Display device and method for manufacturing the same

Abstract

Disclosed is a display device comprising a substrate, an alignment film arranged on the substrate, a polarizing layer arranged on the alignment film, and an optical compensation film arranged between the substrate and the polarizing layer, wherein the optical compensation film has a structure in which a first optical compensation film and a second optical compensation film are stacked on each other, the first optical compensation film has a phase difference value of 1 / 4 of the wavelength of transmitted light, and the second optical compensation film has a phase difference value of 1 / 2 of the wavelength of transmitted light.

Description

Technical Field

[0001] The present disclosure relates to a display device, and more particularly to a display device including an optical compensation film and a method for manufacturing the display device. Background Art

[0002] Display devices are being applied to various electronic devices such as televisions, mobile phones, notebook computers, and tablet computers. For this reason, research on developing thinner, lighter, lower power consumption display devices and the like is continuing.

[0003] The display device may include a liquid crystal display device (LCD), a plasma display device (PDP), a field emission display device (FED), an electrowetting display device (EWD), an organic light emitting display device (OLED), and the like.

[0004] Among them, an organic light-emitting display device (OLED) includes a plurality of pixel areas arranged in a display area for displaying an image and a plurality of organic light-emitting elements corresponding to the plurality of pixel areas. Since the organic light-emitting element is a self-luminous element that emits light by itself, the organic light-emitting display device can have a faster response speed, greater luminous efficiency, brightness and viewing angle, as well as excellent contrast and color gamut compared to other display devices.

[0005] Such an organic light emitting display device has a problem that contrast, that is, the ratio of the brightest color and the darkest color that can be simultaneously expressed in the display device, is reduced based on the intensity of external light. When external light is incident on a stacking surface made of a metal material in the organic light emitting display device, the contrast may be reduced because the external light is reflected from the stacking surface and transmitted to the display area, and the quality of the screen may be reduced.

[0006] Therefore, a method of preventing the reflection of external light and thus the reduction of contrast by introducing a polarizing plate on an organic light-emitting display device is being studied. However, even if a polarizing plate is introduced, when the direction of light reflected from the organic light-emitting display device and the absorption axis of the polarizing plate do not match each other at a viewing angle inclined relative to the display panel, a light leakage defect or a color inversion phenomenon occurs, that is, an unexpectedly expressed color appears, and thus there are problems caused by viewing angle characteristics, such as a reduction in image quality and a reduction in visibility. Summary of the invention

[0007] Accordingly, the present disclosure is directed to a display device including an optical compensation film, and a method for manufacturing the same, which substantially obviate one or more problems due to the above limitations and disadvantages.

[0008] Other features and advantages of the present disclosure will be described in the following description, and partly will be obvious from the description, or can be understood through the practice of the present disclosure. Other advantages of the present disclosure will be realized and achieved through the structures particularly pointed out in the written description and claims and the drawings.

[0009] More specifically, the present disclosure prevents or minimizes light leakage or color inversion defects by introducing an optical compensation film that makes the direction of light reflected from the organic light emitting display device adjacent to or coincide with the direction of the absorption axis of the polarizing layer.

[0010] The present disclosure can achieve excellent image quality even at a certain viewing angle, so that the image quality changes little due to the change in viewing angle.

[0011] The present disclosure also forms optical compensation films with different phase difference values ​​through a continuous manufacturing process.

[0012] Further, the present disclosure provides a method for manufacturing a display device, which can simplify a manufacturing process by forming a structure in which optical compensation films having different optical characteristics are stacked through a continuous manufacturing process.

[0013] The present disclosure is not limited to the above. Other features and advantages of the present disclosure that are not mentioned can be understood from the following description and can be more clearly understood from the various aspects of the present disclosure. In addition, it is easy to understand that the objects and advantages of the present disclosure can be achieved using the means and combinations thereof shown in the claims.

[0014] In one aspect of the present disclosure, a display device includes a substrate, an alignment film arranged on the substrate, a polarizing layer arranged on the alignment film, and an optical compensation film arranged between the substrate and the polarizing layer, and the optical compensation film has a structure in which a first optical compensation film and a second optical compensation film are stacked on each other, the first optical compensation film has a phase difference value of 1 / 4 of the wavelength of the transmitted light, and the second optical compensation film has a phase difference value of 1 / 2 of the wavelength of the transmitted light.

[0015] In one aspect of the present disclosure, a display device includes a substrate, a polarizing layer disposed on the substrate, an alignment film disposed below the polarizing layer, and an optical compensation film disposed between the substrate and the alignment film, and the optical compensation film includes a first optical compensation film and a second optical compensation film, the first optical compensation film having a phase difference value of 1 / 2 of the wavelength of the transmitted light, and the second optical compensation film having a phase difference value of 1 / 4 of the wavelength of the transmitted light.

[0016] In another aspect of the present disclosure, a method for manufacturing a display device includes forming an alignment film optically aligned along a first direction, forming a first optical compensation film on the alignment film, applying a phase difference solution on the first optical compensation film, radiating polarized ultraviolet light onto the phase difference solution to form a second optical compensation film optically aligned along a second direction different from the first direction, disposing the alignment film and an optical compensation film including the first optical compensation film and the second optical compensation film on a substrate, and forming a polarizing layer on the alignment film and the optical compensation film.

[0017] According to the present disclosure, defects such as light leakage or color inversion may be prevented or minimized by introducing an optical compensation film that makes the direction of light reflected from an organic light emitting display device adjacent to or coincide with the direction of an absorption axis of a polarizing layer.

[0018] Further, even when external light is incident on the organic light emitting display device, the external light may be prevented from being reflected outwardly from the display region by the optical compensation film in the organic light emitting display device.

[0019] Further, since the color change caused by the change in viewing angle is small, the accuracy of representing the color to be achieved will also increase at the viewing angle, so that excellent image quality can be achieved.

[0020] Furthermore, since optical compensation films having different phase difference values ​​and optical characteristics are formed through a continuous manufacturing process, the manufacturing process can be simplified.

[0021] Therefore, the reliability of the display device can be improved by preventing defects that occur when two optical compensation films are separately manufactured and bonded to each other.

[0022] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood from the following description by those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are included to provide a further understanding of the present disclosure and constitute a part of this disclosure, illustrate various aspects of the present disclosure and together with the description serve to explain the principles of the present disclosure.

