KR100739295B1 - Red color filter and organic light-emitting display device - Google Patents

Abstract

The present invention relates to a red color filter, and an organic light emitting display device using the same, and more particularly, to a red color filter and an organic light emitting display using the same. Relates to a device. The red color filter according to the present invention is a color conversion member for converting the light of the blue wavelength emitted from the light emitting sources emitting light of the blue and red wavelengths to the light of the green wavelength and the small red wavelength, and the light of the small red wavelength And it characterized in that it comprises a green blocking member for transmitting the light of the red wavelength emitted from the light emitting source.

Color filter, flat panel display, color conversion member, green blocking member, light emitting source

Description

Red color filter and organic light-emitting display device using the same

1 is a schematic diagram of a red color filter according to the prior art.

Figure 2 is a schematic diagram showing an embodiment of a red color filter according to the present invention.

3 is a graph showing light emission spectra of a color conversion member of a red color filter according to the embodiment of FIG. 2;

4 is a graph showing the transmittance of the green blocking member of the red color filter according to the embodiment of FIG.

5 is a cross-sectional view illustrating an embodiment of an organic light emitting display device to which a red color filter according to the present invention is applied.

6 is a graph showing an embodiment of a light emission spectrum of mixed light applied to the present invention.

7 is a cross-sectional view showing another embodiment of an organic light emitting display device to which a red color filter according to the present invention is applied.

8 is a graph showing emission spectra of an organic light emitting display device according to an exemplary embodiment of the present invention in which a red color filter is formed in a blue and green light emitting layers.

FIG. 9 is a graph showing emission spectra of organic light emitting display market values in which a conventional red color filter is formed on blue and green light emitting layers. FIG.

10 is a color coordinate diagram illustrating an improvement in color coordinates of an organic light emitting display device according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100, 200: substrate 110, 210: first electrode

120, 220: organic light emitting layer 130, 230: second electrode

140, 240: color filter 141, 241: color conversion member

143, 243: green blocking member

The present invention relates to a red color filter and a flat panel display device using the same. More particularly, the present invention relates to a red color filter and an organic light emitting display device using the same, which realize red light with improved luminous efficiency and color coordinates from mixed light of blue and red light. .

As a method of implementing full color in a flat panel display device, especially an organic light emitting device, three-color light emission, color filter, and color conversion are known. The tricolor emission method is a method of emitting light of three colors of R, G, and B respectively, and the color filter method is a method of dividing light from a white light source into R, G, and B through color filters. The conversion method is a method of dividing light emitted from a blue light source into R, G, and B using a color conversion material (phosphor) instead of a color filter.

The tri-color emission method has a problem in that the lifetime of one color determines the overall lifetime, and the color filter method has a problem in that white light is absorbed by the color filter and the amount of light falls, and the color conversion method is excited by the color conversion material by blue light. There is a problem that is lowered, has been studied how to implement a full color, longer life, excellent luminous efficiency and color coordinates. In particular, many improvements have been made to the color filter and color conversion method, which is composed of a shadow maskless process and can achieve high definition.

For example, US Patent No. 6515418 discloses an organic light emitting device using a light emitting layer for emitting white light and a color filter formed using photolithography. However, such a color filter has a problem in that luminous efficiency should be reduced to improve color purity of each of R, G, and B.

1 is a schematic diagram of a color light emitting device including a conventional red color filter disclosed in Korean Patent Laid-Open No. 10-2004-00058293, wherein the color light emitting device is composed of white light (R1, G, B) from blue light (B). And a color light emitting device including a red color filter which converts green light (G) into red light (R2) and transmits only red light (R1 + R2), but uses white light as a light emitting source, and still has color coordinates and luminous efficiency. There is a bad problem.

The present invention has been made to solve the above problems, the present invention provides a red color filter including a color conversion member and a green blocking member using a mixed light of blue and red light as a light emitting source and an organic light emitting display device using the same. It aims to do it.

The red color filter according to the present invention is a color conversion member for converting the light of the blue wavelength emitted from the light emitting sources emitting blue and red wavelengths to the light of the green and red wavelengths, and the green to block the light of the green wavelength It characterized in that it comprises a blocking member.

