KR102200343B1 - Organic light emitting diode display panel - Google Patents

Abstract

An organic light-emitting display device display panel according to an embodiment of the present invention includes an organic light-emitting display device layer, a color filter layer, and a color change reduction layer positioned between the organic light-emitting display device layer and the color filter layer, and the organic light-emitting display device layer The first light emitting part including a first light emitting part including a first light emitting layer for generating first light and a second light emitting part including a second light emitting layer for generating second light, wherein the first light and the second light are combined 3 Light exits from the organic light-emitting display element layer and enters the color change reduction layer, and the light emitted from the color change reduction layer is the fourth light, and the peak in the blue wavelength range according to the increase of the viewing angle of the EL spectrum of the third light Compared to the difference between the decrease in the intensity of and the decrease in the intensity of the peak in the yellow-green wavelength region, the decrease in the intensity of the peak in the blue wavelength region according to the increase in the viewing angle and the intensity of the peak in the yellow-green wavelength region of the EL spectrum of the fourth light The difference between the reductions may be smaller.

Description

Organic light emitting display device display panel {ORGANIC LIGHT EMITTING DIODE DISPLAY PANEL}

The present invention relates to an organic light-emitting display device display panel, and more particularly, to provide an organic light-emitting display device display panel in which color distortion according to a change in a viewing angle is minimized.

The organic light-emitting display device (OLED) is a self-emission type display device, and unlike a liquid crystal display device (LCD), it does not require a separate light source, so that a light-weight thin display can be manufactured. In addition, organic light-emitting display devices are not only advantageous in terms of power consumption due to low voltage driving, but also have excellent color realization, response speed, viewing angle, and contrast ratio (CR). It is in the spotlight as a display.

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

However, in addition to the recent high resolution of displays, there is an increasing market demand for a larger display area. As the area of the display increases, the pixel patterning method using a fine metal mask has limitations in its application. This is because a mask sagging phenomenon occurs in the center of the fine metal mask due to the load of the fine metal mask, resulting in an alignment miss in which a light emitting layer cannot be formed in a desired region.

In order to overcome the above problems, a method in which several organic emission layers are commonly stacked on the entire surface of the device in the display panel of the organic light emitting display device may be used. More specifically, white light is formed by combining light generated from several organic light-emitting layers commonly stacked on the entire surface of the device, and the white light passes through the color filter layer corresponding to each pixel into red light, green light, and blue light. Is implemented. When several organic light-emitting layers are commonly formed on the entire surface of the device, the use of a fine metal mask is not required. Therefore, there is no alignment miss due to the use of the fine metal mask.

Accordingly, in the industry, several organic light-emitting layers are commonly stacked on the entire surface of the device in a display panel, and white light formed by combining light emitted from each organic light-emitting layer passes through the color filter layer and passes through the color filter layer. A method in which light of a color desired to be displayed by each sub-pixel is emitted (hereinafter referred to as WOLED method) is applied.

At this time, the top-emission method refers to a method in which light is emitted toward the opposite side of the substrate on which the TFT is formed, and the bottom-emission method refers to a method in which light is emitted toward the substrate on which the TFT is formed. . In the top emission method, a driving region in which a TFT or the like is formed may also be included in the emission area, and thus the aperture ratio of each subpixel is increased compared to the bottom emission method, thereby improving the life of the device. In addition, in the top emission method, a microcavity (micro-resonance) effect can be used by using a reflective electrode and a transflective electrode.

By the way, each light emitted from several organic light emitting layers present in a stacked structure in one device has a different amount of light depending on the viewing angle. In other words, as the viewing angle changes, the luminance reduction rate is different for each wavelength. For this reason, in the WOLED method, as the viewing angle changes, a problem in which colors formed by combining them change, that is, a problem in which the color sense is distorted occurs.

This problem is exacerbated when the top light emission method is taken using a strong microcavity effect. Accordingly, the problem that the luminance decreases and the color sense changes as the viewing angle changes is the biggest problem that must be solved in the top emission method, which has advantages in various aspects compared to the bottom emission method.

Accordingly, the inventors of the present invention invented a display panel of a white organic light emitting display device that minimizes luminance deterioration and color distortion according to a change in viewing angle.

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

Another problem to be solved according to an exemplary embodiment of the present invention is to provide an organic light-emitting display device display panel that minimizes luminance reduction and color distortion due to a change in viewing angle in an organic light-emitting display device display panel.

Another problem to be solved according to an embodiment of the present invention is to provide an organic light emitting display device display panel capable of securing more excellent panel efficiency in an organic light emitting display device display panel.

The problem to be solved according to an embodiment of the present invention is not limited to the problems mentioned above, and other problems that are not mentioned are clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. Can be.