[0024] In the attached figure:

[0025] Figures 1A to 1E is a diagram for illustrating a method for manufacturing a display device according to the first aspect of the present disclosure;

[0026] Figure 2 is a schematic exploded perspective view of a display device including the optical compensation film according to the first aspect of the present disclosure;

[0027] Figure 3 (a) and Figure 3(b) is a diagram for illustrating the movement of light on a Poincare ball when the display device according to the first aspect of the present disclosure is applied;

[0028] Figure 4 is a diagram for illustrating a display device according to a second aspect of the present disclosure;

[0029] Figure 5 is a diagram for illustrating optical compensation characteristics when the display device according to the second aspect of the present disclosure is applied;

[0030] Figure 6 (a) and Figure 6 (b) is a diagram for illustrating the movement of light on a Poincare ball when the display device according to the second aspect of the present disclosure is applied;

[0031] Figure 7 is a diagram illustrating dispersion of color coordinates in the display device according to the first aspect and the second aspect of the present disclosure;

[0032] FIG. 8A to FIG. 8G is a diagram for illustrating a method for manufacturing a display device according to a second aspect of the present disclosure;

[0033] Fig. 9 is a diagram used to illustrate the isomerization process of polymeric materials;

[0034] Fig.10 is a diagram for illustrating a display device according to a third aspect of the present disclosure; and

[0035] FIG. 11A to FIG. 11H is a diagram for illustrating a method for manufacturing a display device according to the third aspect of the present disclosure. DETAILED DESCRIPTION

[0036] The advantages and features of the present disclosure and methods of achieving these advantages and features will become apparent after referring to the various aspects described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the various aspects disclosed below, but can be implemented in various different forms. Therefore, these aspects are set forth only to make the present disclosure complete and fully inform the ordinary technicians of the technical field to which the present disclosure belongs, and the present disclosure is limited only by the scope of the claims.

[0037] The shapes, sizes, ratios, angles, quantities, etc. disclosed in the accompanying drawings for describing various aspects of the present disclosure are exemplary, and the present disclosure is not limited thereto. The same reference numerals refer to the same elements in this article. In addition, in order to simplify the description, the description and details of well-known steps and elements are omitted. In addition, in the following detailed description of the present disclosure, many specific details are set forth in order to provide a comprehensive understanding of the present disclosure. However, it should be understood that the present disclosure can be implemented without these specific details. In other cases, well-known methods, procedures, components and circuits are not described in detail to avoid unnecessarily obscuring various aspects of the present disclosure.

[0038] The terms used herein are only used to describe specific aspects and are not intended to limit the present disclosure. As used herein, the singular forms "one" and "an" are intended to also include plural forms, unless the context clearly indicates. It should be further understood that the terms "including" and "comprising" used in this specification refer to the presence of the described features, integers, operations, elements and / or parts, but do not exclude the presence or increase of one or more other features, integers, operations, elements, parts and / or parts thereof. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. When a statement such as "at least one" is placed in front of a column of elements, it can modify all of the column elements, but cannot modify a single element in the column. When interpreting a numerical value, even if there is no clear description, there may also be errors or tolerances therein.

[0039] In addition, it will be understood that when a first element or layer is referred to as being present on a second element or layer, the first element or layer may be directly disposed on the second element or layer, or may be indirectly disposed on the second element or layer and a third element or layer may be disposed between the first and second elements or layers. It will be understood that when an element or layer is referred to as being "connected to" or "coupled to" another element or layer, it may be directly connected to or coupled to the other element or layer, or there may be one or more intervening elements or layers. In addition, it will be understood that when an element or layer is referred to as being between two elements or layers, it may be the only element or layer between the two elements or layers, or there may also be one or more intermediate elements or layers.

[0040] In addition, as used herein, when a layer, film, region, plate or the like is arranged "on" or "on top" of another layer, film, region, plate or the like, the former may directly contact the latter, or still another layer, film, region, plate or the like may be arranged between the former and the latter. As used herein, when a layer, film, region, plate or the like is directly arranged "on" or "on top" of another layer, film, region, plate or the like, the former directly contacts the latter, and another layer, film, region, plate or the like will not be arranged between the former and the latter. In addition, as used herein, when a layer, film, region, plate or the like is arranged "below" or "below" of another layer, film, region, plate or the like, the former may directly contact the latter, or another layer, film, region, plate or the like may be arranged between the former and the latter. As used herein, when a layer, film, region, plate, or the like is disposed directly “under” or “beneath” another layer, film, region, plate, or the like, the former directly contacts the latter, and the other layer, film, region, plate, or the like is not disposed between the former and the latter.

[0041] In descriptions of temporal relationships, such as a temporal precedent relationship between two events, such as "after," "subsequently," "before," etc., unless "directly after," "directly subsequent," or "directly before" is indicated, the other event may occur in between.

[0042] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, the first element, component, region, layer or part described below may be referred to as a second element, component, region, layer or part without departing from the spirit and scope of the present disclosure.

[0043] The features of various aspects of the present disclosure may be partially or completely combined with each other, and may be technically related or interoperable with each other. Various aspects may be implemented independently of each other, or may be implemented together in an associated relationship.

[0044] When interpreting a numerical value, the numerical value is interpreted as including a range of error unless expressly stated separately.

[0045] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as commonly understood by those of ordinary skill in the art to which the inventive concept belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the relevant technical context and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0046] Hereinafter, a display device according to each aspect of the present disclosure will be described with reference to the accompanying drawings.

[0047] Figures 1A to 1E is a diagram for illustrating a method for manufacturing the display device according to the first aspect of the present disclosure. Figure 2 is a schematic exploded perspective view of a display device including the optical compensation film according to the first aspect of the present disclosure. Figure 3 is a diagram for illustrating the movement of light on a Poincare ball when the display device according to the first aspect of the present disclosure is applied. Figure 4 is a diagram for illustrating a display device according to a second aspect of the present disclosure.

[0048] Reference Figure 1A , a first alignment film 105 and a first optical compensation film 110 are formed on the front side of the first base film 100a. In one example, one of photosensitive polymer-based materials such as polyimide (PI), polystyrene, and polyacrylate can be selected and applied as the first alignment film 105. This photosensitive polymer material is irradiated with light to form the first alignment film 105, the surface of which is aligned in a first direction perpendicular to or parallel to the surface of the first base film 100a. The first optical compensation film 110 is formed by coating a first reactive mesogenic material on the first alignment film 105 and performing a drying process. In this regard, the first reactive mesogenic material can be formed to have a first thickness T1.

[0049] Reference Figure 1B , a second alignment film 115 and a second optical compensation film 117 are formed on the front surface of the second base film 100b. In one example, one of the photosensitive polymer-based materials that is the same as the material of the first alignment film 115 can be selected and applied as the second alignment film 115. This photosensitive polymer material is irradiated with light to form the second alignment film 115, the surface of which is aligned in a second direction perpendicular to or parallel to the surface of the second base film 100b. When the surface of the first alignment film 105 is aligned in the first direction, the surface of the second alignment film 115 is aligned in a second direction different from the first direction of the first alignment film. For example, when the first direction is a vertical direction, the second direction may be a horizontal direction, and when the first direction is a horizontal direction, the second direction may be a vertical direction.

