KR20190063617A - Liquid crystal display device - Google Patents

Abstract

Disclosed is a liquid crystal display device. According to the liquid crystal display device, a light source, a switching element array layer, a liquid crystal layer, a light filter layer, and a wavelength conversion layer are sequentially arranged, and when voltage is applied, the light filter layer emits at least one of red light, green light, and blue light to the wavelength conversion layer. In the liquid crystal display device, a pixel electrode to which a pixel voltage is applied is provided in the switching element array layer. The liquid crystal display device may have a different laid electrode structure in which the pixel electrode and a common electrode are spaced apart from each other with the liquid crystal layer interposed therebetween, wherein a common voltage is applied to a metal pattern layer forming the light filter layer, and a vertical electric field is formed between the pixel electrode and the metal pattern layer when voltage is applied. The liquid crystal display device may have the same laid electrode structure in which the switching element array layer further includes the common electrode. The light filter layer further includes a barrier layer for reducing the vertical electric field formed between the metal pattern layer and the switching element array layer, and a horizontal electric field is formed between the pixel electrode and the common electrode when the voltage is applied.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The invention relates to a liquid crystal display device.

The display device is a device for visually displaying data. 2. Description of the Related Art [0002] As an information society develops, there is a growing demand for display devices for displaying images. Recently, a liquid crystal display (LCD) and an organic light emitting diode (OLED) display devices are mainly used as display devices.

A color filter transmits light from a light source, for example, light of a red wavelength band, light of a green wavelength band, and light of a blue wavelength band, and absorbs light of other wavelengths, , And blue. The color filter absorbs light of a different wavelength band except light of a predetermined color range to be expressed, so that light transmittance or light efficiency may be lowered.

A parallel conducting wire array that arranges parallel conductor wires to polarize only specific polarized light in an electromagnetic wave is generally referred to as a wire grid. The wire grid structure having a period smaller than the wavelength of the light has a polarization characteristic that reflects polarized light in the wire direction with respect to unpolarized incident light and transmits polarized light perpendicular to the wire direction. This has the advantage that the polarized light reflected from the absorption type polarizing plate can be reused, but a patterning technique is required because the alignment period of the conductor lines in the visible region should be 100 nm or less so that the polarizing efficiency is high.

An object of the invention is to provide a liquid crystal display device with improved light efficiency and processability.

An object of the present invention is to provide a liquid crystal display device improved in light efficiency, fairness and color reproduction characteristics.

The problems to be solved by the invention are not limited to those mentioned above, and the problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

A liquid crystal display device includes a light source, a switching element array layer, a liquid crystal layer, an optical filter layer, and a wavelength conversion layer arranged in this order. When the voltage is applied, the optical filter layer converts at least one of red light, It exits. In the liquid crystal display device, a pixel electrode to which a pixel voltage is applied is provided in the switching element array layer.

The liquid crystal display device may have a different laid electrode structure in which the pixel electrode and the common electrode are spaced apart from each other with the liquid crystal layer interposed therebetween. A common voltage is applied to the pattern layer, and when a voltage is applied, a vertical electric field is formed between the pixel electrode and the metal pattern layer.

The liquid crystal display may have the same laid electrode structure in which the switching element array layer further includes the common electrode, wherein the optical filter layer is formed of the metal pattern layer and the switching element And a barrier layer for reducing a vertical electric field formed between the array layers, wherein a horizontal electric field is formed between the pixel electrode and the common electrode when a voltage is applied.

The details of other embodiments are included in the detailed description and drawings.

The invention can provide a liquid crystal display device with improved light efficiency and fairness.

The invention can provide a liquid crystal display device improved in light efficiency, fairness and color reproduction characteristics.

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

1 is a schematic sectional view of a liquid crystal display device having an abnormal layer electrode structure.
2 is a schematic perspective view of an optical filter layer used in the liquid crystal display device of FIG.
3 is an image showing the result of improvement in color purity before and after applying the color purity enhancement layer to the liquid crystal display of Fig.
4 is a schematic cross-sectional view of a liquid crystal display device having the same layer electrode structure.
5 is a schematic perspective view of an optical filter layer used in the liquid crystal display of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

It is to be understood that the invention is not limited to the details of the disclosure herein described, but may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. And the invention is only defined by the scope of the claims.

A detailed description of the related art may be omitted if it is determined that the technical gist of the present invention may be blurred.

Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of layers and regions in the figures may be exaggerated for clarity of illustration.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one element from another, and it goes without saying that the first element may be the second element unless specifically stated otherwise.

Throughout the specification, each element may be singular or plural, unless specifically stated otherwise.

It is to be understood that throughout the specification, when an element is referred to as being "having", "having", or "having" an element, it should be understood that this does not exclude other elements, It can be included.

In the specification, "A and / or B" means A, B, or A and B unless otherwise indicated, and "C to D" C means more than C and D or less.

