, the data wiring 327 intersects the gate wiring 321 to define the pixel region. At this time, the data line 327 may intersect the gate line 321 at right angles or may intersect at an angle. The data line 327 is connected to the source electrode 328 and the data line 327 can be formed in direct contact with the gate insulating film 324. [ Alternatively, a dummy semiconductor pattern having the same layer structure as the semiconductor layer 326 may be formed on the data line 327, that is, between the gate insulating layer 324 and the data line 327.

A first passivation layer 330 is formed under the source and drain electrodes 328 and 329 and the data line 327. The first passivation layer 330 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x).

A second passivation layer 332 is formed under the first passivation layer 330. The second passivation layer 332 has a flat surface and has a drain contact hole 332a exposing the drain electrode 329 together with the first passivation layer 330. [ The second passivation layer 332 may be formed of organic insulating material of benzocyclobutene (BCB) or photo acryl.

Here, one of the first passivation layer 330 and the second passivation layer 332 may be omitted.

A pixel electrode 334 and a common electrode 336 are formed in a pixel region under the second passivation layer 332. The pixel electrode 334 is in contact with the drain electrode 329 through the drain contact hole 332a and the common electrode 336 is arranged alternately away from the pixel electrode 334. [ The pixel electrode 334 and the common electrode 336 may be formed of a transparent conductive material such as indium tin oxide or indium zinc oxide.

Here, a common wiring (not shown) parallel to the gate wiring 321 may be formed on the same layer as the gate wiring 321, and the second protection layer 332 and the first protection layer 330 (Not shown) exposing a common wiring together with the gate insulating film 324, and the common electrode 336 can make contact with the common wiring through the common contact hole.

Alternatively, the pixel electrode 334 and the common electrode 336 may be formed so as to overlap each other corresponding to the pixel region, and the electrode located below the pixel electrode 334 and the common electrode 336 may have a plurality of openings .

Such a first substrate 320 is referred to as an array substrate.

On the other hand, a black matrix 342 is formed on the inner surface of the second substrate 340. The black matrix 342 has an opening corresponding to the pixel region and may be formed corresponding to the gate wiring 321, the data wiring 327, and the thin film transistor T. [

A color filter layer 344 is formed on the black matrix 342 in correspondence with the openings of the black matrix 342. The color filter layer 344 includes red, green, and blue color filters, and one color filter corresponds to one pixel area, and is sequentially and repeatedly arranged.

Here, the structure in which the color filter layer 344 is formed on the second substrate 340 has been described. However, the color filter layer may be formed on the first substrate 320. That is, the liquid crystal panel 310 according to the third embodiment of the present invention includes a color filter on array structure in which a color filter layer is formed on or under the thin film transistor T on the first substrate 320 Lt; / RTI >

Such a color filter-on-array structure can increase the aperture ratio by reducing the cohesion margin of the first and second substrates 320 and 340. At this time, the black matrix may be formed or omitted on the first substrate 320 or the second substrate 340, in which case the aperture ratio can be further increased.

An overcoat layer (not shown) may be formed on the color filter layer 344 in order to protect and planarize the color filter layer 344.

This second substrate 340 is referred to as a color filter substrate.

A first alignment layer is formed under the pixel electrode 334 and the common electrode 336 of the first substrate 320 and a second alignment layer is formed over the color filter layer 344 of the second substrate 340. [ . The first alignment layer and the second alignment layer are rubbed or optically aligned in a predetermined direction, and the surfaces of the first alignment layer and the second alignment layer have an orientation.

A liquid crystal layer 350 is disposed between the first alignment layer and the second alignment layer. The liquid crystal molecules of the liquid crystal layer 350 have an initial alignment state according to the alignment directions of the first and second alignment layers.

7, a first polarizing plate 360, which is an upper polarizing plate, is disposed on a first surface of the liquid crystal panel 310, that is, an upper surface on which an image generated from the liquid crystal panel 310 is output, Lt; / RTI > That is, one side of the first polarizing plate 360 is bonded to the first substrate (320 of FIG. 8) of the liquid crystal panel 310 through the first adhesive layer 382. The first adhesive layer 382 may be a pressure sensitive adhesive, that is, a pressure sensitive adhesive (PSA).

The first polarizing plate 360 is a reflection type polarizing plate and transmits linearly polarized light in the first direction and linearly polarized linearly polarized light in the second direction. Since the first polarizing plate 360 is a film type and its thickness is as thin as several tens of micrometers, the display device 300 can be manufactured in a thin shape, and the transmissivity is higher than that of the conventional upper polarizing plate and half mirror glass structure. . The first polarizing plate 360 may have the structure shown in FIGS. 4 and 5.

