KR20170063304A - Liquid crystal disply device - Google Patents

Abstract

The present invention relates to a liquid crystal display employing a novel light source having a phosphor corresponding to a green color filter having a modified dye combination and newly modifying and combining the dye constituting the green color filter. According to the present invention, by changing the phosphor constituting the green color filter and the phosphor of the light source constituting the backlight unit, not only the overlap ratio of the light passing through the green color filter with the Adobe RGB color coordinates and the overlap ratio with the DCI color coordinates, The brightness can be improved. Therefore, when the liquid crystal display device of the present invention is used, the color reproduction ratio and the luminance can be improved, so that a high-quality image can be realized.

Description

[0001] LIQUID CRYSTAL DISPLY DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly, to a liquid crystal display device capable of improving color reproduction ratio and brightness and realizing high image quality.

BACKGROUND ART A liquid crystal display device (LCD) uses an optical anisotropy and polarization of a liquid crystal to realize an image. The liquid crystal display device is advantageous for moving picture display and has a large contrast ratio (CR), and is widely used as a display device for TVs, monitors, and mobile phones.

2. Description of the Related Art [0002] A liquid crystal display (LCD) generally comprises a liquid crystal panel in which liquid crystal layers are interposed between two substrates in parallel. The direction of the liquid crystal molecules is changed by an electric field applied to the liquid crystal panel Thereby realizing a difference in transmittance. However, since the liquid crystal panel does not have its own light emitting element, a separate light source is required to display the difference in transmittance as an image. To this end, a backlight having a light source is disposed on the back surface of the liquid crystal panel. A cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) are used as a light source of the backlight unit.

In general, a thin film transistor (TFT) is provided on an array substrate among two substrates constituting a liquid crystal panel, and red (R), green (G) A color filter pattern of blue (G) color and a black matrix are provided.

Accordingly, the light emitted from the backlight unit located on the backside of the liquid crystal panel is displayed in the form of a color image by reflecting the color combination of the color filter pattern in the course of transmitting through the liquid crystal panel. On the other hand, an LED generally used as a light source of a liquid crystal display device is composed of an LED chip emitting light and a phosphor. When light is emitted from the LED chip, the emitted light excites the phosphor to emit white light.

Conventionally, pigments such as Green 7 and / or Green 58 have been mainly used as pigments for realizing a green color filter pattern. These pigments are generally dispersed in a solvent in the form of a dispersion and mixed with a monomer, a binder resin, a photopolymerization initiator, etc. involved in the curing reaction, and they are arranged in a suitable pattern on a color filter substrate through a photolithography process using UV or the like do.

However, as the necessity of realizing a high image quality in a liquid crystal display device has increased recently, color reproducibility and brightness of color passing through these color filter patterns have to be increased. In recent display devices, it is necessary to satisfy the Adobe color coordinate standard and DCI (digital cinema initiative) color coordinate standard for high image quality implementation. Table 1 below shows the Adobe color coordinate standard and the DCI color coordinate standard required in the high-definition display device.

Adobe Color coordinates  Specifications and DCI Color coordinates  standard division Rx Ry Gx Gy Bx By Adobe specifications 0.640 0.330 0.210 0.710 0.150 0.060 DCI Specification 0.680 0.320 0.265 0.690 0.150 0.060

 However, the color realized through the green color filter manufactured by combining the conventional pigments does not satisfy all the specifications required for the high-quality display device. For example, with respect to the color recall ratio in the green color filter obtained by curing the resist composition containing the conventional green coloring matter, the overlap ratio with the RGB color coordinates according to the Adobe standard has been somewhat satisfied, The overlap ratio was not satisfied and there was a limit to the color reproduction. In addition, the luminance of the light passing through the conventional green color filter is not satisfactory to be applied to a high-quality display device.

Therefore, in order to increase the green and / or blue color coordinates realized through the green color filter using the conventional green dye, the thickness of the color filter manufactured by the green dye should be increased. As the thickness of the color filter is increased, the content of the pigment increases, so that it is difficult to secure the processability, and in particular, the resist process becomes impossible.

It is an object of the present invention to provide a liquid crystal display device capable of improving color reproduction ratio and brightness and realizing high picture quality.

Another object of the present invention is to provide a liquid crystal display device capable of realizing high picture quality by satisfying an overlay ratio of 100% with Adobe color coordinates and an overlap ratio of 99% with DCI color coordinates.

The present invention having the above-described objects provides a liquid crystal display device having a color reproducibility and a brightness by adjusting a coloring material applied to a green color filter and a light source corresponding to the coloring material.