It is to be understood that when an element or layer is referred to as being "on" or " on "of another element or layer, All included. On the other hand, a device being referred to as "directly on" or "directly above " indicates that no other device or layer is interposed in between.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

1 is a schematic cross-sectional view of a liquid crystal display device having a different laid electrode structure. In a liquid crystal display device having an ideal layer electrode structure, a pixel electrode and a common electrode are arranged apart from each other with a liquid crystal layer interposed therebetween. In a liquid crystal display device having an ideal layer electrode structure, when a voltage is applied, a vertical electric field is formed between the pixel electrode and the common electrode. In a liquid crystal display device having an ideal layer electrode structure, liquid crystal molecules in the liquid crystal layer can be driven by a vertical electric field.

Examples of the liquid crystal display device having the abnormal layer electrode structure include a VA (Vertical Alignment) mode liquid crystal display device or a TN (Twisted Nematic) mode liquid crystal display device. For convenience of explanation, a liquid crystal display device having an abnormal layer electrode structure will be described as an example of a VA mode liquid crystal display device.

1, the VA mode liquid crystal display 100 includes a light source BLU, a polarizer plate POL, a substrate SUB-1, a switching element array layer TFT-Array, a liquid crystal layer LCL, The optical filter layer (TCF-1) and the wavelength conversion layer (CCM) are arranged in this order.

In the VA mode liquid crystal display device 100, the pixel electrode PE is provided in the switching element array layer (TFT-Array), and the common electrode CE is provided in the optical filter layer TCF-1. The VA mode liquid crystal display 100 shown in FIG. 1 illustrates a case of a normally black mode. In this case, when a voltage is applied to the VA mode liquid crystal display 100, ) And the optical filter layer (TCF-1), a vertical electric field is formed. When a voltage is applied to the VA mode liquid crystal display device 100, the initially vertically aligned liquid crystal molecules LC are arranged so that their directors are perpendicular to the vertical electric field, and the polarized light is transmitted through the polarizing plate layer POL, (TCF-1) via the layer LCL. Light incident on the optical filter layer (TCF-1) may be emitted from the optical filter layer (TCF-1) by being at least one of light in a red wavelength band, light in a green wavelength band, and light in a blue wavelength band.

For example, when the optical filter layer (TCF-1) emits light in the blue wavelength band to the wavelength conversion layer (CCM), the wavelength conversion layer (CCM) emits light in the blue wavelength band, It can be converted into light of a red wavelength band. A part of the light of the blue wavelength band is emitted to the outside without passing through the wavelength conversion layer (CCM), and another part of the light of the blue wavelength band passes through the wavelength conversion layer (CCM) The VA mode liquid crystal display device 100 can realize red, green, and blue colors when a voltage is applied to the VA mode liquid crystal display device 100. [

The optical filter layer TCF-1 includes a metal pattern layer MP, and the metal pattern layer MP may serve as a common electrode. A common voltage is maintained in the metal pattern layer MP and a voltage is applied between the pixel electrode PE and the metal pattern layer MP when a pixel voltage is applied to the pixel electrode PE of the switching element array layer A vertical electric field is formed.

The light source BLU may be a direct light type backlight unit, a side type backlight unit, or the like, and is not limited to the side type backlight unit shown in FIG. The side-type backlight unit includes a light-guide plate LG and a light-emitting diode chip LS disposed on the sides of the light guide plate LG. The light emitted from the light emitting diode chip LS is incident on the light guide plate LG so that the light path is directed toward the polarizing plate layer POL and / or the switching element array layer (TFT-Array) disposed on the upper portion of the light source BLU Change. The light emitted from the light source BLU to the polarizing plate layer POL and / or the switching element array layer (TFT-Array) may be white light, blue light, or the like.

The polarizing plate layer POL is disposed on the upper portion of the light source BLU. The polarizing plate layer POL can transmit only the light oscillating in the same direction as the polarization axis among the light emitted from the light source BLU and absorb or reflect the other light to make polarized light in a specific direction. An example of the polarizing plate layer (POL) is an absorption type polarizing plate, and the absorption type polarizing plate may be composed of, for example, a PVA polarizing film in which iodine or a dichroic dye is dyed. An example of the polarizing plate layer POL is a reflection type polarizing plate, and an example of a reflection type polarizing plate is a wire grid polarizing plate (WGP).

The substrate SUB-1 is disposed on the upper side of the polarizing plate layer POL. If the substrate SUB-1 is capable of transmitting visible light, the material and application can be appropriately selected in accordance with the process. The substrate SUB-1 may be made of glass, quartz, acrylic, triacetylcellulose (TAC), cyclic olefin copolymer (COP), cyclic olefin polymer (COC), polycarbonate (PC), polyethylene naphthalate (PET) , Polyimide (PI), polyethylene naphthalate (PEN), polyether sulfone (PES), polyarylate (PAR), and the like.