An organic light emitting display device display panel according to an embodiment of the present invention includes an organic light emitting display device layer, a color filter layer, and a color change reduction layer positioned between the organic light emitting display device layer and the color filter layer, and the organic light emitting display device layer A third light comprising a first light-emitting unit including a first light-emitting layer for generating first light and a second light-emitting unit including a second light-emitting layer for generating second light, and the first light and the second light are combined Is emitted from the organic light-emitting display device layer and enters the color change reduction layer, and 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 region according to the increase of the viewing angle. Rather than the difference between the decrease in intensity and the decrease in intensity of the peak in the yellow-green wavelength band, the decrease in intensity of the peak in the blue wavelength band and the decrease in the intensity of the peak in the yellow-green wavelength band in the EL spectrum of the fourth light according to the increase in the viewing angle The difference between them may be smaller.

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

The organic light emitting display device display panel according to the present invention can minimize an increase in driving voltage by minimizing stacking of an organic light emitting layer for white color.

In addition, the display panel of an organic light emitting diode display according to the present invention can minimize luminance deterioration and color distortion due to a change in viewing angle.

In addition, the display panel of the organic light-emitting display device according to the present invention can secure more excellent panel efficiency.

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

Since the contents of the invention described in the problems to be solved above, the means for solving the problems, and the effects do not specify essential features of the claims, the scope of the claims is not limited by the contents of the invention.

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

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for describing the embodiments of the present invention are exemplary, and the present invention is not limited to the illustrated matters.

The same reference numerals refer to the same elements throughout the specification.

In describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

When'include','have','consists of' and the like mentioned in the specification are used, other parts may be added unless'only' is used.

In the case of expressing the constituent elements in the singular in the present specification, the case including the plural may be included unless otherwise explicitly stated.

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

In the case of the description of the positional relationship in the present specification, for example, when the positional relationship of the two parts is described as'to the upper part','to the upper part','to the lower part','to the side', etc., One or more other parts may be positioned between the two parts unless'directly' or'directly' or'in contact' is used together.

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

In describing the constituent elements of the present invention in the present specification, terms such as first, second, A, B, (a), (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, order, or number of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but other components between each component It is to be understood that is "interposed", or that each component may be "connected", "coupled" or "connected" through other components.

In the present specification, “peak” refers to a convex point in a curve, that is, a point in which the second derivative value is greater or less than zero.

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

In the present specification, the term "blue wavelength band" means a wavelength band of 430 nm or more and 480 nm or less.

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

In the present specification, the "red wavelength band" refers to a wavelength band of more than 580 nm and less than 660 nm.

In this specification, the term "EL spectrum" means an electroluminescence spectrum (hereinafter, referred to as an EL spectrum), which is EL measured at a viewing angle of 0°, that is, from the front of the device, unless otherwise specified. Means spectrum.

In the case of comparing the peak of the EL spectrum of the third light and the peak of the EL spectrum of the fourth light in this specification, the peaks to be compared are the wavelengths of all the peaks of the EL spectrum of the third light and the EL spectrum of the fourth light. When the wavelengths of all the peaks are compared, it means the peak of the EL spectrum of the third light and the peak of the EL spectrum of the fourth light, wherein the difference between the respective wavelengths is 50 nm or less.

In the present specification, the "peak intensity reduction width" means the difference between the intensity of the peak when the viewing angle is 0° and the intensity of the peak when the viewing angle is 60° in a specific wavelength range.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. May be.

An organic light emitting display device according to various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, various layers, which are constituent elements of the organic light emitting display device according to the present invention, are represented by rectangles for convenience. Various layers, which are constituent elements, seem to be clearly separated from the front side and the side surface, but the front side and the side side may not be clearly distinguished and may have a gentle curved shape.

1 is a schematic structure of a top-emission white organic light-emitting display device display panel as an organic light-emitting display device display panel according to an exemplary embodiment of the present invention.

Referring to FIG. 1, an organic light-emitting display device display panel 100 according to an exemplary embodiment of the present invention includes an organic light-emitting display device layer 120, a color change reduction layer 130, and a color filter layer on a substrate 110. 140). In this case, the organic light-emitting display device layer 120 includes a lower electrode 121 and an upper electrode 125 facing each other, and the first light-emitting unit 122 is disposed between the lower electrode 121 and the upper electrode 125. , The charge generation layer 123 and the second light emitting unit 124 has a structure in which multiple layers are stacked. More specifically, the first light emitting part 122 is located on the lower electrode 121, the charge generation layer 123 is located on the first light emitting part 122, and the second light is emitted on the charge generation layer 123 The portion 124 may be positioned, and the upper electrode 125 may be positioned on the second light emitting portion 124. In this case, the first light-emitting part 122 may include a first light-emitting layer (not shown) that generates the first light 122a, and the second light-emitting part 124 is used to generate the second light 124a. It may include a second emission layer (not shown). At this time, the first light emitting unit 122 and the second light emitting unit 124 have a hole injection layer (not shown) to facilitate charge injection and transport to each of the first light emitting layer (not shown) and the second light emitting layer (not shown). Si), a hole transport layer (not shown), an electron injection layer (not shown), an organic layer such as an electron transport layer (not shown) may be further included.