In addition, the organic light emitting display device including a red color filter according to the present invention includes a substrate, a first electrode formed on one surface of the substrate, an organic light emitting layer for emitting mixed light of blue and red wavelengths formed on the first electrode, And a second color electrode formed in the organic light emitting layer, and a red color filter formed in a red pixel region of the other surface of the substrate, wherein the red color filter is configured to emit light of blue wavelength emitted from the organic light emitting layer in a green wavelength and a red wavelength. It characterized in that it comprises a color conversion member for converting the light of the, and a green blocking member for blocking the light of the green wavelength.

In addition, the organic light emitting display device including a red color filter according to the present invention includes a substrate, a first electrode formed on one surface of the substrate, an organic light emitting layer for emitting mixed light of blue and red wavelengths formed on the first electrode, And a second color electrode formed in the organic light emitting layer, and a red color filter formed in a red pixel region outside the second electrode, wherein the red color filter emits light of blue wavelength emitted from the organic light emitting layer. And a color conversion member for converting the light having a red wavelength, and a green blocking member for blocking the light of the green wavelength.

Hereinafter, a preferred embodiment of a red color filter according to the present invention will be described in detail with reference to FIG. 2. 2 is a block diagram of a red color filter according to an embodiment of the present invention. According to this, the red color filter includes a color conversion member and a green blocking member, and the light emitting source used is a mixture of blue light and red light, so that the color coordinates are white light having X = 0.20 to 0.50 and Y = 0.20 to 0.43. desirable.

The color conversion material of the color conversion member is composed of a material for converting blue light emitted from the light emitting source into light of green wavelength and light of small red wavelength, and a graph showing the emission spectrum of the light transmitted through the color conversion member is shown in FIG. 3. Is shown. According to this, the wavelength of light is 450 nm to 630 nm and includes a green region of 450 nm to 610 nm and a red region of 610 to 630 nm.

At this time, the green color conversion material may be composed of only fluorescent dyes and binder resin or fluorescent dyes. For example, 3- (2'-Vanthiathiazolyl) -7-diethylaminocoumarin (hereafter coumarin 6), 3- (2'-benzimidazolyl) -7-N, N-diethylaminocoumarin (hereafter , Coumarin 7), Alq3 or fluorescent inorganic and organic pigments can be used.

The green blocking member is formed in contact with the color converting member, and as shown in FIG. 4, the green blocking member is made of a material obtained by dissolving or dispersing a red pigment or a pigment thereof in a binder resin having a transmittance of 50% or more between 600 nm and 780 nm. . As the red pigment, commonly used perylene pigments, lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, isoindolin pigments, and mixtures thereof may be used.

On the other hand, the color filter 140 is configured such that the color conversion member and the green blocking member are two different layers as shown in FIG. 2, the color conversion member and the green blocking member are mixed with each other to form a single mixed layer. You may.

The light passing through the above red color filter is converted into green light and red light R2 by the color converting member, and the green light G is removed by the green blocking member so that only the red light R2 is original. When combined with the red light R1 emitted from the light source, the light emitter has high red light emission efficiency and color coordinates.

Hereinafter, the flat panel display using the red color filter will be described in detail by applying the above-described red color filter to the organic light emitting display device which is one of the flat panel display devices. However, those skilled in the art will recognize that such a red color filter may be applied to various display devices such as a liquid crystal display device in addition to the organic light emitting display device.

5 is a cross-sectional view of an organic light emitting display device to which a red color filter according to the present invention is applied. Accordingly, the organic light emitting display device includes a substrate, a first electrode 110, an organic light emitting layer 120, a second electrode 130, and a red color filter 141.

The substrate 110 may be a glass or transparent plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness.

Since the first electrode 110 and the second electrode 120 can be used in the present invention without limiting the conventional electrode, a detailed description thereof will be omitted. However, when the electrode is an anode electrode, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), zinc oxide (ZnO) may be used as a member, and in the case of the cathode electrode, lithium, magnesium, Aluminum, aluminum-lithium, calcium, magnesium-indium, magnesium-silver and the like can be used.