[0050] The second optical compensation film 117 is formed by coating a reactive mesogen material on the second alignment film 115 and performing a drying process. In this regard, the second optical compensation film 117 may be formed by applying the reactive mesogen material to have a second thickness T2 that is relatively smaller than the first thickness of the first optical compensation film 110. Accordingly, the first optical compensation film 110 may be formed as a quarter wave plate (QWP) having a quarter wavelength value (λ / 4), and the second optical compensation film 117 may be formed as a half wave plate (HWP) having a half wavelength value (λ / 2).

[0051] Reference Figure 1C , the first optical compensation film 110 and the second optical compensation film 117 are arranged to face each other. Subsequently, an adhesive 130 is applied on the exposed surface of the first optical compensation film 110.

[0052] Reference Figure 1D , the second base film 100b on which the second optical compensation film 117 is formed moves toward the first optical compensation film 110 on which the adhesive 130 is applied, and adheres to the first optical compensation film 110. In addition, the first base film 100a and the second base film 100b are peeled off from the first optical compensation film 110 and the second optical compensation film 117, respectively. Then, a structure in which the first alignment film 105, the first optical compensation film 110, the adhesive 130, the second optical compensation film 117, and the second alignment film 115 are stacked in sequence from the bottom is formed. In this regard, each of the first alignment film 105 and the second alignment film 115 is located at the outermost part of the stacked structure.

[0053] refer to Figure 1E , an optical compensation film including a first optical compensation film 110 and a second optical compensation film 117 is arranged on a substrate 140. On one surface (or bottom side) of the substrate 140, an array 150 in which a circuit including a driving thin film transistor, a storage capacitor, etc. and an organic light emitting element is formed may be provided, and the array 150 may be sealed by a protective film 160 made of an insulating material.

[0054] The optical compensation film including the first optical compensation film 110 and the second optical compensation film 117 may be disposed on another surface of the substrate 140 opposite to one surface where the array 150 and the protective film 160 are disposed, for example, on the upper side of the substrate 140 .

[0055] In addition, a polarizing layer 170 is disposed on the second optical compensation film 117. The polarizing layer 170 changes the polarization characteristics of the incident light. For example, reflection of external light can be prevented. In one example, the polarizing layer 170 may include polyvinyl alcohol (PVA).

[0056] pass Figures 1A to 1EThe display device formed by the process in the embodiment has a structure in which the first optical compensation film 110 and the second optical compensation film 117 are sequentially disposed between the substrate 140 having the organic light emitting element and the polarizing layer 170, as shown in FIG. Figure 2 As shown. In this regard, the first optical compensation film 110 is formed as a quarter wave plate (QWP) having a quarter wavelength value λ / 4, and the second optical compensation film 117 is formed as a half wave plate (HWP) having a half wavelength value λ / 2. In one example, when the angle of the transmission axis of the polarizing layer 170 is 0 degrees, the first optical compensation film 110 has a phase difference axis of 75 degrees, and the second optical compensation film 117 has a phase difference axis of 15 degrees. Further, each of the first optical compensation film 110 and the second optical compensation film 117 is formed as a positive (+) A plate. A positive (+) A plate refers to a positive birefringent A plate (i.e., an A plate having (birefringence) positive Δn, Δn being the difference between the refractive indices of two polarized lights).

[0057] Light in a dark state should first pass through the first optical compensation film 110 from a starting point, then pass through the second optical compensation film 117 again, and then be completely absorbed in the polarization layer 170 so as not to be emitted outward in the same manner when viewed from the front at a certain viewing angle.

[0058] However, when both the first and second optical compensation films 110 and 117 are formed as positive (+) A plates, not all light may be absorbed in the polarization layer 170, and a portion of the light may leak or the light may appear in reversed color. This will be described below with reference to the accompanying drawings.

[0059] When both the first optical compensation film 110 and the second optical compensation film 117 are formed as positive (+) A plates, referring to the diagram showing the movement of light on the Poincare sphere in a dark state. Figure 3 , a horizontal plane is formed by the starting point A, the first measuring point C affected by the angle of the 75-degree phase difference axis of the first optical compensation film 110, and the second measuring point B affected by the angle of the 15-degree phase difference axis of the second optical compensation film 117, and the paths L1 and L2 of the light are determined. In this regard, the value of the first measuring point C is 150 degrees, which is twice the phase difference axis of the first optical compensation film 110 of 75 degrees, and the value of the second measuring point B is 30 degrees, which is twice the phase difference axis of the second optical compensation film 117 of 15 degrees.

[0060] In one example, when displaying the motion of light as viewed from the front of the display panel, Figure 3 In (a), light S1 moves from starting point A along the first optical path L1 so as to initially move to a predetermined position on the horizontal plane after passing through the first optical compensation film 110, and moves along the second optical path L2 so as to subsequently move to the absorption axis S3 of the polarization layer 170 after passing through the second optical compensation film 117, so that a good dark state can be obtained.

[0061] In this regard, reference is made to showing the movement of light when viewed at a certain viewing angle so that the display panel is viewed at a predetermined angle. Figure 3 (b), due to the characteristics of the viewing angle, the starting point A is changed to A', and accordingly, the first measuring point is also changed from C to C', and the second measuring point is also changed from B to B'. The first optical compensation film 110 and the second optical compensation film 117 providing the phase difference value are configured to optically compensate for this change. However, since the first optical compensation film 110 and the second optical compensation film 117 are both formed as positive (+) A plates, these films are also affected by the refractive index of light, and therefore optical compensation cannot be fully achieved.

[0062] For example, in the path of light starting from the changed starting point A', the light having passed through the first optical compensation film 110 is changed on the horizontal plane defined by the changed first measurement point C' and the changed second measurement point B'. Therefore, when viewed from the front, an intermediate arrival point D is formed at a position outside the horizontal plane, so that the light moves along the first optical path L1' so as to preliminarily move to the intermediate arrival point D, and moves along the second optical path L2' so as to then move to a point E1 away from the absorption axis S3 of the polarization layer 170 under the influence of the refractive index of the light after passing through the second optical compensation film 117.

[0063] In other words, even if the first optical compensation film 110 and the second optical compensation film 117 are introduced, the light cannot be blocked because the light is not completely absorbed by the absorption axis S3 of the polarizing layer 170, resulting in light leakage or color inversion defects. Such light leakage and color inversion defects may reduce image quality or visibility, for example, distorting the image.

[0064] In addition, as described above, when the first optical compensation film 110 and the second optical compensation film 117 are manufactured separately, a separate bonding process using the adhesive 130 must be performed in order to integrate the first optical compensation film 110 and the second optical compensation film 117. However, defects may occur during the bonding process, and thus, a position where light passes through the first optical compensation film 110 or the second optical compensation film 117 may be changed. In addition, since an additional process for the bonding process is required, the process operation may be complicated and the manufacturing cost may increase.

[0065] Therefore, in other aspects of the present disclosure, a display device and a method for manufacturing the display device can prevent light leakage and color inversion, and can prevent complicated process operations while preventing defects that may occur in the bonding process when performing separate bonding processes when forming the first optical compensation film and the second optical compensation film. These will be explained with reference to the following figures.

