KR20230041264A - Organic light emitting diode optic compensation film for improvement of optical properties - Google Patents

Abstract

The present invention relates to an optical compensation film for improving optical characteristics of an organic light-emitting device. The optical compensation film includes: a positive C-plate; a negative biaxial retardation film laminated on the C-plate and having reverse wavelength dispersion; and a polarizer laminated on the negative biaxial retardation film.

Description

Optical compensation film for improving optical properties of organic light emitting devices

The present invention relates to an optical compensation film for improving optical characteristics of an organic light emitting device.

Unlike LCDs, Organic Light Emitting Diodes (OLEDs) do not require a backlight, so they are lightweight, can be thinned, have excellent color reproducibility, and have a fast response speed. applied and used.

However, when external light such as sunlight is introduced into the organic light emitting device from the outside, the external light is reflected by the reflector including the metal electrode of the organic light emitting device and leaks out of the organic light emitting device. There is a problem in that display quality is deteriorated due to deterioration of visibility and contrast ratio of the organic light emitting device.

In order to solve this problem, conventionally, a circular polarizing plate composed of a linear polarizing plate and a retardation plate is used to prevent reflected external light from leaking out of the organic light emitting device.

However, the circular polarizing plate according to the prior art could solve the above-described problem caused by external light when viewed from the front, but has a strong viewing angle dependence, so that the performance of preventing the reflected external light from leaking to the outside at the side viewing angle, the so-called There was a problem that the visibility of the organic light emitting device was reduced due to the antireflection performance.

KR 10-1106294 B1

An object of the present invention is to solve the above problems, and a negative biaxial retardation film and a positive C film to prevent external light reflection of an organic light emitting device and at the same time prevent problems caused by external light reflection even at a side viewing angle. - It is to provide an optical compensation film for improving the optical properties of an organic light emitting device including a plate.

The object of the present invention is not limited to the object mentioned above, and other objects not mentioned will be clearly understood from the description below.

In order to achieve the above object, an optical compensation film for improving optical characteristics of an organic light emitting device according to an aspect of the present invention includes a positive C-plate; a negative biaxial retardation film laminated on the C-plate and having reverse wavelength dispersion; and a polarizer stacked on the negative biaxial retardation film.

The optical compensation film for improving the optical characteristics of an organic light emitting device according to an embodiment of the present invention according to the above configuration solves the problem caused by external light being reflected by the reflector of the organic light emitting device when viewed from the front, and at the same time, the side surface Even at a viewing angle of , there is an effect of preventing problems caused by reflection of external light.

1 is a cross-sectional view showing a cross section of an organic light emitting device according to the prior art.
2 is a cross-sectional view showing a cross section of an optical compensation film for improving optical characteristics of an organic light emitting device according to an embodiment of the present invention.
3 is a cross-sectional view showing a state in which an optical compensation film for improving optical characteristics of an organic light emitting device according to an embodiment of the present invention is laminated on an organic light emitting device according to the prior art.
4 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 1;
5 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 2;
6 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 3;
7 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 4;
8 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 5;
9 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 6;
10 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 7;
11 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Example 8;
12 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 1;
13 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 2;
14 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 3;
15 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 4;
16 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 5;
17 is a view showing average measurement results of reflectance according to Test Example 1 of the optical compensation film according to Comparative Example 6;
18 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 1 on a Poincaré sphere.
19 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 2 on a Poincaré sphere.
20 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 3 on a Poincaré sphere.
21 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 4 on a Poincaré sphere.
22 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 5 on a Poincaré sphere.
23 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 6 on a Poincaré sphere.
24 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 7 on a Poincaré sphere.
25 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Example 8 on a Poincaré sphere.
26 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 1 on a Poincaré sphere.
27 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 2 on a Poincaré sphere.
28 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 3 on a Poincaré sphere.
29 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 4 on a Poincaré sphere.
30 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 5 on a Poincaré sphere.
31 is a view showing the polarization state measurement results according to Test Example 2 of the optical compensation film according to Comparative Example 6 on a Poincaré sphere.
32 is a diagram for explaining a deviation angle in the measurement result according to Test Example 2;

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be embodied in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention. Meanwhile, terms used in this specification are for describing embodiments, and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase.