The switching element array layer (TFT-Array) is disposed on the substrate SUB-1. Specifically, the switching element array layer (TFT-Array) includes a gate wiring (not shown), a data wiring (not shown), a storage wiring (not shown), a barrier layer, For example, thin film transistors, a pixel electrode (PE) to which a pixel voltage is applied, and the like. A pixel (not shown) can be defined by the intersection of the gate wiring (not shown) and the data wiring (not shown), and the pixel can be partitioned into sub-pixels (not shown). The subpixel (not shown) may be divided into a first subpixel (not shown), a second subpixel (not shown), and a third subpixel (not shown) (Not shown) may be a red pixel, a second sub-pixel (not shown) may be a green pixel, and a third sub-pixel (not shown) may be a blue pixel.

The liquid crystal layer LCL is disposed on the upper side of the switching element array layer (TFT-Array). The liquid crystal composition constituting the liquid crystal layer (LCL) has a negative dielectric anisotropy. When the voltage is not applied to the VA mode liquid crystal display device 100 (OFF), the liquid crystal molecules LC are vertically and vertically aligned between the pixel electrode PE and the metal pattern layer MP, When the voltage is applied to the VA mode liquid crystal display device 100 (ON), the liquid crystal molecules LC are aligned in the same direction as the pixel electrodes PE and the common electrodes CE The VA mode liquid crystal display device 100 can realize red, green, blue, and the like.

The optical filter layer (TCF-1) is disposed on the upper side of the liquid crystal layer (LCL). The optical filter layer (TCF-1) can selectively transmit light of a specific wavelength band. 2 is a schematic perspective view of an optical filter layer (TCF-1) used in the liquid crystal display 100 of FIG. The optical filter layer (TCF-1) will be described with reference to Figs. 1 and 2. Fig. Referring to FIGS. 1 and 2, the optical filter layer TCF-1 includes a base layer SUB-2, a first dielectric layer DE-1, a dielectric layer DE-2, and a metal pattern layer MP .

The base layer SUB-2 is disposed between the liquid crystal layer LCL and the wavelength conversion layer CCM. The refractive index of the base layer SUB-2 is lower than that of the second dielectric layer DE-2. The base layer SUB-2 may include Si, SiC, ZnS, AlN, BN, GaTe, AgI, TiO ₂ , SiON, and the like. The refractive index of the base layer SUB-2 is lower than that of the first dielectric layer DE-1.

The first dielectric layer DE-1 is disposed between the base layer SUB-2 and the metal pattern layer MP. A first dielectric layer (DE-1) it is, and may include Si, SiC, ZnS, AlN, BN, GaTe, AgI, TiO _2, SiON or the like.

The second dielectric layer DE-2 is disposed between the first dielectric layer DE-1 and the metal pattern layer MP. A second dielectric layer (DE-2) may comprise a Si, SiC, ZnS, AlN, BN, GaTe, AgI, TiO _2, SiON or the like. The second dielectric layer DE-2 has a lower refractive index than the first dielectric layer DE-1.

The metal pattern layer MP is disposed between the base layer SUB-2 and the wavelength conversion layer CCM, and a common voltage is applied. The metal pattern layer MP is formed by stacking a unit block UN made of metal with a predetermined arrangement period Px and Py and arranged on the second dielectric layer DE- (U) may be composed of aluminum (Al), silver (Ag), gold (Au), chromium (Cr), copper (Cu) The arrangement of the unit blocks UN of metallic material in the metal pattern layer MP is such that the metallic unit blocks UN are spaced apart from each other with predetermined arrangement periods Px and Py in the x and y directions, As shown in Fig. In other words, although not shown, the metal pattern layer MP may be formed by stacking a metal unit block UN in a predetermined arrangement period (in the x direction, a predetermined arrangement period is Px, and a predetermined arrangement period Py in the y direction, and are arranged so as to be spaced apart from each other.

The optical filter layer TCF-1 serves as a reflection type polarizing plate that transmits only light of a specific wavelength band corresponding to the arrangement period (Px and / or Py) of the unit block UN made of metal and reflects light of other wavelength band can do. The optical filter layer TCF-1 can serve as a color filter that selectively emits light of a specific color wavelength band by adjusting the arrangement period Px and / or Py of the unit block UN made of metal.

When the transmission central wavelength of the optical filter layer (TCF-1) is set to the visible light band, the arrangement period (Px and / or Py) of the unit block UN made of metal may be 100 nm to 500 nm. (UN) having a line width of 100 nm or less is patterned using electron beam lithography (E-beam lithography), nano imprint lithography, patterning using self-assembly of a block copolymer, It is possible.

In the process of removing the stamp after the transfer of the resin pattern for patterning the metal layer, a part of the resin pattern is peeled together with the stamp and the nano-pattern defect is generated in the nanoimprint lithography There is a problem in that the fairness is lowered in the re-work for resolving the problem, and it is disadvantageous in that it is difficult to substantially increase the area. On the other hand, the patterning using the self-assembly of the block copolymer requires a guide pattern for aligning the hydrophobic block with the hydrophilic block of the block copolymer, complicating the process and limiting the synthesis of a suitable block copolymer.