[0066] Figure 4 is a diagram for illustrating a display device according to a second aspect of the present disclosure. Figure 5 is a diagram for illustrating optical compensation characteristics when the display device according to the second aspect of the present disclosure is applied. Figure 6 is a diagram for illustrating the movement of light on a Poincare ball when the display device according to the second aspect of the present disclosure is applied. Figure 7 is a diagram showing dispersion in color coordinates of the display device according to the first aspect and the second aspect of the present disclosure.

[0067] Reference Figure 4 According to the second aspect of the present disclosure, the display device includes a substrate 225, an array 230 located on a first surface of the substrate 225, and an alignment film 205a, a first optical compensation film 210a, a second optical compensation film 220a and a polarization layer 250 formed in sequence on a second surface of the substrate 225 opposite to the first surface.

[0068] The substrate 225 may include a display substrate made of a polymer or a plastic such as polyimide (PI) or glass. The array 230 positioned on the first side of the substrate 225 includes a circuit having a driving thin film transistor, a storage capacitor, etc., and a plurality of pixels formed with an organic light emitting element. The pixel is composed of a conductive layer and an organic material layer for emitting light of various colors outward. For example, the pixel may include an organic light emitting element composed of a pixel electrode, an organic light emitting layer, and a common electrode. Light is emitted from the organic light emitting element. The array 230 may be sealed by a protective film 235. The protective film 235 may be composed of an inorganic insulating layer or an organic insulating layer, or may have a multilayer structure thereof.

[0069] The alignment film 205a, the first optical compensation film 210a, the second optical compensation film 220a and the polarization layer 250 are sequentially stacked on the second surface of the substrate 225 opposite to the first surface on which the array 230 is disposed.

[0070] The alignment film 205a is made of a photosensitive polymer-based material selected from the group consisting of polyimide (PI), polystyrene, and polyacrylate. The alignment film 205a is in a state of being optically aligned in a first direction perpendicular to or parallel to a planar direction of the substrate 225.

[0071] The polarizing layer 250 is disposed on the second optical compensation film 220a and changes polarization characteristics of incident light. In one example, the polarizing layer 250 may include polyvinyl alcohol.

[0072] One surface of the first optical compensation film 210a is positioned to contact one surface of the alignment film 205a. The first optical compensation film 210a is made of reactive mesogen (RM) material. The first optical compensation film 210a can be formed as a quarter wave plate (QWP). The quarter wave plate (QWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state and transmits the light. The QWP has a phase difference value λ / 4 of 1 / 4 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the first optical compensation film 210a has a phase difference value in the range of 110nm to 130nm.

[0073] The second optical compensation film 220a is arranged to contact with the other surface of the first optical compensation film 210a. The second optical compensation film 220a comprises a polymer material such as azobenzene, which causes a cis-trans isomerization reaction. The second optical compensation film 220a is optically aligned in the second direction, and the second direction is different from the first direction in which the first optical compensation film 210a is optically aligned by the alignment film 205a. For example, when the alignment film 205a is optically aligned in the vertical direction, the second optical compensation film 220a can be optically aligned in the horizontal direction, and when the alignment film 205a is optically aligned in the horizontal direction, the second optical compensation film 220a can be induced to be optically aligned in the vertical direction.

[0074] The second optical compensation film 220a may be formed as a half-wave plate (HWP). The half-wave plate (HWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state and transmits the light. The HWP has a phase difference value λ / 2 that is 1 / 2 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the second optical compensation film 220a is in the range of 220nm to 260nm.

[0075] Since each of the first optical compensation film 210a and the second optical compensation film 220a has a phase difference value that varies depending on the thickness, the second thickness T4 of the second optical compensation film 220a is relatively larger than the first thickness T3 of the first optical compensation film 210a. In addition, the first optical compensation film 210a is formed as a positive (+) A plate, and the second optical compensation film 220a is formed as a negative (-) A plate. The negative (-) A plate refers to a negative birefringent A plate (i.e., an A plate having (birefringence) negative Δn, Δn being the difference between the refractive indices of two polarized lights).

[0076] Specifically, refer to Figure 5, it can be understood that the positive (+) A-plate refers to the case where the direction of one of the three axes (nx, ny, and nz) of the sheet with different dimensions is perpendicular to the light propagation direction, and the dimension of said one axis is greater than the dimensions of the other two axes. When light propagates along the z-axis and the one axis with different dimensions is the y-axis, in the positive (+) A-plate, nx = nz < ny, the positive (+) A-plate has a rod-like shape, and nematic and cholesteric liquid crystal phases are used.

[0077] It can be understood that the negative (-) A-plate refers to the case where the direction of the one axis with different dimensions among the three axes (nx, ny, nz) of the sheet is perpendicular to the light propagation direction, and the dimension of said one axis is smaller than the dimensions of the other two axes. When light propagates along the z-axis and the one axis with different dimensions is the y-axis, in the negative (-) A-plate, nx = nz > ny, the negative (-) A-plate has a disc-like shape.

[0078] In addition, when the positive (+) A-plate and the negative (-) A-plate are placed together, the refractive index of light is Figure 5 cancelled as shown, and nx ≒ ny ≒ nz, such that the refractive index of light has almost the same value.

[0079] In other words, when the first optical compensation film 210a and the second optical compensation film 220a are respectively formed as a positive (+) A-plate and a negative (-) A-plate and are sequentially stacked and arranged, the refractive index of light is cancelled, such that the refractive index of light passing through both the first optical compensation film 210a and the second optical compensation film 220a can have almost the same value. Since the refractive index of light has almost the same value, while providing optical compensation for the movement of light, the influence of the refractive index can be minimized, thereby preventing or minimizing the occurrence of light leakage or color inversion defects.

[0080] Specifically, referring to Figure 6 , a horizontal plane is formed by the starting point A, the first measurement point C affected by the angle of the 75-degree phase difference axis of the first optical compensation film 210a, and the second measurement point B affected by the angle of the 15-degree phase difference axis of the second optical compensation film 220a, and the light paths L3 and L4 are determined. In this regard, the first measurement point C has a value of 150 degrees, which is twice the 75 degrees of the phase difference axis of the first optical compensation film 210a, while the second measurement point B has a value of 30 degrees, which is twice the 15 degrees of the phase difference axis of the second optical compensation film 220a.

[0081] Referring to Figure 6(a) Since the light paths L3 and L4 are respectively set, the light S1 moves from the starting point A so as to initially move to the horizontal plane defined by the first measuring point C and the second measuring point B after passing through the first optical compensation film 210a, and passes through the second optical compensation film 220a and moves to the absorption axis S3 of the polarizing layer 250, so that a good dark state can be obtained.