Hereinafter, an optical compensation film for improving optical characteristics of an organic light emitting device according to embodiments of the present invention will be described with reference to the drawings.

Meanwhile, referring to FIGS. 1 to 3 , an optical compensation film 20 for improving optical characteristics of an organic light emitting device according to an embodiment of the present invention may be laminated on the organic light emitting device 10 .

At this time, the organic light emitting device 10 may have a structure according to the prior art, and may include, for example, an anode 11, an organic light emitting layer 12, and a cathode 13.

The anode 11 may be an electrode into which holes are injected and may be made of a conductive material having a high work function.

The cathode 13 may be an electrode into which electrons are injected and may be made of a conductive material having a low work function.

The organic light emitting layer 12 may include an organic material capable of emitting light when a voltage is applied to the anode 11 and the cathode 13 .

At this time, if at least one of the anode 11 and the cathode 13 is a metal electrode, the metal electrode corresponding to the metal electrode may act as a reflector to reflect external light entering the organic light emitting device 10 .

In addition, the organic light emitting layer 12 may include an inorganic material capable of reflecting light. When the organic light emitting layer 12 includes an inorganic material capable of reflecting light, the organic light emitting layer 12 also acts as a reflector to emit organic light. External light entering the inside of the device 10 may be reflected.

That is, as at least one of the anode 11 , the organic light emitting layer 12 , and the cathode 13 functions as a reflector, external light entering the inside is reflected, and thus brightness and visibility of the organic light emitting device 10 may be reduced.

The optical compensation film 20 for improving the optical properties of the organic light emitting device according to an embodiment of the present invention may be laminated relatively above the cathode 13 of the organic light emitting device 10, and preferably the cathode (13) may be laminated.

The optical compensation film 20 for improving optical characteristics of an organic light emitting device according to an embodiment of the present invention may include a C-plate 100, a retardation film 200, and a polarizer 300.

The C-plate 100 may be a positive uniaxial retardation optical element in which n _x1 = n _y1 < n _z1 .

n _x1 is the refractive index of the C-plate 100 in the x-axis direction, n _y1 is the refractive index of the C-plate 100 in the y-axis direction, n _z1 is the C-plate 100 in the z-axis direction It can be a refractive index.

The C-plate 100 may be a positive uniaxial retardation film in which n _x1 = n _y1 < n _z1 .

That is, the C-plate 100 may be a positive C-plate.

The C-plate 100 may be stacked with a lower surface attached to the organic light emitting device 10, and preferably, the C-plate 100 may be stacked on the cathode 13.

The C-plate 100 may mean a film in which liquid crystals are aligned, and a commercially available one may be used, and one manufactured by a conventional manufacturing method obvious to those skilled in the art may be used.

The C-plate 100 may be manufactured using a liquid crystal composition, may be manufactured by solidifying the liquid crystal composition, or may be manufactured by curing the liquid crystal composition.

On the other hand, when a film composed of the retardation film 200 and the polarizer 300 is attached to the organic light emitting device 10, reflection of external light in the front direction of the organic light emitting device 10 can be prevented, but the external light at the side viewing angle. There is a problem in that the antireflection performance is somewhat lowered, and the visibility of the organic light emitting device 10 is lowered, and viewing angle characteristics are deteriorated.

The C-plate 100 is for improving side viewing angle characteristics of the organic light emitting device 10, and the C-plate 100 is an optical compensation film 20 including a retardation film 200 and a polarizer 300. When stacked on the organic light emitting device 10 , degradation in antireflection performance of external light may not be relatively reduced even at a side viewing angle of the organic light emitting device 10 .

The thickness of the C-plate 100 is not limited as long as it is the thickness of the commonly used C-plate 100, and may be adjusted according to the purpose of the present invention, but may be preferably 2 to 5 μm.

When the thickness of the C-plate 100 is 2 μm to 5 μm, the antireflection performance of external light at the side viewing angle of the optical compensation film 20 can be improved more effectively.

The retardation film 200 may be a negative biaxial retardation film.

