KR20150134593A - Organic light emitting diode display panel - Google Patents

Abstract

An organic light emitting diode display panel according to an embodiment of the present invention comprises: an organic light emitting diode layer; a color filter layer; and a color change reduction layer which is positioned between the organic light emitting diode layer and the color filter layer, wherein the organic light emitting diode layer includes a first light emitting unit including a first light emitting layer generating first light and a second light emitting unit including a second light emitting layer generating second light, third light made by synthesizing the first light with the second light is output from the organic light emitting diode layer and is input to the color change reduction layer, light output from the color change reduction layer is the fourth light, and the difference between an intensity decrease width of a peak in the blue wavelength band and an intensity decrease width of a peak in the yellow-green wavelength band according to an increase in a viewing angle in the EL spectrum of the fourth light may be smaller than the difference between the intensity decrease width of a peak in the blue wavelength band and an intensity decrease width of a peak in the yellow-green wavelength band according to an increase in the viewing angle in the EL spectrum of the third light.

Description

[0001] The present invention relates to an organic light emitting diode (OLED) display panel,

The present invention relates to an organic light emitting diode (OLED) display panel, and more particularly, to an organic light emitting diode (OLED) display panel having minimal color shift caused by a change in viewing angle.

The organic light emitting diode (OLED) is a self light emitting type display device, unlike a liquid crystal display device (LCD), a separate light source is not required, and a lightweight thin display can be manufactured. In addition, the organic light emitting display device is advantageous in terms of power consumption by low voltage driving, and has excellent color implementation, response speed, viewing angle, and contrast ratio (CR) The display is attracting attention.

In order to realize full-color light, the OLED display panel includes red, green, and blue pixels, respectively. At this time, a method of patterning the red light emitting layer, the green light emitting layer, and the blue light emitting layer corresponding to red, green, and blue pixels using a fine metal mask (FMM) may be used.

However, in recent years, there has been an increase in market demand for large-sized displays in addition to high-resolution displays. As the area of the display increases, the application of a pixel patterning method using a fine metal mask is limited. Masking phenomenon occurs at the center of the fine metal mask due to the load of the fine metal mask, and an align miss which can not form a light emitting layer in a desired area is generated.

In order to overcome the above problem, a method of commonly stacking several organic light emitting layers on the entire surface of the OLED display panel may be used. More specifically, light generated from several organic light emitting layers laminated in common on the front surface of the device is combined to form white light, and this white light passes through the color filter layer corresponding to each pixel and is converted into red light, green light and blue light . Thus, when several organic light emitting layers are commonly formed on the front surface of the element, the use of a fine metal mask is not required. Therefore, alignment miss due to use of the fine metal mask does not occur.

In the industry, in the display panel, a plurality of organic light emitting layers are formed in common on the entire surface of a device, and white light, which is formed by combining light generated in each organic light emitting layer, passes through the color filter layer, (Hereinafter referred to as " WOLED " method) in which light of a color intended for each sub-pixel is emitted.

In this case, the top emission means a method in which light is emitted to the opposite side of the substrate on which the TFT is formed, and a method in which light is emitted toward the substrate on which the bottom emission type TFT is formed . In the top emission type, a driving region in which a TFT or the like is formed may also be included in the emission region, so that the aperture ratio of each sub-pixel is higher than that of the bottom emission type, thereby improving the lifetime of the device. In the upper emission type, micro cavities (micro-resonance) effects can be utilized by using the reflective electrode and the transflective electrode.

However, each light generated from several organic light emitting layers existing in a single layer in a single device has different amounts of light depending on viewing angles. In other words, as the viewing angle changes, the luminance reduction rate differs for each wavelength. As a result, the WOLED method has a problem that the colors formed by combination are changed, that is, the colors are distorted, as the viewing angle is changed.

This problem is further exacerbated when the upper light emitting mode using strong micro cavity effect is taken. Therefore, the problem that the luminance is lowered and the color tone is distorted as the viewing angle is changed is the biggest problem that must be solved in the upper light emitting method which has advantages in various aspects in comparison with the lower light emitting method.

Accordingly, the inventors of the present invention invented a white OLED display panel that minimizes luminance deterioration and color shift due to a change in viewing angle.

A problem to be solved according to an embodiment of the present invention is to provide a white OLED display panel in which the increase of the driving voltage is minimized by minimizing the stacking of the organic light emitting layer for realizing the white color in the OLED display panel .

Another object of the present invention is to provide an organic light emitting diode (OLED) display panel, which is capable of minimizing luminance degradation and color shift due to viewing angle changes.

Another object of the present invention is to provide an organic light emitting diode (OLED) display panel capable of securing a superior panel efficiency in an OLED display panel.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. .

The OLED display panel according to an exemplary embodiment of the present invention includes an organic light emitting display device layer, a color filter layer, and a color change reducing layer disposed between the organic light emitting display device layer and the color filter layer. And a second light emitting portion including a first light emitting portion including a first light emitting layer for generating a first light and a second light emitting layer for generating a second light, and a second light emitting portion including a third light Is emitted from the organic light emitting display element layer and enters the color change reduction layer, the light emitted from the color change reduction layer is the fourth light, and the peak of the EL spectrum of the third light in the blue wavelength band region as the viewing angle increases The intensity reduction width of the peak in the blue wavelength region due to the increase of the viewing angle of the EL spectrum of the fourth light is larger than the difference between the intensity reduction width and the intensity reduction width of the peak in the yellow- And the intensity decreasing width of the peak in the yellow-green wavelength band region may be smaller.