The substrate 110 may be a substrate in which a red pixel area (not shown), a green pixel area (not shown), and a blue pixel area (not shown) are defined, and a red pixel area (not shown), a green pixel area (not shown) ), a blue pixel area (not shown), and a white pixel area (not shown) may be defined.

The upper electrode 125 is made of a material having excellent light transmittance and electrical conductivity. More specifically, since the upper electrode 125 is an electrode positioned in the direction in which the first light 122a and the second light 124a are emitted, it is made of a material having excellent light transmittance in the entire visible wavelength range. . In addition, since the upper electrode 125 functions as an electrode, it is made of a material having excellent electrical conductivity. That is, the upper electrode 125 may include a conductive material and transmit light. The upper electrode 125 may be formed of, for example, a transparent conductive oxide (TCO, hereinafter referred to as TCO)-based material such as ITO, IZO, and ZnO, but is not limited thereto. When the optical upper electrode 125 is a cathode, between the second emission layer (not shown) and the upper electrode 125 is a movement path of electrons. In addition, when the upper electrode 125 is an anode, the second emission layer (not shown) and the upper electrode 125 become a moving path of holes.

The color of the first light 122a emitted from the first light emitting unit 122 and the color of the second light 124a emitted from the second light emitting unit 124 are in a complementary color relationship with each other, so that the first light 122a And the second light 124a may be combined to form white light. For example, when the first light 122a emitted from the first light emitting unit 122 is blue light, the second light 124a emitted from the second light emitting unit 124 may be yellow-green light, When the first light 122a emitted from the first light emitting unit 122 is yellow-green light, the second light 124a emitted from the second light emitting unit 124 may be blue light.

For example, when the first light 122a emitted from the first light emitting unit 122 is light having the highest light emission intensity in a wavelength band of 430 nm or more and 480 nm or less, the second light emitted from the second light emitting unit 124 2 The light 124a may be light having the highest emission intensity in a wavelength range of 500 nm or more and 580 nm or less. In addition, when the first light 122a emitted from the first light emitting unit 122 is light having the highest emission intensity in a wavelength band of 500 nm or more and 580 nm or less, the second light emitted from the second light emitting unit 124 (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 range' in the expression'having the highest luminous intensity in a certain wavelength range' means that it has at least one peak in the entire visible wavelength range, and the intensity of the peak is It means'in the wavelength range of the largest peak. That is,'in a certain wavelength range' means, for example,'in the case where there are two or more peaks in the entire visible light wavelength range, in the one peak wavelength range in which the intensity of the peak is the largest'. .

In the organic light-emitting display device display panel 100 according to an exemplary embodiment, the organic light-emitting display device layer 120, the color change reduction layer 130, and the color filter layer 140 will be described in more detail.

The organic light-emitting display device layer 120 emits a third light 120a generated 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 have a complementary color relationship with each other, and in this case, the third light 120a may be white light. The EL spectrum of the third light 120a in the entire visible light wavelength 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 range of 430 nm or more and 480 nm or less and a peak in a wavelength range of 500 nm or more and 580 nm or less.

The color change reduction layer 130 is a layer into which the third light 120a emitted from the upper electrode 125 of the organic light emitting display device layer 120 enters. The refractive index of the color change reduction layer 130 is smaller than the refractive index of the upper electrode 125, which is an electrode closer to the color change reduction layer 130, among the two electrodes of the organic light-emitting display device layer 120, based on a wavelength of 550 nm. 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 reducing layer 130 is titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiOxNy), It may include any one selected from aluminum nitride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), and mixtures thereof. The thickness of the color change reducing 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 based on a wavelength of 1000 nm and 550 nm in thickness. 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 550 nm in thickness. If necessary, a combination of these may be multiple layers.

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 is different from that of the third light 120a.

