KR102090929B1 - Organic light emitting diode display device - Google Patents

Abstract

The present invention is a color filter, a red color filter formed of a first colorant comprising CI pigment (Color Index pigment) Red 177 and CI pigment Yellow 139, and a second colorant comprising CI pigment Green 7 and CI pigment Yellow 185. It includes a green color filter formed of, and a blue color filter formed of a third colorant containing CI pigment Blue 15: 6 and Violet Dye, the light transmittance due to the color filter is improved, and the organic light emitting diode display device Provided is a display device that improves color reproduction.

Description

Organic light emitting diode display device {Organic light emitting diode display device}

The present invention relates to an organic light emitting diode display device, and more particularly, to an organic light emitting diode display device having improved brightness and lifetime, and reduced power consumption.

With the development of the information society, the demand for display devices for displaying images is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panel devices (PDPs), Various flat panel display devices, such as organic light emitting diode display devices (OLEDs), have been utilized.

Among these display devices, the organic light emitting diode display device is capable of being lightweight and thin because a backlight used in a liquid crystal display device using a non-light emitting device is not required by using a self-light emitting device.

In addition, the organic light emitting diode display device has a better viewing angle and contrast ratio than a liquid crystal display device, and is advantageous in terms of power consumption. In addition, the organic light emitting diode display device is capable of driving a DC low voltage, has a fast response speed, and is resistant to external shocks due to its internal components being solid, has a wide operating temperature range, and particularly has low cost in terms of manufacturing cost.

Such an organic light emitting diode display device is a member for displaying an image, and includes a substrate, a thin film transistor, a protective film, an organic light emitting diode, a color filter, and a black matrix.

The organic light emitting diode is electrically connected to the thin film transistor on the substrate, and generates light having a luminance corresponding to a signal applied from the thin film transistor and emits it to the outside.

At this time, when red, green, and blue color filters are deposited to implement a white organic light emitting diode display (WOLED), there is an advantage that a large area of the display device, an improved life of the organic light emitting diode, and mass production are possible.

In addition, the light emitted to the outside transmits the red, green, and blue color filters, and the colors of the respective red, green, and blue color filters are combined to display an image.

The red, green, and blue color filters will be described with reference to the drawings.

1 is a plan view schematically showing a color filter of a conventional organic light emitting diode display device.

As shown in FIG. 1, the color filter of the conventional organic light emitting diode display device is composed of a red color filter (R), a green color filter (G), a blue color filter (B), and a black matrix (BM).

At this time, the black matrix (BM) is formed to surround the boundaries of the red, green, and blue color filters (R, G, B).

In addition, the red color filter (R) is formed of a red colorant in which the color index (CI) pigment Red 254 and CI pigment Red 177 are mixed at a ratio of 50:50, and the green color filter (G) is CI pigment Green 58 and CI. Pigment Yellow 138 is formed of a green colorant mixed at a ratio of 80:20, and the blue color filter (B) is formed of a blue colorant mixed with CI pigment Blue 15: 6 and Violet Dye at a ratio of 87:13.

Such a color filter is manufactured according to the wavelength of a light source of a liquid crystal display device (LCD), and is not suitable for an organic light emitting diode display device that adopts a light source having characteristics different from a backlight light source of a liquid crystal display device. That is, by adopting a color filter that does not match the characteristics of the light source used in the organic light emitting diode display device using the organic light emitting diode as a light source, the light transmittance decreases, and the moisture remaining in the color filter and generated by the color filter Due to the out-gassing, the organic light emitting diode loses light emission characteristics, and thus the light emitting area of the pixel decreases, resulting in a decrease in the lifetime of the organic light emitting diode.

The present invention, the organic light emitting diode display including a color filter formed of a colorant to prevent the light transmittance reduction due to the color filter, and the moisture remaining inside the color filter and the deterioration of the light emitting layer due to outgassing occurring in the color filter It is an object to provide a device.

In order to solve the above problems, the present invention, the first substrate; A thin film transistor formed on the first substrate; As a color filter formed on top of the thin film transistor, a red color filter formed of a first colorant including CI pigment (Color Index pigment) Red 177 and CI pigment Yellow 139, and CI pigment Green 7 and CI pigment Yellow 185 A green color filter formed of a second colorant and a blue color filter formed of a third colorant comprising CI pigment Blue 15: 6 and Violet Dye; A first electrode formed on the color filter; An organic emission layer formed on the first electrode; A second electrode formed on the organic emission layer; An organic light emitting diode display device including a second substrate formed on the second electrode is provided.