The details of other embodiments are included in the detailed description and drawings.

The organic light emitting diode display panel according to the present invention minimizes the stacking of the organic light emitting layer for realizing the white color and minimizes the rise of the driving voltage.

In addition, the organic light emitting diode display panel according to the present invention can minimize the luminance drop and the color shift due to the viewing angle change.

In addition, the OLED display panel according to the present invention can secure a superior panel efficiency.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

The scope of the claims is not limited by the content of the invention, as the contents of the invention described in the above-mentioned subject matter, the problem solving means and the effect to be solved do not specify essential features of the claims.

FIG. 1 is a schematic view of an OLED display panel according to an exemplary embodiment of the present invention. Referring to FIG.
2 is a schematic view of an organic light emitting diode display panel according to another embodiment of the present invention.
3 is an electroluminescence spectrum (hereinafter referred to as EL spectrum) of the third light according to the viewing angle of the organic light emitting diode display panel according to an embodiment of the present invention as the angle changes from 0 ° to 60 °.
FIG. 4 is an EL spectrum of a fourth light according to a change in viewing angle of 0 ° to 60 ° in the organic light emitting diode display panel according to an embodiment of the present invention.
FIG. 5 is a CIE Chromaticity Diagram (hereinafter referred to as "CIE diagram") showing the white color coordinate traces of the device as the viewing angle changes from 0 ° to 60 ° in the comparative example and the embodiment.
6 is a graph of? U'v as the viewing angle changes from 0 to 60 in the comparative example and the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers and the like described in the drawings for describing the embodiments of the present invention are merely exemplary and the present invention is not limited thereto.

Like reference numerals refer to like elements throughout.

In the following description of the present invention, detailed description of known related arts will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured by the present invention.

Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used.

The singular forms of the elements in this specification may include the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements in this specification, even if there is no separate description, it is interpreted as including an error range.

In the case of the description of the positional relationship in the present specification, for example, when the positional relationship between two parts is described as 'on', 'on top', 'under', or 'next to' There may be more than one other part between the two parts, unless the 'right' or 'direct' or 'tangent' is used together.

In the present specification, the first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

In describing the elements of the present invention in this specification, terms such as first, second, A, B, (a), (b) and the like can be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

In the present specification, the term " peak " means a point at which a quadratic function value is greater or less than 0 in a convex point in a curve, i.e., a curve.

In the present specification, the term " entire visible light wavelength band region " means a wavelength band region of 380 nm or more and 780 nm or less.

The term " blue wavelength band region " in this specification means a wavelength band region of 430 nm or more and 480 nm or less.

In this specification, the term "yellow-green wavelength band region" means a wavelength band region of 500 nm or more and 580 nm or less.

In the present specification, " red wavelength band region " means a wavelength band region exceeding 580 nm and less than 660 nm.

The term " EL spectrum " in this specification means an electroluminescence spectrum (hereinafter referred to as EL spectrum), and unless otherwise specified, the EL spectrum measured at a viewing angle of 0 °, that is, Spectrum.

In the present specification, in the case of comparing the peaks of the EL spectrum of the third light and the EL spectrum of the fourth light, the peaks to be compared are the peaks of all the peaks of the EL spectrum of the third light and the peaks of the EL spectrum of the fourth light Means a peak of the EL spectrum of the third light and a peak of the EL spectrum of the fourth light in which the difference between the respective wavelengths is 50 nm or less when the wavelengths of all the peaks are compared.

Means a difference between the intensity of a peak at a viewing angle of 0 DEG and the intensity of a peak at a viewing angle of 60 DEG in a specific wavelength band region.

It is to be understood that each of the features of the various embodiments of the invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

The organic light emitting display according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, various layers constituting elements of the organic light emitting display according to the present invention are represented by rectangles for convenience. The various layers of the component may appear to be clearly distinct from the front and side, but may be gently curved without clearly distinguishing between the front and sides.

FIG. 1 is a schematic diagram of a top-emission white organic light emitting diode (OLED) display panel according to an exemplary embodiment of the present invention. Referring to FIG.

1, an OLED display panel 100 according to an exemplary embodiment of the present invention includes an OLED display element layer 120, a color change reduction layer 130, and a color filter layer 140). The OLED display 120 includes a lower electrode 121 and an upper electrode 125 facing each other and a first light emitting portion 122 between the lower electrode 121 and the upper electrode 125, The charge generation layer 123, and the second light emitting portion 124 are stacked. More specifically, the first light emitting portion 122 is located on the lower electrode 121, the charge generating layer 123 is located on the first light emitting portion 122, the second light emitting portion 122 is formed on the charge generating layer 123, And the upper electrode 125 may be positioned on the second light emitting portion 124. [0035] In this case, the first light emitting portion 122 may include a first light emitting layer (not shown) for generating the first light 122a, and the second light emitting portion 124 may include a second light emitting portion And a second light emitting layer (not shown). At this time, the first light emitting portion 122 and the second light emitting portion 124 are formed in a hole injection layer (not shown) so as to facilitate the charge injection and transport to the first light emitting layer (not shown) and the second light emitting layer (Not shown), a hole transport layer (not shown), an electron injection layer (not shown), and an electron transport layer (not shown).

