KR102507796B1 - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display device is provided. A liquid crystal display device according to an exemplary embodiment of the present invention includes a first substrate through which external light is incident, a second substrate having a smaller size than the first substrate and spaced apart from the first substrate to face the first substrate, and the first substrate and the second substrate. It includes a liquid crystal layer interposed therebetween, a thin film transistor disposed on the first substrate, an external light reflection reduction layer disposed on the first substrate, and a metal layer disposed on the external light reflection reduction layer. The external light reflection reduction layer may be composed of a plurality of layers in which different materials are stacked. Accordingly, in the liquid crystal display device according to an embodiment of the present invention, the first substrate on which the thin film transistors are disposed is disposed on an upper portion where external light is incident to implement a borderless liquid crystal display device, but is configured to include an external light reflection reduction layer Even when the borderless liquid crystal display is not driven, it is possible to provide a reflective sight desired by the user.

Description

Liquid crystal display device {LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display panel capable of reducing reflective time in a borderless liquid crystal display device.

In the recent information age, display devices are rapidly spreading. Such a display device is gradually expanding its application range, such as TVs, monitors, and laptops, as well as mobile phones, PDAs, and smart phones, due to characteristics such as light weight, thinness, and low power consumption.

A liquid crystal display, which is one of the representative display devices whose application range is expanding in this way, is one of the most widely used display devices. It is a display device that controls the amount of transmitted light.

Such a liquid crystal display device includes a liquid crystal display panel that displays images by electrical signals, a bezel that surrounds the liquid crystal display panel to protect the display panel, and a backlight unit that provides light to the liquid crystal display panel, although images are not displayed. .

In particular, the liquid crystal display panel includes a TFT (Thin Film Transistor) substrate on which thin film transistors and pixel electrodes to which data voltages are applied are disposed, and a color filter substrate including color filters and disposed facing the TFT substrate.

At this time, since the color filter substrate is generally disposed above the TFT substrate, the TFT substrate becomes a lower substrate facing the backlight unit, and the color filter substrate becomes an upper substrate through which a user can view an image.

On the other hand, recently, liquid crystal display devices have expanded their use areas, such as desktop computer monitors and wall-mounted televisions, as well as small portable devices. Research on a liquid crystal display device having a wider display area by forming a smaller size is being actively conducted.

However, since the size of the lower substrate is larger than that of the upper substrate, general liquid crystal display devices have limitations in realizing a narrow bezel or borderless display.

Accordingly, in order to realize a wider display area, a liquid crystal display device in which an upper substrate and a lower substrate of a liquid crystal display panel are reversed and a TFT substrate is disposed as an upper substrate through which a user can view an image has been proposed. In this way, a liquid crystal display in which the display area is widened by inverting the upper substrate and the lower substrate is also referred to as a borderless liquid crystal display.

However, in this borderless liquid crystal display, although the non-display area is minimized and the bezel is removed, metal wires such as gate electrodes are exposed to the user's eyes when the borderless liquid crystal display is not driven, and reflection is felt by the wires. There is a problem with this degradation.

[Related technical literature]

1. Flat panel display and its manufacturing method (Korean Patent Application No. 10-2013-0074735)

Therefore, the problem to be solved by the present invention is to implement a borderless liquid crystal display by inverting the upper substrate and the lower substrate and at the same time to improve the configuration of metal wires to minimize the generation of reflected light even when the borderless liquid crystal display is not driven. It is to provide a liquid crystal display device capable of

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

A liquid crystal display device is provided to solve the above problems. A liquid crystal display device according to an exemplary embodiment of the present invention includes a first substrate through which external light is incident, a second substrate having a smaller size than the first substrate and spaced apart from the first substrate to face the first substrate, and the first substrate and the second substrate. It includes a liquid crystal layer interposed therebetween, a thin film transistor disposed on the first substrate, an external light reflection reduction layer disposed on the first substrate, and a metal layer disposed on the external light reflection reduction layer. The external light reflection reduction layer may be composed of a plurality of layers in which different materials are stacked. Accordingly, in the liquid crystal display device according to an embodiment of the present invention, the first substrate on which the thin film transistors are disposed is disposed on an upper portion where external light is incident to implement a borderless liquid crystal display device, but is configured to include an external light reflection reduction layer Even when the borderless liquid crystal display is not driven, it is possible to provide a reflective sight desired by the user.