In the liquid crystal display of the present invention, Green 59, Green 7 and Y 129 pigments, for example, are blended as 58 to 62 parts by weight, 18 to 21 parts by weight and 19 to 21 parts by weight, respectively, as pigments contained in the green color filter, A red fluorescent material having an emission peak wavelength of 600 to 670 nm and a green fluorescent material having a peak wavelength of 530 to 540 nm are mixed with the blue LED chip as the fluorescent material included in the LED light source constituting the unit so that the Adobe RGB overlap ratio and the DCI overlap ratio Almost 100% satisfactory, and improves the brightness of the light passing through the green color filter.

The present invention adopts a light source including a fluorescent material having a peak wavelength corresponding to the color of a color filter, by combining a new coloring material for a green color filter, thereby obtaining an overlap ratio of 100% with Adobe RGB color coordinates and an overlap ratio with DCI color coordinates 99% or more. Further, according to the present invention, it is possible to manufacture a liquid crystal display device improved in brightness by combining a coloring matter applied to a green color filter and a phosphor included in a light source constituting a backlight unit.

By combining the dyes included in the green color filter according to the present invention and incorporating a phosphor having an appropriate peak wavelength corresponding to the dye into the LED light source, a high quality liquid crystal display device with greatly improved color recall and brightness can be manufactured .

1 is a cross-sectional view schematically showing a liquid crystal display device using an LED as a light source according to an exemplary embodiment of the present invention.
2 is an exploded perspective view schematically showing a liquid crystal display device according to an exemplary embodiment of the present invention.
3 is a partially exploded perspective view of a liquid crystal panel constituting the liquid crystal display device shown in Fig.
4 is a graph showing the results of measuring the wavelength and transmittance of a green dye used according to an exemplary embodiment of the present invention.
5A and 5B are graphs showing the results of measurement of transmittance and emission wavelength of a combined dye according to an exemplary embodiment of the present invention. 5A is a graph showing the transmittance and emission wavelength of pigments mixed with Green 59, Green 7 and Yellow 129 at a weight ratio of 60:20:20 according to an exemplary embodiment of the present invention, And FIG. FIG. 5B is a graph showing transmittance and emission wavelengths of pigments in which Green 59, Green 7, and Yellow 129 are mixed at different ratios according to another exemplary embodiment of the present invention.
6 is a graph showing emission wavelengths of green and red phosphors used as an LED light source together with a blue LED chip according to an exemplary embodiment of the present invention.
FIG. 7 is a graph showing the overlap ratio of Adobe color coordinates, overlapping ratio with DCI color coordinates, and luminance (GY) when a color filter in which a green pigment is blended and an LED light source are used according to an exemplary embodiment of the present invention. Green 59, Green 7, and Yellow 129 are blended sequentially from 100: 0: 0 to 0:50:50, respectively.
FIGS. 8A and 8B are graphs showing areas and overlap ratios on a color coordinate system in the case of using a color filter and a LED light source in which a green pigment is blended according to an exemplary embodiment of the present invention. FIG. FIG. 8A shows the color coordinate values of the green region when Green 59, Green 7, and Yellow 129 are sequentially blended from 100: 0: 0 to 0:50:50, respectively, in comparison with the Adobe standard and the DCI standard. FIG. 8B shows the color coordinate values of the green region when Green 59, Green 7, and Yellow 129 are blended in a weight ratio of 58:21:21 to 62:19:19, in comparison with the Adobe standard and the DCI standard.
FIG. 9 is a graph showing the area and superposition ratio on a color coordinate system when a color filter in which a green pigment is blended and a conventional LED light source are used according to the prior art. The color coordinate values of the green region when Green 7 and Yellow 129 were blended in a weight ratio of 50:50 were compared with Adobe Standard and DCI Standard.

The present invention provides a liquid crystal display comprising: a liquid crystal panel including a first substrate including a thin film transistor, and a second substrate including a green color filter pattern containing a green pigment mixed with Green 59 pigment, Green 7 pigment and Yellow 129 pigment; And a backlight unit including a blue LED chip, a green phosphor, an LED including a red phosphor, and an optical sheet disposed on the LED, the reflector being disposed on a lower portion of the liquid crystal panel A liquid crystal display device is provided.

In one exemplary embodiment, the green pigment may be blended in a ratio of 58 to 62 parts by weight of the Green 59 pigment, 19 to 21 parts by weight of the Green 7 pigment and 19 to 21 parts by weight of the Yellow 129 pigment.

The red phosphor includes a red phosphor having a peak wavelength in a range of 600 to 660 nm.

