TW201907596A - Color filter, and organic light emitting display device therewith - Google Patents

Abstract

The present invention relates to a color filter and an organic light emitting display device comprising the same. The color filter comprises a transparent substrate, a black array layer, a colored layer, and a protective layer, and comprises a recessed portion whose shape is characterized by the decreasing radius of each colored layer from the part furthest to the substrate to the transparent substrate.

Description

Color filter and organic light emitting display device having the same

The present invention relates to a color filter for an organic light-emitting display device, and an organic light-emitting display device containing the same. Specifically, the present invention relates to a color filter for an organic light-emitting display device having improved brightness and color difference between a front surface and an inclined surface, And an organic light emitting display device containing the same.

Organic Light Emitting Diode Display (OLED) system includes: a plurality of organic light emitting elements having a positive hole injection electrode, an organic light emitting layer, and an electron injection electrode. A self-luminous display device in which an exciton generated by internal bonding emits light of a specific wavelength from energy generated when the excited state drops to a ground state.

Therefore, an organic light-emitting display device is different from a liquid crystal display device in that it does not require a separate light source, so that not only the power consumption is low, but also the thickness and weight can be reduced. In addition, since it exhibits high-quality characteristics such as high brightness and response speed, the organic light emitting display device has attracted attention as a next-generation display device of a portable electronic device.

In an organic light emitting display device, pixels (pixels), which are basic units for displaying images on a substrate, are arranged in an array.

There are three ways to express colors in organic light-emitting display devices: three-color methods, conversion methods, and color filter methods. In the case of a white organic light-emitting display device using a white light source, each of the pixels is specifically realized as a full-color through a color filter formed with red, green, and blue patterns. In the three-color method, although red, green, and blue light-emitting layers are used to realize full color, in order to improve the purity of the color, a color filter can be used together. The conversion method is a method in which a blue light-emitting layer is prepared, and a part of the emitted light is passed through the color conversion layer to obtain red and green.

In the organic light-emitting display device, in order to realize high-quality colors irrespective of the field of view of the user, it is necessary to display high brightness and not to cause a color difference between the front surface and the inclined surface.

Therefore, an organic light emitting display device disclosed in Korean Patent Publication No. 10-2015-0019325 includes: an organic light emitting display panel; a high-refractive organic film layer formed on the organic light emitting display panel; and formed on the foregoing A low-refractive organic film layer over the high-refractive organic film layer; a color filter formed on the aforementioned low-refractive organic film layer; and a light-shielding member having an opening portion corresponding to the aforementioned color filter; The refractive organic film layer includes a convex portion configured to be convex with respect to the organic light emitting display panel of the color filter, and the low refractive organic film layer includes a concave portion corresponding to the convex portion.

Also, Korean Patent Publication No. 10-2014-0135568 discloses an organic light-emitting display device including an organic light-emitting element including a plurality of subpixels that emit light of different colors, A sealing film on a light-emitting element, and a lens layer including a lens portion having a surface bulging in a light emitting direction and a direction opposite to the light emitting direction, which are disposed in a region corresponding to each sub-pixel formed on the sealing film. And an anti-reflection layer for suppressing reflection of external light, the color filter including a region corresponding to each sub-pixel and formed on the lens layer.

However, in the prior arts such as this, since an additional layer such as a low-refractive and high-refractive organic film layer or a lens layer is formed, there is a problem that the engineering stage increases. [Prior Art Document] [Patent Document] [Patent Document 1] Republic of Korea Publication Patent No. 10-2015-0019325 [Patent Document 2] Republic of Korea Publication Patent No. 10-2014-0135568

[Problems to be Solved by the Invention]

The present invention has been made to solve such a problem of the prior art organic light emitting display device, and an object thereof is to provide a color filter for an organic light emitting display device having improved brightness and color difference between a front surface and an inclined surface, and Organic light emitting display device containing the same.

Another object of the present invention is to provide a color filter for an organic light emitting display device with simple manufacturing process and improved brightness and improved color difference between the front surface and the inclined surface, and an organic light emitting display device including the same. [Means for solving problems]

In order to solve such objects, the present invention provides a color filter, which includes: a transparent substrate, a black array layer on the transparent substrate, a coloring layer formed in each pixel region defined by the black array layer, and A protective layer covering the colored layer; each of the colored layers has a recessed portion, and the recessed portion holds: the depth H of the recessed portion is smaller than the thickness D of the colored layer; the cross section of the recessed portion is circular; The radius of the farthest part of the concave portion of the transparent substrate is a shape having the largest radius among the cross-sectional radii of all the concave portions.