At this time, the organic light emitting layer emits white light in which yellow-green wavelength band 520-590 nm light and blue wavelength band 430-490 nm light are synthesized.

And, the first colorant is C.I pigment Red 177 and the C.I pigment Yellow 139 are mixed at a ratio of 90:10 in an error range of ± 10%.

And, the second colorant is C.I pigment Green 7 and the C.I pigment Yellow 185 are mixed at a ratio of 72:28 in an error range of ± 10%.

In addition, the third colorant is mixed with the CI pigment Blue 15: 6 and the Violet Dye at a ratio of 50:50 in an error range of ± 10%.

The present invention has an effect of improving the light transmittance due to the color filter and improving the color reproducibility of the organic light emitting diode display device by changing the type and composition ratio of the colorant when manufacturing the color filter of the organic light emitting diode display device.

In addition, there is an effect of preventing the deterioration of the light emitting layer due to moisture remaining in the color filter and outgassing occurring in the color filter, thereby increasing the life of the light emitting layer.

1 is a plan view schematically showing a color filter of a conventional organic light emitting diode display device.
2 is a cross-sectional view schematically showing an organic light emitting diode display device according to an embodiment of the present invention.
3 is a view schematically showing a transmittance of a color filter according to an embodiment of the present invention
4 is a diagram illustrating the color gamut of BT709, the color gamut of the organic light emitting diode display device according to the embodiment of the present invention, and the color gamut of the conventional organic light emitting diode display device on the CIE1976 color coordinate system.
5A is an enlarged view of coordinates in blue of the CIE1976 color coordinate system.
5B is an enlarged view showing coordinates in green of the CIE1976 color coordinate system.
5C is an enlarged view of coordinates in red of the CIE1976 color coordinate system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

2 is a cross-sectional view schematically showing an organic light emitting diode display device according to an embodiment of the present invention, and FIG. 3 is a schematic view showing transmittance of a color filter according to an embodiment of the present invention.

2, the organic light emitting diode display device 10 according to an embodiment of the present invention includes a first substrate 100, a thin film transistor T, an interlayer insulating film 120, a color filter 130, and an overcoat. It includes a layer 140, an organic light emitting diode (E), an encapsulant 180, and a second substrate 190.

In this case, the first substrate 100 and the second substrate 190 are disposed to face each other, and the first substrate 100 is made of a transparent material and a lower emission type organic light emitting diode that emits light to the first substrate 100 It may be a display device. For example, the first substrate 100 may be formed of glass, plastic, or the like.

In addition, a thin film transistor T is formed on the first substrate 100 for each pixel area, which is a minimum unit area for realizing a screen.

Although not illustrated, the thin film transistor (T) layer includes a gate electrode pattern, a gate insulating layer, a semiconductor layer, an interlayer insulating layer, and source and drain electrode patterns.

At this time, the gate electrode pattern includes a gate line, a gate electrode, and a storage lower electrode. Then, a gate insulating layer is formed on the gate electrode pattern, and a semiconductor layer is formed on the gate insulating layer.

At this time, the interlayer insulating film 120 is formed on the thin film transistor (T) layer, specifically, the semiconductor layer, and the data line (not shown), the source electrode (not shown), and the drain electrode (not shown) on the interlayer insulating film 120. Source and drain electrode patterns (not shown) including an upper storage electrode (not shown) are formed. At this time, each of the source electrode and the drain electrode is in contact with the gate electrode (not shown) through a contact hole (not shown) passing through the gate insulating film (not shown) and the interlayer insulating film 120.

Then, a color filter 130 is formed on the interlayer insulating layer 120 on the thin film transistor (T) layer.

In this case, the color filter 130 includes a red color filter 130a, a green color filter 130b, and a blue color filter 130c.

In the conventional organic light emitting diode display device, the red color filter is formed of a colorant in which CI pigment Red 254 and CI pigment Red 177 are mixed in a ratio of 50:50, and the green color filter is CI pigment Green 58 and CI pigment Yellow 138 is 80 It is formed of a colorant mixed at a ratio of: 20, and a blue color filter is formed of a colorant mixed with CI pigment Blue 15: 6 and Violet Dye at a ratio of 87:13.

The conventional red, green, and blue color filters are manufactured according to the light source of the liquid crystal display device.

Therefore, the transmittance of light is reduced due to the color filter that does not match the characteristics of the light source used in the organic light emitting diode display device, and the organic material is caused by moisture remaining inside the color filter and out-gassing from the color filter. A problem occurs in that the light emitting diode loses light emission characteristics and the light emitting area of the pixel decreases.