For example, the red phosphor may be KSF (K ₂ SiF ₆ : Mn ⁴⁺ ), KTF (K ₂ TiF ₆ : Mn ⁴⁺ ), Ca ₂ Si ₅ N ₈ : Eu ²⁺ , Sr ₂ Si ₅ N ₈ : Eu ²⁺ , Ba ₂ Si ₅ N ₈ : Eu ²⁺ , CaAlSiN ₃ : Eu ²⁺ , SrS: Eu ²⁺ , CaS: Eu ^2+, and combinations thereof.

The green phosphor may be a green phosphor having a peak wavelength between 530 nm and 540 nm.

In one exemplary embodiment, the green phosphor may be selected from the group consisting of SiAlON: Eu ²⁺ , SrSi ₂ O ₂ N ₂ : Eu ^2+, and combinations thereof.

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

Fig. 1 is a schematic cross-sectional view of a liquid crystal display device adopting an LED as a light source according to an exemplary embodiment of the present invention, Fig. 2 is an exploded perspective view schematically showing a liquid crystal display device in an exemplary embodiment of the present invention, Is a partially exploded perspective view of the liquid crystal panel constituting the liquid crystal display device shown in Fig. As shown in these figures,

The liquid crystal display device 100 is largely divided into a liquid crystal panel 110 and a backlight unit 220. The backlight unit 220 includes a support main body 230 and a top cover 240 and a cover bottom 250, and the like.

More specifically, a plurality of gate lines 116 and a plurality of data lines 118 are vertically and horizontally crossed on one surface of the array substrate 112 (lower substrate, first substrate) to form pixel regions P . A thin film transistor T is provided at the intersection of these two wirings 116 and 118 and is connected in a one-to-one correspondence with the transparent pixel electrode 124 provided in each pixel region P.

On the other hand, a color filter substrate 114 (upper substrate, second substrate) facing the array substrate 112 is disposed with the liquid crystal layer 150 therebetween. The pixel electrode 124 is exposed only on one side of the color filter substrate 114 while covering the non-display elements such as the gate line 116 and the data line 118 of the array substrate 112 and the thin film transistor T. A black matrix 132 of a lattice shape covering the pixel region P is formed. A color filter layer 134 of red (R), green (G), and blue (B), and a transparent common electrode 136 covering all of them ).

Among the color filter patterns constituting the red (R), green (G) and blue (B) color filter layers 134 of the present invention, the coloring matters constituting the green (G) color filter pattern are Green 59 pigment, Green 7 A pigment and a yellow 129 pigment may be used. In the present specification, these pigments can be abbreviated as G58 pigment, G7 pigment, and Y129 pigment, respectively.

In one exemplary embodiment, the green colorant of the green (G) color filter pattern can be formulated in a ratio of 58 to 62 parts by weight of Green 59 pigment, 19 to 21 parts by weight of Green 7 pigment and 19 to 21 parts by weight of Yellow 129 pigment have. Unless otherwise stated herein, the term parts by weight refers to the weight ratio between the components being compounded. The structure of the green pigment constituting the green (G) color filter pattern according to the present invention is shown below.

Green 59

Green 7

Yellow 129

According to the present invention, when Green 58, Green 7, and Yellow 129 are blended as the coloring matter of the green (G) color filter pattern, the overlap ratio of 100% with Adobe color coordinates required by the high image quality display device and the overlap ratio of DCI color coordinates of 99% And the transmittance and brightness are improved as compared with the related art, so that a high-quality display device can be realized, which will be described later.

On the other hand, according to the exemplary embodiment, the pigment constituting the red (R) color filter pattern may be a pigment in which Red 254 pigment and Red 177 pigment are blended in a weight ratio of, for example, 50:50, The dye constituting the color filter pattern may be a dye in which Blue 15: 6 pigment is used singly, or a dye in which Blue 15: 5 pigment and Violet dye are blended in a weight ratio of 87:13, for example. However, other pigments and / or dyes may be used as the coloring matter constituting the red (R) color filter pattern and the coloring matter constituting the blue (B) color filter pattern.

According to the present invention, red (R), green (G) and blue (B) color filter patterns can be produced using the above-mentioned pigments. For example, a resist composition for a color filter in which the above-mentioned dyes corresponding to the pixels of the red (R), green (G) and blue (B) color filter patterns are dispersed in a solvent, a binder resin or the like is subjected to photolithography , A color filter pattern for each pixel region can be implemented by using a pigment / dye dispersion method for forming fine pixels using the above method.