The recessed portion may have a shape in which a radius of a cross section of the recessed portion decreases from a portion farthest from the transparent substrate of the recessed portion toward a direction of the transparent substrate.

The radius R ₂ of the cross section of the farthest part from the transparent substrate of the concave portion may be equal to or less than half the width P of the colored layer.

The radii R ₁ and R ₂ of the cross section of the recessed portion calculated by H / 2 height from the bottom of the recessed portion may both satisfy the condition of 0 <R ₁ / R ₂ <1, and more preferably satisfy 0.3 <R ₁ / R ₂ &lt; 0.8.

The R ₁ and the P may both satisfy the condition of 0.15 ≦ R ₁ /P≦0.4.

The refractive index of the colored layer may be 0.5 to 2.5.

The extinction coefficient of the colored layer may be 0 to 1.8.

The refractive index of the protective layer may be 1.47 to 1.58.

The opposite side of the surface contacting the coloring layer of the protective layer may be flat.

The protective layer may be formed to be buried in the concave portion.

According to another aspect of the present invention, there can be provided an organic light-emitting display device including any one of the foregoing color filters, and an organic light-emitting device including a protective layer disposed on the color filter and driving the organic light-emitting element. And the organic light emitting element panel of the driving element of the organic light emitting element.

The aforementioned organic light emitting element panel may be a three-color organic light emitting element panel using red, green, and blue light sources; an organic light emitting element panel using red, green, blue, and white light sources; and one of the organic light emitting element panels using a white light source. Either. [Inventive effect]

According to the color filter according to the present invention, since the coloring layer of each pixel region has a concave portion, it is possible to improve the brightness and the color difference between the front surface and the inclined surface, thereby improving the display quality of the organic light emitting display device.

In addition, since it is not necessary to form additional layers such as a lens layer, the process is simple, and a color filter for an organic light-emitting display device having high brightness and low color difference between the front surface and the inclined surface can be obtained.

Hereinafter, preferred embodiments of the color filter for an organic light emitting display device and the organic light emitting display device including the same are described in detail with reference to the drawings. In addition, the drawings attached in this specification are merely examples for explaining the present invention, and the present invention is not limited to the drawings. In addition, for convenience of explanation, a part of the constituent elements may be exaggeratedly shown on the drawing, and may be reduced or omitted.

FIG. 1 is a cross-sectional view of a color filter for an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 1, a color filter 100 for an organic light emitting display device according to an embodiment of the present invention has a structure in which a transparent substrate 110, a black array layer 120, a coloring layer 130, and a protective layer 140 are sequentially laminated.

The transparent substrate 110 may be a glass substrate, or in the case where the color filter 100 is used for a flexible display device, it may be a flexible film substrate, particularly a transparent film.

As the transparent film, a film having excellent transparency, mechanical strength, and thermal stability can be used. Specific examples include, for example, polyethylene terephthalate, polyethylene isoterephthalate, Polyester resins such as polyethylene naphthalate, polybutylene terephthalate, etc .; cellulose resins such as diacetyl cellulose, triethyl cellulose, etc .; polycarbonate resins; (Meth) acrylate, polyethyl (meth) acrylate and other acrylic resins; polystyrene, acrylonitrile-styrene copolymers and other styrene resins; polyethylene, polypropylene, ring or Polyolefin resins such as polyolefins and ethylene-propylene copolymers with norbornene structure; vinyl chloride resins; fluorene resins such as nylon and aromatic polyamines; fluorene resins; fluorene ethers碸 resin; 碸 resin; polyether ether ketone resin; vulcanized polyphenylene resin; vinyl alcohol resin; vinylidene chloride resin; vinyl butyral resin; aryl ester resin; Oxymethylene resin; epoxy resin etc. The thermoplastic resin film is formed; the film may also be used by the blend of the thermoplastic resin constituted. In addition, a thermosetting resin or an ultraviolet curing resin made of (meth) acrylic, urethane, acrylic urethane, epoxy, polysiloxane or the like may be used. film.

The thickness of such a transparent film can be appropriately determined. However, in general, from the viewpoints of workability and thinness such as strength and handleability, it is preferably about 1 to 500 μm, and more preferably 1 to 300 μm. ; More preferably 5 to 200 μm.