Meanwhile, in the liquid crystal display according to another embodiment of the present invention, a display area and a non-display area are defined, and an upper substrate having a gate electrode, a source electrode, and a drain electrode disposed in the display area, and a lower substrate disposed facing the upper substrate includes External light is incident on the upper substrate, and the gate electrode may include a first external light reflection reduction layer, a phase compensation layer disposed under the first external light reflection reduction layer, and a second external light reflection reduction layer disposed below the phase compensation layer. . In addition, a driving circuit for driving each of the gate electrode, the source electrode, and the drain electrode is disposed in the non-display area, and the driving circuit may be disposed to face the lower substrate. Accordingly, in the liquid crystal display according to another embodiment of the present invention, a borderless liquid crystal display can be realized by arranging a driving circuit disposed in a non-display area on an upper substrate, and an agent capable of supplementing the reflective visibility of the gate electrode. A first external light reflection reducing layer and a second external light reflection reducing layer are included, but a phase compensation layer is further provided in addition to the external light reflection reducing layer, so that a user's desired visual feeling can be provided more than when the borderless liquid crystal display is not driven.

Other embodiment specifics are included in the detailed description and drawings.

The present invention implements a borderless liquid crystal display device by arranging a first substrate on which thin film transistors are disposed on an upper portion where external light is incident, and disposing a second substrate smaller than the first substrate on a lower portion, and at the same time, thin film transistor electrodes and wiring It is configured to include an external light reflection reducing layer for reducing reflective visibility due to external light, so that reflective visibility desired by a user can be provided even when the borderless liquid crystal display is not driven.

Effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic exploded perspective view for explaining a liquid crystal display according to an exemplary embodiment of the present invention.
2 is a schematic cross-sectional view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.
3 is a schematic cross-sectional view for explaining a part of a liquid crystal display according to an exemplary embodiment of the present invention.
4A and 4B are schematic enlarged views of area A of FIG. 3 .

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

When an element or layer is referred to as “on” another element or layer, it includes all cases where another element or layer is directly on top of another element or another layer or other element intervenes therebetween.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Like reference numbers designate like elements throughout the specification.

The size and thickness of each component shown in the drawings are shown for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated components.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and as those skilled in the art can fully understand, various interlocking and driving operations are possible, and each embodiment can be implemented independently of each other. It may be possible to implement together in an association relationship.

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

1 is a schematic exploded perspective view for explaining a liquid crystal display according to an exemplary embodiment of the present invention. 2 is a schematic cross-sectional view illustrating a liquid crystal display according to an exemplary embodiment of the present invention. Referring to FIGS. 1 and 2 , a liquid crystal display device 100 according to an embodiment of the present invention includes a liquid crystal display panel 110, a guide panel 120, a backlight unit 130, a bottom case 140, a flexible It includes a printed circuit board (Flexible Printed Circuit Board; FPCB, 150) and a printed circuit board (160).

The liquid crystal display panel 110 is a panel that displays an image, and includes a first substrate 111, a second substrate 112 disposed to face the first substrate 111, and the first substrate 111 and the second substrate ( 112) and a liquid crystal layer 170 interposed therebetween. The first substrate 111 and the second substrate 112 are bonded together by a sealing material 111S disposed on the outermost side of the display area DA of the liquid crystal display panel 110 to form the liquid crystal display panel 110 . At this time, the first substrate 111 is disposed on top of the second substrate 112 and has a larger size than the second substrate 112 . Since the first substrate 111 is disposed on top, external light is incident on the first substrate 11 first. A backlight unit 130 is disposed under the second substrate 112 . The liquid crystal display panel 110 displays an image by adjusting transmittance of light emitted from the backlight unit 130 disposed below the second substrate 112 . Such a liquid crystal display panel 110 includes a display area DA and a non-display area NDA.