[0082] Further, reference is made to the movement of light viewed at a certain viewing angle so that the display panel is viewed at a predetermined angle. Figure 6 (b), the starting point A is changed to A', and accordingly, the first measurement point C and the second measurement point B are also changed to C' and B', respectively. Then, the light starting from the starting point A' is changed on the horizontal plane through the changed first measurement point C' and the changed second measurement point B'. Therefore, when viewed from the front, an intermediate arrival point D is formed at a position outside the formed horizontal plane, so that the light moves along the first light path L3' so as to preliminarily move to the intermediate arrival point D, and moves along the second light path L4' so as not to be affected by the refractive index of the light after passing through the second optical compensation film 220a and then moves to the point E2 adjacent to the absorption axis S3.

[0083] In this regard, since the refractive index of light has almost the same value by forming the first optical compensation film 210a and the second optical compensation film 220a as a positive (+) A plate and a negative (-) A plate, respectively, optical compensation is performed without being affected by the refractive index in the movement of light, and thus the paths L3' and L4' of light can be moved to the point E2 adjacent to the absorption axis S3 at the viewing angle. Therefore, the light can be moved to the point E2 adjacent to the absorption axis S3, thereby preventing or minimizing the occurrence of light leakage or color inversion defects.

[0084] Further, since the first optical compensation film 210a and the second optical compensation film 220a are formed as a positive (+) A plate and a negative (-) A plate, respectively, reflectivity when viewed from the front may be reduced and color change characteristics may be improved at all azimuth angles.

[0085] [Table 1]

[0086] Y(％) △a* △b* Comparison examples 6.6468 4.136 3.655 Example 1 6.098 2.922 1.44 △ 0.37 1.214 2.215

[0087] Y: Reflectivity of the front side

[0088] Δa*: maximum a* - minimum a*

[0089] Δb*: maximum b*-min b*

[0090] [Table 1] shows that Figure 4 An example of a structure having Figure 1EThe table shows the measured optical characteristics of the comparative example of the structure. Referring to the reflectivity Y of the front side, it can be seen that the reflectivity decreases because the reflectivity of the comparative example is 6.6468%, while Example 1 shows a reflectivity of 6.098%, which is 0.37% less than the reflectivity of the comparative example.

[0091] Next, in the Figure 4 An example of a structure having Figure 1E The color change characteristics are compared between the comparative examples of the structure of . It can be seen that the color change of the organic light-emitting display device is greater when it is continuously measured along all azimuth angles from 0 degrees to 360 degrees in a state where the polar angle is fixed than when it is measured under the method of fixing the azimuth angle (θ) and changing the polar angle (θ). Therefore, each color change characteristic is measured while changing the azimuth angle from 0 degrees to 360 degrees under the polar angle fixed to 50 degrees to evaluate the color change characteristics.

[0092] In this regard, the measurement values ​​used to measure the color change characteristics are the a*b* values ​​of the ab color coordinates specified by the International Commission on Illumination (CIE) in 1976, such as Figure 7 As shown. Back to [Table 1], in Figure 4 An example of a structure having Figure 1E In each of the comparative examples of the structure, the maximum a* value, the maximum b* value, the minimum a* value and the minimum b* value are obtained respectively, and then their difference Δa* and Δb* values ​​are calculated. In this regard, it can be understood that the smaller the Δ value, the smaller the color change amount at all azimuth angles, that is, the smaller the dispersion in the ab color coordinates. In other words, since the color change characteristics are very good, the accuracy of the color to be achieved will also increase at this viewing angle. Therefore, excellent image quality can be achieved.

[0093] Referring to [Table 1], the Δa* value and Δb* value in the comparative example are 4.136 and 3.655, respectively, while the Δa* value and Δb* value in Example 1 are 2.922 and 1.44, respectively. Therefore, it can be seen that the Δa* value in Example 1 is reduced by 1.214 compared with the comparative example, while the Δb* value in Example 1 is reduced by 2.215 compared with the comparative example. In addition, referring to Figure 7 It can be seen that the dispersion I' of Example 1 is smaller than the dispersion I of the comparative example. That is, since the first optical compensation film 210a and the second optical compensation film 220a are formed as a positive (+) A plate and a negative (-) A plate, respectively, instead of both being formed as a positive (+) A plate, the accuracy of representing the color to be achieved at the viewing angle can be improved while reducing the front reflectivity.

[0094] Next, referring to the accompanying drawings, the method for manufacturing Figure 4 A method for a display device in a display device.

[0095] FIG. 8A to FIG. 8G is a diagram for illustrating a method for manufacturing a display device according to the second aspect. In addition, Fig. 9 is a diagram used to illustrate the isomerization process of polymer materials.

[0096] Reference Fig. 8A , an alignment material 205 is applied to the front side of the base film 200. The base film 200 is made of a material that can be easily peeled off later. The alignment material 205 can be formed by applying a photosensitive material having a property that the side chain is aligned in one direction in response to light. For example, the alignment material 205 can be a group of photosensitive polymer-based materials selected from polyimide (PI), polystyrene and polyacrylate.

[0097] Reference Figure 8B , an exposure process is performed on the alignment material 205 to form an alignment film 205a. The alignment material 205 contains a plurality of disordered side chains. An exposure process of irradiating light onto such an alignment material 205 is performed to form an alignment film 205a in a state of being optically aligned in a first direction. When light is irradiated onto the alignment material 205, a plurality of disordered side chains are aligned in response to the light in one direction, i.e., the first direction, to achieve an optical alignment state. In this regard, the first direction may be a direction perpendicular or parallel to the surface of the base film 200. In addition, the first direction may be a direction perpendicular or parallel to the surface of the substrate on which the alignment film 205a will be subsequently disposed.

[0098] Reference Figure 8C , a reactive mesogen solution 210 is applied onto the alignment film 205a. The reactive mesogen solution 210 may be applied to have a first thickness T3. The reactive mesogen solution 210 may be applied by dissolving a reactive mesogen (RM) material in an organic solvent through a coating device.

[0099] The reactive mesogen (RM) material is a material having a functional group at its end that reacts to light or heat. When ultraviolet light or heat is radiated onto the reactive mesogen material, an optically anisotropic stationary phase is formed by photopolymerization.

[0100] Next, if Fig.8DAs shown, a drying process is performed on the reactive mesogen solution 210 to form a first optical compensation film 210a. The drying process evaporates the organic solvent in the reactive mesogen solution 210 to form a reactive mesogen layer on the alignment film 205a optically aligned in the first direction. The first optical compensation film 210a composed of the reactive mesogen layer is formed on the alignment film 205a by this drying process. The first optical compensation film 210a can be formed as a quarter wave plate (QWP). The quarter wave plate (QWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state, and transmits the light. The QWP has a phase difference value λ / 4 that is 1 / 4 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the first optical compensation film 210a is in the range of 110nm to 130nm.