Such a transparent film may be a substance containing one or more additives as appropriate. The additive may be, for example, an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, an anti-colorant, a flame retardant, an antistatic agent, a pigment, a colorant, and the like. The transparent film may have a structure including various functional layers including a hard coating layer, an anti-reflection layer, and a gas barrier layer on one side or both sides of the film; the functional layer is not limited to these and may be Various functional layers are contained depending on the application.

Moreover, you may apply the surface treatment to a transparent film as needed. Such a surface treatment may be, for example, a chemical treatment such as a plasma treatment, a corona treatment, a base material treatment, a dry treatment, a saponification alkali treatment, or the like.

It may also be a protective film.

The protective film may be a film containing an adhesive layer on at least one side of a film made of a polymer resin, or may be a self-adhesive film such as polypropylene, and may be used to contain a color filter. The purpose of surface protection and engineering improvement of the display device.

The black array layer 120 plays a role of blocking light to prevent color mixing; each pixel region can be defined through the black array layer 120. In order to achieve the purpose of efficient light blocking, the black array layer 120 may be formed of an ochre-colored resin composition.

The coloring layer 130 is a layer currently used for a color display device of a color display device. Generally, red (R), blue (B), and green (G) are patterned and defined by a black array layer 120 formed on a light-shielding layer. Pixel area.

However, the coloring layer does not necessarily contain any one of the patterns of red, blue, and green, or does not have to include only the patterns of red, blue, and green; instead, it may contain only the other as the hue expression of the display device. The pattern of the hue of an arbitrary part among them may be a pattern which further contains other hue such as a white pattern.

The red, blue, and green colored layers 130 can be formed by using a colorant and colored resin compositions that exhibit red, blue, and green colors, respectively. The coloring resin composition may be a thermosetting or light-curing substance; generally, it is a composition containing a colorant, a binder resin, a compounding compound, and a polymerization initiator.

According to an embodiment of the present invention, the coloring resin composition constituting the coloring layer 130 can be considered as the effect of a colorant, and a substance having a refractive index of 0.5 to 2.5 and an erasure coefficient of 0 to 1.8 can be used.

In the color filter 100 for an organic light emitting display device according to an embodiment of the present invention, a recess is formed in the center of the coloring layer 130 formed in each pixel region. This point will be described in detail below.

The protective layer 140 on the colored layer 130 is a layer for protecting the colored layer 130 and flattening the surface of the color filter 100, and may be formed of an organic layer of a thermosetting or photocurable resin composition.

The material of the organic layer may be a polymer material. The aforementioned polymer material includes, for example, polyacrylate, polymethacrylate (for example, PMMA), polyimide, polyamide, polyvinyl alcohol, Polyamic acid, polyolefin (for example, PE, PP), polystyrene, polynorbornene, phenylmaleimide copolymer, Polyazobenzene, polyphenylenephthalamide, polyester (for example, PET, PBT), polyarylate, cinnamate polymer, fragrance One or more selected from the group consisting of a coumarin polymer, a phthalimidine polymer, a chalcone polymer, and an aromatic acetylene polymer.

The thickness of the protective layer 140 may be appropriately determined as needed; generally, strength, handling properties, flatness, and the like are considered, and may be 0.5 to 3.5 μm.

In addition, the refractive index of the protective layer 140 is appropriately determined as needed. In consideration of the refractive index difference between the colored resin composition used in the colored layer 130, the refractive index of the protective layer 140 may be 1.47 to 1.58.

In addition, according to the present invention, there is also provided an organic light emitting display device including a color filter as described above. FIG. 2 is a cross-sectional view of an organic light emitting display device including a color filter according to an embodiment of the present invention.

As shown in FIG. 2, an organic light emitting display device according to an embodiment of the present invention includes a color filter 100 and an organic light emitting element panel 200 as shown in FIG. 1.

The organic light emitting element panel 200 is mounted on the protective layer (FIG. 140: 140) side of the color filter 100. The difference between FIG. 2 and FIG. 1 is that after the color filter 100 is formed, the cross-section of the color filter 100 is shown in the opposite direction.