The organic light emitting layer 120 is configured to emit a mixture of blue and red light, in the present specification, the organic light emitting layer essentially comprises a light emitting layer, hole injection layer, hole transport layer, light emitting layer, hole blocking layer, electron injection layer, electron It is used as a concept to selectively include a transport layer. Matters related to the members, functions, and the like for each layer are well known to those skilled in the art, and thus detailed description thereof will be omitted.

The organic light emitting layer for emitting the mixed light may be configured in various ways. For example, the blue and red light emitting layers may be formed, or the light emitting layers may be divided into a plurality of light emitting materials having blue and red wavelengths. At this time, those skilled in the art will recognize that a dopant may be added to each light emitting material.

Materials for blue light emission include Firpic, (3,5-diCF3ppy) Irpic, (3-CNppy) Irpic, (3,5-diCNppy) Irpic, SDI-BD-785, SDI-BD-735, SBD02 One selected from the group consisting of can be used, the material for the red light emitting material (btp) 2Ir (acac), pq3Ir, pq2Ir (acac), DCM2, DCJTB, etc. Can be used.

6 shows an embodiment of the emission spectrum of the mixed light. Accordingly, it can be seen that the light emission intensity is high even in the red region and the blue region. Such adjustment of the light emission intensity may be efficiently controlled by mixing the above-described members in an appropriate ratio, and adjusting the thickness of the light emitting layer, the ratio of the host and the dopant of the light emitting layer. At this time, the mixed light is preferably white light having a color coordinate of X = 0.20 to 0.50 and Y = 0.20 to 0.43.

The red color filter 141 is formed in the red pixel area of the other surface of the substrate, and the blue color filter 147 and the green color filter 145 may be provided on the color filter substrate, which is formed together. It may also be coated individually.

The red color filter 141 includes a color conversion member 142 and a green blocking member 143. The color conversion member 142 is composed of a material for converting blue light emitted from the light emitting source into light of a green wavelength and light of a small red wavelength, and the wavelength of the converted light is 450 nm to 630 nm as described above. And red regions in the low range of 610-630 nm.

The color conversion member 142 may be composed of only fluorescent dyes and binder resins or fluorescent dyes. For example, 3- (2'-Vanthiathiazolyl) -7-diethylaminocoumarin (hereafter coumarin 6), 3- (2'-benzimidazolyl) -7-N, N-diethylaminocoumarin (hereafter , Coumarin 7) or fluorescent inorganic and organic pigments may be used.

The color conversion member 142 may be formed by forming a color conversion resin composition on a substrate to a desired thickness. In this case, as the film forming method used, a spin coating method, a printing method, a coating method, or the like may be used, and a transfer method may also be used. It is preferable that the film-forming thickness shall be 1-30 micrometers. This is because the color conversion is not smooth in the case of 1 μm or less, and in lithography in the case of 30 μm or more.

The green blocking member 143 is composed of a red pigment or a material obtained by dissolving or dispersing a pigment thereof in a binder resin in a transmittance of 50% or more between 600 nm and 780 nm. Lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, isoindolin pigments, and mixtures thereof may be used.

The green blocking member 143 may be formed by forming a film on the color conversion member 142 to have a desired thickness. In this case, spin coating, roll coating, bar coating, casting, and transfer methods may be used as the film forming method. Lithography and screen printing may be used for patterning after film formation. At this time, the green blocking member may be formed to 0.5 to 5㎛. This is because it is difficult to control the transmittance below 0.5 μm, and there is a difficulty in lithography above 5 μm. Preferably it is 1-2 micrometers.

Meanwhile, for convenience of description, in the present embodiment, additional components constituting the organic light emitting display device, for example, functions of the buffer layer 150, the black matrix 160, the second substrate 170, and the like are known, Since the modification may be carried out, a detailed description thereof will be omitted, but those skilled in the art will be able to easily recognize the same.

Unlike the present embodiment, as described above, the red color filter may be formed of one layer in which the green color conversion material and the green blocking material are mixed. At this time, it is preferable that the film-forming thickness of a mixed layer shall be 1-30 micrometers. This is because the color conversion is not smooth in the case of 1 μm or less, and in lithography in the case of 30 μm or more.

