KR20200060861A - Organic light emitting diodes display - Google Patents

Abstract

The present invention relates to an organic light emitting display device and, more particularly, to an organic light emitting display device with reduced color shift due to an increased viewing angle of red light. According to the present invention, on an upper portion of a substrate to which the light of the OLED is emitted, a total reflection layer including a total reflection pattern is positioned to have a refractive index difference of 0.5 or more, and a red dye pattern is located on the total reflection pattern. The total reflection pattern is positioned corresponding to a red sub-pixel so that light proceeding at a viewing angle of 45 degrees or less among red light emitted from the red sub-pixel is incident into the total reflection pattern and penetrates the red dye pattern, thereby making all the red light emitted from the red sub-pixels have a unique red color. Accordingly, in the OLED according to the embodiment of the present invention, a lateral luminance ratio at the viewing angle of 0 to 45 degrees of red light is implemented differently, thereby preventing the image quality of a product from deteriorating.

Description

Organic light emitting diodes {Organic light emitting diodes display}

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device in which the color shift phenomenon is improved according to an increased viewing angle.

Recently, as the society has entered a full-fledged information age, interest in an information display that processes and displays a large amount of information is increasing, and as the demand to use a portable information medium increases, various various light weights respond to this. And thin flat panel display devices have been developed and are in the spotlight.

In particular, among various flat panel display devices, organic light emitting diodes (OLEDs) are self-luminous devices and do not require a backlight used for a liquid crystal display device (LCD), which is a non-light emitting device. Light and thin is possible.

In addition, the viewing angle and contrast ratio are superior to that of a liquid crystal display device, and it is advantageous in terms of power consumption, DC low voltage driving is possible, response speed is fast, and internal components are solid, so it is strong against external shock and has a wide operating temperature range. It has advantages.

On the other hand, such OLEDs are lost in the process that light emitted from the organic light emitting layer passes through various components of the OLED and is emitted to the outside, so that light emitted to the outside of the OLED is about 20% of the light emitted from the organic light emitting layer. It is only.

Here, since the amount of light emitted from the organic light emitting layer increases with the magnitude of the current applied to the OLED, it is possible to increase the brightness of the OLED by applying more current to the organic light emitting layer, but this increases power consumption, In addition, the lifetime of the OLED is also reduced.

Therefore, recently, studies have been actively conducted to implement the micro-cavity effect in order to improve the light efficiency of the OLED. In the micro-cavity effect, the front luminance is increased, but in the side, the color shifts from the long wavelength to the short wavelength. Phenomenon occurs.

This shows a lot of color difference depending on the direction and angle of viewing the OLED, and acts as a factor that degrades the image quality of the actual product.

The present invention is to solve the above problems, and an object of the present invention is to provide an OLED that is prevented from being deteriorated due to an increase in viewing angle.

To achieve the above object, a substrate including red, green, and blue subpixels, a driving thin film transistor and a light emitting diode provided for each of the red, green, and blue subpixels, the driving thin film transistor, and the light emission A protective film covering the diode and a transmissive layer positioned in a transmission direction of light emitted from the light emitting diode, and having a total reflection pattern corresponding to the red sub-pixel, wherein the total reflection pattern is emitted from the red sub-pixel It provides an organic light emitting display device having a total reflection property for light of 45 degrees or more of the red light.

In this case, the total reflection pattern includes a red dye pattern, and among the red light emitted from the red sub-pixel, light traveling at a viewing angle within 45 degrees penetrates the red dye pattern provided in the total reflection pattern, and the total reflection layer and the The total reflection pattern has a refractive index difference of 0.5 or more.

In addition, the total reflection pattern is formed of a groove having a cylindrical shape, the width of which increases from the lower surface adjacent to the substrate toward the upper surface facing the lower surface, and the red dye pattern is the widest width of the total reflection pattern. It is located correspondingly.

Then, the red dye pattern is made of a low-refractive dye material, and fills the interior of the total reflection pattern, the low-reflection layer is positioned between the light emitting diode and the phase difference plate, and a linear polarizing plate is positioned above the phase difference plate.

In addition, the light emitting diode located in the red subpixel has a first thickness, the light emitting diode located in the green subpixel has a second thickness, and the light emitting diode located in the blue subpixel has a third thickness. And the first to third thicknesses are different from each other, and the first to third thicknesses are distances between the first electrode and the second electrode of the light emitting diode.

In this case, the driving thin film transistor includes a semiconductor layer, a gate insulating film positioned on the semiconductor layer, a gate electrode positioned on the gate insulating film, a first interlayer insulating film positioned on the gate electrode, and a first interlayer insulating film. Source and drain electrodes,

The light emitting diode includes a first electrode connected to the driving thin film transistor, an organic light emitting layer positioned on the first electrode, and a second electrode positioned on the organic light emitting layer.

As described above, according to the present invention, an upper reflection layer including a total reflection pattern is positioned to have a refractive index difference of 0.5 or more to an upper portion of a substrate through which OLED light is emitted, and a red dye pattern is positioned in the total reflection pattern. , The total reflection pattern is positioned in correspondence with the red sub-pixel, so that light traveling at a viewing angle of 45 degrees or less of the red light emitted from the red sub-pixel is incident into the total reflection pattern, and transmitted through the red dye pattern, thereby making the red sub-pixel There is an effect that can cause all of the red light emitted from to have a unique red color.

Through this, the OLED according to the exemplary embodiment of the present invention has different side luminance ratios at a viewing angle of 0 to 45 degrees of red light, thereby preventing the image quality of the product from deteriorating.