The substrate 110 may be a substrate on which a red pixel region (not shown), a green pixel region (not shown) and a blue pixel region (not shown) are defined and includes a red pixel region (not shown), a green pixel region ), A blue pixel region (not shown) and a white pixel region (not shown) are defined.

The upper electrode 125 is made of a material having excellent light transmittance and electrical conductivity. More specifically, the upper electrode 125 is made of a material having a high light transmittance in the entire visible light wavelength range since it is an electrode positioned in a direction in which the first light 122a and the second light 124a are emitted . Further, the upper electrode 125 functions as an electrode and is made of a material having excellent electrical conductivity. That is, the upper electrode 125 may include a conductive material and may transmit light. The upper electrode 125 may be formed of a transparent conductive oxide (TCO) material such as ITO, IZO, or ZnO, but is not limited thereto. When the optical upper electrode 125 is a cathode, a path between the second light emitting layer (not shown) and the upper electrode 125 is an electron movement path. When the upper electrode 125 is an anode, a path between the second light emitting layer (not shown) and the upper electrode 125 is a path for holes.

The color of the first light 122a emitted from the first light emitting portion 122 and the color of the second light 124a emitted from the second light emitting portion 124 are complementary to each other and the first light 122a, And the second light 124a may be combined to become white light. For example, when the first light 122a emitted from the first light emitting portion 122 is blue light, the second light 124a emitted from the second light emitting portion 124 may be yellow-green light, When the first light 122a emitted from the light emitting portion 122 is yellow-green light, the second light 124a emitted from the second light emitting portion 124 may be blue light.

For example, when the first light 122a emitted from the first light emitting portion 122 is light having the highest light emission intensity in a wavelength range of 430 nm or more and 480 nm or less, the light emitted from the second light emitting portion 124 2 light 124a may be light having the highest emission intensity in a wavelength range of 500 nm or more and 580 nm or less. When the first light 122a emitted from the first light emitting portion 122 is light having the highest light emission intensity in the wavelength range of 500 nm or more and 580 nm or less, (124a) may be light having the highest emission intensity in a wavelength range of 430 nm or more and 480 nm or less. Here, 'in a certain wavelength band region' in the expression 'having the highest emission intensity in a certain wavelength band region' means that at least one peak is present in the entire visible wavelength band region, and the intensity of the peak In the wavelength region of the largest peak. That is, 'in a certain wavelength band region' means, for example, in a case where there are two or more peaks in the 'total visible light wave band region, in which one of the peak wavelength band regions having the greatest peak intensity' .

The organic light emitting display device layer 120, the color change reducing layer 130, and the color filter layer 140 will be described in detail in the organic light emitting diode display panel 100 according to an embodiment of the present invention.

The organic light emitting display element layer 120 emits the third light 120a formed by combining the first light 122a and the second light 124a. The color of the first light 122a and the color of the second light 124a may be complementary to each other. At this time, the third light 120a may be white light. The EL spectrum of the third light 120a in the entire visible light wavelength band region may have a peak due to the first light 122a and a peak due to the second light 124a. That is, the EL spectrum of the third light 120a may have a peak corresponding to blue light and a peak corresponding to yellow-green light. Alternatively, it may have a peak in a wavelength band region of 430 nm or more and 480 nm or less and a peak in a wavelength band region of 500 nm or more and 580 nm or less.

The color change reduction layer 130 is a layer on which the third light 120a emitted from the upper electrode 125 of the organic light emitting display element layer 120 is incident. The refractive index of the color change reduction layer 130 is smaller than the refractive index of the upper electrode 125 which is closer to the color change reduction layer 130 than the two electrodes of the OLED display element layer 120, The difference between the refractive index values of the upper electrode 125 and the color change reducing layer 130 may be 0.15 or more and 0.35 or less. The color change reduction layer 130 may be formed of a material selected from the group consisting of titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride And may include any one selected from aluminum nitride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), and mixtures thereof. The thickness of the color change reduction layer 130 may be 900 nm or more and 1200 nm or less. For example, the color change reducing layer 130 may be a single layer of silicon nitride having a refractive index of 1.85 with respect to a wavelength of 1000 nm and a wavelength of 550 nm. Alternatively, it may be a single layer of aluminum oxide having a refractive index of 1.65 based on a wavelength of 1200 nm and a wavelength of 550 nm. And may be a multilayer of a combination of them if necessary.

The third light 120a enters the color change reduction layer 130 and the fourth light 130a passes through the color change reduction layer 130 and exits. The EL spectrum of the fourth light 130a differs from the EL spectrum of the third light 120a.

3 is a graph showing EL spectra at a viewing angle of 0 °, 20 °, 30 °, 40 °, 50 ° and 60 ° of the third light 120a of the organic light emitting diode display panel 100 according to an embodiment of the present invention. admit.

More specifically, all the peaks that the EL spectrum of the third light 120a has in the entire visible light wavelength band region decrease in intensity as the viewing angle gradually increases from 0 DEG. Further, when the viewing angle is 0 °, the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a is much larger than the intensity of the peak in the yellow-green wavelength band region, but as the viewing angle increases, The magnitude difference between the intensity of the peak in the blue wavelength band region and the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the red-light wavelength band 120a is reduced. This means that as the viewing angle increases, the intensity decrease width of the peak in the blue wavelength band region is significantly larger than the intensity decrease width of the peak in the yellow-green wavelength band region.