7 is a cross-sectional view illustrating another embodiment of an organic light emitting display device to which a red color filter according to the present invention is applied. Accordingly, the organic light emitting display device includes a substrate 200, a first electrode 210, an organic light emitting layer 220, a second electrode 230, and a red color filter 241.

In the present embodiment, the color filter 240 is not formed on the substrate 200 side, but is formed on the second electrode 230 side. This indicates that the red color filter according to the present invention can be applied to both the bottom emission and the top emission, and also does not exclude the application to the double emission structure.

In addition, in the present embodiment, the organic light emitting layer 220 is composed of two light emitting layers of blue and red, and the light having a desired color coordinate can be obtained by adjusting the thickness of each light emitting layer, the ratio of the host and the dopant of the light emitting layer.

In the present embodiment, descriptions of various holes and electron transport related layers selectively included in the substrate 200, the first electrode 210, the second electrode 230, and the organic light emitting layer 220 are omitted on the page. do. In addition, as described above, the color conversion member 242 and the green blocking member 243 constituting the red color filter 241 may be composed of individual layers or may be mixed to form a single layer. As described above.

Hereinafter, the manufacturing method according to an embodiment of the red color filter according to the present invention constituting the color conversion member and the green blocking member as an independent layer increases the feasibility of the present invention, and thus the red color according to the present invention. The effect of the filter is compared with a conventional red color filter coated with only a red color filter pigment without a color conversion member.

First, a color conversion member dissolved in a mixture of 25 mg of coumarin 6 (25 mg) and 2.5 g of polyvinylbutyral (PVB) in 7.5 g of ethyl cellusolve is coated within 10 μm and then dried at 80 ° C. for 30 minutes. do. After coating the green blocking member on the dried green color conversion material, the red color filter according to the present invention may be prepared by drying at 80 ° C. for 2 minutes.

On the other hand, Figure 8 is a graph showing the emission spectrum of the light transmitted through the red color filter according to the present invention by emitting light from the blue and red light source, Figure 9 is a red color according to a conventional manufacturing method from the same light source as in FIG. It is a graph showing the emission spectrum of the light passing through the filter. When comparing FIG. 9 with FIG. 8, it can be seen that the red color filter according to the present invention has a higher intensity of light with a higher red wavelength than transmits light of blue wavelength more than a conventional red color filter.

On the other hand, Table 1 compares the color coordinates and luminous efficiency of the red color filters manufactured according to the above-described manufacturing method and the conventional red color filter when the mixed light source of blue and red having color coordinates of (0.34, 0.38) is used. have.

Light source Example Comparative example Color coordinates (0.34,0.38) (0.67, 0.32) (0.65, 0.31) Luminous Efficiency (cd / A) 18 5.5 5.2

Accordingly, it can be seen that the color coordinates of the red color filter according to the present invention are (0.67, 0.32), so that the red light emission can be improved compared to the color coordinates (0.65, 0.31) of the general red color filter. In addition, it can be seen that the luminous efficiency is also improved to 5.5 cd / A compared with the case of applying a 5.2 cd / A ordinary red color filter.

10 is a graph showing the red color coordinates after the light emitted from the light source of the color coordinates of Table 1 passes through the red color filter, and it can be seen that the color coordinates of the red color filters are improved compared with the conventional red color filter. have.

On the other hand, Table 2 shows the results of experiments of the luminous efficiency and color coordinates of the red light transmitted through the red color filter when the mixed light of blue and red is different from the case of Table 1 for reference.

Light source Red light after transmission of red color filter Luminous Efficiency (cd / A) 3.13 1.83 Color coordinates (0.407. 0.239) (0.685, 0.314)

Although the present invention has been described primarily with reference to the above embodiments, those skilled in the art will recognize that many other possible modifications and variations can be made without departing from the spirit and scope of the invention. For example, a change in the material constituting the organic light emitting layer, a change in the material and the thickness of the color conversion layer or the green blocking member, etc. may be easily changed by those skilled in the art.

The red color filter and the organic light emitting display device using the same according to the present invention have the effect of improving the luminous efficiency and color coordinates of the red light when the blue and red mixed light is implemented in red.