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

More specifically, the intensity of all peaks in the EL spectrum of the third light 120a in the entire visible light wavelength range decreases as the viewing angle gradually increases from 0°. In addition, 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 greater than the peak intensity in the yellow-green wavelength band region, but as the viewing angle gradually increases, the third light ( The difference in magnitude between the intensity of the peak in the blue wavelength band region of the EL spectrum of 120a) and the intensity of the peak in the yellow-green wavelength band region is reduced. This means that as the viewing angle increases, the decrease in intensity of the peak in the blue wavelength band is significantly greater than that of the peak in the yellow-green wavelength band.

In this way, since the decrease in intensity of each peak as the viewing angle changes is different for each peak, the first light 122a, which is light in the blue wavelength band, and the second light 124a, is light in the yellow-green wavelength band, as the viewing angle changes. ) The third light 120a formation mixing ratio is significantly different. For this reason, the color coordinate of the third light 120a has a large variation as the viewing angle changes. As a result, the color of the third light 120a formed by combining the first light 122a and the second light 124a is changed as the viewing angle changes. When the third light 120a directly enters the color filter layer 140, a color shift phenomenon occurring as the viewing angle changes becomes a major problem.

4 is an EL spectrum at a viewing angle of 0°, 20°, 30°, 40°, 50°, and 60° of a fourth light 130a of the display panel 100 of the organic light emitting display device according to an exemplary embodiment of the present invention. admit.

More specifically, all peaks of the EL spectrum of the fourth light 130a in the entire visible light wavelength range are also, as in the third light 120a, their intensity as the viewing angle gradually increases from 0°. Decreases. However, when comparing the intensity reduction widths of the peaks in the fourth light 130a and the third light 120a, the EL of the fourth light 130a is less than the intensity reduction widths of all the peaks in the EL spectrum of the third light 120a. The intensity reduction of all peaks in the spectrum is smaller. In addition, as the viewing angle of the third light 120a increases, the intensity decrease width of the peak in the blue wavelength band region is significantly greater than that of the peak in the yellow-green wavelength band region. In the EL spectrum, even if the viewing angle increases, there is no significant difference between the decrease in intensity of the peak in the blue wavelength band and the decrease in intensity of the peak in the yellow-green wavelength band.

That is, when comparing the decrease in intensity of the peak in the blue wavelength band and the decrease in intensity of the peak in the yellow-green wavelength band, the difference between the intensity decrease in both peaks is the fourth light than in the EL spectrum of the third light 120a. It is smaller in the EL spectrum of (130a). This means that the EL spectrum of the fourth light 130a does not change the magnitude of the intensity of each peak even when the viewing angle changes, and that there is little variation in the reduction ratio of the intensity of each peak as the viewing angle changes. In the fourth light 130a having an EL spectrum showing a consistent pattern even when the viewing angle changes, the color shift phenomenon that occurs as the viewing angle changes is remarkably reduced, which is directly connected to the improvement of the image quality of the display panel of the white OLED display.

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 maintains a consistent pattern without changing the magnitude of the intensity of the peak in each wavelength band as the viewing angle changes. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 has the same wavelength band of the EL spectrum of the fourth light 130a at the same viewing angle than 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. Make the intensity of the peak in the region larger.

That is, the color change reduction layer 130 allows a viewing angle region in which the intensity of the peak in the blue wavelength region of the EL spectrum of the fourth light is greater than the intensity of the peak in the blue wavelength region of the EL spectrum of the third light to exist.

For example, if the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a and the peak intensity in the same wavelength band region of the EL spectrum of the fourth light 130a are compared, the viewing angle is 0°, 20 At ° 30°, the intensity in the EL spectrum of the third light 120a is greater, but from a viewing angle of 40° or more, it can be seen that the intensity in the EL spectrum of the fourth light 130a is greater. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 has the EL spectrum of the fourth light 130a at the same viewing angle than the intensity of the peak in the yellow-green wavelength region of the EL spectrum of the third light 120a at a certain viewing angle. Make the intensity of the peak in the same wavelength range larger.

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

Comparing the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a and the peak intensity in the same wavelength band region of the EL spectrum of the fourth light 130a, viewing angles 0°, 20° 30 It can be seen that the intensity in the EL spectrum of the third light 120a is greater at ° and 40°, but the intensity in the EL spectrum of the fourth light 130a is greater from a viewing angle of 50° or more. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 has the magnitude of the peak intensity in the blue wavelength band region of the EL spectrum of the third light 120a at any arbitrary viewing angle, and at the same viewing angle. When the magnitude of the peak intensity in the same wavelength band region of the EL spectrum of the fourth light 130a is compared, the magnitude relationship is reversed.