The display area DA is disposed in an area where the first substrate 111 and the second substrate 112 overlap. A plurality of gate lines and a plurality of data lines are disposed in the display area DA, and a plurality of pixels defined by the plurality of gate lines and the plurality of data lines are arranged. A switching element, a pixel electrode, a common electrode, and a color filter may be disposed in each of the plurality of pixels. In this case, the switching element, pixel electrode, color filter, and common electrode may be disposed on the first substrate 111 . However, it is not limited thereto. In the liquid crystal display device 100 according to an embodiment of the present invention, when a switching element disposed in each pixel is turned on by a control signal input from the outside, a data voltage is applied to a pixel electrode and a common electrode is applied. A common voltage is applied to the liquid crystal molecules are tilted by a voltage difference between the data voltage and the common voltage to display an image.

The non-display area NDA is disposed in an area where the first substrate 111 and the second substrate 112 do not overlap. That is, the first substrate 111 has a larger size than the second substrate 112 , and the non-display area NDA is larger than the second substrate 112 in the display area DA of the first substrate 111 . ) is placed on the outskirts of As shown in FIG. 2 , a driving circuit 111D for driving a plurality of pixels may be disposed in the non-display area NDA. The driving circuit 111D disposed in the non-display area NDA is electrically connected to the printed circuit board 160 through the flexible printed circuit board 150 .

In this case, in the case of a general liquid crystal display device, unlike the liquid crystal display device 100 according to the present embodiment, the switching element, the pixel electrode, and the common electrode are disposed on the second substrate 112, not on the uppermost part of the liquid crystal display device. It can be. In other words, in the case of a general liquid crystal display, the first substrate 111 and the second substrate 112 of the liquid crystal display 100 according to an embodiment of the present invention may be in an inverted state. Accordingly, in the case of a typical liquid crystal display device, the driving circuit 111D is disposed on the second substrate 112, and the flexible circuit board 150 is bent to be electrically connected to the printed circuit board 160. . The flexible circuit board 150 further includes an area bent outward from the non-display area NDA. Accordingly, in the case of a general liquid crystal display device, the width of the non-display area NDA is increased as much as the area where the flexible printed circuit board 150 is bent, and a bezel or housing may be required to surround it.

However, the flexible printed circuit board 150 of the liquid crystal display device 100 according to an embodiment of the present invention may not be bent to surround the first substrate 111 while being electrically connected to the first substrate 111. , is connected to the circuit board 160 within a range that does not deviate from the non-display area NDA of the first substrate 111 . Accordingly, unlike general liquid crystal display devices, the width of the bezel of the liquid crystal display device 100 according to an exemplary embodiment of the present invention may be reduced, and accordingly, a borderless liquid crystal display device may be implemented. In addition, as described above, a switching element, a pixel electrode, a color filter, and a common electrode are disposed on the first substrate 111 of the liquid crystal display panel 110. The structure of the first substrate 111 is shown in FIG. 3 below. Let's take a closer look.

The guide panel 120 is a mechanism supporting the liquid crystal display panel 110 and is fastened to the bottom case 140 . Guide panel 120 may, in some embodiments, be omitted.

The backlight unit 130 is disposed below the second substrate 112 of the liquid crystal display panel 110 . The backlight unit 130 disposed in this way provides light toward the lower surface of the second substrate 112 so that an image is displayed on the liquid crystal display panel 110 . The backlight unit 130 includes a light source unit 131 and a light guide plate 132 . Also, although not shown, the backlight unit 130 may further include a plurality of optical sheets and reflectors. Hereinafter, only the light source unit 131 and the light guide plate 132 among the components of the backlight unit 130 will be described.

The light source unit 131 generates light and radiates the generated light to the light guide plate 132 . The light source unit 131 is disposed to correspond to one side of the light guide plate 132 . In FIG. 1 , the light source unit 131 is shown as an edge type disposed on one side of the light guide plate 132, but is not limited thereto, and the light source unit 131 may be disposed directly below the light guide plate 132. there is. The light source unit 131 may have a structure in which a plurality of light sources are disposed on a circuit board. In this case, the plurality of light sources may be any one of a light emission diode (LED), a cold cathode fluorescent lamp (CCFL), and an external electrode fluorescent lamp (EEFL).