1 is a plan view schematically showing an arrangement of some pixels and subpixels of an OLED according to an embodiment of the present invention.
2 is a graph showing luminance distribution according to a viewing angle of red light.
FIG. 3 is a cross-sectional view schematically showing a first red pixel of FIG. 1 and a second red subpixel of a second pixel adjacent to the first pixel.
4A to 4C are schematic diagrams showing the relationship between the total reflection pattern and the red sub-pixels according to an embodiment of the present invention.
5 is a graph showing the results of measuring whether total reflection occurs depending on the viewing angle according to the difference in refractive index between the total reflection layer and the total reflection pattern.
Figure 6 is a cross-sectional view schematically showing another configuration of the total reflection layer according to an embodiment of the present invention.
7 is a cross-sectional view schematically showing a luminance enhancement film including a total reflection layer according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

1 is a plan view schematically showing an arrangement of some pixels and subpixels of an OLED according to an embodiment of the present invention.

As illustrated, the OLED 100 according to an embodiment of the present invention includes a plurality of pixels 1P, 2P, and each one pixel 1P, 2P includes four subs to realize full color. Pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP).

4 subpixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) are red subpixels (1R-SP, 2R-SP) And blue sub-pixels (1B-SP, 2B-SP) and first and second green sub-pixels (1G-SP, 2G-SP, 3G-SP, 4G-SP).

That is, the first red sub-pixel (1R-SP) and the first blue sub-pixel (1B-SP) and the first and second green sub-pixels (1G-SP, 2G-SP, 3G-SP, 4G-SP) The first pixel 1P is formed, and the second red subpixel (2R-SP), the second blue subpixel (2B-SP), and the third and fourth green subpixels (3G-SP, 4G-SP) The second pixel 2P is formed.

Here, since the green sub-pixel (1G-SP, 2G-SP, 3G-SP, 4G-SP) has the highest luminance weight among the three primary colors of R, G, and B, one OLED 100 according to an embodiment of the present invention The luminance is increased by including two green sub-pixels (1G-SP, 2G-SP, 3G-SP, and 4G-SP) in the pixels 1P and 2P.

However, sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) of the OLED 100 are not limited thereto, and the OLED 100, red, green, and blue sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) are each provided one by one Or red subpixel (1R-SP, 2R-SP), green subpixel (1G-SP, 2G-SP, 3G-SP, 4G-SP) and blue subpixel (1B-SP, 2B-SP) In addition, a white sub-pixel (W-SP) may be further included.

And, the area of the green sub-pixels (1G-SP, 2G-SP, 3G-SP, 4G-SP) is shown the smallest, and the area of the blue sub-pixel (1B-SP, 2B-SP) is shown the largest, The area of the sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) is not limited thereto. However, the two green subpixels (1G-SP, 2G-SP, 3G-SP, 4G-SP) provided are red and blue subpixels (1R-SP, 2R-SP, 1B-SP, 2B-SP). It is preferable to form a small area compared to, and the blue sub-pixels (1B-SP, 2B-SP) are red and green sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP) , 4G-SP), it is preferable to form a large area of the blue sub-pixels (1B-SP, 2B-SP) because of poor luminous efficiency.

In addition, each sub-pixel (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) is shown as a polygon, but this is not limited thereto. , Each sub-pixel (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) can have various shapes such as circular, elliptical, and semi-elliptical have.

These sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP) each include a light emitting area (EA, see FIG. 3), , A bank 117 (see FIG. 3) is disposed along the edge of the light emitting area EA (see FIG. 3) to form a non-light emitting area (NEA, see FIG. 3 ), but for convenience of description, light is used here. Only the emitting region (EA, see FIG. 3) emitting light is shown as sub-pixels (1R-SP, 2R-SP, 1G-SP, 2G-SP, 3G-SP, 4G-SP, 1B-SP, 2B-SP). .

Here, as the OLED 100 according to an embodiment of the present invention is designed to implement a micro-cavity effect to improve light efficiency, the front luminance increases, but on the side, light moves from long wavelength to short wavelength. .

That is, the micro-cavity effect is a phenomenon in which the luminance or light intensity of light having a specific wavelength is increased when the optical distance between two surfaces having reflectivity or translucency for incident light satisfies an interference condition for light of a specific wavelength As a result, as the OLED 100 implementing the micro-cavity effect changes the viewing angle from 0 to 60 degrees, the spectral spectrum of red, green, and blue light changes.

2 is a graph showing the distribution of luminance according to the viewing angle of red light, the horizontal axis represents the viewing angle, and the vertical axis represents the color difference (Δu'v', a.u.(arbitrary unit)).

The color contrast to the front is a numerical value expressing a difference from the color at the viewing angle based on the color of light emitted from the light emitting diode (E, see FIG. 3). That is, the difference in color at various viewing angles based on the colors of red, green, blue, and white at 0 degrees is converted into a u'v' value and displayed. .

Referring to FIG. 2, in the case of red light, as the viewing angle changes from 0 to 60 degrees, the peak of the wavelength is moved up to 60 nm, which increases the viewing angle and the color shifts from the long wavelength to the short wavelength. Because it occurs.

Particularly, as the red light changes from 0 to 45 degrees, it can be seen that the rate of change of the red light emission intensity rapidly increases, and after 45 degrees, it can be seen that the rate of change of the red light intensity gradually decreases.

Accordingly, since the lateral luminance ratio at the viewing angle of 0 to 45 degrees is implemented differently, it acts as a large factor that degrades the image quality of the actual product.