For example, the resist composition for forming a green (G) color filter pattern may be a resist composition comprising at least one of propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), propylene glycol propyl ether (PGPE), propylene glycol ethyl ether acetate ), A dye combined with G59 / G7 / Y129, a binder resin such as an acrylic binder resin or a carcass binder resin involved in the curing reaction, a photopolymerizable monomer such as an acrylic monomer, and a photopolymerization initiator. , A dispersant for dispersing the coloring matter, a surfactant, and a functional additive such as a coupling agent.

The resist composition for a color filter can constitute a color filter pattern through a photolithography process. Specifically, a resist composition for a color filter is applied to a substrate, pre-baking is performed on the applied resist composition, and then an exposure process for a photolithography process, a post-baking (post -baking process to finally produce a green color filter. The red (R) color filter pattern and the blue (B) color filter pattern can also be produced in a similar manner, except for the pigments used.

Next, the configuration of the liquid crystal display device 100 according to the present invention will be described. On the outer surfaces of the array substrate 112 and the color filter substrate 114, polarizers 119a and 119b selectively transmitting only specific light are attached. Although not clearly shown in the drawings, the upper and lower alignment films for determining the initial alignment direction of the liquid crystal are interposed at the boundary between the array substrate 112 and the color filter substrate 114 and the liquid crystal layer 150, A seal pattern (not shown) is formed along the edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layer 150 filled between the substrate 112 and the color filter substrate 114.

At this time, the array substrate 112 has a larger size than the color filter substrate 114. When the substrates 112 and 114 are attached to each other, one side edge of the array substrate 112 is exposed to the outside, which includes a plurality of data pads 122 connected to a plurality of data lines 118, A plurality of gate pads (not shown) connected to the wirings 116 are located.

The plurality of data pads 122 and gate pads (not shown) are connected to an external printed circuit board 218 via a connection member 216 such as a tape carrier package (TCP) The circuit board 218 is mounted with a timing controller, a gamma voltage generator, and the like that processes various kinds of signal information input from an external device such as a computer and supplies signal voltages necessary for image display.

The printed circuit board 218 is brought into close contact with the side of the support main body 230 or the backside of the cover bottom 250 in the modularization process. An image signal transmitted to the data line 118 of the liquid crystal panel 110 through a signal voltage transmitted from the printed circuit board 218 and a gate line 116 are transmitted to the connection member 216, And a gate driver IC for generating and outputting a scan signal including an on / off signal of an on / off switch (not shown).

A signal for on / off of the thin film transistor T is sequentially applied to the gate wiring 16 so that the image signal of the data wiring 118 is applied to the pixel electrode An image signal is transmitted to the image processing unit 124. Accordingly, the liquid crystal molecules between the array substrate and the color filter substrates 112 and 114 are driven by the electric field therebetween, and various images can be displayed by the light transmittance change.

In addition, the liquid crystal display device 100 according to the present invention is provided with a backlight unit 220 for supplying light from the rear surface of the liquid crystal display device 100 so that the difference in transmittance represented by the liquid crystal panel 110 is externally expressed. The backlight unit 220 includes an LED assembly 229, a white or silver reflective plate 225, a light guide plate 223 resting on the reflective plate 225, and an optical sheet 221 interposed therebetween .

The LED assembly 229 is disposed on one side of the light guide plate 223 so as to face the light incident portion of the light guide plate 223. The LED assembly 229 includes a plurality of LEDs 229a for emitting light and a PCB 229b for mounting the LEDs 229a at a predetermined distance. For example, the LED 229a includes an LED chip (not shown) and a phosphor (not shown) that emits light. When light is emitted from an LED chip (not shown), the emitted light passes through a phosphor And emits light.

For example, the LED 229a may include a blue LED chip (not shown) and an RG phosphor combined with a red phosphor and a green phosphor so as to improve brightness. The blue LED chip constituting the LED 229a may use sapphire as a substrate and a material having a peak wavelength in the range of 440 to 460 nm, preferably 446 to 452 nm. In one exemplary embodiment, the material constituting the blue LED chip is GaN, InGaN, InGaN / GaN, BaMgAl 10 O 7: Eu 2+, CaMgSi 2 O 6: from the group consisting of Eu ²⁺ and combinations thereof The present invention is not limited thereto.

On the other hand, the red phosphor and the green phosphor can strongly absorb the blue light emitted by the blue LED chip and use a material having an emission wavelength in a predetermined range. These phosphors can be applied, for example, on a blue LED chip to form a white LED as a whole. In one exemplary embodiment, the red phosphor is a red phosphor having an emission peak at a wavelength in the range of 600 to 660 nm, that is, a peak wavelength in this range.

