KR100759669B1 - Dye-based polarizing film and organic light emitting display device having the same - Google Patents

Abstract

The present invention relates to a dye-based polarizing film and an organic light emitting display device having the same, wherein the dye-based polarizing film of the present invention is located at a boundary between light of a wavelength band and a blue and green wavelength located at a boundary between green and red wavelengths. It has a structure in which the dye composition whose composition ratio is adjusted so that light of a wavelength band is absorbed more than light of another wavelength band is dyed. By selectively absorbing more light in the non-emission band located at the boundary between green and red, blue and green wavelengths, it has improved polarization characteristics, and has high durability such as thermal characteristics, so that polarization characteristics are not degraded at high temperatures, and high temperature, high humidity, etc. It does not deteriorate easily in harsh environments. In addition, the organic light emitting display device including the dye-based polarizing film of the present invention has a high contrast ratio due to high polarization degree and less reflection of an external light source due to selective light absorption characteristics of the dye-based polarizing film.

Description

Dye polarization film and organic light emitting display device having the same

1 is a schematic cross-sectional view illustrating a general organic light emitting display device.

2 is a light emission spectrum of a typical organic light emitting display.

3 is a graph measuring the transmittance of the dye-based polarizing film according to the present invention.

4 to 7 are cross-sectional views illustrating an organic light emitting display device including a dye-based polarizing film according to an exemplary embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10, 100: insulated substrate

20, 110: light emitting element

30, 120: sealing substrate

40, 130: phase difference plate

50: polarizing film

140: dye-based polarizing film

150: shield

The present invention relates to a dye-based polarizing film and an organic light emitting display having the same, and more particularly, to a dye-based polarizing film having improved polarization characteristics and an organic light emitting display having the same.

As the information and communication industry is rapidly developed, the use of display devices is rapidly increasing, and in recent years, display devices capable of satisfying conditions of low power, light weight, thinness, and high resolution are required. In response to these demands, display devices using liquid crystal displays or organic light emitting characteristics have been developed.

In such display devices, a polarizing film is used to prevent contrast degradation due to reflection of an external light source. For example, a polarizing film and a λ / 4 retardation plate are formed on the surface of the substrate along which the emitted light travels (see Korean Patent Application No. 2000-60523 (October 14, 2000)), or a circular shape capable of adjusting phase difference A polarizing plate is formed to suppress reflection of external light.

1 is a schematic cross-sectional view illustrating an example of a conventional organic light emitting display device using a polarizing film and a λ / 4 retardation plate.

A light emitting device 20 for emitting a predetermined light is formed on the insulating substrate 10 made of a transparent material such as glass, and an encapsulation substrate 30 made of a transparent material is sealed on the light emitting device 20. (Not shown) to adhere to the insulating substrate 10. In addition, the upper portion of the insulating substrate 10 or (and) the encapsulation substrate 30 along the path of the light emitted from the light emitting element 20 is lambda / 4 phase difference plate 40 for changing the phase of the incident light by a predetermined angle ) Is disposed, and a polarizing film 50 for reflecting light in a specific polarization direction is disposed on the λ / 4 retardation plate 40.

The light emitting device 20 is configured in a passive matrix method including a lower electrode, an organic thin film layer, and an upper electrode, or includes a lower electrode, an organic thin film layer, and an upper electrode, and a thin film transistor (TFT) in which an operation of each pixel serves as a switch. It can be configured in an active matrix manner controlled by.

The organic light emitting diode display configured as described above is injected through a hole and an upper electrode which are injected through the lower electrode when a predetermined voltage is applied to the lower electrode used as the anode electrode and the upper electrode used as the cathode electrode of the light emitting device 20. The electrons recombine in the organic light emitting layer and emit light due to the energy difference generated in the process.

While the light emitted from the light emitting device 20 is emitted to the outside, external light is incident on the organic light emitting diode display from an external light source. At this time, the polarizing film 50 passes only a specific wavelength, for example, a horizontal wave, from the incident external light. The horizontal wave passing through the polarizing film 50 is reflected by the internal metal electrode, and the phase is changed by the λ / 4 retardation plate 40 so that the horizontal wave does not pass through the polarizing plate and disappears. Therefore, since the phase difference is induced by the λ / 4 retardation plate 40 and the incident external light is not emitted, the reflection of the external light is reduced.

Generally, a polarizing film is classified into an iodine-based polarizing film in which an iodine compound is adsorbed and a dye-based polarizing film in which dichroic dyes are adsorbed and oriented. System polarizing film is used.