The organic light emitting element panel 200 is configured by including a plurality of organic light emitting elements (not shown) and a plurality of driving elements (not shown) that drive the organic light emitting elements. The detailed structure of the organic light-emitting element panel 200 is not limited in the present invention; it can be used without limitation: a variety of structures used in the technical field of organic light-emitting display devices. For example, a three-color organic light-emitting element panel using red, green, and blue light-emitting layers may be used; or an organic light-emitting element panel using a white light source in addition to red, green, and blue may also be used. In addition, an organic light emitting element panel for a white organic light emitting display device can also be used.

Next, a structure of a coloring layer of a color filter for an organic light emitting display device according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4.

3 and 4 are cross-sections of a colored layer and a recessed portion formed in a pixel region of a pixel region of a color filter for an organic light emitting display device according to an embodiment of the present invention. FIG. 3 is a longitudinal cross-section in the direction opposite to the vertical direction after the color filter is formed in the same manner as FIG. 2; FIG. 4 is a cross-sectional view corresponding to the longitudinal cross-section in the same direction as FIG. 3.

First, referring to FIG. 3, a conical-like recess having a diameter of 2R ₂ and a height of H is formed in the colored layer. The height H, in other words, is the depth of the recess.

The height H is smaller than the thickness D of the colored layer; the diameter 2R ₂ is the same as or smaller than the width P of the pixel region. The width P of the pixel area, in other words, it is the distance between the centers of the black array on both sides of the pixel that defines the pixel area.

Next, referring to FIG. 4, when the shape of the recessed portion is viewed from the cross section of the lower section, the radius is from the transparent substrate (FIG. 110) where the colored layer is formed from the distance to the plane of thickness D from the colored layer. That is, the shape is similar to a cone formed by a circle decreasing from the plane farthest from the transparent substrate toward the transparent substrate.

Specifically, a play only away from the substrate to the colored layer thickness D of the flat location center O of the circle of radius R _2; half height H is formed in place of the plane P of the center of _a circle of radius R .

Here, R ₁ and R ₂ may be 0 <R ₁ / R ₂ <1; more specifically, it may be 0.3 <R ₁ / R ₂ <0.8.

Furthermore, from the relationship with the width P of the pixel region, R ₁ may be 0.15 ≦ R ₁ /P≦0.4.

On the other hand, in FIGS. 3 and 4, the cross section of the recessed portion shows a shape in which the slope becomes larger toward the substrate; however, the shape of the recessed portion is not limited to this. Specifically, for example, the concave portion may be formed in a conical shape with a constant slope; or may be formed in a shape with a reduced slope.

In addition, the shape of the concave portion is not limited to a shape in which the cross-sectional radius of the concave portion is continuously reduced; for example, the cross-sectional radius may be kept constant in a section, or the cross-sectional radius may be locally increased.

According to the present invention, by forming a color filter having a recessed portion in the coloring layer of each pixel region as described above, it is possible to improve the brightness and the color difference between the front surface and the inclined surface, and to improve the display quality of the organic light emitting display device.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the examples and comparative examples are merely used to explain the present invention, so the scope of the present invention is not limited to this, and it should be obvious to those skilled in the art.

A coloring resin composition having a thickness of 2.5 μm was applied to a surface on one side of a transparent substrate (soda lime glass, thickness 0.7 mm) to prepare a color filter as shown in Table 1 below. FIG. 5a and FIG. 5b are graphs each showing a result of measuring a refractive index and an extinction coefficient of a resin composition used for forming a colored layer.

In the case of Comparative Example 1, the colored layer was formed in a form without recesses; in the cases of Examples 1 to 4, recesses having R ₁ and R ₂如 shown in Table 1 were formed, respectively. The measurement of the shape of the recessed part was measured using a Bruker Contour GT dry gage microscope; FIG. 6 is a photograph showing an example of the measured shape of the recessed part.

An organic light-emitting surface light source device was fabricated in an organic light-emitting display element panel, and the front luminance was measured with a spectroradiometer SR-3AR from Topcon. From the xy coordinates on the CIE xy chromaticity diagram, the hue 値 between the case where the color difference between the front and the inclined plane is 0 ° (front) and the case where the angle is 30 ° (inclined plane) is determined. The 値 obtained by dividing the obtained 値 by 100 is described in Table 1. 【Table 1】

As can be understood from Table 1, in the case of Comparative Example 1 without the recessed portions, the front luminance is 18.8, 219.8, and 89.9 with respect to blue, green, and red, respectively. In Examples 1 to 4, the front luminances of blue, green, and red are respectively 20 or more, 250 or more, and 100 or more, and it can be understood that it is greatly improved.