More specifically, the retardation film 200 may be a negative biaxial retardation film of n _x2 > n _y2 > n _z2 .

n _x2 is the refractive index of the retardation film 200 in the x-axis direction, n _y2 is the refractive index of the retardation film 200 in the y-axis direction, and n _z2 is the refractive index of the retardation film 200 in the z-axis direction.

The retardation film 200 may be a negative biaxial retardation film having reverse wavelength dispersion characteristics in which the retardation increases as the wavelength of incident light increases.

In this case, the wavelength may correspond to the visible light region, and may be, for example, 380 to 780 nm.

If the retardation film 200 is a negative biaxial retardation film having reverse wavelength dispersion characteristics, the optical compensation film 20 according to an embodiment of the present invention may have excellent external light reflection prevention performance not only from the front side but also from the side viewing angle. .

The in-plane retardation value and the retardation value in the thickness direction of the retardation film 200 may be expressed by Equations 1 and 2 below, respectively.

[Equation 1]

R _in = (n _x2 -n _y2 ) × d ₁

Here, R _in may be the in-plane retardation value of the retardation film 200, n _x2 may be the refractive index of the retardation film 200 in the x-axis direction, and n _y2 may be the refractive index of the retardation film 200 in the y-axis direction and d ₁ may be the thickness of the retardation film 200 .

[Equation 2]

R _th ={((n _x2 +n _y2 )/2)-n _z2 } × d ₁

Here, R _th may be a thickness direction retardation value of the retardation film 200, n _x2 may be a refractive index of the retardation film 200 in the x-axis direction, n _y2 is a refractive index of the retardation film 200 in the y-axis direction , n _z2 may be the refractive index of the retardation film 200 in the z-axis direction, and d ₁ may be the thickness of the retardation film 200 .

The in-plane retardation value of the retardation film 200 may be 5 to 15 μm, and the retardation value in the thickness direction may be greater than 0 and less than 20 μm.

When the in-plane retardation value and the retardation value in the thickness direction of the retardation film 200 each satisfy the above ranges, the optical compensation film 20 can more effectively improve the problem of external light reflection of the organic light emitting device 10, and The degradation of the anti-reflection performance in can be prevented more effectively.

The refractive index ratio N _z of the retardation film 200 is It may be expressed as in Equation 3 below, and the refractive index ratio of the retardation film 200 may be 1 to 1.5.

[Equation 3]

N _z =(n _x2 -n _z2 )/(n _x2 -n _y2 )

Here, N _z is the ratio of the retardation value in the thickness direction of the retardation film 200 to the in-plane retardation value of the retardation film 200, n _x2 may be the refractive index of the retardation film 200 in the x-axis direction, n _y2 may be the refractive index of the retardation film 200 in the y-axis direction, and n _z2 may be the refractive index of the retardation film 200 in the z-axis direction.

If the ratio of the retardation value in the thickness direction of the retardation film 200 to the in-plane retardation value of the retardation film 200 is less than 1, the retardation is small and the light transmitted through the retardation film 200 does not reach the circularly polarized light, so that the optical compensation film 20 ) may not smoothly prevent external light reflection of the organic light emitting device 10, and if it exceeds 1.5, diffuse reflection occurs when light passes through the retardation film 200, and the optical compensation film 20 (10) may not effectively prevent reflection of external light.

The thickness of the retardation film 200 is not limited as long as it is the thickness of the commonly used retardation film 200, and may be adjusted according to the purpose of the present invention, but may be preferably 30 to 500 μm.

When the thickness of the retardation film 200 is 30 to 500 μm, the optical compensation film 20 can effectively prevent reflection of external light from the organic light emitting device 10 .

Meanwhile, the C-plate 100 may have a phase difference value Δnd expressed by Equation 4 below. At this time, the phase difference value Δnd may be 30 to 191 nm, 30 to 100 nm, and 45 to 115 nm, 65 to 137 nm, 84 to 155 nm, 104 to 175 nm, and 122 to 191 nm.