The scope of the above-described invention is defined in the following claims, and is not bound by the description in the text of the specification, all modifications and variations belonging to the equivalent scope of the claims will fall within the scope of the present invention.

Claims (22)

And a color converting member for converting the blue wavelength light emitted from the light emitting sources emitting the blue and red wavelengths into the green wavelength and the red wavelength light, and a green blocking member for blocking the green wavelength light. The red color filter of the conversion member and the green blocking member each form an independent layer. And a color converting member for converting the blue wavelength light emitted from the light emitting sources emitting the blue and red wavelengths into the green wavelength and the red wavelength light, and a green blocking member for blocking the green wavelength light. The conversion member and the green blocking member are mixed with each other to form a red color filter. The method according to claim 1 or 2, The color conversion member is a coumarin series red color filter including coumarin 6 or coumarin 7. The method according to claim 1 or 2, The color conversion member is a red color filter is an inorganic or organic pigment. The method according to claim 1 or 2, Transmittance of the green blocking member is a red color filter having a transmittance of 50% or more between 600nm to 780nm. delete Board, A first electrode formed on one surface of the substrate, An organic light emitting layer for emitting mixed light of blue and red wavelengths formed on the first electrode; A second electrode formed on the organic light emitting layer, It comprises a red color filter formed in the red pixel region of the other surface of the substrate, The red color filter includes a color conversion member for converting light of blue wavelength emitted from the organic light emitting layer into light of green wavelength and red wavelength, and a green blocking member for blocking light of the green wavelength. The method of claim 7, wherein Wherein the mixed light has a color coordinate of X = 0.20 to 0.50 and Y = 0.20 to 0.43. The method of claim 7, wherein The blue light emitting material of the organic light emitting layer is Firpic, (3,5-diCF3ppy) Irpic, (3-CNppy) Irpic, (3,5-diCNppy) Irpic, SDI-BD-785, SDI-BD-735, and SBD02. An organic light emitting display device comprising a member selected from the group consisting of. The method of claim 7, wherein The red light emitting material of the organic light emitting layer includes a member selected from the group consisting of (btp) 2Ir (acac), pq3Ir, pq2Ir (acac), DCM2, and DCJTB. The method of claim 7, wherein And the color conversion member and the green blocking member each form an independent layer. The method of claim 11, The first layer of the color conversion member is 1 to 30㎛, the second layer of the green blocking member is 0.5 to 5㎛ organic light emitting display device. The method of claim 7, wherein And the color conversion member and the green blocking member are mixed with each other to form a mixed layer. The method of claim 13, The thickness of the mixed layer is an organic light emitting display device 1 to 10㎛. Board, A first electrode formed on one surface of the substrate, An organic light emitting layer for emitting mixed light of blue and red wavelengths formed on the first electrode; A second electrode formed on the organic light emitting layer, and And a red color filter formed in the red pixel area outside the second electrode. The red color filter includes a color conversion member for converting light of blue wavelength emitted from the organic light emitting layer into light of green wavelength and red wavelength, and a green blocking member for blocking light of the green wavelength. The method of claim 15, Wherein the mixed light has a color coordinate of X = 0.20 to 0.50 and Y = 0.20 to 0.43. The method of claim 15, The blue light emitting material of the organic light emitting layer is Firpic, (3,5-diCF3ppy) Irpic, (3-CNppy) Irpic, (3,5-diCNppy) Irpic, SDI-BD-785, SDI-BD-735, and SBD02. An organic light emitting display device comprising a member selected from the group consisting of. The method of claim 15, The red light emitting material of the organic light emitting layer includes a member selected from the group consisting of (btp) 2Ir (acac), pq3Ir, pq2Ir (acac), DCM2, and DCJTB. The method of claim 15, And the color conversion member and the green blocking member each form an independent layer. The method of claim 19, The first layer of the color conversion member is 1 to 10㎛, the second layer of the green blocking member is 0.5 to 5㎛ organic light emitting display device. The method of claim 20, And the color conversion member and the green blocking member are mixed with each other to form a mixed layer. The method of claim 21, The thickness of the mixed layer is an organic light emitting display device 1 to 10㎛.

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