As can be understood from Table 1, when the color filter of Comparative Example 1 without a concave portion is used, the color differences between the front and the oblique surfaces with respect to blue, green, and red are 0.0301, 0.4100, and 0.0304, respectively. Relatively large chromatic aberrations. In contrast, in Examples 1 to 4 of the present invention, the chromatic aberrations between the front and the inclined surfaces with respect to blue, green, and red are reduced to 0.0300 or less, 0.3500 or less, and 0.0250 or less, respectively.

As long as it is a person skilled in the art, it should be understood that, with reference to the above description, without departing from the essential characteristics of the present invention, there is a possibility that the present invention can be embodied in various modified forms.

Therefore, the explicit embodiment should be considered as: not a limiting point of view but a descriptive point of view; the scope of the present invention is not only the foregoing description, but is shown in the scope of patent application; the scope equivalent to these All differences within should also be construed as being included in the present invention.

110‧‧‧ transparent substrate

120‧‧‧ Black Array

130‧‧‧colored layer

140‧‧‧ protective layer

100‧‧‧ color filter

200‧‧‧ organic light-emitting element panel

FIG. 1 is a cross-sectional view of a color filter for an organic light emitting display device according to an embodiment of the present invention. 2 is a cross-sectional view of an organic light emitting display device including a color filter according to an embodiment of the present invention. 3 is a cross-sectional view showing a coloring layer of one pixel of a color filter for an organic light emitting display device according to an embodiment of the present invention. 4 is a cross-sectional view of a recessed portion formed in a coloring layer of a color filter for an organic light emitting display device according to an embodiment of the present invention. 5a and 5b are graphs showing the results of measuring the refractive index and the extinction coefficient of the resin composition used in the formation of the colored layer in the examples of the present invention, respectively. FIG. 6 is a photograph for measuring the shape of a recessed portion formed in an example of the present invention.

Claims (13)

A color filter includes: a transparent substrate, a black array layer on the transparent substrate, a coloring layer formed in each pixel region defined by the black array layer, and a protective layer covering the coloring layer; Each of the colored layers has a recessed portion; the recessed portion holds: the depth H of the recessed portion is less than the thickness D of the colored layer, the cross-section of the recessed portion is circular, and has the longest distance from the transparent substrate of the recessed portion. The radius of the part is the shape having the largest radius among the cross-sectional radii of the recesses. The color filter according to claim 1, wherein the recessed portion has a shape in which a cross-sectional radius of the recessed portion decreases from a portion farthest from the transparent substrate of the recessed portion toward the transparent substrate. The color filter according to claim 1, wherein the radius R ₂ of the cross section of the farthest portion from the transparent substrate of the concave portion is equal to or less than one and a half of the width P of the colored layer. The color filter according to claim 3, wherein the radius R ₁ of the cross section of the recessed portion and the foregoing R _{2 that are} H / 2 in height from the bottom of the recessed portion satisfy the condition of 0 <R ₁ / R ₂ <1. . The color filter according to claim 4, wherein the radius R ₁ of the cross section of the recessed portion and the foregoing R _{2 that are} H / 2 in height from the bottom of the recessed portion satisfy the condition of 0.3 <R ₁ / R ₂ <0.8 . The color filter according to claim 4, wherein the aforementioned R ₁ and the aforementioned P satisfy a condition of 0.15 ≦ R ₁ /P≦0.4. The color filter according to claim 1, wherein the refractive index of the colored layer is 0.5 to 2.5. The color filter according to claim 1, wherein the extinction coefficient of the colored layer is 0 to 1.8. The color filter according to claim 1, wherein the refractive index of the protective layer is 1.47 to 1.58. The color filter according to claim 1, wherein the opposite side of the surface contacting the colored layer of the protective layer is flat. The color filter according to claim 1, wherein the protective layer is formed so as to be buried in the recess. An organic light-emitting display device, comprising: the color filter according to any one of claims 1 to 11; and an organic light-emitting element disposed on the protective layer side of the color filter and containing the organic light-emitting element, And an organic light emitting element panel for driving the driving element of the organic light emitting element. The organic light-emitting display device according to claim 12, wherein the organic light-emitting element panel is: a three-color organic light-emitting element panel using red, green, and blue light sources; and an organic light-emitting element using red, green, blue, and white light sources An element panel; and an organic light emitting element panel using a white light source.