KR20170081011A - Polarizing plate and organic light emitting diode display device - Google Patents

Abstract

The present invention relates to a polarizing plate and an organic electroluminescent display device including the same.
According to the present invention, iodide ions including I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- are adsorbed on a base film, and a single transmission having a wavelength of 600 to 750 nm A polarizing plate having a larger group transmittance can be provided. As a result, it is possible to provide an organic light emitting display device including the above polarizing plate and having an improved visual field color difference.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polarizing plate and an organic light emitting display panel including the polarizing plate,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an OLED display device including a polarizer having a transmittance characteristic controlled to a red wavelength, And an electroluminescent display device.

In addition, the present invention relates to a polarizing plate in which transmittance characteristics with respect to a red wavelength are controlled by controlling the adsorption amount of various iodide ions, and an organic light emitting display panel including the same.

2. Description of the Related Art Recently, the most widely used display devices include liquid crystal display devices and organic light emitting diode display devices.

Among them, in the case of a liquid crystal display device, a separate backlight unit for supplying light to the panel and an optical sheet are included. In addition, polarizers are attached to the front and rear surfaces of the liquid crystal panel.

In general, the polarizing plate on the back surface of the liquid crystal panel serves to pass only the light vibrating vertically in the light of various vibrations, and the polarizing plate on the back surface of the liquid crystal panel plays the role of determining the brightness of the screen by passing only the light vibrating horizontally through the liquid crystal. .

In the case of an organic electroluminescent display device not including a liquid crystal, a polarizer is not essential, but a polarizer is often disposed for reflection prevention purposes.

However, unlike a liquid crystal display device requiring a separate backlight unit, a conventional organic light emitting display device including an organic light emitting diode does not include an optical sheet and the like, .

Therefore, if the emission characteristic of the organic material changes according to the angle, it is recognized as a color change at the viewing angle position in the image quality. As described above, in the case of the polarizing plate arranged in the conventional organic electroluminescence display device, the polarizing plate mainly has the purpose of preventing reflection of external light, and has no function of improving the color difference.

Korean Unexamined Patent Application Publication No. 10-2005-0039587 (published on Mar. 29, 2005) discloses a liquid crystal display device capable of improving the contrast characteristics at the front and oblique angles in a planar switching liquid crystal display device and minimizing a color change according to a viewing angle in a black state, A viewing angle compensation film comprising positive uniaxial retardation films + A-Plate and + C-plate between a polarizing plate and a liquid crystal cell has been proposed.

In such an organic electroluminescent display device, it is difficult to apply a method of adjusting the reflection feeling of black state in a conventional liquid crystal display device as it is to change the color difference of the transmission state.

Therefore, there is a need for a method capable of reducing the decrease in color difference in the transmission state in the organic electroluminescence display device.

An object of the present invention is to provide a polarizing plate capable of reducing color difference reduction at a viewing angle position.

Another object of the present invention is to provide an organic electroluminescent display device capable of improving the visual field color difference by changing the transmittance characteristic of the polarizing plate without changing the design of the basic organic electroluminescent display device.

In order to achieve the above object, a polarizing plate according to an embodiment of the present invention is characterized in that iodide ions including I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- are adsorbed on a base film. At this time, the ratio of the total adsorption amount of I ₅ ^- and I ₇ ^{- to} the total adsorption amount of I ₂ ^- and I ₃ ^- is 1: 1.2 to 1: 1.5. In this case, in the polarizing plate, the polarizing plate may have a larger single transmittance at a wavelength of 600 to 750 nm than a single transmission having a wavelength of 450 to 550 nm.

In the case of the organic light emitting display panel in which the polarizing plate having the transmittance of the red region is disposed on the first substrate or the second substrate, the difference in the visual sense of color with respect to the red wavelength having a large amount of spectral fluctuation at the viewing angle position can be increased.