As the viewing angle changes, the first light 122a, which is the light in the blue wavelength band region, and the second light 124a, which is the light in the yellow-green wavelength band region, The mixing ratio of the third light 120a is significantly different. As a result, the color coordinates of the third light 120a vary greatly depending on the viewing angle. As a result, the color of the third light 120a formed by combining the first light 122a and the second light 124a varies as the viewing angle changes. When the third light 120a is directly incident on the color filter layer 140, a color shift phenomenon occurs as the viewing angle varies.

4 is a graph showing EL spectra of the fourth light 130a of the organic light emitting diode display panel 100 according to an embodiment of the present invention at viewing angles of 0 °, 20 °, 30 °, 40 °, 50 ° and 60 ° admit.

More specifically, as in the third light 120a, all the peaks of the EL spectrum of the fourth light 130a in the entire visible light wave length band region also increase as the viewing angle increases from 0 DEG . However, by comparing the strength reduction widths of the peaks in the fourth light 130a and the third light 120a with each other, it can be seen that the intensity of decrease in the intensity of all the peaks of the EL spectrum of the third light 120a All the peaks in the spectrum have a smaller decrease in intensity. Further, as the viewing angle increases, the EL spectrum of the third light 120a is significantly larger in the intensity reduction width of the peak in the blue wavelength band region than in the peak intensity in the yellow-green wavelength band region, The EL spectrum does not show a significant difference between the intensity decrease of the peak in the blue wavelength region and the intensity decrease of the peak in the yellow-green wavelength region even when the viewing angle is increased.

That is, when the intensity reduction width of the peak in the blue wavelength band region and the intensity reduction width of the peak in the yellow-green wavelength band region are compared, the difference between the intensity reduction widths of the both peaks is larger than that in the EL spectrum of the third light 120a. Lt; RTI ID = 0.0 > 130a. ≪ / RTI > This means that the EL spectrum of the fourth light 130a does not change in magnitude of magnitude of the intensity of each peak even if the viewing angle varies, and the variation in the intensity reduction ratio of each peak as the viewing angle varies is small. Even if the viewing angle is changed, the fourth light 130a having an EL spectrum having a consistent pattern is significantly reduced in color shift caused by changing the viewing angle, which is directly related to the improvement of the picture quality of the white OLED display panel.

The difference between the third light 120a and the fourth light 130a originates from the color change reduction layer 130. [

That is, the color change reduction layer 130 can maintain a coherent pattern without changing the magnitude of the intensity of the peak in each wavelength band region as the viewing angle changes. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

The color change reduction layer 130 is formed so that the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a at a certain viewing angle is smaller than the intensity of the peak of the EL spectrum of the fourth light 130a in the same viewing angle band So that the intensity of the peak in the region is larger.

That is, the color change reduction layer 130 has a viewing angle range in which the intensity of the peak in the blue wavelength band region of the EL spectrum of the fourth light is larger than the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light.

For example, when the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a and the intensity of the peak in the same wavelength band region of the EL spectrum of the fourth light 130a are compared, It can be seen that the intensity of the third light 120a in the EL spectrum is larger at 30 ° but the intensity of the fourth light 130a in the EL spectrum is larger at a viewing angle of 40 ° or more. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

The color change reduction layer 130 is formed so that the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a at any viewing angle is smaller than the intensity of the peak of the EL spectrum of the fourth light 130a at the same viewing angle So that the intensity of the peak in the same wavelength band region is larger.

That is, the color change reduction layer 130 has a larger viewing angle range in which the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the fourth light is larger than the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light .

When the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a and the intensity of the peak in the same wavelength band region of the EL spectrum of the fourth light 130a are compared, At 40 °, the intensity of the third light 120a in the EL spectrum is larger, but the intensity of the fourth light 130a in the EL spectrum is larger at a viewing angle of 50 ° or more. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

The color change reduction layer 130 is formed so that the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a at any arbitrary viewing angle and the intensity of the peak in the blue wavelength band region at any arbitrary viewing angle, The magnitude of the intensity of the peak in the same wavelength band region of the EL spectrum of the fourth light 130a is inverted.

For example, if the magnitude of the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a is within the range of the same wavelength band of the EL spectrum of the fourth light 130a in the same viewing angle up to a viewing angle of 0 deg. The magnitude of the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a is larger than the intensity of the peak of the fourth light 130a in the same viewing angle The intensity of the peak in the same wavelength band region of the EL spectrum can be made smaller than the magnitude of the intensity of the peak in the same wavelength band region of the EL spectrum. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

In addition, the color change reduction layer 130 has the same magnitude of the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a at any arbitrary viewing angle, The magnitude of the intensity of the peak in the same wavelength band region of the EL spectrum of the fourth light 130a in the first wavelength band is inverted.

For example, when the magnitude of the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a is smaller than the magnitude of the EL spectrum of the fourth light 130a at the same viewing angle The magnitude of the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a from the view angle of 50 degrees or more is larger than the magnitude of the intensity of the peak in the same wavelength band region, The magnitude of the intensity of the peak in the same wavelength band region of the EL spectrum of the light 130a can be made smaller. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

In other words, the color change reduction layer 130 is formed so that the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light and the intensity of the peak of the blue or yellow- So that the magnitude relation of the intensity of the peak in the green wavelength band region is reversed.