[0101] refer to Fig. 8E , the phase difference solution 220 is applied to the first optical compensation film 210a. The phase difference solution 220 may be applied to have a second thickness T4. In this regard, the phase difference solution 220 may be applied to have a second thickness T4 that is relatively larger than the first thickness T3 of the first optical compensation film 210a. The phase difference solution 220 may be applied by dissolving a polymer material in an organic solvent through a coating device. In one example, the phase difference solution 220 may include a polymer material that causes a cis-trans isomerization reaction like azobenzene.

[0102] Subsequently, the phase difference solution 220 is pre-baked to evaporate the organic solvent in the phase difference solution 220 .

[0103] Next, if Figure 8F As shown, an exposure process and a drying process are performed on the phase difference solution 220 in which the organic solvent is evaporated to form a second optical compensation film 220a that is optically aligned in a second direction. In this regard, the second direction can be a direction perpendicular or parallel to the surface of the base film 200, and can be a direction different from the first direction of the alignment film 205a. For example, when the alignment film 205a is optically aligned in the vertical direction, the second optical compensation film 220a can be optically aligned in the horizontal direction, and when the alignment film 205a is optically aligned in the horizontal direction, the second optical compensation film 220a is optically aligned in the vertical direction. Further, the second direction can be a direction perpendicular to or parallel to the surface of the substrate on which the second optical compensation film 220a will be subsequently disposed.

[0104] The exposure process radiates polarized ultraviolet light. During the exposure process, the ultraviolet light can be radiated at a polarization angle of 10 to 20 degrees relative to the absorption axis of the polarizing layer formed later, and its wavelength is in the range of 200 nanometers to 400 nanometers. The ultraviolet light has an angle of 60 degrees relative to the optical axis of the first optical compensation film 210a.

[0105] The exposure process can be performed by irradiating polarized ultraviolet light onto the phase difference solution 220. When the polymer material causing the cis-trans isomerization reaction is irradiated with light such as ultraviolet light, optical alignment occurs as one isomer is changed to another isomer. Fig. 9 (wherein, the arrow line D indicates the direction of ultraviolet light radiation), when polarized ultraviolet light is radiated onto the polymer material including azobenzene, an isomerization phenomenon occurs, that is, the molecules aligned in the first direction (a) having a predetermined angle α with the direction of the radiated ultraviolet light rotate to the second direction (b) and the third direction (c) within one cycle. In addition, when such a cycle is repeated and the molecules rotate to the fourth direction (d), the fifth direction (e) and the sixth direction (f) after n cycles, the isomerization phenomenon ends in a state where the molecules rotate by an angle β of 90 degrees relative to the direction of the radiated ultraviolet light.

[0106] When azobenzene is aligned at an angle of 90 degrees relative to the irradiation direction of ultraviolet light, the refractive index is also induced to have an angle of 90 degrees relative to the irradiation direction of ultraviolet light, thereby causing refractive index anisotropy, which results in optical alignment in the second direction.

[0107] Subsequently, a drying process is performed on the phase difference solution 220 that has been subjected to the exposure process to form a second optical compensation film 220a. The drying process can be performed by placing the base film 200 on which the phase difference solution 220 is formed on a drying device such as a hot plate and heating the base film 200. The second optical compensation film 220a can be formed by fixing the alignment that generates the refractive index anisotropy by relying on the drying process.

[0108] The second optical compensation film 220a may be formed as a half-wave plate (HWP). The half-wave plate (HWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state and transmits light. The HWP has a phase difference value λ / 2 that is 1 / 2 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the second optical compensation film 220a is in the range of 220nm to 260nm.

[0109] Each of the first optical compensation film 210a and the second optical compensation film 220a has a phase difference value that varies depending on its refractive index and thickness. Since the first optical compensation film 210a according to one aspect of the present disclosure is formed as a quarter wave plate (QWP) and the second optical compensation film 220a is formed as a half wave plate (HWP), the second thickness T4 of the second optical compensation film 220a is relatively larger than the first thickness T3 of the first optical compensation film 210a.

[0110] refer to Figure 8G, an optical compensation film including a first optical compensation film 210a and a second optical compensation film 220a is disposed on an array substrate 240. The array substrate 240 may include a substrate 225 and an array 230 and a protective film 235 disposed on one surface (or bottom side) of the substrate 225. The substrate 225 may include a display substrate made of a polymer or plastic such as polyimide (PI) or glass.

[0111] The array 230 may include a circuit having a driving thin film transistor, a storage capacitor, etc., and a plurality of pixels formed by an organic light emitting element. The pixel is composed of a conductive layer and an organic material layer for emitting light of various colors outward. For example, the pixel may include an organic light emitting element composed of a pixel electrode, an organic light emitting layer, and a common electrode. Light may be emitted from the organic light emitting element.

[0112] The array 230 may be sealed by a protective film 160 made of an insulating material. The protective film 235 may be composed of an inorganic insulating layer or an organic insulating layer, or may have a multi-layer structure thereof, to prevent external moisture, oxygen or impurities from penetrating into the organic light emitting element and degrading its performance.

[0113] The stacked structure of the alignment film 205a, the first optical compensation film 210a, and the second optical compensation film 220a may be arranged on the other surface of the substrate 225 opposite to the one surface on which the array 230 and the protective film 235 are arranged, for example, the upper side of the substrate 225. To this end, the base film 200 is peeled off from the alignment film 205a, and the alignment film 205a is bonded to the other surface (or the upper side) of the substrate 225.

[0114] In addition, a polarizing layer 250 is formed on the second optical compensation film 220a. The polarizing layer 250 changes polarization characteristics of incident light. In one example, the polarizing layer 250 may include polyvinyl alcohol (PVA).

[0115] As described above, when manufacturing the first optical compensation film and the second optical compensation film, instead of manufacturing two optical compensation films separately and bonding the two films to each other, the two films are formed through a continuous manufacturing process, which simplifies the process of manufacturing the optical compensation films while preventing defects from occurring in the bonding process.

[0116] In one example, the stacking order of the first optical compensation film formed as a quarter wave plate and the second optical compensation film formed as a half wave plate on the substrate may be changed. This will be described with reference to the following drawings.

[0117] Fig.10 is a diagram for illustrating a display device according to a third aspect of the present disclosure.

[0118] Reference Fig.10The display device includes a substrate 325, an array 327 located on a first surface of the substrate 325, and a second optical compensation film 315a, a first optical compensation film 310a, an alignment film 305a and a polarization layer 335 formed in sequence on a second surface opposite to the first surface of the substrate 325.

[0119] The array 327 located on the first surface of the substrate 325 includes a circuit having a driving thin film transistor, a storage capacitor, etc., and a plurality of pixels formed by an organic light emitting element. The pixel is composed of a conductive layer and an organic material layer for emitting light of various colors outward. For example, the pixel may include an organic light emitting element composed of a pixel electrode, an organic light emitting layer, and a common electrode. Light is emitted from the organic light emitting element. The array may be sealed by a protective film 329 containing an insulating material.