Here, the OLED 100 according to an embodiment of the present invention is a polarizing plate 130 positioned on the outer surface of the substrate 101 (see FIG. 3) through which light is transmitted corresponding to the red sub-pixels 1R-SP and 2R-SP. It is characterized in that the total reflection pattern 210 (refer to FIG. 3) including the red dye pattern 220 (refer to FIG. 3) is located in FIG.

The total reflection pattern 210 (refer to FIG. 3) guides light incident at a viewing angle of 0 to 45 degrees to pass through the red dye pattern 220 (refer to FIG. 3), so that a color shift phenomenon at a viewing angle of 0 to 45 degrees is prevented. It can be prevented from occurring.

Through this, the OLED 100 according to an embodiment of the present invention implements different lateral luminance ratios at a viewing angle of 0 to 45 degrees of red light, thereby preventing the image quality of a product from deteriorating.

This will be described in more detail with reference to FIG. 3.

FIG. 3 is a cross-sectional view schematically showing a first red pixel of FIG. 1 and a second red subpixel of a second pixel adjacent to the first pixel.

Prior to the description, each of the sub-pixels (1R-SP, 2R-SP, G-SP, B-SP) of the OLED 100 according to an embodiment of the present invention is a switching and driving thin film transistor (not shown, DTr) However, for convenience of description and conciseness of the drawings, the driving thin film transistor DTr is shown in only one sub-pixel 1R-SP.

In addition, only the first green sub-pixel G-SP is illustrated in the first pixel 1P, and the area in which the light emitting diode E is formed is compared along the edges of the light emitting area EA and the light emitting area EA. It is defined as the light emitting area NEA, and the area in which the driving thin film transistor DTr is formed in the non-light emitting area NEA is defined as the switching area TrA.

In addition, the OLED 100 according to an embodiment of the present invention is divided into an upper emission type (top emission type) and a lower emission type (bottom emission type) according to the transmission direction of the emitted light. Let me explain with an example.

As illustrated, in the OLED 100 according to an embodiment of the present invention, the substrate 101 on which the driving thin film transistor DTr and the light emitting diode E are formed is encapsulated by the protective film 102. .

Looking at this in more detail, the semiconductor layer 103 is located in the switching region TrA of each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) on the substrate 101. 103) is made of silicon, and its central portion is composed of active regions (103a) constituting a channel and source and drain regions (103b, 103c) doped with high concentrations of impurities on both sides of the active region (103a).

The gate insulating layer 105 is positioned above the semiconductor layer 103.

The gate insulating layer 105 is provided with a gate electrode 107 corresponding to the active region 103a of the semiconductor layer 103 and a gate wiring (not shown) extending in one direction although not shown in the drawing.

In addition, the first interlayer insulating film 106a is positioned above the gate electrode 107 and the gate wiring (not shown), wherein the first interlayer insulating film 106a and the lower gate insulating film 105 are active. First and second semiconductor layer contact holes 109 exposing the source and drain regions 103b and 103c located on both sides of the region 103a are provided.

Next, the source and drain regions exposed through the first and second semiconductor layer contact holes 109 spaced apart from each other above the first interlayer insulating film 106a including the first and second semiconductor layer contact holes 109 ( Source and drain electrodes 108a and 108b are respectively provided in contact with 103b and 103c).

In addition, the second interlayer insulating film 106b is positioned on the first interlayer insulating film 106a exposed between the source and drain electrodes 108a and 108b and the two electrodes 108a and 108b.

At this time, the semiconductor layer 103 including the source and drain electrodes 108a and 108b and the source and drain regions 103b and 103c contacting these electrodes 108a and 108b and a gate located on the semiconductor layer 103 The insulating film 105 and the gate electrode 107 form a driving thin film transistor DTr.

On the other hand, although not shown in the drawing, a data wiring (not shown) defining a sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) crossing a gate wiring (not shown) is located, and a switching thin film The transistor (not shown) has the same structure as the driving thin film transistor DTr, and is connected to the driving thin film transistor DTr.

In addition, in the drawing, the switching thin film transistor (not shown) and the driving thin film transistor DTr show, as an example, a top gate type in which the semiconductor layer 103 is made of a polysilicon semiconductor layer or an oxide semiconductor layer. For example, it may be provided as a bottom gate type made of amorphous silicon of pure water and impurities.

At this time, when the semiconductor layer 103 is made of an oxide semiconductor layer, a light blocking layer (not shown) may be further positioned below the semiconductor layer 103, and a buffer layer (not shown) may be provided between the light blocking layer (not shown) and the semiconductor layer 103. City) can be located.

In addition, the first interlayer insulating film 106a and the second interlayer insulating film 106b include a drain contact hole PH exposing the drain electrode 108b, and a driving thin film transistor is disposed above the second interlayer insulating film 106b. The first electrode 111, which is connected to the drain electrode 108b of (DTr) and which forms, for example, a material having a relatively high work function value, forms an anode of the light emitting diode E, is located.

The first electrode 111 is a metal oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO), a metal oxide such as ZnO:Al or SnO ₂ :Sb , Poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole and conductive polymers such as polyaniline. In addition, it may be made of carbon nanotubes (CNT), graphene, silver nanowires, and the like.

The first electrode 111 is located for each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP), and each sub-pixel (1R-SP, 2R-SP, G-SP, B- The banks 117 are positioned between the first electrodes 111 positioned for each SP). That is, the first electrode 111 sets the bank 117 as a boundary for each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) and sub-pixels (1R-SP, 2R-SP, G) -SP, B-SP).