That is, the first polarizing plate 360 has a structure in which the first film 162 (FIG. 4) and the second film 164 (FIG. 4) are alternately stacked. The first film (162 in Fig. 4) has a structure in which a first layer (162a in Fig. 5) having a first refractive index n1 and a second layer (162b in Fig. 5) having a second refractive index n2 are alternately stacked And transmits linearly polarized light in the first direction and linearly polarized linearly polarized light in the second direction.

Also, the second film (164 in Fig. 4) includes a dichroic dye, and transmits linearly polarized light in the first direction and linearly polarized light in the second polarized direction. At this time, the long axis direction of the dichroic dye may be parallel to the second direction. The second film 164 may be a structure in which layers having different refractive indices are laminated.

On the other hand, a second polarizing plate 370, which is a lower polarizing plate, is attached to the second surface of the liquid crystal panel 310, that is, the first surface, through the second adhesive layer 384. That is, one side of the second polarizing plate 370 is bonded to the second substrate 340 (FIG. 8) of the liquid crystal panel 310 through the second adhesive layer 384. The second adhesive layer 384 may be a pressure-sensitive adhesive, that is, a pressure-sensitive adhesive.

The second polarizing plate 370 is an absorption type polarizing plate, and the absorption axis of the second polarizing plate 370 is parallel to the transmission axis of the first polarizing plate 360. Accordingly, the second polarizing plate 370 absorbs the linearly polarized light in the first direction and transmits the linearly polarized light in the second direction.

The second polarizing plate 370 includes a polarizing layer 372 and first and second protective films 374 and 376. The polarizing layer 372 is disposed between the first and second protective films 374 and 376 and includes a first protective film 374, a polarizing layer 372, (376).

The polarizing layer 372 may be made of polyvinyl alcohol (PVA), and each of the first and second protective films 374 and 36 may be formed of triacetyl cellulose (TAC) or a cyclic olefin polymer cyclic olefin polymer (COP). Here, the first and second protective films 374 and 376 may be referred to as a support film.

The second polarizing plate 370 is formed by stretching polyvinyl alcohol in which iodine ions or dichroic dyes are dyed to form a polarizing layer 372 having an absorption axis in the stretching direction, And attaching first and second protective films 374 and 376 to both sides of the polarizing layer 372 to prevent the polarizing layer 372 from shrinking.

A backlight unit 390 is disposed below the second polarizer 370 to supply light to the liquid crystal panel 310. [

The display device 300 according to the third embodiment of the present invention is used in a mirror mode and a video display mode depending on whether a voltage is applied or not. That is, when no voltage is applied, the external light is reflected by the first polarizer 360 to have a mirror function. When a voltage is applied, light from the backlight unit 390 is reflected by the second polarizer 370, Through the panel 310 and the first polarizing plate 360, and has an image display function.

FIGS. 9A and 9B are cross-sectional views schematically showing an operation mode of a display device according to a third embodiment of the present invention, wherein FIG. 9A shows a mirror mode and FIG. 9B shows a video display mode.

9A, of the external light incident on the display device 300 when the display device 300 is off, that is, when no voltage is applied, the linearly polarized light L1 in the first direction, The first polarizing plate 360, and the second polarizing plate 360, respectively. A part L11 of the linearly polarized light L1 in the first direction transmitted through the first polarizing plate 360 is reflected by the metal layer 320a formed on the inner surface of the first substrate 320 of the liquid crystal panel 310, 1 polarizer plate 360 and is output to the outside. Here, the metal layer 320a may be at least one of the gate wiring 321 and the data wiring 327 in FIG.

The rest L12 of the linearly polarized light L1 in the first direction transmitted through the first polarizing plate 360 is reflected by the first substrate 320 and the liquid crystal layer 350 of the liquid crystal panel 310 and the second substrate 340 And reaches the second polarizing plate 370 as it is. At this time, the rest L12 of the linearly polarized light L1 in the first direction reaching the second polarizing plate 370 coincides with the absorption axis direction of the second polarizing plate 370, so that it is absorbed by the second polarizing plate 370. [

On the other hand, when the display device 300 is in the off state, the linearly polarized light L2 in the second direction perpendicular to the first direction of the external light incident on the display device 300 is reflected by the first polarizing plate 360.

Therefore, the display device 300 has a mirror function by the linearly polarized light L11 in the first direction and the linearly polarized light L2 in the reflected second direction, which are output to the outside.

On the other hand, as shown in FIG. 9B, when the display device 300 is in the ON state, that is, when the voltage is applied, the linearly polarized light L3 in the first direction among the lights supplied from the backlight unit 390, Reaches the second polarizing plate 370. At this time, the linearly polarized light L3 in the first direction coincides with the absorption axis direction of the second polarizer 370, and thus is absorbed by the second polarizer 370. [

On the other hand, when the display device 300 is on, the linearly polarized light L4 in the second direction of the light supplied from the backlight unit 390 passes through the second polarizing plate 370, The polarizing direction is changed to the first direction and reaches the first polarizing plate 360 and is transmitted through the first polarizing plate 360. Therefore, the display device 300 displays an image.