Accordingly, in the present invention, the type of the pigment used as the colorant employed in each color filter and the blending ratio of the pigment are changed to improve the transmittance of the color filter, the fine dispersion of the pigment, dispersion stabilization and coloring power, and the life of the organic light emitting diode. You can.

For example, the red color filter 130a is formed of a first colorant in which a color index (CI) pigment Red 177 and CI pigment Yellow 139 having good microdispersity and dispersion stability are mixed at a ratio of 90:10, and a green color filter. (130b) CI pigment Green 7 and CI pigment Yellow 185, which also have good microdispersity and dispersion stability, are formed as a second colorant mixed at a ratio of 72:28.

In addition, the blue color filter (130c) is characterized in that it comprises a third colorant mixed in a ratio of 50:50 C.I pigment Blue 15: 6 with good microdispersity and dispersion stability and Violet Dye having a fluorescence characteristic.

The transmittance improvement of the color filter 130 will be described with reference to FIG. 3.

At this time, as a light source, white light was synthesized from light in the yellow-green wavelength band 520-590 nm and light in the blue wavelength band 430-490 nm.

As shown, the transmittance (1300, 1400, 1500) of the color filter 130 according to the embodiment of the present invention is compared to the transmittance (300, 400, 500) of the conventional color filter in each of red, green, and blue. It can be seen that the overall improvement.

In more detail, in an experiment using white light synthesized with light in the yellow-green wavelength band 520 to 590 nm and blue wavelength band 430 to 490 nm as a light source, when transmittance according to the wavelength of red (R) is confirmed, the present invention The transmittance 1300 according to the embodiment of the present invention can be confirmed that the transmittance at the same wavelength is improved due to an improved slope compared to the conventional transmittance 300.

In addition, the transmittance according to the green (G) wavelength, the transmittance 1400 according to an embodiment of the present invention can be confirmed that the transmittance at the same wavelength is improved as the slope is improved compared to the conventional transmittance 400.

In addition, the transmittance according to the blue (B) wavelength also shows that the transmittance at the same wavelength is improved because the transmittance 1500 according to an embodiment of the present invention has an improved slope compared to the conventional transmittance 500.

That is, by employing a color filter in combination with a suitable colorant according to an embodiment of the present invention, it is possible to implement a high brightness organic light emitting diode display device.

In addition, the organic light emitting diode display device according to an embodiment of the present invention has a color coordinate closer to the color coordinate of BT709, which is a standard representing the color reproduction ratio of an HDTV (High Definition Television) for realizing an image. We will look at this in more detail later.

In addition, although not shown, the color filter 130 is surrounded by a black matrix and borders of red, green, and blue color filters 130a, 130b, and 130c inside. The black matrix may be formed of, for example, carbon black or chrome oxide.

Such a black matrix can block external light from entering the organic light emitting diode display device.

Meanwhile, the color filter 130 and the black matrix are completely covered with an overcoat layer 140 excellent in heat resistance, light resistance, and transparency for flattening.

In addition, an organic light emitting diode E including a first electrode 150, an organic light emitting layer 160 and a second electrode 170 is formed on the overcoat layer 140.

At this time, the first electrode 150 is formed of a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) as an anode. The second electrode 170 may have a reflective characteristic as a cathode or may be formed by selecting an opaque metal material.

That is, the second electrode 170 serves as a reflector in the lower emission type organic light emitting diode, for example, a metal material such as aluminum (Al), gallium (Ga), calcium (Ca), and magnesium (Mg). It can be made of either.

In addition, the organic emission layer 160 is positioned between the first electrode 160 and the second electrode 170.

At this time, although not shown, the organic light emitting layer 160 includes a light emitting layer, a first carrier transport layer, and a second carrier transport layer.

The first carrier transport layer is located between the light emitting layer and the first electrode 160, and when the first electrode 160 is used as an anode, a hole injection layer (HIL) and a hole transport layer (hole transporting) layer; HTL) is a stacked structure.

The second carrier transport layer is located between the light emitting layer and the second electrode 170, and when the second electrode 170 is used as a cathode, the second carrier transport layer is an electron transporting layer (ETL). And an electron injection layer (EIL).

The light emitted from the organic light emitting layer 160 to the outside includes light in the yellow-green wavelength band 520 ~ 590nm and light in the blue wavelength band 430 ~ 490nm.

Accordingly, light in the yellow-green wavelength band 520-590 nm and light in the blue wavelength band 430-490 nm are synthesized and white light is emitted to the outside.

Meanwhile, the second substrate 190 is positioned on the organic light emitting diode E, and the sealing process is performed using the second substrate 190.