And the organic light emitting layer 113 is positioned on the first electrode 111, the organic light emitting layer 113 may be composed of a single layer made of a light emitting material, a hole injection layer (hole injection layer) to increase the light emission efficiency , A hole transport layer, an emitting material layer, an electron transport layer, and an electron injection layer.

In addition, a second electrode 115 forming a cathode is positioned on the front side of the organic light emitting layer 113.

The second electrode 115 may be made of a material having a relatively small work function value. At this time, the second electrode 115 has a double layer structure, and a single metal of a first metal made of Ag or the like, which is a metal material having a low work function, and a second metal made of Mg or the like are composed of a single layer of an alloy or a plurality of layers thereof. Can be configured.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to the selected signal, the OLED 100 is provided from the holes injected from the first electrode 111 and the second electrode 115. Electrons are transported to the organic light emitting layer 113 to form excitons, and when these excitons transition from an excited state to a ground state, light is generated and emitted in the form of visible light.

Here, as light emitted from the organic light emitting layer 113 of each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) passes through the first electrode 111 and is emitted to the outside, the light-emitting region (EA) may be defined corresponding to the area of the first electrode 111 through which light is transmitted, wherein the first electrode 111 is connected to the driving thin film transistor DTr located in the switching region TrA. Except for, it may be defined corresponding to only an area through which light is substantially transmitted. Meanwhile, the OLED 100 according to an embodiment of the present invention is a bottom emission type in which light emitted from the organic light emitting layer 113 is output to the outside through the first electrode 111, at this time, the second The electrode 115 further includes a reflective layer (not shown) made of an opaque conductive material. In one example, the reflective layer may be formed of an aluminum-paladium-copper (APC) alloy, and the second electrode 115 may have a triple layer structure of ITO/APC/ITO.

In addition, the first electrode 115 may be formed of a semi-transmissive conductive material, such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). When the first electrode 111 is formed of a semi-transmissive metal material, light emission efficiency may be increased by a micro cavity.

That is, the light emitting diode E according to an embodiment of the present invention is between the first electrode 111 and the second electrode 115 for each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) By forming the distance of different, it is to implement the micro-cavity effect.

Here, the micro cavity effect means that only light of a certain wavelength is maintained and light of the other wavelengths is canceled as the light reflected between the mirror and the mirror is canceled or constructively interfered, thereby increasing the intensity of light of a specific wavelength or , It decreases the intensity of light of a specific wavelength.

In order to realize the micro-cavity effect, the first electrode 111 and the second electrode for each sub-pixel (1R-SP, 2R-SP, G-SP, B-SP) have a resonance wavelength corresponding to a desired peak color wavelength. A microcavity depth or length between 115 or between the first and second electrodes 111 and 115 and the light emitting film of the organic light emitting layer 113 is configured.

Looking at this in more detail, in the OLED 100 according to the present application, one unit pixel 1P may be composed of adjacent red, green, and blue subpixels (1R-SP, G-SP, B-SP) , Here, since the effective micro-cavity depth is defined by the optical distance, which is the wavelength, the micro-cavity depth for the red sub-pixel (1R-SP) is higher than that of the green sub-pixel (G-SP) because the wavelength of the red light is longer than the wavelength of the green light. It can be configured to be deeper than the depth of the microcavity.

In addition, since the wavelength of the green light is longer than the wavelength of the blue light, the depth of the micro cavity for the green sub-pixel (G-SP) may be configured to be deeper than the depth of the micro cavity for the blue sub-pixel (B-SP).

Here, the red, green, and blue sub-pixels (1R-SP, G-SP, B-SP) preferably satisfy the following (Equation 1) in order to realize the micro-cavity effect.

(Equation 1)

nd = (2m-1)λ(m=0, 1, 2, ?)

Here, n is the refractive index of the light emitting film EML of the organic light emitting layer 113, d is the distance between the light emitting film EML and the second electrode 115, m is a constant, and λ is a desired center wavelength.

Accordingly, as an example, the first electrode 111 of the red sub-pixel (1R-SP) is formed with a first thickness, and the first electrode 111 of the green sub-pixel (G-SP) is the second thinner than the first thickness. The first electrode 111 of the blue sub-pixel (B-SP) may be formed to a third thickness thinner than the second thickness.

The first electrode 111 of the red sub-pixel (1R-SP) by the first electrode 111 formed of a differential thickness for each of the red, green and blue sub-pixels (1R-SP, G-SP, B-SP) ), the distance from the first electrode 111 of the blue sub-pixel (B-SP) to the second electrode 115 is the closest, and the green sub-pixel (G-SP) The distance from the first electrode 111 to the second electrode 115 may be formed to have an intermediate distance.

That is, the micro cavity depth of the red subpixel (1R-SP) is the longest, the micro cavity depth of the blue subpixel (B-SP) is the shortest, and the micro cavity depth of the green subpixel (G-SP) is the medium length. It can be formed to have.

Accordingly, since the emitted light can be reinforced for each sub-pixel (1R-SP, G-SP, B-SP), the luminous efficiency in each sub-pixel (1R-SP, G-SP, B-SP) can be improved. It can be optimized to lower power consumption.

And, after placing the thin film layer-shaped encap substrate 102 on top of the driving thin film transistor DTr and the light emitting diode E, it is transparent between the light emitting diode E and the encap substrate 102 and has adhesive properties. By bonding the encapsulation substrate 102 and the substrate 101 through a face seal 104 made of an organic or inorganic insulating material, the display panel 110 is encapsulated.