For example, the red phosphor may be composed of a silicon-based, a nitride-based, a sulfide-based, and a combination thereof having a peak wavelength in this range. In one exemplary embodiment, the red phosphor comprises KSF (K ₂ SiF ₆ : Mn ⁴⁺ ), KTF (K ₂ TiF ₆ : Mn ⁴⁺ ), Ca ₂ Si ₅ N ₈ : Eu ²⁺ , Sr ₂ Si ₅ And may be selected from the group consisting of N ₈ : Eu ²⁺ , Ba ₂ Si ₅ N ₈ : Eu ²⁺ , CaAlSiN ₃ : Eu ²⁺ , SrS: Eu ²⁺ , CaS: Eu ²⁺ and combinations thereof.

The green phosphor can use a material having a peak wavelength in the range of 530 to 540 nm. For example, the green phosphor may be selected from the group consisting of SiAlON: Eu ²⁺ , SrSi ₂ O ₂ N ₂ : Eu ^2+, and combinations thereof.

As described above, according to the present invention, a blue color having an emission wavelength in the range of 440 to 460 nm, preferably 446 to 452 nm, a red color having an emission wavelength in the range of 600 to 660 nm, nm green light having an emission wavelength in the range of 1 nm to 5 nm. By using the blue LED chip / green phosphor / red phosphor according to the present invention, it is possible to satisfy the Adobe color coordinate standard 100%, the DCI color coordinate standard 99% or more together with the color of the green color filter pattern described above, Transmittance and luminance are improved, and a high-quality display device can be realized, which will be described later.

 On the other hand, the light guide plate 223 constituting the backlight unit 220 of the liquid crystal display device 100 is configured such that the light incident from the LED 229a travels in the light guide plate 223 by total reflection several times, So as to provide a surface light source to the liquid crystal panel 110. The light guide plate 223 may include a pattern of a specific shape on the back surface to supply a uniform surface light source.

The reflection plate 225 is disposed on the back surface of the light guide plate 223 and reflects light passing through the back surface of the light guide plate 223 toward the liquid crystal panel 110 to further improve the brightness of light. The plurality of optical sheets 221 formed on the light guide plate 223 may include a diffusion sheet and at least one light condensing sheet and may diffuse or condense the light passing through the light guide plate 223, To be incident on the liquid crystal panel 110.

The liquid crystal panel 110 and the backlight unit 220 are modularized through a top cover 230, a support main 240 and a cover bottom 250. The liquid crystal panel 110 and the backlight unit 220 are supported by a support The main body 240 has a square tee shape.

The cover bottom 250 provides a horizontal plane on which the backlight unit 220 and the support main 240 including the liquid crystal panel 110 are mounted to support the entire liquid crystal display device and minimize the occurrence of light- Frame, and the edge of the horizontal plane is bent perpendicularly to form a side surface. Here, the cover bottom 250 functions to stably guiding the support main 240 to prevent the modularized liquid crystal display device from shaking and to maintain a stable fixed state.

The top cover 230 prevents the liquid crystal panel 110 and the backlight unit 220 from being attached and detached forward and removes light leakage that may occur in the gap between the liquid crystal panel 110 and the support main 240 Frame. The top cover 230 has a rectangular frame shape bent in a "? &Quot; shape so as to cover the upper surface edge and the side surface of the liquid crystal panel 110. The top cover 230 is opened in the liquid crystal panel 110 Is displayed.

Therefore, the top cover 230, the support main 240, and the cover bottom 250 constituting the liquid crystal display 100 of the present invention are assembled and fastened to each other so that the liquid crystal panel 110 and the backlight unit 220 are integrally formed . In this case, the top cover 240 may be referred to as a case top or a top case, and the support main 230 may be referred to as a guide panel or a main support or a mold frame. The cover bottom 250 may be referred to as a bottom cover or a bottom cover I will.

Next, according to the present invention, it is possible to improve the color reproduction ratio according to the combination of the combination of the dyes constituting the green (G) color filter pattern and the combination of the red phosphor / green phosphor excited by the light emission of the blue LED chip constituting the LED 229a Improvement of luminance / transmittance will be examined. As described above, the coloring matters constituting the green (G) color filter pattern constituting the color filter layer 134 of the liquid crystal panel 110 of the present invention are Green 59, Green 7 and Yellow 129. Green 59, Green 7, and Yellow 129 constituting the green (G) color filter pattern may be blended with, for example, 58 to 62 parts by weight, 19 to 21 parts by weight and 19 to 21 parts by weight, respectively.