The light guide plate 132 is disposed on substantially the same plane as the light source unit 131 . The light guide plate 132 guides the light emitted from the light source unit 131 so that it is transmitted to the display panel 110 . The light guide plate 132 is made of a transparent material. For example, the light guide plate 132 may be made of polymethyl-methacrylate (PMMA), but is not limited thereto, and may be made of various transparent materials capable of guiding light. In addition, the light guide plate 132 may be made of a rigid material, but is not limited thereto and may be made of a flexible material. As shown in FIG. 1 , the light guide plate 132 may have a flat plate shape or a wedge shape.

As shown in FIG. 1 , the bottom case 140 has a box shape with an open upper surface and accommodates the backlight unit 130 therein.

As described above, in the liquid crystal display device 100 according to an exemplary embodiment of the present invention, the first substrate 111 on which the switching element, the pixel electrode, and the common electrode are disposed and the first substrate 111 are disposed to face each other. By inverting the two substrates 112 and arranging them, a borderless liquid crystal display 100 capable of reducing a bezel area can be realized.

Hereinafter, FIGS. 3 to 4B are also referred to for a detailed description of the structure of the first substrate 111 of the liquid crystal display device 100 according to an exemplary embodiment of the present invention.

3 is a schematic cross-sectional view for explaining a part of a liquid crystal display according to an exemplary embodiment of the present invention. 4a and 4b are schematic enlarged views of FIG. 3 . More specifically, FIG. 3 shows the structure of the first substrate 111 of the liquid crystal display panel 110 in detail, and FIGS. 4A and 4B show the structure of some metal wires of the first substrate 111 in detail.

3 to 4B, the first substrate 111 of the liquid crystal display panel 110 includes a base substrate 111B, a metal wiring L, a thin film transistor TR, a color filter CF, and a common electrode ( CE) and a pixel electrode PE. In FIGS. 3 to 4B, the base substrate 111B is described as being disposed below for convenience of description, but as in FIG. 1, since the base substrate 111B is a substrate through which external light is incident, the base substrate is disposed on top The rest of the components can be placed below in order.

The base substrate 111B may be an insulating substrate. For example, the base substrate 111B may be made of glass, quartz or resin. In addition, the base substrate 111B may be made of polymer or plastic having high heat resistance. In some embodiments, the base substrate 111B may have flexibility. In other words, the base substrate 111B may be a substrate capable of being deformed by rolling, folding, or bending. A gate electrode GE is disposed on the base substrate 111B.

The gate electrode GE is disposed on the base substrate 111B to protrude from a gate line extending in a first direction, eg, a horizontal direction. The gate electrode GE includes an external light reflection reducing layer GE1 disposed in direct contact with the base substrate 111B and a metal layer GE2 disposed on the external light reflection reducing layer GE1.

The external light reflection reducing layer GE1 is composed of a plurality of layers in which different materials are stacked. More specifically, the external light reflection reduction layer GE1 includes a first sub external light reflection reduction layer GE11 and a second sub external light reflection reduction layer GE12 as shown in FIGS. 4A and 4B .

The first sub external light reflection reducing layer GE11 is disposed in contact with the base substrate 111B. However, the present invention is not limited thereto, and a buffer layer may be disposed between the first sub external light reflection reduction layer GE11 and the base substrate 111B. The first sub external light reflection reduction layer GE11 may be formed of a metal material that absorbs a portion of external light and reflects the remaining external light. Here, the reflected external light is offset with a phase difference of about 180 degrees from external light reflected from the metal layer GE2 to be described later. Accordingly, when the first sub external light reflection reduction layer GE11 is formed of a metal material, external light reflected from the metal layer GE2 may be canceled by using a destructive interference phenomenon with a part of the reflected light. In other words, a metal having a refractive index and an absorption coefficient of about 2 to 4 is appropriate for the first sub external light reflection reduction layer GE11. For example, the first sub external light reflection reduction layer GE11 may be formed of molytitanium (MoTi) or molybdenum (Mo). Meanwhile, the first sub external light reflection reduction layer GE11 may have a height h1 of 30 Å or more and 100 Å or less. If the height h1 of the first sub external light reflection reducing layer GE11 is less than 30 Å or greater than 100 Å, the user may not be satisfied with the reflective time when the liquid crystal display 100 is not driven. Accordingly, the reflection amount of external light can be adjusted by disposing the first sub external light reflection reduction layer GE11 to contact the base substrate 111B and adjusting the height h1 of the first sub external light reflection reduction layer GE11. . Since the reflection amount of the first sub external light reflection reduction layer GE11 is determined by considering the external light reflected from the metal layer GE2, the height h1 of the first sub external light reflection reduction layer GE11 is the reflectivity of the metal layer GE2. can be commensurate with