That is, the sealing material 180 between the first substrate 100 and the second substrate 190 is formed through an ultraviolet curing sealant (UV sealant), a frit sealant, a hybrid encap. It prevents moisture or air from penetrating inside.

At this time, the second substrate 190 may be a lower emission type organic light emitting diode display device made of an opaque material and blocking light. For example, the second substrate 190 may be formed of opaque glass or plastic.

The organic light emitting diode display device according to the exemplary embodiment of the present invention improves transmittance by adjusting the type and ratio of the raw material of the color filter 130, and the color reproduction rate satisfies the standard color coordinate of BT709, which is a color coordinate system.

Here, the color gamut refers to a range of colors that can be expressed by a display device, which measures the color coordinates and luminance of the red, green, and blue states respectively, and based on this, the color reproduction for the three primary colors. Can be obtained.

The color reproduction rate will be described below with reference to the drawings.

4 is a diagram showing the color gamut of BT709, the color gamut of the organic light emitting diode display device according to an embodiment of the present invention, and the color gamut of the conventional organic light emitting diode display device on the CIE1976 color coordinate system, FIGS. 5A and 5B. , FIG. 5C is an enlarged view of coordinates in blue, green, and red of the CIE1976 color coordinate system, respectively.

At this time, as a light source, white light was synthesized from light in the yellow-green wavelength band 520-590 nm and light in the blue wavelength band 430-490 nm.

And, the area of the color gamut of BT709 (standard color coordinate) is indicated by A, the area of the color gamut of the conventional organic light emitting diode display device is indicated by A1, and the color of the organic light emitting diode display device according to the embodiment of the present invention The area of the reproducibility was indicated by A2.

And, when comparing the color gamut area A, A1, A2, the area A2 of the color gamut of the organic light emitting diode display device according to the embodiment of the present invention is BT709 compared to the color gamut A1 of the conventional organic light emitting diode display device It can be seen that it has an area similar to the color gamut A.

In more detail, as shown in FIGS. 5A, 5B, and 5C, the triangular area can be calculated by connecting each of the blue, green, and red color coordinates determined on the color coordinates, and the color gamut is the area above. Can be calculated by comparing the area of the color coordinates with NTSC (national television system committee).

That is, the color reproduction ratio is expressed as the ratio of the relative area when the value of the standard color coordinate area (A) of NTSC is assumed to be 100.

If the standard color coordinate of BT709, a color coordinate system representing the color reproduction rate of HDTV (High Definition Television), is realized as the area of A, CI pigment Red 254 and CI pigment Red 177 are mixed with a red colorant in a ratio of 50:50, and CI pigment A conventional organic light emitting diode display device that adopts a green colorant in which Green 58 and CI pigment Yellow 138 are mixed in a ratio of 80:20, and a blue colorant in which CI pigment Blue 15: 6 and Violet Dye are mixed in a ratio of 87:13, It is implemented as the area of A1 on the color coordinate.

In addition, according to an embodiment of the present invention, CI pigment Red 177 and CI pigment Yellow 139 are mixed in a ratio of 90:10 and a first colorant and CI pigment Green 7 and Yellow 185 are mixed in a ratio of 72:28. The organic light emitting diode display device employing a colorant, and a third colorant in which the CI pigment Blue 15: 6 and Violet Dye are mixed at a ratio of 50:50, is realized in the area of A2 on the color coordinate.

At this time, A1 and A2 are compared and are shown in Tables 1 and 2 with reference to FIGS. 5A, 5B, and 5C, which are enlarged views of CIE1976.

Red green blue u v Y (brightness) u v Y (brightness) u v Y (brightness) A1 0.472 0.528 5.63 0.111 0.573 21.38 0.165 0.157 2.07 A2 0.460 0.530 7.50 0.123 0.560 29.05 0.167 0.147 2.19

Overlap ratio for BT709 Area ratio for BT709 A1 99% 113.9 A2 100% 108.3

Referring to Table 1 and Table 2, it can be seen that the overall color coordinates of red, green, and blue of A1 and A2 are different.

That is, the area ratio of A1 to A is 113.9%, and the area ratio of A2 to A is 108.3%, and it can be seen that the area of A2 is closer to the area of A than A1.

And, the overlapping ratio with BT709 standard color coordinates refers to the amount overlapping the area of A on the color coordinates, the overlapping ratio of A1 to A is 99%, the overlapping ratio of A2 to A is 100%, and A2 is to A1. It can be seen that it overlaps with A more.