For example, the intensity of the peak in the blue wavelength band region of the EL spectrum of the third light 120a is the same wavelength band of the EL spectrum of the fourth light 130a at the same viewing angle until the viewing angle is 0° or more and less than 40°. The magnitude of the peak intensity in the region is greater than the magnitude of the peak intensity in the region, but from a viewing angle of 40° or more, the magnitude of the peak intensity in the blue wavelength band region of the EL spectrum of the third light 120a is the same as that of the fourth light 130a at the same viewing angle. It may be smaller than the magnitude of the intensity of the peak in the same wavelength range of the EL spectrum. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 has the same viewing angle as the intensity of the peak in the yellow-green wavelength band of the EL spectrum of the third light 120a at any viewing angle in the entire viewing angle. When the magnitude of the peak intensity in the same wavelength band region of the EL spectrum of the fourth light 130a at is compared, the magnitude relationship is reversed.

For example, the intensity of the peak in the yellow-green wavelength band region of the EL spectrum of the third light 120a up to a viewing angle of 0° or more and less than 50° is the EL spectrum of the fourth light 130a at the same viewing angle. The intensity of the peak in the yellow-green wavelength range of the EL spectrum of the third light 120a is greater than the intensity of the peak in the same wavelength range, and from a viewing angle of 50° or more, the fourth intensity at the same viewing angle. The intensity of the peak in the same wavelength range of the EL spectrum of the light 130a may be smaller. In this case, 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 at the same level within an error range.

In other words, the color change reducing layer 130 has the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light and the blue or yellow color of the EL spectrum of the fourth light at the entire viewing angle. The intensity of the peak in the green wavelength range is reversed.

In addition, the color change reduction layer 130 has a decrease in intensity of the peak in the blue wavelength band region in the EL spectrum of the third light 120a and the peak in the blue wavelength band region in the EL spectrum of the fourth light 130a. When comparing the intensity reduction width, it is made 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, when the intensity of the peak in the blue wavelength band is 0.2696 (@ wavelength 456 nm) when the viewing angle is 0°, and 0.07446 (@ wavelength 452 nm) when the viewing angle is 60°, the peak The strength reduction of is 0.19514, the difference between 0.2696 and 0.07446.

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

When comparing the intensity reduction width of the peak according to the viewing angle in the blue wavelength region, it is 0.19514 in the EL spectrum of the third light 120a, and 0.0444 in the EL spectrum of the fourth light 130a, and in the EL spectrum of the third light 120a. It can be seen that in the EL spectrum of the fourth light 130a, the intensity reduction width of the peak according to the viewing angle in the blue wavelength band region is smaller. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 has a decrease in intensity of the peak in the yellow-green wavelength band region in the EL spectrum of the third light 120a, and the yellow-green wavelength band region in the EL spectrum of the fourth light 130a. When comparing the intensity reduction width of the peak at, it is made 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), when the intensity of the peak in the yellow-green wavelength range is 0.1935 (@ wavelength 552 nm) when the viewing angle is 0°, and 0.06861 (@ wavelength 544 nm) when the viewing angle is 60°. , The intensity reduction width of the peak is 0.12489, the difference between 0.1935 and 0.06861.

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

When comparing the intensity reduction width of the peak according to the viewing angle in the yellow-green wavelength region, the EL spectrum of the third light 120a is 0.12489, and the EL spectrum of the fourth light 130a is 0.0192, and the EL of the third light 120a is It can be seen that the intensity reduction width 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. In this case, 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 at the same level within an error range.

In addition, the color change reduction layer 130 compares the magnitude of the decrease in the intensity of the peak in the blue wavelength region and the decrease in intensity of the peak in the yellow-green wavelength region as the viewing angle gradually increases from 0°. It is made smaller in the EL spectrum of the fourth light 130a than in the EL spectrum of (120a).

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

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

In the EL spectrum of the third light 120a, the difference between the decrease in the intensity of the peak in the blue wavelength region and the decrease in the intensity of the peak in the yellow-green wavelength region, and in the blue wavelength region in the EL spectrum of the fourth light 130a Comparing the difference between the decrease in intensity of the peak and the decrease in intensity of the peak in the yellow-green wavelength range, the decrease in intensity of the peak in the blue wavelength range and in the yellow-green wavelength range in the EL spectrum of the former third light 120a It can be seen that the difference in the intensity reduction width of the peak of is larger.

The color filter layer 140 includes a red color filter (not shown) that causes the incident fourth light 130a to emit red from a red pixel area (not shown), and the incident fourth light 130a is a green pixel area A green color filter (not shown) for emitting green from (not shown), and a blue color filter (not shown) for allowing the incident fourth light 130a to emit blue from a blue pixel area (not shown). Can include. The color filter layer 140 may further include a white color filter (not shown) that causes the incident fourth light 130a to emit white from a white pixel area (not shown).