The color change reduction layer 130 is a layer in which the intensity reduction of the peak in the blue wavelength band region of the EL spectrum of the third light 120a and the intensity decrease of the peak in the blue wavelength band region of the EL spectrum of the fourth light 130a The intensity of the fourth light 130a is smaller in the EL spectrum of the fourth light 130a than in the EL spectrum of the third light 120a.

In the case of the EL spectrum of the third light 120a, the intensity of the peak in the blue wavelength band region is 0.2696 (wavelength 456 nm) when the viewing angle is 0 °, 0.07446 (wavelength 452 nm) when the viewing angle is 60 °, Is 0.19514, which is the difference between 0.2696 and 0.07446.

In the case of the EL spectrum of the fourth light 130a, the intensity of the peak in the blue wavelength band region is 0.1791 (wavelength 460 nm) when the viewing angle is 0 °, 0.1347 (wavelength 456 nm) when the viewing angle is 60 °, Is 0.0444, which is the difference between 0.1791 and 0.1347.

The EL spectrum of the third light 120a is 0.19514 and the EL spectrum of the fourth light 130a is 0.0444 and the intensity of the peak of the third light 120a is 0.19514 in the EL spectrum of the third light 120a It can be seen that the intensity reduction width of the peak according to the viewing angle in the blue wavelength band region in the EL spectrum of the fourth light 130a is smaller than that in the blue wavelength band region. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

Further, the color change reduction layer 130 can reduce the intensity decrease of the peak in the yellow-green wavelength band region in the EL spectrum of the third light 120a and the intensity decrease width of the yellow light band in the EL spectrum of the fourth light 130a, The intensity of the peak of the fourth light 130a is smaller in the EL spectrum of the fourth light 130a than in the EL spectrum of the third light 120a.

In the case of the EL spectrum of the third light 120a, the intensity of the peak in the yellow-green wavelength band region is 0.1935 (wavelength of 552 nm) when the viewing angle is 0 ° and 0.06861 (wavelength 544 nm) when the viewing angle is 60 ° , And the strength reduction width of the peak is 0.12489, which is a difference of 0.1935 and 0.06861.

In the case of the EL spectrum of the fourth light 130a, the intensity of the peak in the yellow-green wavelength band region is 0.1288 (wavelength 552 nm) when the viewing angle is 0 ° and 0.1096 (wavelength 548 nm) when the viewing angle is 60 ° , And the intensity decrease width of the peak is 0.0192 which is a difference of 0.1288 and 0.1096.

The EL spectrum of the third light 120a is 0.12489 and the EL spectrum of the fourth light 130a is 0.0192 in the EL light of the third light 120a by comparing the intensity reduction width of the peak according to the viewing angle in the yellow- It can be seen that the intensity reduction of the peak according to the viewing angle in the yellow-green wavelength band region in the EL spectrum of the fourth light 130a is smaller than in the spectrum. At this time, the integrated value of the EL spectrum of the third light 120a and the integrated value of the EL spectrum of the fourth light 130a may be the same level within the error range.

When the magnitude of the intensity decrease of the peak in the blue wavelength band region and the intensity decrease width of the peak in the yellow-green wavelength band region are compared with each other as the viewing angle gradually increases from 0 deg., The color change reduction layer 130, Is smaller in the EL spectrum of the fourth light 130a than in the EL spectrum of the second light 120a.

In the case of the EL spectrum of the third light 120a, the intensity of the peak in the blue wavelength band region is 0.2696 (wavelength 456 nm) when the viewing angle is 0 °, 0.07446 (wavelength 452 nm) when the viewing angle is 60 °, Is 0.19514, which is the difference between 0.2696 and 0.07446. The intensity of the peak in the yellow-green wavelength range is 0.1935 (wavelength of 552 nm) when the viewing angle is 0 °, 0.06861 (wavelength 544 nm) when the viewing angle is 60 °, and the intensity decrease of the peak is 0.1935 and 0.06861 , 0.12489. That is, the difference between the intensity reduction width of the peak in the blue wavelength band region and the intensity reduction width of the peak in the yellow-green wavelength band region in the EL spectrum of the third light 120a is 0.07025, which is a difference of 0.19514 and 0.12489.

In the case of the EL spectrum of the fourth light 130a, the intensity of the peak in the blue wavelength band region is 0.1791 (wavelength 460 nm) when the viewing angle is 0 °, 0.1347 (wavelength 456 nm) when the viewing angle is 60 °, Is 0.0444, which is the difference between 0.1791 and 0.1347. The intensity of the peak in the yellow-green wavelength range is 0.1288 (wavelength of 552 nm) when the viewing angle is 0 °, 0.1096 (wavelength 548 nm) when the viewing angle is 60 ° and the intensity reduction of the peak is 0.1288 and 0.1096 , 0.0192. That is, the difference between the intensity decrease of the peak in the blue wavelength band region and the intensity decrease width of the peak in the yellow-green wavelength band region in the EL spectrum of the fourth light 120a is 0.0252, which is a difference of 0.0444 and 0.0192.