[0120] On a second surface opposite to the first surface of the substrate 325 on which the array 327 is disposed, a second optical compensation film 315 a , a first optical compensation film 310 a , an alignment film 305 , and a polarization layer 335 are sequentially stacked.

[0121] The second optical compensation film 315a is positioned to contact the second face of the substrate. The second optical compensation film 315a includes a polymer material causing a cis-trans isomerization reaction, such as azobenzene. The second optical compensation film 315a can be formed as a quarter wave plate (QWP). The quarter wave plate (QWP) has a phase difference value λ / 4 of 1 / 4 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the second optical compensation film is in the range of 110nm to 130nm.

[0122] The alignment film 305a is made of a material selected from the group consisting of photosensitive polymer-based materials such as polyimide (PI), polystyrene, and polyacrylate, etc. The alignment film 305a is in a state of being optically aligned in a first direction perpendicular to or parallel to the plane direction of the substrate.

[0123] One surface of the first optical compensation film 310a contacts the surface of the alignment film 305a, and the other surface opposite to the one surface is positioned to contact the surface of the second optical compensation film 315a. The first optical compensation film 310a is made of reactive mesogen (RM) material. The first optical compensation film 310a can be formed as a half-wave plate (HWP). The half-wave plate (HWP) has a phase difference value λ / 2 of 1 / 2 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the first optical compensation film 310a is in the range of 220nm to 260nm.

[0124] Since each of the first optical compensation film 310a and the second optical compensation film 315a has a phase difference value that varies depending on the thickness, the second thickness T6 of the second optical compensation film 315a is relatively smaller than the first thickness T5 of the first optical compensation film 310a. In addition, the second optical compensation film 315a is formed as a negative (-) A plate, while the first optical compensation film 310a is formed as a positive (+) A plate.

[0125] The following drawings will be used to illustrate the method for manufacturing Fig.10 A method for a display device in a display device.

[0126] FIG. 11A to FIG. 11H is a diagram for illustrating a method of manufacturing the display device according to the third aspect.

[0127] Reference Fig.11A , an alignment material 305 is applied to the front side of the base film 300. The alignment material 305 can be formed by applying a photosensitive material having a property of being aligned in one direction in response to light. For example, the alignment material 305 can be one selected from a group including photosensitive polymer-based materials such as polyimide (PI), polystyrene, and polyacrylate.

[0128] Reference Fig. 11B , a light exposure process is performed on the alignment material 305 to form an alignment film 305a. The exposure process can be performed on a plurality of disordered side chains contained in the alignment material 305 so that the side chains are aligned in a first direction, thereby achieving an optical alignment state of the side chains. In this regard, the first direction can be a direction perpendicular to or parallel to the surface of the base film 300.

[0129] Reference Fig. 11C , a reactive mesogen solution 310 is applied onto the alignment film 305a. The reactive mesogen solution 310 may be applied to have a third thickness T5. The reactive mesogen solution 310 may be applied by dissolving a reactive mesogen (RM) material in an organic solvent through a coating device.

[0130] Reference Fig.11D , a drying process is performed on the reactive mesogen solution 310 to form a first optical compensation film 310a. The drying process evaporates the organic solvent in the reactive mesogen solution 310 to form a reactive mesogen layer on the alignment film 305a aligned along the first direction. The first optical compensation film 310a may be formed as a half-wave plate (HWP). The half-wave plate (HWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state and transmits the light. The HWP has a phase difference value λ / 2 of 1 / 2 of the wavelength λ of the transmitted light.

[0131] Reference Fig.11E, a phase difference solution 315 is applied to the first optical compensation film 310a. The phase difference solution 315 may be applied to have a second thickness T6 that is relatively smaller than the first thickness T5 of the first optical compensation film 310a. The phase difference solution 315 may be applied by dissolving a polymer material that causes a cis-trans isomerization reaction, such as azobenzene, in an organic solvent. Subsequently, a pre-baking process is performed on the phase difference solution 315 to evaporate the organic solvent in the phase difference solution 315.

[0132] Reference Fig.11F , for the phase difference solution 315 (see Fig.11E ) performs an exposure process of radiating polarized ultraviolet light and a drying process to form a second optical compensation film 315a optically aligned in a second direction. In this regard, the second direction may be a direction different from the first direction of the alignment film 305a. For example, when the alignment film 305a is optically aligned in the vertical direction, the second optical compensation film 315a may be optically aligned in the horizontal direction, and when the alignment film 305a is optically aligned in the horizontal direction, the second optical compensation film 305a may be optically aligned in the vertical direction.

[0133] The exposure process radiates polarized ultraviolet light. During the exposure process, the ultraviolet light can be radiated at a polarization angle of 70 to 80 degrees relative to the absorption axis of the polarizing layer formed later, and its wavelength is in the range of 200nm to 400nm. The ultraviolet light has an angle of 60 degrees relative to the optical axis of the first optical compensation film 315a.

[0134] When polarized ultraviolet light is irradiated onto a phase difference solution containing a polymer material including azobenzene, Fig. 9 As described above, an isomerization phenomenon occurs, in which one isomer changes to another isomer as the molecule rotates. In addition, when the isomerization phenomenon ends when the molecule is rotated to a state where it is at an angle β of 90 degrees relative to the direction of the polarized ultraviolet light, refractive index anisotropy occurs. In other words, the polarized ultraviolet light has a state of phase difference in a direction perpendicular to the radiation direction of the polarized ultraviolet light. The second optical compensation film 315a is formed by performing a drying process for fixing the alignment in which the refractive index anisotropy is generated.

[0135] The second optical compensation film 315a may be formed as a quarter wave plate (QWP). The quarter wave plate (QWP) converts the state of light from a circular polarization state to a linear polarization state, and converts the state of light from a linear polarization state to a circular polarization state and transmits the light. The QWP has a phase difference value λ / 4 that is 1 / 4 of the wavelength λ of the transmitted light. For example, when the wavelength λ of the transmitted light is 550nm, the phase difference value of the second optical compensation film 315a is in the range of 110nm to 130nm.

[0136] Each of the first optical compensation film 310a and the second optical compensation film 315a has a phase difference value that varies depending on its refractive index and thickness. Since the first optical compensation film 310a according to one aspect of the present disclosure is formed as a half-wave plate (HWP) and the second optical compensation film 315a is formed as a quarter-wave plate (QWP), the third thickness T5 of the first optical compensation film 310a is relatively larger than the fourth thickness T6 of the second optical compensation film 315a.

[0137] Reference Fig.11G In the structure where the alignment film 305a, the first optical compensation film 310a and the second optical compensation film 315a are stacked, the base film 300 is peeled off from the alignment film 305a (see Fig.11F ). Subsequently, the structure is inverted so that the exposed surface of the alignment film 305a is located at the top of the structure and the exposed surface of the second optical compensation film 315a is located at the bottom of the structure. Then, the second optical compensation film 315a is located at the bottom of the structure, and the alignment film 305a is located at the top of the structure.