Therefore, the area of A2 is 100% overlapped with the area of A while being smaller than the area of A1. As a result, the organic light emitting diode display device of the present invention satisfies the standard color coordinate of BT709, which is a color coordinate system representing the color reproducibility of HDTV (High Definition Television), compared to the conventional organic light emitting diode display device. It can be seen that it has been improved.

In addition, it can be seen that the luminance of red, green, and blue of A2 was also improved compared to A1, and more specifically, the luminance of red increased by 33.2%, green of 35.9%, and blue of 5.8%.

Therefore, the organic light emitting diode display device according to the exemplary embodiment of the present invention can satisfy both high luminance and color reproduction.

As described above, the first colorant in which CI pigment Red 177 and CI pigment Yellow 139 are mixed in a ratio of 90:10, the second colorant in which CI pigment Green 7 and Yellow 185 are mixed in a ratio of 72:28, and CI pigment Blue 15 The organic light emitting diode display device adopting the third colorant in which the: 6 and the Violet Dye are mixed at a ratio of 50:50 can improve the coloring power, the fine dispersion of the pigment, and the dispersion stabilization due to the change of the pigment. In addition, it is possible to prevent residual gas inside the color filter and outgassing from the color filter.

That is, the organic light emitting diode display device according to the embodiment of the present invention according to the characteristics of the pigment due to the change of the pigment improves the coloring power of the pigment, the fine dispersion and dispersion stabilization of the pigment, and the moisture and out of the color filter Gasing can be prevented.

The mixing ratio of the first to third coloring agents described above is a ratio for obtaining an optimum effect, for example, when the first to third coloring agents are mixed with an error range of ± 10%, CI pigment Red 177 and CI pigment Yellow 139 is the first colorant mixed at a ratio of 90:10, CI pigment Green 7 and the second colorant is yellow 185 is mixed at a ratio of 72:28, CI pigment Blue 15: 6, and Violet Dye is 50:50 It may have characteristics similar to the third colorant mixed in the proportion of

Although described above with reference to preferred embodiments of the present invention, those skilled in the art variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You can understand that you can.

100: first substrate 120: protective layer
130: color filter 130a: red color filter
130b: green color filter 130c: blue color filter
140: overcoat layer 150: first electrode
160: organic light emitting layer 170: second electrode
180: sealing material 190: the second substrate

Claims (5)

A first substrate;
A thin film transistor formed on the first substrate;
An interlayer insulating film formed on the thin film transistor;
As a color filter formed on the interlayer insulating film, a red color filter formed of a first colorant including CI pigment (Color Index pigment) Red 177 and CI pigment Yellow 139, and CI pigment Green 7 and CI pigment Yellow 185 A green color filter formed of a second colorant comprising a blue color filter formed of a third colorant comprising CI pigment Blue 15: 6 and Violet Dye;
An overcoat layer formed on the color filter;
A first electrode formed on the overcoat layer;
An organic emission layer formed on the first electrode;
A second electrode formed on the organic emission layer;
An encapsulant formed on the second electrode;
It includes a second substrate formed on top of the encapsulant,
The red, green, and blue color filters are respectively formed in correspondence with the pixel areas displaying red, green, and blue,
The organic light emitting layer is integrally formed on the entire surface of the three pixel areas displaying red, green, and blue.
The first colorant is CI pigment Red 177 and the CI pigment Yellow 139 are mixed in a ratio of 90:10,
The second colorant is the CI pigment Green 7 and the CI pigment Yellow 185 is mixed in a ratio of 72:28,
The third colorant is the CI pigment Blue 15: 6 and the Violet Dye is mixed in a ratio of 50:50,
An organic light emitting diode display device in which a color gamut is displayed in a triangular area having vertices as the first color coordinates (0.460, 0.530), second color coordinates (0.123, 0.560), and third color coordinates (0.167, 0.147).
According to claim 1,
The organic light emitting layer is an organic light emitting diode display device that emits white light in which yellow-green wavelength band 520-590 nm light and blue wavelength band 430-490 nm light are synthesized.
According to claim 1,
The first colorant is an organic light emitting diode display device in which the CI pigment Red 177 and the CI pigment Yellow 139 are mixed at a ratio of 90:10 in an error range of ± 10%.
According to claim 1,
The second colorant is an organic light emitting diode display device in which the CI pigment Green 7 and the CI pigment Yellow 185 are mixed at a ratio of 72:28 in an error range of ± 10%.
According to claim 1,
The third colorant is an organic light emitting diode display device in which the CI pigment Blue 15: 6 and the Violet Dye are mixed at a ratio of 50:50 in an error range of ± 10%.

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