As described above, the display device 300 according to the third embodiment of the present invention can be used in a mirror mode and an image display mode depending on whether a voltage is applied or not.

The display device 300 according to the third embodiment of the present invention is configured such that by linearly polarized light L11 in a first direction that is reflected and output from the metal layer 320a of the first substrate 320 of the liquid crystal panel 310, Since the reflectance is higher than that of the display apparatus according to the first embodiment (100 in Fig. 3A), a better mirror function can be provided.

The reflectance can be changed according to the area occupied by the metal layer 320a in the display device 300 and the reflectance of the metal layer 320a. Under the same conditions, the display device according to the first embodiment (100 in FIG. 3A) While the display device 300 according to the third embodiment has a reflectance of about 68%.

In the display device 300 according to the third embodiment of the present invention, the gate wiring (321 in FIG. 8) and the data wiring (327 in FIG. 8) used as the metal layer 320a are made of copper However, the reflectance of the display device 300 can be further increased in the mirror mode by using a material having a reflectance higher than that of copper for at least one of the gate wiring (321 in FIG. 8) and the data wiring (327 in FIG. 8).

Since the total area of the gate wiring (321 in FIG. 8) is larger than that of the data wiring (327 in FIG. 8), gate wiring (321 in FIG. 8) is formed of a material having a reflectance higher than copper, (321 in Fig. 8) and a data wiring (327 in Fig.

8) may be made of aluminum (Al) or silver-palladium-copper (Ag-Pd-Cu: APC) Al) or silver-palladium-copper (Ag-Pd-Cu: APC) alloy has a reflectance of about 95%.

Fourth Embodiment

10 is a cross-sectional view schematically showing a display panel of a display device according to a fourth embodiment of the present invention.

10, the display panel 410 of the display device according to the fourth embodiment of the present invention is a liquid crystal panel, and includes a first substrate 420, a second substrate 440, And a liquid crystal layer 450 between two substrates 420 and 440. The image generated in the display panel 410 is output to the outside through the first substrate 420.

A gate wiring 421 is formed on the inner surface of the first substrate 420. The gate wiring 421 has a double-layer structure including a first gate layer 421a and a second gate layer 421b. The first gate layer 421a is made of a metal material having a relatively high reflectance and the second gate layer 421b is made of a metal material having a relatively low specific resistance. That is, the reflectance of the first gate layer 421a is larger than that of the second gate layer 421b, and the resistivity of the second gate layer 421b is smaller than that of the first gate layer 421a. For example, the first gate layer 421a may be made of aluminum (Al) or a silver-palladium-copper (APC) alloy and the second gate layer 421b may be made of copper have.

A gate insulating film 424 is formed substantially on the entire surface of the first substrate 420 under the gate wiring 421.

A data line 427 intersecting the gate line 421 is formed under the gate insulating film 424. The data line 427 has a double-layer structure including a first data layer 427a and a second data layer 427b. The first data layer 427a is made of a metal material having a relatively high reflectance and the second data layer 427b is made of a metal material having a relatively low specific resistance. That is, the reflectance of the first data layer 427a is larger than that of the second data layer 421b, and the resistivity of the second data layer 427b is smaller than that of the first data layer 427a. For example, the first data layer 427a may be made of aluminum or a silver-palladium-copper alloy, and the second data layer 427b may be made of copper.

Though not shown, a thin film transistor is formed on the inner surface of the first substrate 410, and the thin film transistor includes a gate electrode, a semiconductor layer, a source electrode, and a drain electrode. The gate electrode is formed of the same material as the gate wiring 421 and the source and drain electrodes are formed of the same material in the same layer as the data wiring 427. The semiconductor layer may be located between the gate electrode and the source and drain electrodes.

A first passivation layer 430 and a second passivation layer 432 are formed substantially sequentially on the entire surface of the first substrate 420 under the data line 427 and the thin film transistor.

A pixel electrode 434 and a common electrode 436 are formed under the second passivation layer 432 and the pixel electrode 434 and the common electrode 436 are alternately arranged. The pixel electrode 434 and the common electrode 436 include a metal material having a relatively high reflectance. For example, the pixel electrode 434 and the common electrode 436 may comprise aluminum or a silver-palladium-copper alloy. Here, the pixel electrode 434 and the common electrode 436 may have a single-layer structure including aluminum or a silver-palladium-copper alloy.

Alternatively, the pixel electrode 424 and the common electrode 436 may have a double-layer structure of a first electrode layer and a second electrode layer. At this time, the first electrode layer may be made of aluminum or silver-palladium-copper alloy, and the second electrode layer may be made of a transparent conductive material of indium tin oxide or indium zinc oxide. have.