[Equation 4]

Δnd=(n _e -n _o ) × d ₂

Here, Δnd may be a phase difference value of the C-plate 100, n _e may be an extraordinary refractive index of the C-plate 100, and n _o may be a normal refractive index of the C-plate 100 ( ordinary refractive index), and d ₂ may be the thickness of the C-plate 100.

If the retardation value (Δnd) of the C-plate 100 is out of the value corresponding to the above range, the light passing through the C-plate 100 has an elliptically polarized state instead of circularly polarized light, so that the optical compensation film 20 In addition to not improving the problem caused by external light reflection of the organic light emitting device 10, the external light reflection prevention performance at the side viewing angle may be deteriorated, and if the value corresponds to the above range, the optical compensation film 20 may Reflection of external light in the front direction of the light emitting device 10 may be prevented, and reflection of external light may be effectively prevented at a side viewing angle.

The retardation value (Δnd) of the C-plate 100 and the refractive index ratio (N _z ) of the retardation film 200 may be proportional to each other. In order to prevent reflection more effectively, the retardation value (Δnd) of the C-plate 100 may increase by 150 to 220 nm with respect to an increase of 1 in units of the refractive index ratio (N _z ) of the retardation film 200 .

However, at this time, when the refractive index ratio (N _z ) of the retardation film 200 is 1, the retardation value (Δnd) of the C-plate 100 may be 30 to 100 nm.

That is, the retardation value (Δnd) of the C-plate 100 and the refractive index ratio (N _z ) of the retardation film 200 may have a relationship that satisfies Equation 5 below.

[Equation 5]

Δnd = (Δnd) ₀ + αβ

Here, (Δnd) ₀ is the retardation value (Δnd) of the C-plate 100 when the refractive index ratio (N _z ) of the retardation film 200 is 1, and may be 30 to 100 nm, and α is the retardation film 200 The increase in the retardation value ( _Δnd ) of the C-plate 100 relative to the unit increase in the refractive index ratio (N z ) of may be 150 to 220 nm, and β may be the increase in the refractive index ratio (N _z ) of the retardation film 200. there is.

That is, the retardation value (Δnd) of the C-plate 100 calculated by Equation 5 may be the retardation value (Δnd) when the refractive index ratio (N _z ) of the retardation film 200 is 1+β.

For example, referring to Equation 5, if (Δnd) ₀ is 100 nm, α is 150 nm, and β is 0.1, the C-plate 100 when the refractive index ratio (N _z ) of the retardation film 200 is 1.1. The phase difference value Δnd of ) may be calculated as 115 nm.

If the retardation value (Δnd) of the C-plate 100 and the refractive index ratio (N _z ) of the retardation film 200 have a relationship that satisfies Equation 5, the optical compensation film 20 is the front surface of the organic light emitting device 10. Not only can reflection of external light be prevented from a direction, but also performance of preventing reflection of external light may not be deteriorated even at a side viewing angle.

The polarizer 300 may be laminated on the retardation film 200 .

The polarizer 300 may be a commonly used linear polarizer, and may linearly polarize transmitted light so as to vibrate in one direction.

The polarizer 300 is not limited as long as it is a normal linear polarizer, and for example, a urea polarizer made of a polyvinyl alcohol (PVA)-based resin film and a dichroic dye-based polarizer may be used.

The absorption axis of the polarizer 300 and the optical axis of the retardation film 200 may be obliquely aligned, and the angle formed by the absorption axis of the polarizer 300 and the optical axis of the retardation film 200 may be 43 to 47 degrees, , 133 to 137 degrees.

The C-plate 100 of the optical compensation film 20, the retardation film 200, and the retardation film 200 and the polarizer 300 are bonded through at least one of commonly used pressure-sensitive adhesives and adhesives, thereby maintaining a laminated state. In this case, as the pressure-sensitive adhesive and the adhesive, an optically transparent pressure-sensitive adhesive and an optically clear adhesive may be used, respectively.

In addition, the C-plate 100 of the optical compensation film 20 and the retardation film 200, and the retardation film 200 and the polarizer 300 may be laminated with each other by direct coating.

<Example 1>

An optical compensation film 20 including a C-plate 100, a retardation film 200 stacked on the C-plate 100, and a polarizer 300 stacked on the retardation film 200 was prepared.