That is, the color filter layer 140 includes a red color filter (not shown) and a green color filter (not shown) corresponding to a red pixel area (not shown), a green pixel area (not shown), and a blue pixel area (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 bonding between the color change reducing layer 130 and the color filter layer 140 may be further included in the display panel 100 of the organic light emitting display device. 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 the two layers may be 0.15 or more and 0.35 or less based on a wavelength of 550 nm. 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 cured resin layer having a refractive index of 1.5 based on a wavelength of 3000 nm and 550 nm in thickness. In this case, the light incident on the color filter layer 140 may be light emitted through the fourth light 130a passing through the resin layer (not shown).

2 is a schematic structure of a bottom-emission white organic light-emitting display device display panel as an organic light-emitting display device display panel according to another exemplary embodiment of the present invention.

Referring to FIG. 2, an organic light emitting diode display panel 200 according to another embodiment of the present invention includes a substrate 210, a color filter layer 220, a color change reduction layer 230, and a color change reduction layer 230. And an organic light emitting display device layer 240 positioned thereon. In this case, the organic light-emitting display device layer 240 includes a lower electrode 241 and an upper electrode 245 facing each other, and a first light-emitting unit 242 between the lower electrode 241 and the upper electrode 245 , The charge generation layer 243 and the second light emitting unit 244 have a structure in which multiple layers are stacked. More specifically, the first light emitting unit 242 is positioned on the lower electrode 241, the charge generation layer 243 is positioned on the first light emitting unit 242, and the second light is emitted on the charge generation layer 243. The portion 244 may be positioned, and an upper electrode 245 may be positioned on the second light emitting portion 244. In this case, the first light-emitting part 242 may include a first light-emitting layer (not shown) that generates the first light 242a, and the second light-emitting part 244 is used to generate the second light 244a. It may include a second emission layer (not shown). At this time, the first light emitting unit 242 and the second light emitting unit 244 have a hole injection layer (not shown) to facilitate charge injection and transport to each of 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 organic layer such as an electron transport layer (not shown) may be further included.

The lower electrode 241 is made of a material having excellent light transmittance and electrical conductivity. More specifically, the lower electrode 241 is an electrode positioned in the direction in which the first light 242a and the second light 244a are emitted, and thus is made of a material having excellent light transmittance in the entire wavelength range. In addition, since the lower electrode 241 functions as an electrode, it is made of a material having excellent electrical conductivity. That is, the lower electrode 241 may include a conductive material and transmit light. When the lower electrode 241 is a cathode, the first emission layer (not shown) and the lower electrode 241 become a moving path for electrons. In addition, when the lower electrode 241 is an anode, a movement path of holes between the first emission layer (not shown) and the lower electrode 241 is formed.

The substrate 210, the color filter layer 220, the color change reduction layer 230, the organic light emitting display device layer 240, the first light of the organic light emitting display device display panel 200 according to another embodiment of the present invention 242a), the second light 244a, the third light 240a, and the fourth light 230a are respectively described on the substrate 110 of the display panel 100 of the organic light emitting diode display according to the exemplary 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, the fourth light 130a ), the same applies. Accordingly, in the description of the organic light emitting display device display panel 200 according to another embodiment of the present invention, substantially the same contents as the description of the organic light emitting display device display panel 100 according to an embodiment of the present invention The description of this will be omitted and other parts will be further described.

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 device layer 240 enters. The refractive index of the color change reduction layer 230 is smaller than the refractive index of the lower electrode 241, which is an electrode closer to the color change reduction layer 230, of the two electrodes of the organic light emitting display device layer 240, based on a wavelength of 550 nm. The difference between the refractive index values of the two layers may be 0.15 or more and 0.35 or less.

In the following, the performance of Comparative Examples and Examples is compared.

A comparative example is an organic light-emitting display device display panel including a substrate, an organic light-emitting display device layer, a resin layer, and a color filter layer, wherein the organic light-emitting display device layer is a lower electrode serving as an anode, and blue light is generated. It consists of a light emitting part, a charge generation layer, a yellow-green light emitting part that emits bright-green light, and an upper electrode serving as a cathode. At this time, the upper electrode was formed of IZO having a refractive index of n=2 in the 550 nm wavelength band to a thickness of 120 nm, and the resin layer was formed of a cured resin material having a refractive index of n=1.5 in the 550 nm wavelength band to a thickness of 3000 nm. That is, in the comparative example, the color change reducing layer is not applied. That is, in the comparative example, the third light is directly incident on 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 device layer 120 and a resin layer (not shown) as the organic light emitting display device layer used in the comparative example were applied. In addition, silicon nitride (SiNx) having a refractive index of n=1.85 in the 550 nm wavelength band was formed to a thickness of 1000 nm by using a chemical vapor deposition method between the organic light emitting display device layer 120 and the resin layer (not shown). I did. That is, in the embodiment, since the color change reducing layer 130 is applied, the fourth light 130a, not the third light, enters the color filter layer 140 in the embodiment.