However, the iodine polarizing film is easily deteriorated in a harsh environment such as high temperature and high humidity, and has a disadvantage in that polarization characteristics are degraded at high temperature. Therefore, when the display device is exposed to strong light or irradiated with strong light from another light source and the temperature is increased, polarization characteristics are deteriorated, thereby increasing reflection of external light.

Although the dye-based polarizing film has superior durability, such as thermal properties, than the iodine-based polarizing film, its polarization characteristics are lower than that of the iodine-based polarizing film.

An object of the present invention is to provide a dye-based polarizing film with improved polarization properties than the prior art.

Another object of the present invention is to provide a dye-based polarizing film having high durability and selective light absorption characteristics.

Another object of the present invention is to provide an organic light emitting display device having an improved contrast ratio by a dye-based polarizing film having high durability and selective light absorption characteristics.

Dye-based polarizing film according to an aspect of the present invention for achieving the above object is a dye composition is adjusted dye composition is adjusted so that the light of the wavelength band located at the boundary of the green and red wavelength is absorbed more than the light of the other wavelength band Has a structure.

According to another aspect of the present invention, there is provided an organic light emitting display device having a dye-based polarizing film, which is formed between a first substrate and a second substrate, and emits light having a predetermined wavelength. The dye composition is disposed on the substrate of the path of the light emitted from the light emitting device, the dye composition is adjusted to adjust the composition ratio so that the light of the wavelength band located at the boundary of the green and red wavelength is absorbed more than the light of the other wavelength band Dye-based polarizing film.

An organic light emitting display device having a dye-based polarizing film according to another aspect of the present invention for achieving the above object is formed on a substrate, a light emitting device for emitting light of a predetermined wavelength, formed on the light emitting device A protective film and a dye-based polarizing film is disposed on the protective film, the dye-based polarizing film is a dye composition whose composition ratio is adjusted so that the light of the wavelength band located at the boundary between the green and red wavelengths is absorbed more than the light of the other wavelength band.

In addition, the composition ratio of the dye composition is adjusted so that light in the wavelength band located at the boundary between the blue and green wavelengths is absorbed more than light in the other wavelength band.

The wavelength band located at the boundary between the green and red wavelengths is 530 to 590 nm, and the wavelength band located at the boundary between the blue and green wavelengths is 440 to 470 nm.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. no.

In general, the organic light emitting diode display emits blue, green, and red light. FIG. 2 is a light emission spectrum of green (G1 and G2) and red (R1 and R2) emitted from a general organic light emitting display configured in an active matrix manner, and green (G1 and G2) have a wavelength of about 500 nm and red It can be seen that (R1 and R2) have a wavelength of about 630 nm. In addition, it can be seen that the non-emission wavelength band exists at the boundary portion between the green (G) and red (R) wavelengths.

If the light of the non-emission wavelength band that does not contribute to the display of an image, that is, the light of the wavelength band located at the boundary of blue (B) and green (G) and the boundary of green (G) and red (R), If it is not emitted to the outside may be improved polarization characteristics.

According to the present invention, a dye-based polarizing film is prepared by blending various types of dyes, for example, 4-5 types of dyes, to dye the polyvinyl alcohol film so that uniform absorption occurs over a visible light propagation band. When the dyes are formulated to produce a dye composition, it absorbs more light in the non-emission wavelength band located at the boundaries of the green (G) and red (R) wavelengths, which contributes to the display of the image. Adjust the composition ratio of the dyes. In addition, if necessary, the composition ratio of the dyes is adjusted to further absorb light in the non-emission wavelength band located at the boundary between the blue (B) and green (G) wavelengths.

The non-emitting wavelength band located at the boundary between the green (G) and red (R) wavelengths is about 530 to 590 nm, and the non-emitting wavelength band located at the boundary between the blue (B) and green (G) wavelengths is 440 to 470. It is about nm.

Dyestuffs formulated to have uniform absorption across the visible light field have a light absorption bandwidth on the order of 10 to 100 nm. Therefore, by adjusting the composition ratio of the dyes, the light of the non-emission wavelength band located at the boundary of the green (G) and red (R) wavelengths and the non-emission wavelength band located at the boundary of the blue (B) and green (G) wavelengths is further added. By absorbing, the transmittance of the wavelength band can be lowered. Japanese Patent Laid-Open Nos. 62-123405, 62-156602 and 1-260402 describe materials and composition ratios that absorb light in the wavelength band.