According to the present invention, the total adsorption amount of I ₂ ^- and I ₃ ^- or the total adsorption amount of I ₅ ^- and I ₇ ^- so that the single transmittance at a wavelength of 600 to 750 nm is larger than that of a single transmission at a wavelength of 450 to 550 nm The present invention can provide an organic light emitting display panel and an apparatus in which the difference in visual color sense is increased without changing the device design.

1 schematically shows an example of an organic light emitting display panel according to the present invention.
2 shows the light source spectrum at the front position.
3 shows the light source spectrum at the viewing angle position.
FIG. 4 is a graph showing that the mass transmittance of the red region is changed when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased.
FIG. 5 shows that the color coordinate center is changed when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased or when the total adsorption amount of I ₂ ^- and I ₃ ^- is increased.
FIG. 6 shows the amount of color change at a viewing angle of 60 ° according to the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- .

Hereinafter, a polarizing plate and an organic light emitting display including the same according to the present invention will be described in detail with reference to the drawings.

The terms including ordinals such as first, second, etc. in the following can be used to describe various elements, but the constituent elements are not limited by such terms. These terms are used only to distinguish one component from another.

Also, in the present invention, the expression " is in a state of being in contact with another part "means not only" in which part is in contact with another part, On top of other parts in the state of being further formed in the middle ".

1 schematically shows an example of an organic light emitting display panel according to the present invention.

Referring to FIG. 1, the organic light emitting display panel 10 includes a first substrate 20, a second substrate 80, and a polarizing plate 90.

1, the organic light emitting display includes an organic light emitting display panel 10 including a thin film transistor and an organic light emitting diode for outputting an image, an organic light emitting display panel 10, And a supporting member for supporting the rear surface. The support member may be a case top, a middle cabinet, a cover bottom, or the like.

On the first substrate 20, a thin film transistor 34 for driving a pixel is disposed.

In the example shown in Fig. 1, an active layer 44 is disposed on the first substrate 20, and a gate insulating film 50 and a gate electrode 52 are disposed thereon.

Further, source and drain electrodes 48 of the thin film transistor 34 are disposed. However, the thin film transistor 34 is not limited to the example shown in Fig. 1, and can be arranged in various known structures.

An anode electrode 36 is disposed on the thin film transistor 34 and an organic light emitting layer 38 is disposed on the anode electrode 36. [

In FIG. 1, a first interlayer insulating film 54 and an anode electrode 36 are sequentially arranged on the gate electrode 52. An electrode line 56 connecting the anode electrode 36 and the drain region 48 of the thin film transistor is disposed between the gate insulating film 50 and the first interlayer insulating film 54.

On the other hand, a cathode electrode 40 is disposed on the organic light emitting layer 38, and a protective film 42 is disposed on the cathode electrode 40.

In Fig. 1, a second interlayer insulating film 60 is formed on the anode electrode 36 so as to cover a part between the anode electrodes 36. In Fig. On the second interlayer insulating film 60, an organic light emitting layer 38 having a multilayer structure is disposed. The protective film 42 may include an adhesive film 72 and a shield cap 74.

On the other hand, the second substrate 80 may be a separate substrate and may mean a protective film 42.

On the second substrate 80, a polarizing plate 92 is disposed. In FIG. 1, a polarizing plate 92 is disposed on the second substrate 80. However, the polarizing plate 92 is not limited to this, and may be disposed above the first substrate 20 on which the thin film transistor 34 and the organic light emitting diodes 36, 38, 40 are disposed, or below the second substrate .

The polarizing plate 92 can be produced by dyeing and uniaxially stretching by adsorption of iodine onto a base film, for example, a polyvinyl alcohol (PVA) film having excellent optical properties.

The polarizing plate 92 may be a single layer, or may have a multilayer structure including, for example, a? / 4 retardation layer and a linear polarization layer.

On the upper side of the polarizing plate 92, a cellulose-based protective film 94 such as a triacetylcellulose (TAC) film may be further disposed. The protective film 940 may be disposed under the polarizer 92 or on both sides. The protective film 94 is disposed so that the protective effect of the polarizing plate 92 can be obtained. 1 shows a multi-layer protective film 90 comprising a polarizing plate 92 and a protective film 940. In Fig.