Table 1 below shows the device luminous efficiency according to the device evaluation of each of the comparative examples and examples, and the panel efficiency (Cd/A) simulation values of each of the comparative examples and examples expected when each device is applied to a panel. Here, the device evaluation for the embodiment defines the substrate 110, the organic light emitting display device layer 120, and the color change reduction layer 130 as one device, and the luminous efficiency (Cd/A) of the device In the evaluation of the device for the comparative example, the substrate and the organic light emitting display device layer were defined as one device, and the luminous efficiency of the device was 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 case of the device luminous efficiency of red, the Example appears to be higher than that of the Comparative Example, and in the case of device luminous efficiency in other colors, the Example appears to be lower than that of the Comparative Example. However, in terms of panel efficiency in which the frequency of use of each color is reflected as a factor in consideration in standard moving picture driving, the Example appears to be higher than the Comparative Example. This makes it possible to express more colorful colors when viewed from the side of the panel as a whole, due to the effect of increasing the device luminous efficiency in red without using an additional red emission layer, and the frequency of use for newly added color areas. Is reflected in the panel efficiency.

Accordingly, in the organic light emitting display device display panel 100 according to an embodiment of the present invention, the third light 120a passes through the color change reduction layer 130 rather than incident on the color filter layer 140 as it is. It can be seen that injecting the fourth light 130a onto the color filter layer 140 is advantageous in terms of panel efficiency of the display panel of the OLED display.

Table 2 below shows Δu'v of the white CIE color coordinates at each viewing angle, based on the white CIE color coordinates according to the viewing angle change from 0° to 60° and the white CIE color coordinates at the viewing angle 0° of Comparative Examples and Examples. 'Is the value. Here, the X coordinate of the CIE color coordinate is expressed as CIEx(u'), and the Y coordinate of the CIE color coordinate is expressed as 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 the white CIE color coordinates as the viewing angle changes from 0° to 60° in the Comparative Example and Example as shown in FIG. 5 can be obtained. In addition, Δu'v' graphs of the white CIE color coordinates at each viewing angle based on the white CIE color coordinates at a viewing angle of 0° in the comparative examples and examples as shown in FIG. 6 can be obtained.

Referring to FIG. 5, it can be seen that the white CIE color coordinate trace according to the changing viewing angle of the example is shorter than the white CIE color coordinate trace according to the changing viewing angle of the comparative example. The shorter the white CIE color coordinate trace as the viewing angle changes, the less the change in white color as the viewing angle changes. That is, the embodiment having a relatively short white CIE color coordinate trace according to the change of the viewing angle has less color distortion than the comparative example.

6, it can be seen that the value of Δu'v', which means the difference from the white CIE color coordinate at the viewing angle of 0°, is lower in the Example than in the Comparative Example at all viewing angles. The shorter the Δu'v' value, the smaller the color change of white. That is, the embodiment in which the value of Δu'v' is relatively low at a certain viewing angle has less color distortion than the comparative example.

Accordingly, in the organic light emitting display device display panel 100 according to an embodiment of the present invention, the third light 120a passes through the color change reduction layer 130 rather than incident on the color filter layer 140 as it is. It can be seen that incidence of the fourth light 130a on the color filter layer 140 is advantageous in terms of minimizing a color distortion phenomenon due to a change in the viewing angle of the display panel of the OLED display.

An organic light-emitting display device display panel according to an embodiment of the present invention includes an organic light-emitting display device layer, a color filter layer, and a color change reduction layer disposed between the organic light-emitting display device layer and the color filter layer, and the organic light-emitting display device layer Silver includes a first light-emitting unit including a first light-emitting layer for generating first light and a second light-emitting unit including a second light-emitting layer for generating second light, and a third light-emitting unit formed by combining the first light and the second light The light exits from the organic light-emitting display element layer and enters the color change reduction layer, and 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 region according to the increase of the viewing angle. Rather than the difference between the decrease in intensity and the decrease in intensity of the peak in the yellow-green wavelength band, the decrease in intensity of the peak in the blue wavelength band and the decrease in the intensity of the peak in the yellow-green wavelength band in the EL spectrum of the fourth light according to the increase in the viewing angle The difference between them is smaller.

In this case, the color change reduction layer has a viewing angle in which the intensity of the peak in the blue or yellow-green wavelength band of the EL spectrum of the fourth light is greater than the intensity of the peak in the blue or yellow-green wavelength band of the EL spectrum of the third light. You can make the area exist.