Here, the protective film 102 is used by laminating at least two inorganic protective films to prevent external oxygen and moisture from penetrating into the OLED 100, wherein the inorganic protective films are interposed between the two inorganic protective films. It is preferable that an organic protective film is interposed to compensate for the impact resistance of.

In such a structure in which the organic protective film and the inorganic protective film are alternately stacked alternately, the inorganic protective film is preferably composed of a structure that completely covers the organic protective film because moisture and oxygen must be prevented from penetrating through the side surface of the organic protective film. Do.

Therefore, the OLED 100 can prevent moisture and oxygen from penetrating into the OLED 100 from the outside.

Through this, due to oxygen or moisture introduced into the inside, oxidation and corrosion of the electrode layer can be prevented, and thus, the emission characteristics of the organic emission layer 113 are reduced, and the life of the organic emission layer 113 is shortened. Problems can be prevented.

In addition, current leakage and short circuits can be prevented, and pixel defects can be prevented. This prevents a problem in which luminance or image characteristics are non-uniform.

In addition, in the OLED 100 according to an embodiment of the present invention, a polarizing plate 130 for preventing a decrease in contrast due to external light is positioned on the outer surface of the substrate 101 through which light is transmitted.

That is, the OLED 100 improves contrast by positioning the polarizing plate 130 that blocks external light incident from the outside in the transmission direction of the light emitted through the organic light emitting layer 113 in the driving mode for realizing an image. .

At this time, a first adhesive layer 131a that is transparent and has adhesive properties may be interposed between the polarizing plate 130 and the substrate 101.

The polarizing plate 130 is a circular polarizing plate for blocking external light, and is composed of a retardation plate 133 and a linear polarizing plate 135 attached to the outer surface of the substrate 101, the linear polarizing plate 135 and the retardation plate 133 The second adhesive layer 131b is interposed therebetween, and the linearly polarizing plate 135 and the retardation plate 133 are also attached to each other.

At this time, the stacking order of the linearly polarizing plate 135 and the retardation plate 133 is preferably a structure in which the linearly polarizing plate 135 is disposed to be close to the incident direction of external light and the retardation plate 133 is disposed therein.

The phase difference plate 133 is made of a quarter wave plate (QWP) having a 1/4λ phase delay value.

Then, the linearly polarizing plate 135 has a polarization axis, and linearly polarizes light in the direction of the polarization axis. Specifically, the linear polarizing plate 135 passes light that matches the polarization axis and absorbs light that does not match the polarization axis. Therefore, when the light passes through the linear polarizing plate 135, it is linearly polarized in the polarization axis direction.

In addition, a surface treatment layer (not shown) may be further included on the outside of the linear polarizing plate 135, and the surface treatment layer (not shown) includes anti-glare containing silica beads (not shown). ) Layer, or a hard coating layer for preventing damage to the surface of the polarizing plate 135.

Through this, the OLED 100 according to an embodiment of the present invention can minimize the reflection of external light through the polarizing plate 130 to prevent a decrease in contrast.

Particularly, in the OLED 100 according to an embodiment of the present invention, the total reflection layer 200 provided with the total reflection pattern 210 is further positioned between the phase difference plate 133 and the substrate 101, that is, the phase difference plate 133. The third adhesive layer 131c is interposed between the total reflection layer 200 and the first adhesive layer 131a is interposed between the total reflection layer 200 and the substrate 101.

The total reflection layer 200 includes a total reflection pattern 210, the total reflection pattern 210 includes a red dye pattern 220 to transmit light guided by the total reflection pattern 210, and the total reflection pattern 210 Is positioned corresponding to only the red sub-pixels (1R-SP, 2R-SP).

That is, the total reflection pattern 210 is positioned to correspond to the emission area EA of the red sub-pixels (1R-SP, 2R-SP), by the total reflection pattern 210, to the red sub-pixel (1R-SP , 2R-SP), among the red light emitted from the light, the light traveling from a viewing angle of 45 degrees to 60 degrees where color migration does not occur is totally reflected and is emitted outward, but from 0 to 45 degrees where color migration occurs The light traveling at the viewing angle is transmitted through the red dye pattern 220 provided in the total reflection pattern 210.

Through this, it is possible to prevent the color shift phenomenon from occurring at a viewing angle of 0 to 45 degrees.

Through this, the OLED 100 according to the exemplary embodiment of the present invention has different lateral luminance ratios at a viewing angle of 0 to 45 degrees, thereby preventing the image quality of the product from deteriorating.

It will be described in more detail with reference to FIGS. 4A and 4C.

4A to 4C are schematic diagrams showing easily the relationship between the total reflection pattern and the red sub-pixel according to an embodiment of the present invention.

And, Figure 5 is a graph showing the results of measuring whether total reflection occurs depending on the viewing angle, depending on the difference in refractive index between the total reflection layer and the total reflection pattern.

As illustrated in FIGS. 4A to 4B, a total reflection pattern (from the red sub-pixels 1R-SP, 2R-SP) to the front in which red light is emitted corresponding to each red sub-pixel (1R-SP, 2R-SP) The total reflection layer 200 including 210 is located, wherein the total reflection pattern 210 is a cylindrical groove having a narrower width from the upper surface 201 of the total reflection layer 200 toward the lower surface 202. Is made of

Here, the upper surface 201 of the total reflection layer 200 is defined as one surface in close contact with the third adhesive layer (131c of FIG. 3) of the polarizing plate (130 of FIG. 3), and the lower surface 202 of the OLED (FIG. 3) 100) is defined as the other surface in close contact with the first adhesive layer (131a in FIG. 3) provided for adhesion to the substrate (101 in FIG. 3).