In the polarizing plate according to the present invention, iodide ions including I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- are adsorbed on a base film such as a PVA film.

At this time, the polarizing plate according to the present invention has a total absorption amount of I ₂ ^- and I ₃ ^{- and} a total absorption amount of I ₅ ^- and I ₃ ^- so that a single transmission having a wavelength of 600 to 750 nm is larger than a single transmission of a wavelength of 450 to 550 nm, And I ₇ ^- is controlled. More specifically, the polarizing plate according to the invention, 450 and a ratio of simple substance transmittance of a wavelength of 550nm of the simple substance transmittance and 600 ~ 750nm wavelength to so that remarkable color improvement in the viewing angle positions: I ₂ to be 1.05 or higher ^- and I ₃ ^{- and} the total adsorption amount of I ₅ ^- and I ₇ ^- are adjusted.

In the case of a conventional polarizing plate, the single light transmittance of 450 to 550 nm and the single light transmittance of 600 to 750 nm or the single light transmittance of 450 to 550 nm are larger than the single light transmittance of 600 to 750 nm wavelength, Is relatively higher than a single transmittance of a wavelength of 450 to 550 nm. This can be achieved by lowering the single transmittance at a wavelength of 450 to 550 nm or conversely by increasing the single transmittance at a wavelength of 600 to 750 nm. One example of controlling the transmittance of the wavelength band by mass is to increase the total adsorption amount of I ₂ ^- and I ₃ ^- or decrease the total adsorption amount of I ₅ ^- and I ₇ ^{- by} the amount of adsorption of iodide ions in the polarizing plate Can be presented.

Among the iodide ions, I ₂ ^- plays a role of absorbing short wavelengths of blue and green regions, and I ₃ ^- plays a role of absorbing wavelengths of green regions. I ₅ ^- and I ₇ ^- of the iodide ions absorb the short wavelength of the red region.

At this time, when the total adsorption amount of I ₂ ^- and I ₃ ^- is increased or the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased, the long wavelength absorption amount of the red region is decreased, thereby increasing the single transmittance of long wavelengths in the red region .

On the contrary, when the total adsorption amount of I ₂ ^- and I ₃ ^- is decreased or the total adsorption amount of I ₅ ^- and I ₇ ^- is increased, the short wavelength absorption amount of the green region is decreased, and accordingly, the short wavelength single wavelength transmittance of the green region is increased.

Using this principle, a desired long wavelength single-unit transmittance or short-wavelength single-unit transmittance can be obtained by adjusting at least one of the total adsorption amount of I ₂ ^- and I ₃ ^{- and} the total adsorption amount of I ₅ ^- and I ₇ ^{- in} the polarizing plate .

As a method of controlling the total adsorption amount of I ₂ ^- and I ₃ ^- or the total adsorption amount of I ₅ ^- and I ₇ ^{- in} the polarizing plate, a method of controlling the amount of the potassium iodide solution and a method of controlling the degree of stretching of the base film have. As the amount of potassium iodide solution is increased, the total adsorption amount of I ₂ ^- and I ₃ ^- increases and the total adsorption amount of I ₅ ^- and I ₇ ^- may decrease relatively. Further, as the degree of stretching of the base film is lowered, the total adsorption amount of I ₂ ^- and I ₃ ^- may be relatively increased while the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased.

At this time, it is more preferable that the ratio of the total adsorption amount of I ₅ ^- and I ₇ ^{- to} the total adsorption amount of I ₂ ^- and I ₃ ^- is 1: 1.2 to 1: 1.5. When the total adsorption amount of I ₂ ^- and I ₃ ^- which absorbs a shorter wavelength relative to the adsorption amount of I ₅ ^- and I ₇ ^- which absorbs the long wavelength of the red region is less than 1.2 times, the present invention improves the visual field color difference It may be insufficient. However, when the total adsorption amount of I ₂ ^- and I ₃ ^- exceeds 1.5 times, when the stretching of the base film is very small or the addition amount of potassium iodide is excessively large, the polarization performance which is the basic performance of the polarizing plate may be lowered .