[0138] Reference Fig.11H , the optical compensation films including the first optical compensation film 310a and the second optical compensation film 315a are arranged on the array substrate 330. The array substrate 330 may be composed of a substrate 325, and an array 327 and a protective film 329 disposed on one surface (or bottom side) of the substrate 325. The substrate 325 may include a display substrate (not shown) made of a polymer or plastic such as polyimide (PI) or glass.

[0139] Array 327 may include a circuit having a driving thin film transistor, a storage capacitor, etc., and a plurality of pixels formed by an organic light emitting element. The pixel is composed of a conductive layer and an organic material layer for emitting light of various colors outward. For example, the pixel may include an organic light emitting element composed of a pixel electrode, an organic light emitting layer, and a common electrode. Light may be emitted from the organic light emitting element.

[0140] The array 327 may be sealed by a protective film 329 made of an insulating material. The protective film 329 may be composed of an inorganic insulating layer or an organic insulating layer, or may have a multi-layer structure thereof, to prevent external moisture, oxygen or impurities from penetrating into the organic light emitting element (OLED) and degrading its performance.

[0141] The structure in which the second optical compensation film 315a, the first optical compensation film 310a and the alignment film 305a are stacked in sequence may be disposed on another surface of the substrate 325 opposite to the surface on which the array 327 and the protective film 329 are disposed, for example, the upper side of the substrate 325.

[0142] In addition, a polarization layer 335 is formed on the alignment film 305a. The polarization layer 335 changes polarization characteristics of incident light. In one example, the polarization layer 335 may include polyvinyl alcohol (PVA).

[0143] According to one aspect of the present disclosure, since the optical compensation film is introduced between the substrate and the polarizing layer as a positive (+) A plate and a negative (-) A plate, the optical path formed makes the direction of the light reflected from the display device adjacent to or coincident with the direction of the absorption axis of the polarizing layer, thereby preventing or minimizing defects such as light leakage or color inversion. Further, since the optical compensation film is formed as a positive (+) A plate and a negative (-) A plate, the refractive index of the light has almost the same value, so that optical compensation can be performed without being affected by the refractive index, thereby reducing the light leakage phenomenon even at a viewing angle.

[0144] Further, according to various aspects of the present disclosure, excellent image quality can be achieved because the color change caused by the change in viewing angle is small, and the accuracy of representing the color to be achieved is also increased at the viewing angle. In addition, since the optical compensation films with different phase difference values ​​and optical characteristics are formed by a continuous manufacturing process, the manufacturing process can be simplified. Thus, by preventing defects that occur when two optical compensation films are manufactured separately and bonded to each other, the reliability of the display device can be improved.

[0145] The scope of protection of the present disclosure should be interpreted by the scope of the claims, and all technical ideas within the equivalent scope thereof should be interpreted as included within the scope of the present disclosure. Although various aspects of the present disclosure have been described in more detail with reference to the accompanying drawings, the present disclosure is not limited to these aspects. The present disclosure can be implemented in various modified ways without departing from the scope of the technical idea of ​​the present disclosure. Therefore, the various aspects disclosed in the present disclosure are not intended to limit the technical idea of ​​the present disclosure, but to describe the present disclosure. The scope of the technical idea of ​​the present disclosure is not limited by the various aspects. Therefore, it should be understood that the above-mentioned various aspects are illustrative and non-restrictive in all aspects. The scope of protection of the present disclosure should be interpreted by the claims, and all technical ideas within the scope of the present disclosure should be interpreted as included within the scope of the present disclosure.

Claims

1. A display device, include: substrate; a polarizing layer positioned on the substrate; an alignment film positioned below the polarizing layer and optically aligned along a first direction; as well as an optical compensation film positioned between the substrate and the alignment film; Wherein, the optical compensation film comprises a first optical compensation film and a second optical compensation film, the first optical compensation film has a phase difference value (λ / 2) of 1 / 2 of the wavelength (λ) of the transmitted light, the second optical compensation film has a phase difference value (λ / 4) of 1 / 4 of the wavelength (λ) of the transmitted light, the second optical compensation film is optically aligned along a second direction different from the first direction, the first optical compensation film is formed as a positive (+) A plate, and the second optical compensation film is formed as a negative (-) A plate; wherein the second optical compensation film is formed by applying a phase difference solution on the first optical compensation film and irradiating polarized ultraviolet light onto the phase difference solution; and A first surface of the first optical compensation film is disposed in direct contact with one surface of the alignment film, and a second surface of the first optical compensation film opposite to the first surface is disposed in direct contact with a surface of the second optical compensation film without an adhesive; Wherein, the second optical compensation film is in contact with the substrate, the alignment film is in contact with the polarization layer, the first optical compensation film is in contact with the alignment film, and the second optical compensation film is in contact with the first optical compensation film in the absence of an adhesive; The first optical compensation film has a first thickness, and the second optical compensation film has a second thickness that is smaller than the first thickness of the first optical compensation film.

2. The display device according to claim 1, in, The second optical compensation film includes a polymer material.

3. The display device according to claim 2, in, The polymer material is azobenzene which causes a cis-trans isomerization reaction.

4. A method for manufacturing a display device, the method include: forming an alignment film optically aligned along a first direction; forming a first optical compensation film on the alignment film; applying a phase difference solution on the first optical compensation film; irradiating polarized ultraviolet light onto the phase difference solution to form a second optical compensation film optically aligned in a second direction different from the first direction, wherein the first optical compensation film is formed as a positive (+) A plate and the second optical compensation film is formed as a negative (-) A plate; Disposing the alignment film and the optical compensation film including the first optical compensation film and the second optical compensation film on a substrate; and forming a polarizing layer on the alignment film and the optical compensation film; wherein a first surface of the first optical compensation film is disposed in direct contact with one surface of the alignment film, and a second surface of the first optical compensation film opposite to the first surface is disposed in direct contact with a surface of the second optical compensation film in the absence of an adhesive; Wherein, disposing the alignment film and the optical compensation film on the substrate comprises disposing the alignment film and the optical compensation film on the substrate so that the second optical compensation film contacts the substrate, the alignment film contacts the polarizing layer, the first optical compensation film contacts the alignment film, and the second optical compensation film contacts the first optical compensation film without an adhesive; The first optical compensation film has a first thickness, and the second optical compensation film has a second thickness that is smaller than the first thickness of the first optical compensation film.

5. The method according to claim 4, in, The first optical compensation film includes a half-wave plate, and the second optical compensation film includes a quarter-wave plate.

6. The method according to claim 4, in, The phase difference solution includes a polymer material which is optically aligned along the second direction by irradiation with polarized ultraviolet light.

7. The method according to claim 6, in, The polymer material includes azobenzene which causes a cis-trans isomerization reaction.

Images