On the other hand, the transmission center wavelength of the optical filter layer TCF-1 is not limited to the arrangement period Px and / or Py of the unit block UN of the metal but also the thickness and / or the refractive index of the first dielectric layer DE- , The thickness and / or refractive index of the second dielectric layer (DE-2), the thickness and / or the refractive index of the base layer (SUB-2). The optical filter layer TCF-1 may have a thickness and / or a refractive index of the first dielectric layer DE-1, a thickness and / or a refractive index of the second dielectric layer DE-2, a thickness of the base layer SUB-2 and / Since the minimum arrangement period of the unit block UN made of metal can be controlled to be about 250 nm to 300 nm by adjusting the refractive index, Compared to the wire grid polarizer in which the unit period of the unit block (UN) of the metal material is set to be 100 nm or less in order to control the corresponding transmission central wavelength and obtain high polarization efficiency, there is an advantage in terms of processability.

For example, when the transmission central wavelength of the optical filter layer (TCF-1) corresponds to the wavelength of light of the red wavelength band, the arrangement period (Px and / or Py) of the unit block UN made of metal is about 285 nm And the arrangement period Px and / or Py of the unit block UN of the metal material is about 355 nm when the center wavelength of transmission of the optical filter layer TCF-1 corresponds to the wavelength of light of the green wavelength band And the arrangement period Px and / or Py of the unit block UN of the metal material is about 395 nm when the center wavelength of transmission of the optical filter layer TCF-1 corresponds to the wavelength of light of the blue wavelength band Lt; / RTI >

For example, when the refractive indexes of the base layer SUB-2 and the second dielectric layer DE-2 are the same, the transmission central wavelength of the optical filter layer TCF-1 is expressed by the following equations (1) and Can be determined.

식 (1)

Equation (1)

N1 is the refractive index of the base layer SUG-2 and the refractive index of the second dielectric layer DE-2, and n2 is the refractive index of the first dielectric layer DE-1 (DE-1). In the formula (1), Hh is the thickness of the first dielectric layer DE- And kn1 and kn2 are the propagation rates of the second dielectric layer DE-2 and the first dielectric layer DE-1, respectively, and w represents the propagation constant of the waveguide mode. rho is 0 in the case of TE (incident polarized light perpendicular to the arrangement direction of the unit blocks), and 1 in the case of TM (incident polarized light parallel to the array direction of the unit blocks).

식 (2)

Equation (2)

는 금속 패턴층(MP)에 회절되는 회절 성분의 크기를 의미하며, Λ 는 금속 패턴층(MP)의 배열주기(Px 및/또는 Py) 를 나타낸다.In the above formula (2)

Denotes the size of the diffraction component diffracted to the metal pattern layer MP and A denotes the arrangement period (Px and / or Py) of the metal pattern layer MP.

가 같아지는 파장에서 투과 현상이 일어난다.The propagation constant? W of the waveguide mode of the formula (1) and the magnitude of the diffraction component of the formula (2)

The transmission phenomenon occurs at the same wavelength.

(H1 + h2 + h2 + h2 + h2 + h2 + h2 + h2 + h2 + h2 + h3 are formed at a level at which the metal pattern layer MP serves as a common electrode and does not weaken or shield the vertical electric field formed between the pixel electrode PE and the metal pattern layer MP, But is not limited to, for example, less than 2 占 퐉, may be 1.5 占 퐉 or less, and may be 1 占 퐉 or less.

The wavelength conversion layer (CCM) is disposed on top of the optical filter layer (TCF-1). The wavelength conversion layer (CCM) can convert light of a short wavelength into a long wavelength. The wavelength conversion layer (CCM) includes a color conversion material (CCM) that absorbs light having a short wavelength and converts the light into light having a long wavelength.

The wavelength conversion layer CCM may include a first conversion unit CCM-1 and a second conversion unit CCM-2 that emits light of a shorter wavelength than the first conversion unit CCM-1. The wavelength conversion layer CCM has a predetermined pattern such as a stripe type, a mosaic type, or a delta type formed by arranging the first conversion unit CCM-1 and the second conversion unit CCM-2 apart from each other .

For example, when the light at the central transmission wavelength band of the optical filter layer (TCF-1) is the wavelength band of blue light, when the blue light is incident on the wavelength conversion layer (CCM), the first conversion section The second conversion unit CCM-2 can emit, for example, the green light G. In this case, In this case, the wavelength conversion layer CCM may be composed of a first conversion unit CCM-1 for emitting red light R and a second conversion unit CCM-2 for emitting green light G, 1 conversion section CCM-1 and the second conversion section CCM-2 may be arranged so as to overlap with the red pixel and the green pixel respectively and the blue light B emitted from the optical filter layer TCF- Can be expressed externally in the region overlapping with the blue pixel without passing through the conversion layer (CCM).

The first conversion unit CCM-1 and the second conversion unit CCM-2 may be formed through a photolithography process or the like using a precursor material including a color conversion material and a photosensitive resin.