The difference between the intensity reduction width of the peak in the blue wavelength band region and the intensity reduction width of the peak in the yellow-green wavelength band region in the EL spectrum of the third light 120a and the difference between the intensity reduction width of the peak in the blue- Comparing the difference between the intensity reduction width of the peak and the intensity decreasing width of the peak in the yellow-green wavelength band region, it can be seen that the intensity decrease width of the peak in the blue wavelength band region in the EL spectrum of the electron- The difference in the intensity reduction width of the peak of the peak is larger.

The color filter layer 140 includes a red color filter (not shown) for causing the incident fourth light 130a to emit red light in a red pixel region (not shown), a red color filter A green color filter (not shown) for emitting green light from a blue pixel region (not shown), and a blue color filter (not shown) for causing the incident fourth light 130a to emit blue light from a blue pixel region . The color filter layer 140 may further include a white color filter (not shown) for causing the incident fourth light 130a to emit white light from a white pixel region (not shown).

That is, the color filter layer 140 includes a red color filter (not shown), a green color filter (not shown) corresponding to a red pixel region (not shown), a green pixel region (not shown) And a blue color filter (not shown). When the substrate 110 further includes a white pixel region (not shown), the color filter layer 140 may further include a white color filter (not shown).

A resin layer (not shown) for adhesion between the color change reducing layer 130 and the color filter layer 140 may be further included in the OLED display panel 100. In this case, the refractive index of the resin layer (not shown) is smaller than the refractive index of the color change reducing layer 130, and the difference between the refractive index values of both layers when the wavelength of 550 nm is used as the reference may be 0.15 or more and 0.35 or less. The thickness of the resin layer (not shown) may be 2000 nm or more and 4000 nm or less. For example, the resin layer (not shown) may be a resin-cured layer having a refractive index of 1.5 with respect to a wavelength of 3000 nm and a wavelength of 550 nm. In this case, the light incident on the color filter layer 140 may be the light through which the fourth light 130a passes through the resin layer (not shown).

FIG. 2 is a schematic structure of a bottom emission white OLED display panel according to another embodiment of the present invention. Referring to FIG.

2, the organic light emitting diode display panel 200 includes a substrate 210, a color filter layer 220, a color change reduction layer 230, and a color change reduction layer 230, And the organic light emitting display element layer 240 positioned on the organic light emitting display element layer 240. The organic light emitting display element layer 240 includes a lower electrode 241 and an upper electrode 245 facing each other and a first light emitting portion 242 is formed between the lower electrode 241 and the upper electrode 245, The charge generation layer 243, and the second light emitting portion 244 are stacked. More specifically, the first light emitting portion 242 is located on the lower electrode 241, the charge generating layer 243 is located on the first light emitting portion 242, and the second light emitting portion 243 is formed on the charge generating layer 243. And the upper electrode 245 may be positioned on the second light emitting portion 244. [ In this case, the first light emitting portion 242 may include a first light emitting layer (not shown) that generates the first light 242a, and the second light emitting portion 244 may include a second light emitting portion 244b that generates the second light 244a And a second light emitting layer (not shown). At this time, the first light emitting portion 242 and the second light emitting portion 244 are formed in a hole injection layer (not shown) so as to facilitate the charge injection and transport to the first light emitting layer (not shown) and the second light emitting layer ), A hole transport layer (not shown), an electron injection layer (not shown), and an electron transport layer (not shown).

The lower electrode 241 is made of a material having excellent light transmittance and electrical conductivity. More specifically, since the lower electrode 241 is an electrode positioned in a direction in which the first light 242a and the second light 244a are emitted, the lower electrode 241 is made of a material having excellent light transmittance in the entire wavelength band region. Further, the lower electrode 241 functions as an electrode and is made of a material having excellent electrical conductivity. That is, the lower electrode 241 may include a conductive material and may transmit light. When the lower electrode 241 is a cathode, a path between the first light emitting layer (not shown) and the lower electrode 241 is an electron movement path. In addition, when the lower electrode 241 is an anode, the path between the first light emitting layer (not shown) and the lower electrode 241 is a hole.

The color filter layer 220, the color change reduction layer 230, the organic light emitting display element layer 240, the first light (not shown) of the organic light emitting diode display panel 200 according to another embodiment of the present invention, The description of the second light 244a, the third light 240a and the fourth light 230a is omitted in the description of the substrate 110 of the OLED display panel 100 according to an embodiment of the present invention. The organic light emitting display device layer 120, the color change reduction layer 130, the color filter layer 140, the first light 122a, the second light 124a, the third light 120a, ) Are equally applied. Therefore, in the description of the organic light emitting diode display panel 200 according to another embodiment of the present invention, substantially the same contents as the description of the organic light emitting diode display panel 100 according to the embodiment of the present invention Will be omitted and further explanations will be given to the other parts.

The color change reduction layer 230 is a layer on which the third light 240a emitted from the lower electrode 241 of the organic light emitting display element layer 240 is incident. The refractive index of the color change reduction layer 230 is smaller than the refractive index of the lower electrode 241 that is closer to the color change reduction layer 230 than the two electrodes of the organic light emitting display element layer 240, , The difference in refractive index values of both layers can be 0.15 or more and 0.35 or less.

Hereinafter, the performance of the comparative example and the embodiment will be compared.