At this time, the color change reduction layer is at the entire viewing angle, the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light, and the blue or yellow-green wavelength band region of the EL spectrum of the fourth light. The magnitude relationship of the intensity of the peak of can be reversed.

In this case, the color change reduction layer has a greater decrease in intensity of the peak in the blue or yellow-green wavelength range of the EL spectrum of the fourth light than in the blue or yellow-green wavelength range of the EL spectrum of the third light. You can make it small.

In this case, the color change reduction layer is less than the difference between the decrease in intensity of the peak in the blue wavelength band region and the decrease in intensity of the peak in the yellow-green wavelength region of the EL spectrum of the third light, in the blue wavelength region of the EL spectrum of the fourth light. The difference between the decrease in intensity of the peak at and the decrease in intensity of the peak in the yellow-green wavelength range can be made smaller.

In this case, the organic light-emitting display device layer may further include an upper electrode and a lower electrode facing each other, and the refractive index of the color change reduction layer may be smaller than that of an electrode closer to the color change reduction layer among the upper and lower electrodes. .

At this time, the color change reducing layer is titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiOxNy), It may include any one selected from aluminum nitride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy), and mixtures thereof.

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

In this case, the color of the first light and the color of the second light may have a complementary color relationship with each other.

In this case, the third light may be white light.

In this case, 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 more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

110, 210: substrate
120, 240: organic light emitting display device layer
120a, 240a: third light
121, 241: lower electrode
122, 242: first light emitting unit
122a, 242a: first light
123, 243: charge generation layer
124, 244: second light emitting unit
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: OLED display device display panel

Claims (11)

An organic light emitting display device layer, a color filter layer, and a color change reduction layer positioned between the organic light emitting display device layer and the color filter layer,
The organic light-emitting display device layer includes a first light-emitting part including a first light-emitting layer for generating first light and a second light-emitting part including a second light-emitting layer for generating second light,
The third light generated by the combination of the first light and the second light is emitted from the organic light-emitting display device layer and enters the color change reduction layer,
The light emitted from the color change reduction layer is the fourth light,
In the EL spectrum of the third light, compared to the difference between the decrease in intensity of the peak in the blue wavelength band region according to the increase in the viewing angle and the decrease in intensity of the peak in the yellow-green wavelength band region, the EL spectrum of the fourth light blue according to the viewing angle increases. The difference between the decrease in intensity of the peak in the wavelength band region and the decrease in intensity of the peak in the yellow-green wavelength region is smaller,
Organic light-emitting display device display panel. The method of claim 1,
The color change reduction layer,
A viewing angle region in which the intensity of the peak in the blue or yellow-green wavelength region of the EL spectrum of the fourth light is greater than the intensity of the peak in the blue or yellow-green wavelength region of the EL spectrum of the third light ,
Organic light-emitting display device display panel. The method of claim 1,
The color change reduction layer,
In the entire viewing angle, the intensity of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the third light and the peak intensity in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light To reverse the relationship,
Organic light-emitting display device display panel. The method of claim 1,
The color change reduction layer,
To make the intensity decrease width of the peak in the blue or yellow-green wavelength band region of the EL spectrum of the fourth light 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,
Organic light-emitting display device display panel. The method of claim 1,
The color change reduction layer,
In the EL spectrum of the third light, the difference between the decrease in intensity of the peak in the blue wavelength region and the decrease in intensity of the peak in the yellow-green wavelength region in the EL spectrum of the fourth light, So that the difference between the decrease in intensity of the peak in the yellow-green wavelength region is smaller,
Organic light-emitting display device display panel. The method of claim 1,
The organic light-emitting display device layer further includes an upper electrode and a lower electrode facing each other,
The refractive index of the color change reduction layer is smaller than the refractive index of an electrode closer to the color change reduction layer among the upper electrode and the lower electrode,
Organic light-emitting display device display panel. The method of claim 1,
The color change reducing layer is titanium nitride (TiNx), titanium oxide (TiOx), titanium oxynitride (TiOxNy), silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiOxNy), aluminum nitride. Including any one selected from ride (AlNx), aluminum oxide (AlOx), aluminum oxynitride (AlOxNy) and mixtures thereof,
Organic light-emitting display device display panel. The method of claim 1,
Further comprising a resin layer between the color change reducing layer and the color filter layer,
Organic light-emitting display device display panel. The method of claim 1,
The color of the first light and the color of the second light are complementary to each other,
Organic light-emitting display device display panel. The method of claim 1,
The third light is white light,
Organic light-emitting display device display panel. The method of claim 1,
One of the first light and the second light is blue light, and the other is yellow-green light,
Organic light-emitting display device display panel.

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