The color conversion material may be, for example, a Quantum Dot, a fluorescent dye, or a combination thereof. Fluorescent dyes include, for example, organic fluorescent materials, inorganic fluorescent materials, and combinations thereof.

The quantum dot may be selected from, but not limited to, a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV element, a Group IV compound, or a combination thereof. Group II-VI compounds are selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; A trivalent element selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, Small compounds; And a silane compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof. The III-V compound is selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and mixtures thereof; A trivalent compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP and mixtures thereof; And a photonic compound selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and mixtures thereof. Group IV-VI compounds are selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; A triple compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; And a silane compound selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof. Group IV elements may be selected from the group consisting of Si, Ge, and mixtures thereof. The IV group compound may be the element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

At this time, the elemental compound, the trivalent compound or the silane compound may be present in the particle at a uniform concentration, or may be present in the same particle by dividing the concentration distribution into a partially different state. One quantum dot may also have a core / shell structure surrounding other quantum dots. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell becomes lower toward the center.

The quantum dot may have a full width of half maximum (FWHM) of the emission wavelength spectrum of about 45 nm or less, preferably about 40 nm or less, more preferably about 30 nm or less, and the color purity or color reproducibility . Also, light emitted through the quantum dots is emitted in all directions, so that a wide viewing angle can be improved.

The shape of the quantum dots is not particularly limited, but may be a generally used form, and more specifically, a nanoparticle of a spherical shape, a pyramidal shape, a multi-arm or a cubic shape, a nanotube, Nanofibers, nano-sized particles, and the like can be used.

The fluorescent dye may be, for example, a red fluorescent dye, a green fluorescent dye, a dye emitting light of a third color other than that, or a combination thereof.

(Ca, Sr, Ba) S, (Ca, Sr, Ba) ₂ Si ₅ N ₈ , and Caustic CaAlSiN ₃ ), CaMoO ₄ , and Eu ₂ Si ₅ N ₈ . Further, the red fluorescent dye may be, for example, a substance having a maximum emission peak at 617 nm to 637 nm and a half-width (FWHM) of 40 nm to 50 nm. In an embodiment, as the red fluorescent dye, a material having a maximum emission peak at 627 nm and a half width (FWHM) of 44 nm may be used. However, the red fluorescent dye is not limited to the above-mentioned examples.

Green fluorescent dye is a material that emits light of a green wavelength band by absorbing light of a blue wavelength band, for example, yttrium aluminum garnet (yttrium aluminum garnet, YAG), (Ca, Sr, Ba) 2 SiO 4, SrGa 2 S _4, barium magnesium aluminate (BAM), alpha-siAlON (α-siAlON), sialon between the beta _{(β-siAlON), Ca 3} Sc 2 Si 3 O 12, Tb 3 Al 5 O 12, BaSiO 4, CaAlSiON, ( Sr _1-x Ba _x ) Si ₂ O ₂ N ₂ . Further, the green fluorescent dye may be, for example, a substance having a maximum emission peak at 510 nm to 525 nm and a half-width (FWHM) of 60 nm to 70 nm. In a specific example, the green fluorescent dye has a first green fluorescent dye having a maximum emission peak at 520 nm and a full width at half maximum (FWHM) of 62 nm, a maximum emission peak at 511 nm, a full width at half maximum (FWHM) of 64 nm A second green fluorescent dye can be used. However, the green fluorescent dye is not limited to the above-mentioned examples.

The VA mode liquid crystal display device 100 may further optionally include a color purity improving layer (YCF) disposed on top of the wavelength converting layer (CCM). The color purity enhancement layer YCF absorbs light (blue light B) in the wavelength range of 400 nm to 450 nm in the light emitted from the wavelength conversion layer CCM, The color purity of the VA mode liquid crystal display device 100 can be improved.

When the optical filter layer TCF-1 outputs the blue light B to the wavelength conversion layer CCM, the first conversion section CCM-1 can emit, for example, the red light R, The area superimposed on the first conversion unit CCM-1 absorbs the blue light B mixed in the red light R emitted from the first conversion unit CCM-1, The area of the second conversion unit CCM-2 that is arranged to overlap with the second conversion unit CCM-2 can improve the red purity of the device 100, and the blue light mixed with the green light G emitted from the second conversion unit CCM- The green purity of the VA mode liquid crystal display device 100 can be improved.

In this case, the color purity enhancement layer YCF may be disposed only in the region overlapping with the first conversion section CCM-1 and the second conversion section CCM-2. The color purity enhancement layer YCF may be arranged in a predetermined pattern such as a stripe shape, a mosaic shape or a delta shape so as to overlap with the first conversion portion CCM-1 and the second conversion portion CCM-2, Irrespective of the pattern of the first conversion unit CCM-1 and the second conversion unit CCM-2 in the area overlapping with the first conversion unit CCM-1 and the second conversion unit CCM-2, It may be formed as a single piece.