The total reflection layer 200 has a relatively high refractive index compared to the total reflection pattern 210. The total reflection layer 200 has a refractive index of 1.5 or more, and a refractive index difference of 0.5 or more from the total reflection pattern 210.

Therefore, the total reflection layer 200 is made of a mixture of any one or two or more of siloxane polymer material, metalloxane polymer, polyimide, acrylate, and urethane resin The total reflection pattern 210 may be made of the above materials within a limit in which a difference in refractive index between the total reflection layer 200 and 0.5 or more is obtained.

Also, the total reflection pattern 210 may be made of air having a refractive index of 1.

5 is a graph showing the luminance distribution according to the viewing angle by total reflection, the horizontal axis represents the viewing angle, and the vertical axis represents the color difference (au (arbitrary unit)) compared to the front, and the total reflection layer 200 and the total reflection pattern 210 ) Is the experiment result of measuring the luminance distribution due to the occurrence of total reflection by varying only the refractive index difference.

Here, A'represents a case where the difference in refractive index between the total reflection layer 200 and the total reflection pattern 210 is 0.1, and B'represents a case where the difference in refractive index between the total reflection layer 200 and the total reflection pattern 210 is 0.2. And, C'is a case where the total reflection layer 200 and the total reflection pattern 210 have a refractive index difference of 0.3, D'is 0.5, E'represents a case having a refractive index difference of 0.6.

Referring to FIG. 5, it can be seen that the luminance distribution does not occur at any viewing angle when the refractive index difference between the total reflection layer 200 and the total reflection pattern 210 is 0.4 or less, which in turn results in the total reflection layer 200 and the total reflection pattern 210. When the difference in refractive index of is designed to be 0.4 or less (A', B', C'), total reflection does not occur, which means that the luminance distribution remains the same.

On the other hand, when the difference in refractive index between the total reflection layer 200 and the total reflection pattern 210 is 0.5 or more (D', E'), it can be seen that total reflection occurs from a viewing angle of 30 degrees or more, through which a viewing angle of 30 degrees or more If the difference between the refractive indices of the total reflection layer 200 and the total reflection pattern 210 is 0.5 or more, the traveling light is totally reflected by the total reflection pattern 210.

Therefore, by designing the refractive index difference between the total reflection layer 200 and the total reflection pattern 210 of the present invention to be 0.5 or more, the OLED according to an embodiment of the present invention (100 in FIG. 3) proceeds with a viewing angle of 45 degrees or more. Through the total reflection pattern 210 may be reflected.

In addition, the total reflection pattern 210 further includes a red dye pattern 220, and the red dye pattern 220 corresponds to the widest width of the total reflection pattern 210 so that light entering the total reflection pattern 210 is transmitted. Will be located.

Accordingly, among the red lights emitted from the red sub-pixels 1R-SP and 2R-SP, light F1 traveling at a viewing angle of 45 degrees or less as shown in FIG. 4A, that is, emitted from the red sub-pixels 1R-SP Since the light F1 positioned between the 0 and 45 degrees of the angle of progress of the generated light proceeds to the total reflection pattern 210 at an angle smaller than the critical angle, the light F1 proceeding at an angle smaller than the critical angle is total reflection pattern 210 ) To enter the total reflection pattern 210.

Here, the total reflection pattern 210 serves to guide the light F1 traveling at a viewing angle between 0 and 45 degrees into the total reflection pattern 210.

Therefore, the light F1 traveling at a viewing angle between 0 and 45 degrees passes through the total reflection pattern 210 and enters into the total reflection pattern 210, and thus the light incident into the total reflection pattern 210 ( F1) are either immediately transmitted through the red dye pattern 220 or again totally reflected within the total reflection pattern 210 to transmit the red dye pattern 220.

Since the light F1 traveling at a viewing angle within 0 to 45 degrees passing through the red dye pattern 220 has a natural red color without a color shift phenomenon, a red light with improved color purity is finally output. .

Accordingly, all of the red light emitted from the red sub-pixel (1R-SP) has a unique red color, and is transmitted through the total reflection layer 200.

Through this, in the OLED according to the embodiment of the present invention (100 in FIG. 3), light (F1) traveling at a viewing angle of 0 to 45 degrees is color shifted, so that a side luminance ratio at a viewing angle of 0 to 45 degrees is different for red light. It is possible to prevent it from being implemented.

On the other hand, as shown in FIG. 4B, among the light emitted from the red sub-pixels 1R-SP and 2R-SP, the light F2 proceeds at a viewing angle of 45 degrees or more, that is, the red sub-pixels 1R-SP, 2R -The light F2 emitted from the SP is greater than or equal to the critical angle with the total reflection pattern 210 because the angle of travel of 45 degrees or more is reflected by the total reflection pattern 210 to reflect the total reflection layer 200. It penetrates and is immediately discharged to the outside.

Here, light F2, which typically proceeds with a viewing angle of 45 degrees or more, may be defined as light incident from neighboring red sub-pixels 1R-SP and 2R-SP.

As the red light F2 traveling at a viewing angle of 45 degrees or more generates relatively little color shift, the red light emitted from the red sub-pixels (1R-SP, 2R-SP) transmits the total reflection layer 200 as it is and transmits it to the outside. Will be released.