At this time, as the C-plate 100, a positive C-plate having a retardation value (Δnd) of 70 nm represented by Equation 4 was used.

As the retardation film 200, a refractive index ratio (N _z ) represented by Equation 3 is 1, and a negative biaxial retardation film having reverse wavelength dispersion characteristics was used.

As the polarizer 300, a PVA-based linear polarizer having an absorption axis in one direction was used, and one in which the absorption axis formed an angle of 45 ° with the optical axis of the retardation film 200 was used.

<Example 2>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, the optical compensation film 20 was prepared by using a positive C-plate having a retardation value (Δnd) of 30 nm instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100 .

<Example 3>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, the optical compensation film 20 was prepared by using a positive C-plate having a retardation value (Δnd) of 100 nm instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100.

<Example 4>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, a positive C-plate having a retardation value (Δnd) of 90 nm is used instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100, and a refractive index ratio (N _z ) is used as the retardation film 200 An optical compensation film 20 was prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 1.1 instead of a negative biaxial retardation film having a value of 1.

<Example 5>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, a positive C-plate having a retardation value (Δnd) of 109 nm is used instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100, and a refractive index ratio (N _z ) is used as the retardation film 200 An optical compensation film 20 was prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 1.2 instead of a negative biaxial retardation film having a value of 1.

<Example 6>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, a positive C-plate having a retardation value (Δnd) of 126 nm is used instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100, and a refractive index ratio (N _z ) is used as the retardation film 200 An optical compensation film 20 was prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 1.3 instead of a negative biaxial retardation film having a value of 1.

<Example 7>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, a positive C-plate having a retardation value (Δnd) of 142 nm is used instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100, and a refractive index ratio (N _z ) is used as the retardation film 200 An optical compensation film 20 was prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 1.4 instead of a negative biaxial retardation film having a value of 1.

<Example 8>

An optical compensation film 20 was prepared in the same manner as in Example 1.

However, a positive C-plate having a retardation value (Δnd) of 160 nm is used instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100, and a refractive index ratio (N _z ) is used as the retardation film 200 An optical compensation film 20 was prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 1.5 instead of a negative biaxial retardation film having a value of 1.

<Comparative Example 1>

An optical compensation film was prepared in the same manner as in Example 1.

However, an optical compensation film was prepared by using a negative C-plate having a retardation value (Δnd) of -70 nm instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100 .

<Comparative Example 2>

An optical compensation film was prepared in the same manner as in Example 1.

However, an optical compensation film composed of a retardation film 200 and a polarizer 300 stacked on the retardation film 200 was prepared without a C-plate.

<Comparative Example 3>

An optical compensation film was prepared in the same manner as in Example 1.

However, the optical compensation film 20 was prepared by using a positive C-plate having a retardation value (Δnd) of 10 nm instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100.

<Comparative Example 4>

An optical compensation film was prepared in the same manner as in Example 1.

However, the optical compensation film 20 was prepared by using a positive C-plate having a retardation value (Δnd) of 120 nm instead of a positive C-plate having a retardation value (Δnd) of 70 nm as the C-plate 100.

<Comparative Example 5>

An optical compensation film was prepared in the same manner as in Example 1.

However, the optical compensation film 20 is prepared using a negative biaxial retardation film having a refractive index ratio (N _z ) of 0.5 instead of a negative biaxial retardation film having a refractive index ratio (N _z ) of 1 as the retardation film 200 . did

<Comparative Example 6>

An optical compensation film was prepared in the same manner as in Example 1.

However, the optical compensation film 20 is prepared by using a negative biaxial retardation film having a refractive index ratio (N _z ) of 2 instead of a negative biaxial retardation film having a refractive index ratio (N _z ) of 1 as the retardation film 200 . did

Table 1 below summarizes the conditions of the C-plate 100 and the retardation film 200 used in the optical compensation films according to Examples 1 to 8 and Comparative Examples 1 to 6.