That is, in the present invention, a composition is prepared by combining various types of dyes so that uniform absorption occurs over a visible light propagation band, and a non-light-emitting wavelength band and a blue ( The composition ratio of the dyes is adjusted to absorb more light in the non-emission wavelength band located at the boundary of B) and green (G) wavelengths than light in other wavelength bands. Then, the composition thus prepared is mixed with an aqueous solution such as distilled water to form an aqueous dye solution, and the composition is deposited on the polyvinyl alcohol film using the aqueous dye solution. The dye adsorption process may occur before, during or after stretching the polyvinyl alcohol film. When the adsorption and stretching process is completed, the processes such as fixing, washing and drying are performed.

Figure 3 is a graph measuring the transmittance according to the wavelength after manufacturing the dye-based polarizing film as described above, by adjusting the composition ratio of the dye composition to further absorb the light of the non-emitting wavelength band transmittance in the 530 to 590 nm band It can be seen that the polarization characteristic is effectively reduced, thereby improving.

4 to 6 are schematic cross-sectional views illustrating an organic light emitting display device including a dye-based polarizing film according to an exemplary embodiment of the present invention.

A light emitting device 110 for emitting a predetermined light is formed on the insulating substrate 100 made of a transparent material such as glass, and an encapsulation substrate 120 made of a transparent material is formed on the light emitting device 110. ) To the insulating substrate 100. In addition, a phase difference plate 130 is disposed on the insulating substrate 100 or the encapsulation substrate 120 along the path of the light emitted from the light emitting element 110 to change the phase of incident light by a predetermined angle. do. The dye-based polarizing film 140 is disposed on the retardation plate 130 to transmit light in a specific polarization direction and absorb light in a polarization direction different from the polarization direction. An anti-reflection film (not shown) such as an anti-glare film or an anti-reflection film may be formed on the surface of the dye-based polarizing film 140 to reduce reflection of external light.

The light emitting device 110 is configured in a passive matrix method including a lower electrode, an organic thin film layer, and an upper electrode, or includes a lower electrode, an organic thin film layer, and an upper electrode, and a thin film transistor (TFT) in which an operation of each pixel serves as a switch. It can be configured in an active matrix manner controlled by. The lower electrode is an anode electrode, and is formed of a transparent electrode material such as ITO, IZO, ITZO, etc., and the organic thin film layer has a structure in which a hole transport layer, an organic light emitting layer, and an electron transport layer are stacked, or a hole injection layer and an electron transport layer formed in the hole transport layer. An electron injection layer formed on the may be further included. The upper electrode is a cathode electrode, and is formed of a metal having a low work function such as Ca, Mg, Al, Ag, or the like.

The retardation plate 130 is composed of, for example, a λ / 4 retardation plate capable of changing the phase of incident light by 45 °.

The dye-based polarizing film 140 is light emitted from the light emitting device 110, that is, light in a wavelength band located at a boundary between green (G) and red (R) wavelengths and / or at a boundary between blue and green wavelengths. The dye composition whose composition ratio is adjusted so that light in a wavelength band is absorbed more than light in another wavelength band has a structure in which a dye composition is dyed in a polyvinyl alcohol film.

The non-emitting wavelength band located at the boundary between the green (G) and red (R) wavelengths is about 530 to 590 nm, and the non-emitting wavelength band located at the boundary between the blue (B) and green (G) wavelengths is 440 to 470. It is about nm.

As the first embodiment of the present invention, when the light emitting device 110 is configured in the bottom emission method, as shown in Figure 4, the retardation plate 130 and the dye-based polarizing film 140 in the lower portion of the insulating substrate 100 Is placed.

As a second embodiment of the present invention, when the light emitting device 110 is configured in a top emission method, as shown in FIG. 5, the retardation plate 130 and the dye-based polarizing film 140 on the encapsulation substrate 120. Is placed.

As a third embodiment of the present invention, when the light emitting device 110 is configured in a double-sided light emission method, as shown in Figure 6, the retardation plate 130 on the lower portion of the insulating substrate 100 and the upper portion of the encapsulation substrate 120, respectively ) And the dye-based polarizing film 140 is disposed.

4 to 6 illustrate a structure in which the retardation plate 130 and the dye-based polarizing film 140 are disposed on the insulating substrate 100 and the encapsulation substrate 120, but the insulating substrate 100 and the encapsulation substrate ( The retardation plate 130 and the dye-based polarizing film 140 may be disposed on the rear surface of the 120, and any layer may be interposed between the retardation plate 130 and the dye-based polarizing film 140. have.

FIG. 7 is a cross-sectional view illustrating an organic light emitting diode display including a dye-based polarizing film according to a fourth exemplary embodiment of the present invention. Although FIG. 7 is structurally similar to the organic light emitting diode display illustrated in FIG. On the entire upper surface of the protective film 150 is formed of a SiNx, SiO ₂ , a multi-layered film of SiNx / SiO ₂ , a multi-layered film of Al ₂ O ₃ / organic, etc., the protective film 150 without forming the encapsulation substrate (120 of FIG. 5). ), The retardation plate 130 and the dye-based polarizing film 140 is disposed.