In the liquid crystal display 100 of the present invention, the LED 229a, which is a combination of a blue LED chip, a red phosphor having an emission wavelength in a range of 600 to 660 nm and a green phosphor in a range of 530 to 540 nm, ) As a light source.

The white light emitted from the LED 229a according to the present invention passes through the color filter layer 134, particularly the green (G) color filter pattern of the liquid crystal panel 110 so that the overlap ratio with the Adobe color coordinate specification is 100% , The color reproduction ratio can be improved, and the luminance and the transmittance can be improved.

That is, in the present invention, the transmittance and the luminance are improved by changing the colorant constituting the green (G) color filter pattern having low light transmittance and insufficient color reproducibility. For this purpose, a composite pigment in which Green 59, Green 7 and Yellow 129 pigments are blended as a coloring matter constituting the green (G) color filter pattern among the color filters 134 is used. Green 59, Green 7 and Yellow 129 pigments may be blended in a proportion of 58 to 62 parts by weight, 19 to 21 parts by weight and 19 to 21 parts by weight, respectively, among the pigments constituting the green (G) color filter pattern. For example, when blended in a proportion of 58 to 62 parts by weight, 19 to 21 parts by weight and 19 to 21 parts by weight, respectively, the Green 59, Green 7 and Yellow 129 pigments have a superposition ratio of 100% with Adobe color coordinates, Of 99% or more can be achieved.

The Green 59 pigment used as a preserver of the green pigment has a higher transmittance than the Green 7 pigment and has a sufficiently high color characteristic. Accordingly, the green (G) color filter of the present invention can improve the transmittance and improve the color reproducibility as compared with the prior art.

If necessary, the transmittance of the red color can be improved by blending the Red 254 pigment and the Red 177 pigment as the red (R) pigment. In addition, when Blue 15: 6 is used alone as a blue (G) pigment or Violet Dye capable of reducing scattering of light based on Blue 15: 6 is blended, light scattering is reduced to reduce light loss, the transmittance of the blue color is also improved. Therefore, the luminance can be improved by improving the transmittance of the pigments of the red (R), green (G) and blue (B) color filter patterns of the present invention (see Figs. 5A and 5B)

In addition, when the dye constituting the green (G) color filter pattern is changed according to the present invention, the green (G) color filter pattern is shifted to a longer wavelength as compared with the case where the existing coloring matter is applied (see FIG. 5A) . Therefore, the color reproduction ratio realized from the liquid crystal display device 100 can be maximized by using the LED light source corresponding to the maximum spectral wavelength band (530 to 540 nm) of the new green (G) color filter pattern.

In one exemplary embodiment, a blue LED chip having an emission wavelength in the range of 440 to 460 nm, preferably 446 to 452 nm is used as the LED 229a light source, and a blue LED chip having an emission wavelength in the range of 660 to 670 nm A red phosphor and a green phosphor having an emission wavelength in the range of 530 to 540 nm can be combined.

Among the phosphors used as the light source of the LED 229a according to the present invention, a green phosphor in particular can have an emission peak at a wavelength band shifted to a long wavelength region as compared with a green phosphor used conventionally (see FIG. 6).

For example, a blue LED chip having an emission wavelength in the range of 440 to 460 nm, preferably 446 to 452 nm is used, and a red phosphor having an emission wavelength in the range of 660 to 670 nm and a red phosphor in the emission range of 530 to 540 nm If the green phosphors having wavelengths are combined, the color reproduction rate realized from the display device can be improved in correspondence with the color of the changed green (G) color filter pattern.

That is, according to the present invention, the green colorant of the green (G) color filter pattern is changed to G58 / G7 / Y129 and the red phosphor having the emission peak in the range of 660 to 670 nm as the phosphor of the LED 229a light source, By combining a green phosphor having an emission peak in the range of 540 nm to 540 nm, it is possible to improve the color reproduction rate by implementing not only the luminance improvement but also the overlap ratio of 100% and the DCI overlap ratio of 99% or more according to the Adobe standard, Can be manufactured.

Hereinafter, the present invention will be described in more detail with reference to exemplary embodiments. However, the present invention is not limited to the invention described in the following examples.