C-plate phase difference value (Δnd, unit: nm) Refractive index ratio of retardation film (N _z ) Example 1 70 One Example 2 30 One Example 3 100 One Example 4 90 1.1 Example 5 109 1.2 Example 6 126 1.3 Example 7 142 1.4 Example 8 160 1.5 Comparative Example 1 -70
(negative C-plate) One Comparative Example 2 not used One Comparative Example 3 10 One Comparative Example 4 120 One Comparative Example 5 70 0.5 Comparative Example 6 70 2

<Test Example 1>

In Test Example 1, the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6 had a omnidirectional angle (0 to 360 degrees) and a maximum inclination angle of 90 degrees for light with a wavelength of 380 to 780 nm. The reflectance average at was simulated with a simulator (Techwiz 1D plus, manufactured by Sanai System Co., Ltd.).

For the test according to Test Example 1, the simulator is set to a structure in which the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6 are laminated on a plurality of organic light emitting devices 10, respectively. did

At this time, the lower surface of the positive C-plate 100 is attached to the organic light emitting device 10, and when the positive C-plate 100 is not provided, the lower surface of the retardation film 200 is attached to the organic light emitting device 10. It was laminated so that they were in contact with each other.

The test results are shown in Figures 4 to 17.

4 to 17 are views showing simulation results of omnidirectional reflectance according to Test Example 1 of the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6, respectively.

In more detail, referring to FIGS. 4 to 17, the center of the circle means the front (inclination angle 0°, azimuth angle 0°), and the inclination angle increases from the minimum 0° to the maximum 90° from the center of the circle in the circumferential direction. .

In addition, referring to FIGS. 4 to 17, it means that the azimuth angle increases from the right (0°) counterclockwise along the radial direction of the circle, and the angle written along the circumference means the azimuth angle.

In addition, referring to FIGS. 4 to 17, the closer to black means a lower average reflectance for light with a wavelength of 380 to 780 nm, and the closer to white, the higher the average reflectance for light with a wavelength of 380 to 780 nm. can

Referring to FIGS. 4 to 17, the average reflectance measured at a 70° inclination angle and 0 to 360° azimuth angle for light of 380 to 780 nm wavelength of the optical compensation films according to Examples 1 to 8 and Comparative Examples 1 to 6 is shown in the table below. 2.

reflectance average Example 1 0.0380 Example 2 0.0597 Example 3 0.0644 Example 4 0.0379 Example 5 0.0378 Example 6 0.0375 Example 7 0.0376 Example 8 0.0377 Comparative Example 1 0.2570 Comparative Example 2 0.112 Comparative Example 3 0.0918 Comparative Example 4 0.0985 Comparative Example 5 0.1800 Comparative Example 6 0.2848

4 to 17 and Table 2, it can be seen that the average reflectance of the optical compensation films according to Comparative Examples 1 to 6 is higher than that of the optical compensation films 20 according to Examples 1 to 8. It is a result confirming that the optical compensation films 20 according to Comparative Examples 1 to 6 have better performance in preventing reflection of external light than the optical compensation films according to Comparative Examples 1 to 6.

In particular, it can be seen that the average reflectance of the optical compensation film according to Comparative Example 4 is higher than the average reflectance of the optical compensation film 20 according to Examples 1 to 8, which indicates that the retardation value (Δnd) of the C-plate 100 When the increase amount is greater than the increase amount of the refractive index ratio (N _z ) of the retardation film 200 , it can be confirmed that the antireflection performance of external light at the side viewing angle of the optical compensation film 20 is deteriorated.

<Test Example 2>

In Test Example 2, in Test Example 1, light having a short wavelength of 550 nm is applied to the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6 in a diagonal direction (inclination angle 45°, azimuth angle 45°). The polarization state was simulated and displayed on a Poincare sphere. At this time, Techwiz 1D plus (manufactured by Sanai System Co., Ltd.) was used as a simulator for simulation.

For the test according to Test Example 2, the simulator is set to a structure in which the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6 are laminated on a plurality of organic light emitting devices 10, respectively. did

The test results are shown in Figures 18 to 31.