A comparative example is an OLED display panel including a substrate, an OLED display element layer, a resin layer, and a color filter layer. In this case, the OLED display layer includes a lower electrode serving as an anode, A light-emitting portion, a charge generating layer, a yellow-green light-emitting portion generating brisk-green light, and an upper electrode serving as a cathode. At this time, the upper electrode was formed to have a thickness of 120 nm with a refractive index n = 2 at a wavelength of 550 nm and a resin curing material having a refractive index n = 1.5 at a wavelength of 550 nm with a thickness of 3000 nm. That is, the comparative example is a case where the color change reduction layer is not applied. That is, the comparative example is a case where the third light directly enters the color filter layer.

The embodiment is an organic light emitting diode display panel 100 according to an embodiment of the present invention. In the embodiment, the same organic light emitting display element layer 120 and a resin layer (not shown) as the organic light emitting display element layer used in the comparative example are applied. Silicon nitride (SiNx) having a refractive index n = 1.85 at a wavelength of 550 nm is formed between the OLED display element layer 120 and a resin layer (not shown) to a thickness of 1000 nm by a chemical vapor deposition method Respectively. That is, since the color change reduction layer 130 is applied to the embodiment, the fourth light 130a is incident on the color filter layer 140 instead of the third light.

The following Table 1 shows the device luminous efficiency according to the device evaluation of each of the comparative example and the example, and the panel efficiency (Cd / A) simulation value of each of the comparative example and the example expected when each device is applied to the panel. Here, the evaluation of the device according to the embodiment defines one element as the substrate 110, the organic light emitting display element layer 120, and the color change reduction layer 130, and the luminous efficiency Cd / A for the corresponding element The element evaluation for the comparative example is that the substrate up to the organic light emitting display element layer is defined as one element and the luminous efficiency of the element is evaluated.

color Example Comparative Example Device luminous efficiency
(Cd / A) Red 5.08 3.43 green 20.27 25.06 blue 2.95 2.98 White 58.15 67.64 Panel efficiency (Cd / A) 22.82 21.53

In the device luminous efficiency, the example of the red color is higher than that of the comparative example, and the device luminous efficiency of the other colors is lower than that of the comparative example. However, the panel efficiency in which the frequency of use of each color is reflected as a consideration factor in driving the standard moving picture shows that the embodiment is higher than the comparative example. This is because the device luminous efficiency of red is increased rather than using the red light emitting layer, so that it is possible to express a more colorful color as viewed from the side of the panel as a whole, and the frequency of use Is reflected in the panel efficiency.

In this case, in the organic light emitting diode display panel 100 according to the embodiment of the present invention, the third light 120a passes through the color change reduction layer 130 It is found that the fourth light 130a is incident on the color filter layer 140 in terms of the panel efficiency of the OLED display panel.

Table 2 below shows the white CIE color coordinates of the white CIE color coordinates at each viewing angle with reference to the white CIE color coordinates at the viewing angle of 0 to 60 degrees and the white CIE color coordinates at the viewing angle of 0 deg. 'Value. Here, the X coordinate of the CIE color coordinate is denoted by CIEx (u ') and the Y coordinate of the CIE color coordinate is denoted by CIEx (v').

division Example Comparative Example Angle (°) CIEx CIEy Δu'v ' CIEx CIEy Δu'v ' 0 0.316 0.342 0.000 0.286 0.343 0.000 10 0.314 0.340 0.001 0.284 0.342 0.001 20 0.313 0.342 0.002 0.279 0.349 0.007 30 0.313 0.346 0.004 0.274 0.362 0.015 40 0.316 0.354 0.008 0.275 0.378 0.023 50 0.318 0.359 0.010 0.286 0.386 0.024 60 0.322 0.362 0.011 0.306 0.380 0.021

Based on this, traces of white CIE color coordinates can be obtained as the viewing angle changes from 0 DEG to 60 DEG in the comparative example and the embodiment as shown in Fig. Further, a graph of? U'v 'of the white CIE color coordinates at each viewing angle with reference to the white CIE color coordinate at the viewing angle of 0 占 of the comparative example and the embodiment as shown in Fig. 6 can be obtained.

According to Fig. 5, it can be seen that the white CIE color coordinate trace is shorter than that of the white CIE color coordinate trace as the viewing angle of the comparative example is changed, as the viewing angle of the embodiment is changed. The shorter the white CIE color coordinate trace as the viewing angle changes, the less the color change of the white color as the viewing angle changes. That is, the embodiment in which the white CIE color coordinate trace is relatively short in accordance with the change of the viewing angle is less likely to cause a color shift than the comparative example.

6, it can be seen that the value of? U'v ', which is the difference from the white CIE color coordinate at a viewing angle of 0 °, is lower in all viewing angles than the comparative example. The shorter the Δu'v 'value, the less the color change of white. That is, the embodiment in which the value of? U'v 'is relatively low at any viewing angle is less disturbed in color tone than the comparative example.

In this case, in the organic light emitting diode display panel 100 according to the embodiment of the present invention, the third light 120a passes through the color change reduction layer 130 It can be seen that the fourth light 130a is incident on the color filter layer 140 in terms of minimizing color shift due to a change in the viewing angle of the OLED display panel.