Example 1: Measurement of transmittance and emission peak of green pigment

The transmittance and emission wavelength of three pigments (Green 7, Green 59, and Green 58 pigment), which can be used as the pigment of the green color filter pattern, were measured. The measurement results are shown in Fig. As shown in Fig. 4, the G59 pigment has a higher π-electron density than the G7 pigment, and the energy band gap is low, indicating that the emission peak is shifted to the long wavelength band of the Red region. In particular, the G59 pigment has an increased area of overlap with the color matching function Y (Y), so that the transmittance of the G59 pigment is higher than that of the G7 pigment, and the coloring effect is better than that of G58. The color characteristics of the three green pigments are shown in Table 2 below.

Color characteristics of green pigment division G7 G59 G58 x 0.131 0.168 0.259 y 0.495 0.497 0.590 Y 27.2 37.0 54.2

Example 2: Fabrication of a green color filter pattern

Green 59, Green 7 and Yellow 129 as pigments for realizing a green color filter were prepared in various weight ratios of 100: 0: 0 to 0:50:50, respectively. Each prepared dye was photolithographically processed to produce a green color filter pattern. The thickness of the green color filter pattern was 2.5 mu m.

Comparative Example 1: Production of a conventional green color filter pattern

Green color filter pattern was prepared by repeating the procedure of Example 1, except that a coloring matter for forming a green color filter was used and a coloring matter in which Green 7 and Yellow 129 were blended in a weight ratio of 50:50.

Example 3: Measurement of transmittance and emission peak of a green color filter pattern

The transmittance and the emission peak of the green color filter pattern prepared in Example 2 and Comparative Example 1 were measured. The measurement results for the green color filter pattern in which the green 59, green 7, and yellow 129 are blended in a weight ratio of 60:20:20 are shown in FIG. 5A together with the measurement results for the color filter pattern of the comparative example, 7 and Yellow 129 are blended in a weight ratio of 58:21:21 and 62:19:19 are shown in FIG. 5b. According to the embodiment of the present invention, the transmittance was increased in the color filter pattern using Green 59 as the main material of the green pigment, and the emission peak was shifted to the red region as a whole. In particular, it can be seen that the peak fluctuation occurred near 470 nm and 530 nm depending on the composition ratio.

Example 4: Design of LED light source phosphor

Based on the results of Example 3, a light source suitable for a maximum spectral wavelength band (530 nm) was designed for a new green color filter pattern. GaN having an emission peak in the range of 446 to 452 nm was used as a blue LED chip, KSF (K ₂ SiF ₆ : Mn ⁴⁺ ) was used as a red phosphor, and a nitride phosphor having a luminescence peak at a wavelength of 535 nm Based phosphor SiAlON: Eu ²⁺ was used.

Comparative Example 2: Design of LED light source phosphor

An LED light source phosphor corresponding to a green color filter pattern in which Green 7 and Yellow 129 used in Comparative Example 1 were blended in a ratio of 50:50 was used. GaN was used as a blue LED chip, nitride-based CaAlSiN: Eu ²⁺ having an emission peak of 660 nm wavelength was used as a red phosphor, and silicon-based SiAlON: Eu ²⁺ having an emission peak of 521 nm wavelength was used as a green phosphor Respectively.

Example 5: Measurement of luminescence characteristics of LED light source

The emission peak of the green phosphor and the red phosphor was measured using the blue LED chip constituting the LED light source manufactured in Example 4 and Comparative Example 2 as the excitation light source. The measurement results are shown in Fig. It can be seen that the emission peak of the green phosphor of the present invention is shifted to the longer wavelength region as compared with the emission peak of the green phosphor of the comparative example.

Example 6: Fabrication of display device

A green color filter pattern fabricated in Example 2 and a LED light source fabricated in Example 4 were applied to fabricate a display device. As the pigment for the red color filter pattern, R254 and R177 were mixed in a weight ratio of 50:50, and B15: 6 was used as a pigment for the blue color filter pattern.

Comparative Example 3: Fabrication of display device

A green color filter pattern produced in Comparative Example 1 and a LED light source manufactured in Comparative Example 2 were applied to fabricate a display device.

Example 7: Measurement of overlap ratio between a color filter pattern and a display device to which an LED light source is applied

 For the display devices manufactured in Example 6 and Comparative Example 3, the superimposing ratio and the superimposing ratio and the luminance of the DCI color coordinate standard were measured for the Adobe color coordinate standard.

7 shows the overlap ratio of the Adobe color coordinates and the DCI overlap ratio when all the green color filter patterns in which Green 59, Green 7, and Yellow 129 are sequentially blended from 100: 0: 0 to 0:50:50 are used .