Fig. 2 shows the light source spectrum at the front position, and Fig. 3 shows the light source spectrum at the 60 ° viewing angle position.

Referring to FIG. 2 and FIG. 3, it can be seen that the spectral change amount of the long wavelength is larger than that of the short wavelength spectrum in the light source spectrum at the 60 ° viewing angle position with respect to the light source spectrum at the front position.

As described above, in the case of a specific organic light emitting display device, the red color tone is deteriorated at the viewing angle.

In this case, there is a need to increase the transmittance of long wavelength and to reduce the deterioration of color tone at the viewing angle. With this method, there is a method of increasing the total adsorption amount of I ₂ ^- and I ₃ ^- or reducing the total adsorption amount of I ₅ ^- and I ₇ ^- , as described above.

FIG. 4 is a graph showing that the mass transmittance of the red region is changed when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased. In FIG. 4, the ratio of the total adsorption amount of I ₅ ^- and I ₇ ^{- to} the total adsorption amount of I ₂ ^- and I ₃ ^- was 1: 1.4.

Referring to FIG. 4, when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased, there is almost no change in the simple transmittance at other wavelengths, but the transmittance is increased by at least 5% in the red wavelength region of 600 to 750 nm.

In FIG. 4, the result of the decrease in the total adsorption amount of I ₅ ^- and I ₇ ^- results in an increase in the single transmittance at a wavelength of 600 to 750 nm without changing the transmittance of the other wavelength band. On the other hand, if the total adsorption amount of I ₂ ^- and I ₃ ^- is increased, the mass transmittance at a wavelength of 600 to 750 nm is hardly changed, but instead the relative transmittance at a wavelength of 450 to 550 nm is relatively low have.

Therefore, by increasing the total adsorption amount of I ₂ ^- and I ₃ ^- or decreasing the total adsorption amount of I ₅ ^- and I ₇ ^- , it is possible to increase the mass transmittance in the red region, It is possible to reduce color degradation.

FIG. 5 shows that the color coordinate center is changed when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased or when the total adsorption amount of I ₂ ^- and I ₃ ^- is increased.

Referring to FIG. 5, when the total adsorption amount of I ₅ ^- and I ₇ ^- decreases, the center of color coordinates shifts from left to right. In FIG. 5, the ratio of the total adsorption amount of I ₅ ^- and I ₇ ^{- to} the total adsorption amount of I ₂ ^- and I ₃ ^- was 1: 0.8 before the change in adsorption amount, and I ₅ ^- and I ₇ ^- And the ratio of the total adsorption amount of I ₂ ^- and I ₃ ^- was 1: 1.4.

On the other hand, the chromaticity coordinates obtained when the total adsorption amount of I ₅ ^- and I ₇ ^- is decreased or when the total adsorption amount of I ₂ ^- and I ₃ ^- is increased is about 0 to 10 on the a axis and about 3 to 9 on the b axis .

FIG. 6 shows the amount of color change at a viewing angle of 60 ° according to the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- .

Referring to FIG. 6, when the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- is 1: 0.8 (ref), I ₅ ^- and I ₇ ^- the total adsorption amount, and I ₂ ^- and I ₃ ^- the total adsorption amount ratio is 1: if 1.2 (a), I ₅ ^- and I ₇ ^- total adsorption amount, and I ₂ of the ^- and I ₃ ^- total amount of adsorption ratio of (C) when the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- is 1: 1.4 (B) in case of 1: 1.3, (Δu'v ') is reduced.

Particularly, when the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- is 1: 0.8 (ref), the color variation amount (Δu'v ') at a viewing angle of 60 ° is 0.014 (C) when the total adsorption amount of I ₅ ^- and I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- is 1: 1.4, the color variation amount (Δu'v ' ) Is significantly lowered to 0.007 level.