Here, the red light (F1, F2) emitted from the red sub-pixels (1R-SP, 2R-SP) is relatively lower in luminance as the viewing angle increases, which occurs in both blue light and green light in addition to the red light (F1, F2) As a natural phenomenon, when the red light F2 traveling at a viewing angle of 45 degrees or more that does not cause a separate color shift phenomenon is transmitted through the red dye pattern 220, its luminance is further lowered.

Therefore, the red light F2 traveling at a viewing angle of 45 degrees or more that does not cause a separate color shift phenomenon is totally reflected by the total reflection pattern 210 so that it does not pass through the red dye pattern 220 and is still emitted to the outside. It is preferable to prevent the luminance of the red light F2 going at a viewing angle of 45 degrees or more from being lowered.

That is, the OLED according to an embodiment of the present invention (100 in FIG. 3) is a light traveling from 0 to 45 degrees as the color shift phenomenon occurs only at light (F1) traveling at a viewing angle of 0 to 45 degrees, the light traveling at a viewing angle from 0 to 45 degrees ( By allowing only F1) to be totally reflected by the total reflection pattern 210 so as to pass through the red dye pattern 220, it is possible to prevent the color shift phenomenon caused by light F1 proceeding from a viewing angle of 0 to 45 degrees from occurring. Will be.

Therefore, the color shift phenomenon of the light F1 proceeding from a viewing angle of 0 to 45 degrees prevents the lateral luminance ratio at a viewing angle of 0 to 45 degrees from being differently implemented, thereby degrading the image quality of the product. At the same time, the light F2 traveling at a viewing angle of 45 degrees or more in which a color shift phenomenon is not relatively generated is totally reflected by the total reflection pattern 210 so that the red dye pattern 220 is not transmitted. , It is possible to prevent the light F2 traveling at a viewing angle of 45 degrees or more from being lowered by the red dye pattern 220.

Here, in the OLED according to the embodiment of the present invention (100 in FIG. 3), the red dye pattern 220 corresponds to the red sub-pixels (1R-SP, 2R-SP), respectively, and each red sub-pixel (1R-SP, 2R) In the process of placing the light of -SP in the front where light is emitted, the area of each red dye pattern 220 is formed similarly to each red sub-pixel (1R-SP, 2R-SP), but is substantially red sub-pixel. When the area of the (1R-SP, 2R-SP) and the area of the red dye pattern 220 are formed similarly, the light emitted from the red sub-pixels (1R-SP, 2R-SP) as shown in FIG. 4C. Some of the light F3 does not proceed toward the total reflection pattern 210 but directly passes through the total reflection layer 200 and is emitted to the outside.

Accordingly, a color shift phenomenon may occur due to the light F3, and in order to prevent this, the area D2 of the red dye pattern 220 is the area D1 of the red sub-pixels 1R-SP and 2R-SP. In comparison, an area d corresponding to a slope of up to 45 degrees of red light emitted from the red sub-pixels 1R-SP and 2R-SP may be formed to be larger.

That is, the red dye pattern 220 is preferably formed to have a larger area (D2) that satisfies (Equation 1) below the area (D1) of the red sub-pixels (1R-SP, 2R-SP).

(Equation 1)

d = a*tan45°

Here, d represents the distance of one side extending from the red sub-pixels (1R-SP, 2R-SP), and a represents the distance between the red sub-pixels (1R-SP, 2R-SP) and the total reflection pattern 210 .

Therefore, all of the red lights F1, F2, and F3 traveling at a viewing angle within 45 degrees can be transmitted through the red dye pattern 220 provided in the total reflection pattern 210.

Through this, it is possible to more effectively prevent the color shift phenomenon caused by the red light (F1, F2, F3) emitted from the red sub-pixel (1R-SP, 2R-SP).

However, when the area of the red dye pattern 220 is formed larger than the area of the red sub-pixels 1R-SP and 2R-SP, red light emitted from the red sub-pixels 1R-SP and 2R-SP is formed. The color shift phenomenon due to can be more significantly reduced, but some of the blue light and green light emitted from the blue sub-pixel (B-SP in FIG. 3) and the green sub-pixel (G-SP in FIG. 3) are red dye patterns 220 ).

The blue light and the green light that are transmitted through the red dye pattern 220 are redish, and the luminance of the blue light and green light may be lowered. Therefore, in consideration of this, the area of the red dye pattern 220 is intended to be realized. It should be properly designed according to the purpose and effect.

Preferably, it is desirable to design to satisfy d <1/2 *D1, so that only the color shift phenomenon of red light can be minimized without deteriorating the luminance of blue light and green light.

6 is a cross-sectional view schematically showing another configuration of the total reflection layer according to the embodiment of the present invention.

As shown in the figure, the total reflection pattern 210 provided in the total reflection layer 200 is made of a cylindrical groove having a narrower width as it goes toward the lower surface 202 from the upper surface 201 of the total reflection layer 200. In this case, a red low-refractive dye material 230 may be included in the total reflection pattern 210.

Here, the low-refractive dye material 230 may have a low-refractive property of the red dye itself, or a low-refractive bead and a red pigment may be randomly arranged in the resin.

A separate base film (not shown) may be further positioned on the lower surface 202 of the total reflection layer 200, but the configuration of the base film (not shown) is not limited.

In addition, the total reflection layer 200 according to an embodiment of the present invention, as shown in Figure 7, the polarizing plate (130 in FIG. 3), the light emitted from the OLED (100 in FIG. 3) 101 of the substrate 101 By absorbing external light to the top, it can be positioned in an OLED transmittance controllable film (OTF) 140 that has excellent light-shielding properties and can realize a low reflection effect.