The color purity improving layer (YCF) may comprise a yellow dye and a polymer compound. The yellow dye is not particularly limited but may be, for example, an azo yellow dye. Examples of the azo yellow dye include CI reactive yellow. Examples of the CI reactive yellow dye include, CI Reactive Yellow 1, 2, 3, 4, 5, 13, 14, 15, 16, 17, 18, 22, 23, 25, 35, 36: , 57, 66, 72, 76, 78, 81, 84, 85, 86, 95, 105, 107, 121, 133, 135, 138, 143, 145, 148, 151, 154, 156, 157, 158, 160 , 161, 162, 164, 167, 174, 176, 178, 179, 184, 185, 186, 193, 201, 202, 205, 206, 207, 208, 209, 210, 211, 212 and 213 have.

3 is an image showing the result of improvement in color purity before and after applying the color purity enhancement layer to the liquid crystal display of Fig. 3A shows the transmittance of light of red wavelength band (blue / R CCM), green wavelength band (Blue / G CCM), and blue wavelength band (blue) before application of the color purity improvement layer (YCF) ) Is the transmittance of light of red wavelength band (Y-Blue / R CCM), green wavelength band (Y-Blue / G CCM) and blue wavelength band (Blue) after applying the color purity enhancement layer (YCF).

1 and 3, when blue light is emitted from the optical filter layer (TCF-1), for example, red light (red light) emitted through the first conversion unit CCM- A blue light B peak is blocked in the green light G emitted via the color conversion layer R and the second conversion portion CCM-2 and the color purity improving layer YCF to form red, green, and blue It is possible to reproduce pure color.

3 (A), before applying the color purity enhancement layer YCF, the red light (Blue / R CCM) emitted from the first conversion unit CCM-1 and the red light (Blue / R CCM) Green light (Blue / G CCM) emitted from a light source (not shown) includes blue light. 3 (B), after applying the color purity enhancement layer YCF, red light (Y-Blue / R CCM) emitted via the first conversion portion CCM-1 and the color purity enhancement layer YCF, The blue light (Blue) is not included in the green light (Y-Blue / G CCM) emitted via the second conversion unit (CCM-2) and the color purity improving layer (YCF).

4 is a schematic cross-sectional view of a liquid crystal display device having the same laid electrode structure. In a liquid crystal display device having the same layer electrode structure, when a voltage is applied to a liquid crystal display device having a pixel electrode and a common electrode in the same layer and having the same layer electrode structure, a horizontal electric field is generated between the pixel electrode and the common electrode .

Examples of the liquid crystal display device having the same layer electrode structure include an IPS (In-Plane Switching) mode liquid crystal display device or an FFS (Fringe Field Switching) mode liquid crystal display device. For convenience of explanation, a liquid crystal display device having the same-layer electrode structure will be described as an example of an IPS mode liquid crystal display device. In a liquid crystal display device having the same layer electrode structure, liquid crystal molecules in the liquid crystal layer can be driven by a transverse electric field.

Hereinafter, only the difference between the IPS mode liquid crystal display device 200 shown in FIG. 4 and the VA mode liquid crystal display device 100 shown in FIG. 1 will be described in detail. Since it has been explained, it will be omitted.

1 and 4, the IPS mode liquid crystal display device 200 is a liquid crystal display device in which a switching element array layer (TFT-Array) includes both a pixel electrode PE and a common electrode CE, Mode liquid crystal display device 100 in which a pixel electrode PE and a metal pattern layer (MP in FIG. 2) serving as a common electrode are arranged apart from each other with a gap between the pixel electrode PE and the liquid crystal cell LCL. The IPS mode liquid crystal display 200 is a liquid crystal display device in which the liquid crystal composition constituting the liquid crystal layer LCL has positive dielectric constant anisotropy because the liquid crystal composition constituting the liquid crystal layer LCL has a negative dielectric anisotropy, Mode liquid crystal display device 100 according to the present invention.

When the voltage is applied (ON) to the IPS mode liquid crystal display device 200, the directors of the liquid crystal molecules LC are arranged in parallel to the horizontal electric field formed between the pixel electrode PE and the common electrode CE , And the IPS mode liquid crystal display device 200 can display images represented by red, green, and blue colors.

The IPS mode liquid crystal display device 200 has the VA mode having the optical filter layer TCF-1 not including the barrier layer BA in that the optical filter layer TCF-2 further includes the barrier layer BA. Which is different from the liquid crystal display device 100.

5 is a schematic perspective view of an optical filter layer (TCF-2) used in the liquid crystal display device 200 of FIG.

The optical filter layer TCF-2 is formed by sequentially stacking the barrier layer BA, the base layer SUB-2, the first dielectric layer DE-1, the second dielectric layer DE-2, and the metal pattern layer MP in this order . The barrier layer BA is disposed between the base layer SUB-2 and the liquid crystal layer LCL.