The second sub external light reflection reduction layer GE12 may be formed of a material and thickness such that a phase difference between external light reflected from the first sub external light reflection reduction layer GE11 and external light reflected from the metal layer GE2 is 180 degrees. For example, the second sub external light reflection reduction layer GE12 may be formed of a transparent material, preferably a transparent conductive material such as ITO or IZO. The second sub external light reflection reduction layer GE12 may have a height h2 for canceling interference between the reflected light from the first sub external light reflection reduction layer GE12 and the reflected light from the metal layer GE2. For example, the second sub external light reflection reduction layer GE12 may have a height h2 of 450 Å or more and 550 Å or less. If, as described above, the height of the first sub external light reflection reduction layer GE11 is formed to have a height of 30 Å or more and 100 Å or less, the height of the second sub external light reflection reduction layer GE12 is 450 Å or more and 550 Å or less. In the case where the condition is not satisfied, the phase difference between the external light reflected from the first sub external light reflection reduction layer GE11 and the external light reflected from the metal layer GE2 may not be 180 degrees. Accordingly, the user is not satisfied with the reflective luminous feeling caused by external light. A phase difference between the external light reflected by the first sub external light reflection reduction layer GE11 and the metal layer GE2 is determined by the height of the second sub external light reflection reduction layer GE12. For example, the height ratio of the first sub external light reflection reduction layer GE11 and the second sub external light reflection reduction layer GE12 may be approximately 1:15.

A metal oxide layer GE13 may be interposed between the first sub external light reflection reduction layer GE11 and the second sub external light reflection reduction layer GE12 as shown in FIG. 4B .

Due to the characteristics of the second sub external light reflection reduction layer GE12, the metal oxide film GE13 prevents the first and second sub external light reflection reduction layers GE11 and the second sub external light reflection reduction layer GE12 from being deposited in the same chamber. can be formed by In other words, the metal oxide film GE13 is formed by depositing the first sub external light reflection reduction layer GE11 on the base substrate 111B and then forming the base substrate 111B on which the first sub external light reflection reduction layer GE11 is deposited. It can be formed by taking it out of the chamber and exposing it to the atmosphere. The metal oxide film GE13 may play a role of compensating for the phase difference by an amount out of phase of 180 degrees when it is difficult for the second sub external light reflection reduction layer GE12 to maintain the phase difference of reflected light at 180 degrees in the visible light wavelength. . Accordingly, the metal oxide film GE13 may also be referred to as a phase compensation layer. In order to reduce external light reflection, it may be determined by the height of the second sub external light reflection reduction layer GE12. In some cases, the phase of external light each reflected from the metal layer GE2 is not 180 degrees, and the light may not be completely offset in the entire visible light region. In case of disposing the metal oxide film GE13 in preparation for this case, that is, the metal oxide film GE13 having a different interface between the first sub reflection reduction layer GE11 and the second sub reflection reduction layer GE12. When placed, the refractive index of light changes once again, so that the factory problem or the phase of some light that is not canceled in the entire area changes, so the cancellation efficiency of rain can be further improved. In addition, the reason why the metal oxide film GE13 is disposed in this way is that it can be naturally formed when the chamber is out of the chamber after the first sub external light reflection reduction layer GE11 is formed in the process, so that the process yield can be improved. However, a step of forming a metal oxide layer GE13 may be further included as one step of the process in order to further increase the offset efficiency. That is, the metal oxide layer GE13 may be formed by injecting O ₂ into the chamber to deposit the metal oxide layer GE13 .