The luminance enhancement film 140 includes a light blocking layer 141 that absorbs light, and it is preferable that the total reflection layer 200 is positioned closer to the OLED (100 in FIG. 3) than the light blocking layer 141. .

That is, a first adhesive layer 151 having a transparent and adhesive property may be interposed between the luminance enhancement film 140 and the substrate 101, and the total reflection layer 200 is in close contact with the light blocking layer 141 From 201 to the lower surface 202 in close contact with the first adhesive layer 151, it includes a total reflection pattern 210 made of a columnar groove having a narrower width.

In addition, the red dye pattern 220 is positioned to correspond to the widest width of the total reflection pattern 210.

Therefore, the luminance enhancement film 140 including the total reflection layer 200 according to an exemplary embodiment of the present invention absorbs external light and has excellent light-shielding properties and a low reflection effect, and the total reflection layer 200 It is possible to prevent the color shift phenomenon at a viewing angle of 0 to 45 degrees of red light. Through this, the side luminance ratio at the viewing angle of 0 to 45 degrees is implemented differently, thereby preventing the image quality of the product from deteriorating.

As described above, the OLED according to an embodiment of the present invention (100 in FIG. 3) is the top of the substrate 101 through which light is emitted, and the total reflection layer 200 including the total reflection pattern 210 to have a refractive index difference of 0.5 or more. ), and the red dye pattern 220 is positioned on the total reflection pattern 210, and proceeds at a viewing angle of 45 degrees or less among the red lights emitted from the red sub-pixels (1R-SP and 2R-SP in FIG. 4B ). The red light emitted from the red sub-pixels (1R-SP and 2R-SP in FIG. 4B) is made by allowing the light (F1 in FIG. 4B) to enter the total reflection pattern 210 and transmit the red dye pattern 220. All can have their own red color.

Through this, the OLED according to an embodiment of the present invention (100 in FIG. 3) has different lateral luminance ratios at a viewing angle of 0 to 45 degrees of red light, thereby preventing image quality of a product from deteriorating.

The present invention is not limited to the above-described embodiments, and can be implemented by variously changing within the limits without departing from the spirit of the present invention.

100: OLED
101: substrate, 102: protective film
103: semiconductor layer (103a: active region, 103b, 103c: source and drain regions)
104: face seal, 105: gate insulating film, 106a, 106b: first and second interlayer insulating film
107: gate electrode, 108a, 108b: source and drain electrodes
109: first and second semiconductor layer contact hole,
E: light emitting diode (111: first electrode, 113: organic light emitting layer, 115: second electrode)
117: Bank, PH: Drain contact hole
130: polarizing plate (131a, 131b, 131c: first to third adhesive layer, 133: retardation plate, 135: linear polarizing plate)
200: total reflection layer (210: total reflection pattern, 220: red dye pattern)
DTr: Driving thin film transistor

Claims (11)

A substrate including red, green, and blue sub-pixels;
A driving thin film transistor and a light emitting diode provided for each of the red, green, and blue sub-pixels;
A protective film covering the driving thin film transistor and the light emitting diode;
Located in the transmission direction of light emitted from the light emitting diode, the total reflection layer is provided with a total reflection pattern corresponding to the red sub-pixel
It includes,
The total reflection pattern includes a red dye pattern, and guides light traveling at a viewing angle of 45 degrees or less out of the red light emitted from the red sub-pixel toward the red dye pattern,
An organic light emitting display device having a total reflection characteristic for light traveling at a viewing angle of 45 degrees or more among the red light emitted from the red sub-pixel.
According to claim 1,
The total reflection layer and the total reflection pattern is an organic light emitting display device having a refractive index difference of 0.5 or more.
According to claim 1,
The total reflection pattern is an organic light emitting display device formed of a groove having a cylindrical shape, the width of which increases from the lower surface adjacent to the substrate toward the upper surface facing the lower surface.
The method of claim 3,
The red dye pattern is an organic light emitting display device positioned to correspond to the widest width of the total reflection pattern.
According to claim 1,
The red dye pattern is made of a low-refractive dye material, an organic light emitting display device that fills the interior of the total reflection pattern.
According to claim 1,
The area of the red dye pattern is an organic light emitting display device corresponding to the area of the red sub-pixel.
According to claim 1,
The area of the red dye pattern is larger than the area of the red sub-pixel, the organic light emitting display device.
According to claim 1,
The low reflection layer is located between the light emitting diode and the phase difference plate,
An organic light emitting display device having a linear polarizing plate positioned above the retardation plate.
According to claim 1,
The light emitting diode located in the red sub-pixel has a first thickness,
The light emitting diode located in the green sub-pixel has a second thickness,
The light emitting diode located in the blue sub-pixel has a third thickness,
The first to third thickness of the organic light emitting display device different from each other.
The method of claim 9,
The first to third thickness is an organic light emitting display device that is the distance between the first electrode and the second electrode of the light emitting diode.
According to claim 1,
The driving thin film transistor includes a semiconductor layer, a gate insulating film on the semiconductor layer, a gate electrode on the gate insulating film, a first interlayer insulating film on the gate electrode, and a source on the first interlayer insulating film. And a drain electrode,
The light emitting diode is an organic light emitting display device including a first electrode connected to the driving thin film transistor, an organic light emitting layer positioned above the first electrode, and a second electrode positioned above the organic light emitting layer.

Images