In the organic light emitting diode display according to the present invention configured as described above, light of blue (B), green (G), and red (R) wavelengths of the light emitted from the light emitting element 110 is transmitted through the dye-based polarizing film 140. Although emitted by the light, the light of the wavelength band located at the boundary between the blue (B) and green (G) and the green (G) and red (R) wavelength is absorbed by the dye-based polarizing film 140 and is not emitted to the outside.

Therefore, the light of the wavelength band located at the boundary between the blue (B), green (G), and red (R) wavelengths is absorbed by the dye-based polarizing film 140 as described above, and the reflection of external light is also reduced by the same principle. As a result, the polarization characteristic is improved, and the contrast ratio indicating the degree to which the image can be clearly recognized is improved.

As described above, the preferred embodiment of the present invention has been disclosed through the detailed description and the drawings. The terms are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the dye-based polarizing film of the present invention has improved polarization characteristics by selectively absorbing light in a non-emission band located at the boundary between blue and green and green and red wavelengths, and has high durability, such as thermal characteristics, at high temperatures. The polarization characteristics do not deteriorate and are not easily altered in harsh environments such as high temperature and high humidity.

In addition, the organic light emitting display device including the dye-based polarizing film of the present invention has a high contrast ratio due to high polarization degree and less reflection of an external light source due to selective light absorption characteristics of the dye-based polarizing film.

Claims (15)

A dye-based polarizing film in which the dye composition whose composition ratio is adjusted is soaked that light in a wavelength band positioned at a boundary between green and red wavelengths is absorbed more than light in another wavelength band. The dye-based polarizing film of claim 1, wherein the wavelength band located at the boundary between the green and red wavelengths is 530 to 590 nm. The dye-based polarizing film of claim 1, wherein the composition ratio of the dye composition is adjusted so that light in a wavelength band positioned at a boundary between blue and green wavelengths is absorbed more than light in the other wavelength band. The dye-based polarizing film of claim 3, wherein the wavelength band located at the boundary between the blue and green wavelengths is 440 to 470 nm. The dye-based polarizing film of claim 1, wherein the dye composition is dyed to a polyvinyl alcohol film. A first substrate and a second substrate, A light emitting element formed between the first substrate and the second substrate and emitting light having a predetermined wavelength; The dye composition is disposed on the substrate of the path of the light emitted from the light emitting device, the dye composition is adjusted to adjust the composition ratio so that the light of the wavelength band located at the boundary of the green and red wavelengths is absorbed more than the light of the other wavelength band An organic light emitting display device comprising a dye-based polarizing film comprising a dye-based polarizing film. The organic light emitting diode display of claim 6, wherein the wavelength band positioned at the boundary between the green and the red wavelengths is 530 to 590 nm. The organic light emitting diode display of claim 6, further comprising a dye-based polarizing film having a composition ratio of the dye composition adjusted so that light in a wavelength band positioned at a boundary between blue and green wavelengths is absorbed more than light in the other wavelength band. The organic light emitting diode display of claim 8, wherein the wavelength band positioned at the boundary between the blue and the green wavelengths is 440 nm to 470 nm. The dye-based polarizing film of claim 6, further comprising a retardation plate disposed between the substrate and the dye-based polarizing film of the path of the light emitted from the light emitting element, and changing the phase of incident light. An organic light emitting display device. Board, A light emitting device formed on the substrate and emitting light; A protective film formed on the light emitting element, A dye-based polarizing film comprising a dye-based polarizing film is disposed on the protective film, the dye-based polarizing film is a dye composition whose composition ratio is adjusted so that the light of the wavelength band located at the boundary of the green and red wavelength is absorbed more than the light of the other wavelength band An organic light emitting display device having a. The organic light emitting diode display of claim 11, wherein the wavelength band positioned at the boundary between the green and the red wavelengths is 530 to 590 nm. The organic light emitting diode display of claim 11, further comprising a dye-based polarizing film whose composition ratio of the dye composition is adjusted so that light in a wavelength band positioned at a boundary between blue and green wavelengths is absorbed more than light in the other wavelength band. The organic light emitting diode display of claim 13, wherein the wavelength band positioned at the boundary between the blue and the green wavelengths is 440 nm to 470 nm. The organic light emitting display device of claim 11, further comprising a phase difference plate disposed between the protective layer and the dye-based polarizing film and changing a phase of incident light.

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