The metal layer GE2 serves as a resistor of the gate electrode GE. This metal layer GE2 may be made of a metal material having low resistance. The metal layer GE2 may be, for example, Cu or a Cu alloy. The metal layer GE2 may have a height of 4000 Å or more and 6000 Å or less. Accordingly, the height ratio of the metal layer GE2 to the second sub external light reflection reduction layer GE12 may be 1:0.1. As described above, the height ratio adjusts the phase difference of external light reflected from the first sub external light reflection reduction layer GE11 and the metal layer GE2 to 180 degrees by the height of the second sub external light reflection reduction layer GE12. can be set to As described above, the external light reflected from the metal layer GE2 has a phase difference of about 180 degrees from the external light reflected from the first sub external light reflection reduction layer GE11 and is offset, and is not recognized by the user's eyes. According to the characteristics of the second sub external light reflection reduction layer GE12, the metal layer GE2 is not formed in the same chamber as the second sub external light reflection reduction layer GE12, and the second sub external light reflection reduction layer GE12 is the base substrate 111B. ) and then out of the chamber and then inserted into the chamber again. Referring to FIG. 3 , a gate insulating layer 111I1 is disposed on the gate electrode GE including the external light reflection reduction layer GE1 and the metal layer GE2 .

The gate insulating layer 111I1 may be made of an insulating material, for example, an inorganic insulating material such as silicon nitride, silicon oxide, or silicon oxynitride. The gate insulating layer 111I1 may have a single-layer structure or a multi-layer structure in which a plurality of insulating layers are stacked. An active layer AL is disposed on the gate insulating layer 111I1.

The active layer AL is disposed to overlap the gate electrode GE. The active layer AL may be formed of, for example, an oxide semiconductor, amorphous silicon, or polycrystalline silicon. A source electrode SE and a drain electrode DE are disposed on the active layer AL.

The source electrode SE and the drain electrode DE are spaced apart from each other on the gate electrode GE and partially overlap the active layer AL. The source electrode SE includes a first source electrode SE1 and a second source electrode SE2, and the drain electrode DE includes a first drain electrode DE1 and a second drain electrode DE2. . In this case, the first source electrode SE1 and the first drain electrode DE1 may be external light reflection reduction layers, and the second source electrode SE2 and the second drain electrode DE2 may be metal layers. Since the description of this configuration has been described in the above-described gate electrode, a detailed description thereof will be omitted. In addition to the source electrode SE and the drain electrode DE, the thin film transistor TR includes both the gate electrode GE and the active layer AL. A passivation film 111I2 is disposed on the thin film transistor TR.

The passivation layer 111I2 is disposed to protect the thin film transistor TR, and may be made of an organic insulating material or an inorganic insulating material. A metal wiring layer L and a color filter CF are disposed on the passivation film 111I2.

The metal wiring layer L may be a gate line. The metal wiring layer L includes an external light reflection reduction layer L1 and a metal layer L2. Since the description of this configuration has been described in the above-described gate electrode, a detailed description thereof will be omitted.

The color filter CF is disposed to overlap the metal wiring layer L, the pixel electrode PE and the common electrode CE, which will be described later. The color filter CF includes red (R), green (G), and blue (B) color filters. A color filter is disposed for each pixel, and red (R), green (G), and blue (B) color filters are alternately disposed for each pixel. A planarization layer 111P1 is disposed on the color filter CF and the passivation layer 111I2.

A contact hole exposing a part of the drain electrode DE is formed in the planarization layer 111P1 to electrically connect the pixel electrode PE and the drain electrode DE. Such a contact hole is also formed in the passivation film 111I2. Accordingly, the pixel electrode PE may receive the data voltage when the thin film transistor TR is turned on. The planarization layer 111P1 may be made of an insulating material. A common electrode CE is disposed on the planarization layer 111P1.

The common electrode CE and the pixel electrode PE form an electric field so that the liquid crystal molecules of the liquid crystal layer 170 are tilted. A common voltage is applied to the common electrode CE. The common electrode CE may be made of a transparent conductive material, such as ITO or IZO. An insulating layer 111P2 may be disposed on the common electrode CE.

The insulating layer 111P2 is disposed to protect the common electrode CE and to insulate the common electrode CE and the pixel electrode PE. The insulating layer 111P2 is made of an insulating material, and the pixel electrode PE is disposed on the insulating layer 111P2.