The OLED display panel according to an exemplary embodiment of the present invention includes an organic light emitting display device layer, a color filter layer, and a color change reducing layer disposed between the organic light emitting display device layer and the color filter layer. Includes a second light emitting portion including a first light emitting portion including a first light emitting layer for generating first light and a second light emitting layer for generating a second light, and a second light emitting portion including a third light emitting portion formed by combining the first light and the second light. The light emitted from the organic light emitting display element layer enters the color change reduction layer, the light emitted from the color change reduction layer is the fourth light, and the peak of the EL spectrum of the third light in the blue wavelength band region The intensity decrease width of the peak in the blue wavelength range region due to the increase in the viewing angle of the EL spectrum of the fourth light and the decrease in the intensity of the peak in the blue- The difference between the intensity decrease of the peak in the color-green wavelength band region is smaller.

At this time, the color change reduction layer is formed so that the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light is larger than the intensity of the peak in the blue or yellow- Area can exist.

At this time, the color change reducing layer is formed so that the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light and the intensity of the peak of the EL spectrum of the fourth light in the blue or yellow- The magnitude of the intensity of the peak of the peak can be reversed.

At this time, in the color change reduction layer, the intensity decrease width of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light is smaller than the intensity decrease width of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light .

At this time, the color change reduction layer is formed so that the difference between the intensity reduction width of the peak in the blue wavelength band region and the intensity reduction width of the peak in the yellow-green wavelength band region of the EL spectrum of the third light is smaller than the difference The difference between the intensity decrease of the peak in the yellow-green wavelength band region and the intensity decrease width of the peak in the yellow-green wavelength band region can be made smaller.

At this time, the organic light emitting display device layer may further include upper and lower electrodes facing each other, and the refractive index of the color change reducing layer may be smaller than the refractive index of the electrode closer to the color change reducing layer in the upper electrode and the lower electrode .

In this case, the color change reducing layer may be formed of at least one selected from the group consisting of titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride And may include any one selected from aluminum nitride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), and mixtures thereof.

At this time, a resin layer may be further included between the color change reducing layer and the color filter layer.

At this time, the color of the first light and the color of the second light may be complementary to each other.

At this time, the third light may be white light.

At this time, one of the first light and the second light may be blue light and the other may be yellow-green light.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

110, 210: substrate
120, and 240: an organic light emitting display element layer
120a, 240a: third light
121, 241: Lower electrode
122, and 242:
122a, 242a: first light
123, 243: charge generation layer
124, 244:
124a, 244a: second light
125, 245: upper electrode
130, 230: color change reduction layer
130a, 230a: fourth light
140, 220: Color filter layer
100, 200: organic light emitting diode display panel

Claims (11)

An organic light emitting display element layer, a color filter layer, and a color change reducing layer disposed between the organic light emitting display element layer and the color filter layer,
Wherein the organic light emitting display element layer includes a first light emitting portion including a first light emitting layer for generating first light and a second light emitting portion including a second light emitting layer for generating a second light,
A third light formed by combining the first light and the second light is emitted from the organic light emitting display element layer and is incident on the color change reduction layer,
The light emitted from the color change reduction layer is the fourth light,
Wherein the difference between the intensity decrease width of the peak in the blue wavelength band region and the intensity decrease width of the peak in the yellow-green wavelength band region of the EL spectrum of the third light as the viewing angle increases, The difference between the intensity decrease of the peak in the wavelength band region and the intensity decrease band of the peak in the yellow-green wavelength band region is smaller,
(OLED) display panel. The method according to claim 1,
Wherein the color change reducing layer comprises
The peak intensity in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light is greater than the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light ,
(OLED) display panel. The method according to claim 1,
Wherein the color change reducing layer comprises
Wherein the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light and the intensity of the peak of the EL spectrum of the fourth light in the blue or yellow- In order for the relationship to be reversed,
(OLED) display panel. The method according to claim 1,
Wherein the color change reducing layer comprises
The intensity reduction width of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light is made smaller than the intensity reduction width of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light.
(OLED) display panel. The method according to claim 1,
Wherein the color change reducing layer comprises
The intensity reduction width of the peak of the EL spectrum of the fourth light in the blue wavelength band region and the intensity decrease width of the peak of the fourth wavelength of the EL spectrum of the third light are larger than the difference between the intensity decrease width of the peak in the blue wavelength band region and the intensity decrease width of the peak in the yellow- Lt; RTI ID = 0.0 > a < / RTI > difference between the intensity drop width of the peak in the yellow-
(OLED) display panel. The method according to claim 1,
Wherein the organic light emitting display element layer further comprises an upper electrode and a lower electrode facing each other,
Wherein the color change reduction layer has a smaller refractive index than the refractive index of an electrode closer to the color change reduction layer among the upper electrode and the lower electrode,
(OLED) display panel. The method according to claim 1,
Wherein the color change reducing layer is formed of a material selected from the group consisting of titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), and mixtures thereof.
(OLED) display panel. The method according to claim 1,
Further comprising a resin layer between the color change reducing layer and the color filter layer,
(OLED) display panel. The method according to claim 1,
Wherein the color of the first light and the color of the second light are complementary to each other,
(OLED) display panel. The method according to claim 1,
Wherein the third light is white light,
(OLED) display panel. The method according to claim 1,
Wherein one of the first light and the second light is blue light and the other is yellow-
(OLED) display panel.

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