Referring to FIG. 6, as the total adsorption amount ratio of I ₂ ^- and I ₃ ^{- to} the total adsorption amount of I ₅ ^- and I ₇ ^- increases, the color variation amount Δu'v 'decreases at a viewing angle of 60 ° You can see that the effect is bigger. However, when the total adsorption amount ratio of I ₂ ^- and I ₃ ^{- to} the total adsorption amount of I ₅ ^- and I ₇ ^- exceeds 1.5 times, the polarizing property itself is lowered. In the present invention, I ₅ ^- and The total adsorption amount of I ₇ ^- and the total adsorption amount ratio of I ₂ ^- and I ₃ ^- were set to 1: 1.2 to 1: 1.5.

As described above, by applying the polarizer plate in which the total adsorption amount of I ₂ ^- and I ₃ ^- or the total adsorption amount of I ₅ ^- and I ₇ ^- is controlled, the visual field color of the organic electroluminescence display panel and the apparatus So that the decrease in the car can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is therefore to be understood that such changes and modifications are intended to be included within the scope of the present invention unless they depart from the scope of the present invention.

10: Organic electroluminescence display panel
20: first substrate 34: thin film transistor
36: anode electrode 38: organic light emitting layer
40: cathode electrode 42:
44: active layer 48: source and drain regions
50: gate insulating film 52: gate electrode
54: first interlayer insulating film 56: electrode line
60: second interlayer insulating film 80: second substrate
92: polarizer 94: protective film

Claims (10)

Iodine ions including I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- are adsorbed on the base film, and the total adsorption amount of I ₅ ^- and I ₇ ^{- and} the total adsorption of I ₂ ^- and I ₃ ^- Is in the range of 1: 1.2 to 1: 1.5.
The method according to claim 1,
Wherein the polarizing plate has a larger single transmittance at a wavelength of 600 to 750 nm than a single transmission at a wavelength of 450 to 550 nm.
3. The method of claim 2,
Wherein the polarizer has a ratio of a single transmittance at a wavelength of 450 to 550 nm and a single transmittance at a wavelength of 600 to 750 nm of 1: 1.05 or more.
The method according to claim 1,
Wherein the base film is a stretched polyvinyl alcohol (PVA) film.
A first substrate on which a thin film transistor and an organic light emitting diode are disposed;
A second substrate disposed on the first substrate; And
I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- are attached to at least one of the first substrate and the second substrate and the iodide ion including I ₂ ^- , I ₃ ^- , I ₅ ^- and I ₇ ^- Wherein the polarizing plate includes a polarizing plate having a larger unit transmittance at a wavelength of 600 to 750 nm.
5. The method of claim 4,
Wherein the polarizer has a ratio of a total adsorption amount of I ₅ ^- and I ₇ ^{- to} a total adsorption amount of I ₂ ^- and I ₃ ^- of from 1: 1.2 to 1: 1.5.
5. The method of claim 4,
Wherein the polarizer has a ratio of a single transmittance of a wavelength of 450 to 550 nm and a single transmittance of a wavelength of 600 to 750 nm of 1: 1.05 or more.
An organic light emitting display panel including a thin film transistor and an organic light emitting diode and outputting an image and having a polarizing plate disposed thereon; And
And at least one supporting member for supporting a front surface and a rear surface of the organic light emitting display panel,
The polarizing plate is characterized in that iodide ions including I ₂ ^- , I ₃ ^- , I ₅ ^-, and I ₇ ^- are adsorbed on the base film, and the single polarized light having a wavelength of 600 to 750 nm, Organic electroluminescence display device.
9. The method of claim 8,
Wherein the polarizer has a ratio of a total adsorption amount of I ₅ ^- and I ₇ ^{- to} a total adsorption amount of I ₂ ^- and I ₃ ^- of from 1: 1.2 to 1: 1.5.
9. The method of claim 8,
Wherein the polarizing plate has a ratio of a single transmittance of a wavelength of 450 to 550 nm and a single transmittance of a wavelength of 600 to 750 nm of 1: 1.05 or more.

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