Hereinafter, only differences between the optical filter layer TCF-2 shown in FIG. 5 and the optical filter layer TCF-1 shown in FIG. 2 will be described in detail. Therefore, it is omitted.

2 and 5, the optical filter layer TCF-2 includes a metal pattern layer MP and a pixel electrode PE and / or a common electrode CE of a switching element array layer (TFT-Array) And a barrier layer (BA) for reducing the vertical electric field that can be formed between the barrier layer (BA) and the barrier layer (BA). In this respect, the optical filter layer (TCF-2) differs from the optical filter layer (TCF-1) not including the barrier layer (BA).

The barrier layer BA is formed such that a horizontal electric field formed between the pixel electrode PE and the common electrode CE is formed between the metal pattern layer MP and the pixel electrode PE and / So as not to be influenced by the vertical electric field. The influence of the vertical electric field which can be formed between the metal pattern layer MP and the pixel electrode PE and / or the common electrode CE on the horizontal electric field formed between the pixel electrode PE and the common electrode CE The thickness H of the barrier layer BA is set so that the thickness h1 of the first dielectric layer DE-1, the thickness h2 of the second dielectric layer DE-2 and the thickness h2 of the base layer SUB (H1 + h2 + h3) obtained by adding all the thicknesses h1 and h2 of the thicknesses h1 and h2.

The thickness H of the barrier layer BA is set such that the liquid crystal molecules LC in the liquid crystal layer LCL can be driven by a horizontal electric field formed between the pixel electrode PE and the common electrode CE, Provided that the vertical electric field that can be formed between the layer MP and the pixel electrode PE and / or the common electrode CE can be minimized or shielded, for example, And more specifically, from the viewpoint of thinning of the IPS mode liquid crystal display device 200, it may be 2 탆 to 5 탆.

The barrier layer BA may be composed of, for example, Si, SiC, ZnS, AlN, BN, GaTe, AgI, TiO ₂ , SiON, or the like. The refractive index of the first dielectric layer DE-1 is higher than the refractive index of the second dielectric layer DE-2 and / or the base layer SUB-2. In addition, the refractive index of the first dielectric layer DE-1 is higher than that of the barrier layer BA.

Though not shown, when the optical filter layer TCF-2 does not include the barrier layer BA in the IPS mode liquid crystal display device 200, the thickness h1 of the first dielectric layer DE- The total sum of the thickness h2 of the dielectric layer DE-2 and the thickness h3 of the base layer SUB-2 may be 2 탆 or more and specifically 2 탆 to 5 탆 or 3 탆 to 5 탆 It is possible.

In the liquid crystal display device having the abnormal layer electrode structure according to the present invention, since the optical filter layer can simultaneously perform the role of the common electrode, the color filter, and the reflection type polarizing plate, unlike the liquid crystal display device of the conventional abnormal layer electrode structure, A common electrode, a color filter, and a polarizing plate are not required as components, so that the structure can be simplified and the processability can be improved.

In the liquid crystal display device having the abnormal layer electrode structure according to the invention, in the case where the optical filter layer functions as a color filter and a reflective polarizer, the alignment period of the unit blocks of the metal pattern layer, the thicknesses of the first and second dielectric layers, , The transmission central wavelength of the optical filter layer is determined through the thickness and the refractive index of the base layer. Thus, even when the arrangement period of the unit blocks is not 100 nm or less, as in the conventional wire grid polarizer, high polarization efficiency can be obtained There is an advantage in that the light efficiency of the light passing through the optical filter layer is not lowered unlike the conventional color filter which can improve the processability and absorb light of other wavelength band except light of a predetermined wavelength range. As a result, the liquid crystal display device having the abnormal layer electrode structure can be improved in light efficiency and processability.

According to the invention, in the liquid crystal display device having the abnormal layer electrode structure, the optical filter layer includes the metal pattern layer, and the wavelength conversion layer is disposed on the upper part of the metal pattern layer so that part of the light emitted from the wavelength conversion layer can be reused Therefore, there is an advantage that the light efficiency can be improved.

In the liquid crystal display device having the abnormal layer electrode structure according to the present invention, when the color conversion layer further includes a color purity enhancement layer, the liquid crystal display device of the present invention is a liquid crystal display device having a blue color light mixture of red light and green light emitted from the first conversion portion and the second conversion portion And the color purity is improved, whereby the color reproduction characteristic can be obtained.

The liquid crystal display device having the same layer electrode structure according to the present invention can perform the function of the color filter and the reflection type polarizing plate at the same time. Therefore, unlike the conventional liquid crystal display device having the double layer electrode structure, And the reflection type polarizing plate are not required, so that the structure can be simplified and the processability can be improved.