The pixel electrode PE is electrically connected to the drain electrode DE to receive a data voltage by the switching operation of the thin film transistor TR, and forms a voltage difference with the common electrode CE to which the common voltage is applied. The pixel electrode PE may be made of a transparent conductive material such as ITO or IZO.

As described above, the liquid crystal display 100 according to an exemplary embodiment of the present invention may implement a borderless liquid crystal display by disposing the first substrate 111 on which the thin film transistors are disposed on an upper portion where external light is incident.

As described above, the liquid crystal display device 100 according to an exemplary embodiment of the present invention includes not only the first sub external light reflection reducing layer GE11 made of an opaque metal material, but also the second sub-external light reflection reducing layer GE11 made of a transparent material and a material that reflects external light. By forming the external light reflection reduction layer by laminating the sub-external light reflection reduction layer (GE12), even if the substrate on which the thin film transistor is disposed has a structure in which the substrate is exposed to the user first, the reflectance by external light can be minimized and the user can provide the desired visual experience.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and may be variously modified and implemented without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: liquid crystal display
110: liquid crystal display panel
111: first substrate
112: second substrate
120: guide panel
130: backlight unit
140: bottom case
150: flexible printed circuit board
160: printed circuit board
170: liquid crystal layer
GE: gate electrode
GE1: External light reflection reduction layer
GE11: first sub external light reflection reduction layer
GE12: second sub external light reflection reduction layer
GE2: metal layer
AL: active layer
SE: source electrode
DE: drain electrode
TR: thin film transistor
CF: color filter

Claims (17)

a first substrate on which external light is incident;
a second substrate having a smaller size than the first substrate and spaced apart from the first substrate;
a liquid crystal layer interposed between the first substrate and the second substrate;
a thin film transistor disposed on the first substrate; and
An external light reflection reduction layer disposed on the first substrate and a metal layer disposed on the external light reflection reduction layer;
The external light reflection reducing layer includes a metal film disposed in contact with the first substrate and a transparent film disposed on the metal film,
The transparent film has a height of 450 Å or more and 550 Å or less,
The metal layer has a height of 4000 Å or more and 6000 Å or less so that the phase difference between the transparent film and external light is 180 degrees. According to claim 1,
A liquid crystal display device, wherein a backlight unit is disposed on the second substrate. delete According to claim 1,
The external light reflection reducing layer further includes a metal oxide layer interposed between the metal layer and the transparent layer. According to claim 1,
The liquid crystal display device, wherein the transparent film has a height for destructive interference with respect to external light. delete According to claim 5,
The height of the transparent film is greater than the height of the metal film, the liquid crystal display device. According to claim 7,
The height of the metal film is 30 Å or more and 100 Å or less, the liquid crystal display device. delete According to claim 1,
The metal layer is made of a metal material having low resistance, the liquid crystal display device. an upper substrate on which a display area and a non-display area are defined, and a gate electrode, a source electrode, and a drain electrode are disposed in the display area; and
Including a lower substrate disposed opposite to the upper substrate,
External light is incident on the upper substrate,
The gate electrode includes a first external light reflection reducing layer, a phase compensation layer disposed under the first external light reflection reduction layer, a second external light reflection reduction layer disposed under the phase compensation layer, and an external light reflection reduction layer disposed below the second external light reflection reduction layer. Including a metal layer disposed on,
The second external light reflection reduction layer has a height of 450 Å or more and 550 Å or less,
The metal layer has a height of 4000 Å or more and 6000 Å or less so that the phase difference between the second external light reflection reduction layer and external light is 180 degrees. According to claim 11,
A driving circuit for driving each of the gate electrode, the source electrode, and the drain electrode is disposed in the non-display area;
The liquid crystal display device of claim 1 , wherein the driving circuit is disposed to face the lower substrate. According to claim 12,
The drive circuit is electrically connected by a printed circuit board and a flexible printed circuit board,
The liquid crystal display device of claim 1 , wherein the driving circuit and the flexible printed circuit board are electrically connected within a range of the non-display area. delete According to claim 11,
The liquid crystal display device of claim 1, wherein the height ratio of the first external light reflection reducing layer and the second external light reflection reducing layer is 1:15. According to claim 11,
The height ratio of the second external light reflection reduction layer and the metal layer is 1:10, the liquid crystal display device. delete

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