FIG. 8A shows the color coordinate values of the green region when Green 59, Green 7, and Yellow 129 are sequentially blended from 100: 0: 0 to 0:50:50, respectively, in comparison with the Adobe standard and the DCI standard. FIG. 8B shows the color coordinate values of the green region when Green 59, Green 7, and Yellow 129 are blended in a weight ratio of 58:21:21 to 62:19:19, in comparison with the Adobe standard and the DCI standard. FIG. 9 is a graph showing the area on the color coordinates and the overlapping ratio in the case of using the LED and the color filter in which the green pigment is blended according to Comparative Example 3. FIG. The color coordinate values of the green region in the case where Green 7 and Yellow 129 were blended in a weight ratio of 50:50 were compared with the Adobe standard and the DCI standard.

Table 3 below shows the overlap ratios with respect to the Adobe color coordinates in the case of applying a green color filter in which Green 59, Green 7, and Yellow 129 are blended in a weight ratio of 58:21:21 to 62:19:19, And luminance.

Adobe Overlap Ratio, DCI Overlap Ratio and Luminance Green color filter
Pigment composition G59 / G7 / Y129
(58:21:21) G59 / G7 / Y129
(60:20:20) G59 / G7 / Y129
(62:19:19) G7 / Y129
(50:50 Light source
(Green peak) B-rg
(535 nm) B-rg
(535 nm) B-rg
(535 nm) B-rg
(521 nm) Gx 0.193 0.192 0.191 0.202 Gy 0.670 0.666 0.662 0.713 Adobe Overlays 100% 100% 100% 100% DCI overlap ratio 99.3% 99.3% 99.3% 97.8% Green luminance 28.1 28.1 28.1 26.7

As shown in Table 3 and Figs. 7-9, the display device manufactured according to the present invention had an overlap ratio of 100% with the color coordinates according to the Adobe standard, and an overlap ratio with the color coordinates according to the DCI standard was 99%. On the other hand, conventionally used display devices meet the Adobe standard, but only 97.8% of the color coordinates according to the DCI standard are satisfied.

In addition, when the green color filter pattern used in the present invention was applied, the luminance was improved by 5.2% as compared with the conventional green color filter pattern. In addition, since the thickness of the color filter pattern must exceed 4.0 탆 in order to meet the same color coordinate values as the present invention by combining G7 and Y129 which are conventionally used green color filters, it is also confirmed that the processability is lowered and the resist process is difficult to perform Respectively.

Although the present invention has been described based on the exemplary embodiments and examples of the present invention, the present invention is not limited to the technical ideas described in the above-described embodiments and examples. Those skilled in the art will appreciate that various modifications and changes may be made without departing from the scope of the present invention. It will be apparent, however, that such modifications and changes are all within the scope of the present invention.

100: liquid crystal display device 110: liquid crystal panel
112: array substrate 114: color filter substrate
132: black matrix 134: color filter pattern
220: Backlight unit 229: LED assembly
229a: LED P: pixel area

Claims (6)

A liquid crystal panel including a first substrate provided with a thin film transistor, and a second substrate including a green color filter pattern containing a green pigment mixed with Green 59 pigment, Green 7 pigment and Yellow 129 pigment;
And a backlight unit including an optical sheet disposed on an upper portion of the LED, the backlight unit including a reflective LED disposed on a lower portion of the liquid crystal panel, and a blue LED chip, a green phosphor, a red phosphor,
And the liquid crystal display device.
The method according to claim 1,
The green pigment is blended at a ratio of 58 to 62 parts by weight of the Green 59 pigment, 19 to 21 parts by weight of the Green 7 pigment and 19 to 21 parts by weight of the Yellow 129 pigment.
The method according to claim 1,
Wherein the red phosphor includes a red phosphor having a peak wavelength in the range of 600 to 660 nm.
The method according to claim 1 or 3,
Wherein the red phosphor is at least one selected from the group consisting of KSF (K ₂ SiF ₆ : Mn ⁴⁺ ), KTF (K ₂ TiF ₆ : Mn ⁴⁺ ), Ca ₂ Si ₅ N ₈ : Eu ²⁺ , Sr ₂ Si ₅ N ₈ : Eu ²⁺ , _{Ba 2 Si 5 N 8: Eu} 2+, CaAlSiN 3: Eu 2+, SrS: Eu 2+, CaS: Eu 2+ and the liquid crystal display device selected from the group consisting of a combination thereof.
The method according to claim 1,
Wherein the green phosphor is a green phosphor having a peak wavelength between 530 nm and 540 nm.
6. The method according to claim 1 or 5,
Wherein the green phosphor is selected from the group consisting of SiAlON: Eu ²⁺ , SrSi ₂ O ₂ N ₂ : Eu ^2+, and combinations thereof.

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