In the liquid crystal display device having the same layer electrode structure according to the invention, in the case where the optical filter layer functions as a color filter and a reflective polarizer, the alignment period of the unit blocks of the metal pattern layer, the thicknesses of the first and second dielectric layers, , The transmission central wavelength of the optical filter layer is determined through the thickness and the refractive index of the base layer. Thus, even when the arrangement period of the unit blocks is not 100 nm or less, as in the conventional wire grid polarizer, high polarization efficiency can be obtained There is an advantage in that the light efficiency of the light passing through the optical filter layer is not lowered unlike the conventional color filter which can improve the processability and absorb light of other wavelength band except light of a predetermined wavelength range. As a result, the liquid crystal display device having the same layer electrode structure can be improved in light efficiency and processability.

According to the invention, in the liquid crystal display device of the same layer electrode structure, the optical filter layer includes the metal pattern layer, the wavelength conversion layer is disposed on the upper part of the metal pattern layer, and a part of the light emitted from the wavelength conversion layer can be reused Therefore, there is an advantage that the light efficiency can be improved.

In the liquid crystal display device having the same layer electrode structure according to the invention, when the color conversion layer further includes a color purity enhancement layer, the liquid crystal display device of the same layer has a structure in which blue light And the color purity is improved, whereby the color reproduction characteristic can be obtained.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100, 200: liquid crystal display
CCM: wavelength conversion layer
YCF: color purity improvement layer
PE: pixel electrode
CE: Common electrode
TCF: optical filter layer
TFT-Array: switching element array layer
POL: polarizer layer
LCL: liquid crystal layer
BLU: Light source

Claims (8)

Light source;
A wavelength conversion layer for converting light of a short wavelength into a long wavelength;
A switching element array layer disposed between the light source and the wavelength conversion layer and including pixel electrodes;
A liquid crystal layer disposed between the wavelength conversion layer and the switching element array layer and including liquid crystal molecules (LC); And
An optical filter layer disposed between the wavelength conversion layer and the liquid crystal layer and including a metal pattern layer to which a common voltage is applied, the optical filter layer selectively transmitting light of a specific wavelength band;
/ RTI >
Wherein when a voltage is applied, a vertical electric field is formed between the pixel electrodes and the metal pattern layer,
Liquid crystal display device. The method according to claim 1,
A color purity enhancement layer disposed over the red pixel and the green pixel out of the red pixel, the green pixel, and the blue pixel to absorb the blue light; Further comprising:
Wherein the wavelength conversion layer is disposed between the color purity enhancement layer and the optical filter layer,
Liquid crystal display device. 3. The method of claim 2,
Wherein the light source emits blue light to the switching element array layer,
Wherein the wavelength conversion layer emits the red light and the green light,
Liquid crystal display device. The method according to claim 1,
The optical filter layer includes:
A base layer disposed between the liquid crystal layer and the wavelength conversion layer,
A metal pattern layer disposed between the base layer and the wavelength conversion layer and maintaining a common voltage,
A first dielectric layer disposed between the base layer and the metal pattern layer,
A second dielectric layer disposed between the first dielectric layer and the metal pattern layer and having a lower refractive index than the first dielectric layer,
Wherein the base layer has a refractive index lower than that of the second dielectric layer,
Liquid crystal display device. Light source;
A wavelength conversion layer for converting light of a short wavelength into a long wavelength;
A switching element array layer disposed between the light source and the wavelength conversion layer and including a pixel electrode to which a pixel voltage is applied and a common electrode to which a common voltage is applied;
A liquid crystal layer disposed between the wavelength conversion layer and the switching element array layer and including liquid crystal molecules (LC); And
An optical filter layer disposed between the wavelength conversion layer and the liquid crystal layer and including a metal pattern layer to which a predetermined voltage is applied, the optical filter layer selectively transmitting light of a specific wavelength band; / RTI >
The optical filter layer further includes a barrier layer between the metal pattern layer and the liquid crystal layer for reducing a vertical electric field between the switching element array layer and the metal pattern layer when a voltage is applied,
Wherein when a voltage is applied, a horizontal electric field is formed between the pixel electrode and the common electrode,
Liquid crystal display device. 6. The method of claim 5,
Further comprising a color purity enhancement layer disposed over the red pixel and the green pixel out of the red pixel, the green pixel, and the blue pixel to absorb the blue light,
Wherein the wavelength conversion layer is disposed between the color purity enhancement layer and the optical filter layer,
Liquid crystal display device. The method according to claim 6,
Wherein the light source emits blue light to the switching element array layer,
Wherein the wavelength conversion layer emits the red light and the green light,
Liquid crystal display device. 6. The method of claim 5,
The optical filter layer includes:
A base layer disposed between the liquid crystal layer and the wavelength conversion layer,
A metal pattern layer disposed between the base layer and the wavelength conversion layer and maintaining a common voltage,
A first dielectric layer disposed between the base layer and the metal pattern layer,
A second dielectric layer disposed between the first dielectric layer and the metal pattern layer and having a lower refractive index than the first dielectric layer,
A barrier layer which is disposed between the base layer and the liquid crystal layer and reduces a vertical electric field between the switching element array layer and the metal pattern layer,
Wherein the base layer and the barrier layer have a refractive index lower than that of the second dielectric layer,
Liquid crystal display device.

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