Meanwhile, the arrival point (A) shown in FIGS. 18 to 31 indicates the arrival point of the polarization state of light transmitted through the optical compensation film, and the arrival point (A) is the S1 axis (D), S2 axis (E), and S3 axis (F ) may have a coordinate value corresponding to At this time, if the destination point (A) is located on the circumference of the circle (B) passing through the S1 axis (D) and the S3 axis (F) and the coordinate value corresponding to the S2 axis (E) is 0, the optical compensation film 20 is transmitted. It can be determined that one light has reached a circular polarization state.

18 to 31 to determine the extent to which the polarization state of light transmitted through the optical compensation films 20 according to Examples 1 to 8 and the optical compensation films according to Comparative Examples 1 to 6 deviated from the circular polarization state, respectively. The departure angle (θ) is shown in Table 3 below.

At this time, referring to FIG. 32, the deviation angle (θ) may mean an angle between a line (C) passing through the origin and destination point (A) of the coordinate system and the S3 axis (F).

Departure angle (θ, unit: ˚) Example 1 0 Example 2 8.15 Example 3 4.78 Example 4 0 Example 5 0 Example 6 0 Example 7 0 Example 8 0 Comparative Example 1 26.21 Comparative Example 2 0 Comparative Example 3 11.69 Comparative Example 4 8.52 Comparative Example 5 15.24 Comparative Example 6 32.87

Referring to FIGS. 18 to 31 and Table 3, it can be confirmed that the departure angle of the optical compensation films 20 according to Examples 1 to 8 is smaller than the departure angles of the optical compensation films according to Comparative Example 1 and Comparative Examples 3 to 6, , This is a result confirming that the antireflection performance of the optical compensation films 20 according to Examples 1 to 8 is lower than that of the optical compensation films according to Comparative Example 1 and Comparative Examples 3 to 6 at a side viewing angle.

In particular, it can be seen that the departure angle (θ) of the optical compensation film according to Comparative Example 4 is greater than the departure angle (θ) of the optical compensation film 20 according to Examples 1 to 8, which is the C-plate 100 If the retardation value (Δnd) of Δnd is too large than the refractive index ratio (N _z ) of the retardation film 200, the anti-reflection performance of external light in the front direction of the optical compensation film 20 is deteriorated and the anti-reflection performance of external light in the side viewing angle It is the result that can confirm this degradation.

Those skilled in the art to which the present invention pertains will understand that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description above, and all changes or modifications derived from the scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention.

10: organic light emitting element,
11: anode, 12: organic material layer, 13: cathode,
20: optical compensation film,
100: C-plate,
200: retardation film,
300: polarizer.

Claims (5)

positive C-plate;
a negative biaxial retardation film laminated on the C-plate and having reverse wavelength dispersion; and
including a polarizer laminated on the negative biaxial retardation film;
Optical compensation film for improving the optical properties of a phosphorus organic light emitting device. According to claim 1,
An average of reflectance measured at a 70° inclination angle and 0 to 360° azimuth angle for light with a wavelength of 380 to 780 nm is 0.0377 to 0.0597
Optical compensation film for improving the optical properties of a phosphorus organic light emitting device. According to claim 1,
The C-plate is
The retardation value represented by Equation 1 below is 30 to 191 nm
Optical compensation film for improving the optical properties of a phosphorus organic light emitting device.
(Equation 1)
Δnd=(n _e -n _o ) × d
Here, Δnd is the retardation value of the C-plate, n _e is the ideal refractive index of the C-plate, n _o is the normal refractive index of the C-plate, and d is the thickness of the C-plate. According to claim 1,
The phase difference film
A refractive index ratio of 1 to 1.5 represented by Equation 2 below at a wavelength of 380 to 780 nm
Optical compensation film for improving the optical properties of a phosphorus organic light emitting device.
(Equation 2)
N _z =(n _x -n _z )/(n _x -n _y )
Here, N _z is a refractive index ratio of the retardation film, and n _x , n _y , and n _z are refractive indices of the retardation film in the x-, y-, and z-axis directions, respectively. According to claim 1,
An angle between the absorption axis of the polarizer and the optical axis of the retardation film is 43 to 47 degrees or 133 to 137 degrees
Optical compensation film for improving the optical properties of a phosphorus organic light emitting device.

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