Particularly, when the pixel electrode 434 and the common electrode 436 include a silver-palladium-copper alloy, the pixel electrode 434 and the common electrode 436 are formed in order to prevent oxidation of the silver-palladium- Layer structure is preferable.

A black matrix 442 is formed on the inner surface of the second substrate 440 and a color filter layer 444 is formed on the black matrix 442. The color filter layer 444 and / or the black matrix 442 may be formed on the first substrate 420.

A liquid crystal layer 450 is disposed between the pixel electrode 434 and the common electrode 436 of the first substrate 420 and the color filter layer 444 of the second substrate 440.

In the display device according to the fourth embodiment of the present invention including the display panel 410, a first polarizer (not shown), which is a reflective polarizer, is disposed on the outer surface of the first substrate 420 of the display panel 410 And a second polarizing plate (not shown), which is an absorption type polarizing plate, is attached to the outer surface of the second substrate 440 of the display panel 410, and the first polarizing plate has the structure shown in Figs. 4 and 5 have.

Therefore, the display device according to the fourth embodiment of the present invention is used in a mirror mode and a video display mode depending on whether a voltage is applied or not.

At this time, in the display device according to the fourth embodiment of the present invention, not only the gate wiring 421 and the data wiring 427 but also the pixel electrode 434 and the common electrode 436 include a metal material having a relatively high reflectivity , It is possible to further increase the reflectance in the mirror mode in comparison with the display device 300 according to the third embodiment (300 in Fig. 9A).

Under the same conditions, the display device according to the third embodiment (300 in FIG. 9A) has a reflectance of about 68%, and the display device according to the fourth embodiment has a reflectance of about 72%.

Further, in the display device according to the fourth embodiment of the present invention, since the gate wiring 421 and the data wiring 427 further include a metal material having a relatively low specific resistance, the display device according to the third embodiment It is possible to further increase the reflectance in the mirror mode and to prevent image quality deterioration due to signal delay.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

100: curved liquid crystal display device 110: liquid crystal panel
160: first polarizing plate 162: first film
164: second film 170: second polarizer
172: polarizing layer 174: first protective film
176: second protective film 182: first adhesive layer
184: second adhesive layer 190: backlight unit

Claims (13)

A display panel including a plurality of pixels and outputting an image through the first surface;
A first polarizing plate attached to the first surface of the display panel and transmitting linearly polarized light in a first direction and reflecting linearly polarized light in a second direction perpendicular to the first direction,
/ RTI >
When no voltage is applied, external light is reflected by the first polarizing plate to be used in a mirror mode, and when a voltage is applied, an image from the display panel is output through the first polarizing plate / RTI >
The method according to claim 1,
The first polarizing plate includes a first film that transmits linearly polarized light in the first direction and reflects linearly polarized light in the second direction and a second film that transmits linearly polarized light in the first direction and absorbs linearly polarized light in the second direction / RTI >
3. The method of claim 2,
Wherein the first polarizing plate has a structure in which the first film and the second film are alternately stacked.
3. The method of claim 2,
Wherein the first film has a structure in which a first layer having a first refractive index and a second layer having a second refractive index different from the first refractive index are alternately stacked.
3. The method of claim 2,
Wherein the second film comprises a dichroic dye and the long axis direction of the dichroic dye is parallel to the second direction.
The method according to claim 1,
And a touch panel positioned above the first polarizer.
7. The method according to any one of claims 1 to 6,
A second polarizer attached to a second surface of the display panel and absorbing linearly polarized light in the first direction and transmitting linearly polarized light in the second direction;
And a backlight unit positioned outside the second polarizer plate,
Wherein the display panel comprises a liquid crystal layer between the first and second substrates and the first and second substrates.
8. The method of claim 7,
Wherein the first substrate includes a gate wiring, a data wiring, a thin film transistor, a pixel electrode, and a common electrode,
And the first polarizing plate is attached to the first substrate.
9. The method of claim 8,
Wherein at least one of the gate wiring and the data wiring comprises aluminum or a silver-palladium-copper alloy.
9. The method of claim 8,
Wherein at least one of the gate wiring and the data wiring has a double layer structure including a first metal layer and a second metal layer, the reflectance of the first metal layer being larger than that of the second metal layer, Smaller display.
11. The method of claim 10,
Wherein the first metal layer is made of aluminum or a silver-palladium-copper alloy, and the second metal layer is made of copper.
11. The method of claim 10,
Wherein the pixel electrode and the common electrode comprise a first electrode layer made of aluminum or silver-palladium-copper alloy.
13. The method of claim 12,
Wherein the pixel electrode and the common electrode further comprise a second electrode layer made of indium-tin-oxide or indium-zinc-oxide.

Images