Color film substrate, display panel, display device, and method for manufacturing color film substrate

Abstract

The present invention discloses a color filter substrate, a display panel, a display device, and a method for manufacturing the color filter substrate. The color filter substrate comprises: a base substrate; a color filter layer disposed on one side of the base substrate; a buffer layer disposed on a side of the color filter layer away from the base substrate; the buffer layer comprising a high refractive index region and a low refractive index region; and a black matrix disposed on a side of the buffer layer away from the base substrate. The black matrix has openings located on the surface of the high refractive index region, and non-openings located on the surface of the low refractive index region. The present invention can effectively improve the light extraction efficiency of a display panel.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a color film substrate, a display panel, a display device, and a method for manufacturing the color film substrate. Background Art

[0002] Currently, widely used display panel technologies include OLED (Organic Light Emission Diode) display panels and LCD (Liquid Crystal Display) display panels. The light output efficiency of a display panel is an important indicator for measuring its performance. For example, in order to improve the light output efficiency of OLED display panels, a top-emitting device process is used. Because top-emitting devices emit light from the cathode, the aperture ratio can be increased. In addition, the anode of top-emitting OLED devices has high reflectivity and the cathode is a semi-transparent metal. This can improve the light output efficiency of the display panel to a certain extent, but the effect is still limited.

[0003] Therefore, how to further improve the light extraction efficiency of the display panel has become an urgent problem to be solved. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a color filter substrate, a display panel, a display device and a method for manufacturing the color filter substrate, which can effectively improve the light extraction efficiency of the display panel.

[0005] In a first aspect, a color filter substrate is provided, comprising: a base substrate; a color filter layer, arranged on one side of the base substrate; a buffer layer, arranged on a side of the color filter layer away from the base substrate; the buffer layer comprising a high refractive index region and a low refractive index region; a black matrix, arranged on a side of the buffer layer away from the base substrate; an opening region of the black matrix is ​​located on a surface of the high refractive index region, and a non-opening region of the black matrix is ​​located on a surface of the low refractive index region.

[0006] Optionally, the color filter layer includes multiple color resist units; the width of the longitudinal section of the low refractive index area decreases from the side close to the black matrix to the side close to the base substrate; the longitudinal section is between any two adjacent color resist units and is perpendicular to the base substrate.

[0007] Optionally, the longitudinal section is trapezoidal.

[0008] Optionally, an angle between the interface between the high refractive index region and the low refractive index region and the black matrix is ​​65° to 90°.

[0009] Optionally, the angle between the interface between the high refractive index region and the low refractive index region and the surface of the black matrix satisfies:

[0010] The incident angle of the incident light is greater than a preset critical angle; the incident light is the light incident on the interface from a direction away from the substrate, and the critical angle is the angle at which the light is totally reflected from the high refractive index area to the low refractive index area.

[0011] Optionally, the refractive index range of the high refractive index region is 1.7 to 2; the refractive index range of the low refractive index region is 1.3 to 1.5.

[0012] Optionally, the thickness of the buffer layer ranges from 0.5um to 5um.

[0013] Optionally, the material of the high refractive index region includes one or more of sulfur-containing epoxy resin, epoxy resin containing multiple benzene rings, silicon-containing resin material, molybdenum trioxide and titanium dioxide; the material of the low refractive index region includes silicon nitride and / or silicon dioxide.

[0014] In the second aspect, based on the same inventive concept, a display panel is also provided, comprising: a TFT array substrate and the color film substrate described in the first aspect, wherein a side of the color film substrate on which the black matrix is ​​provided is bonded to the light-emitting side of the TFT array substrate.

[0015] In a third aspect, based on the same inventive concept, a display device is also provided, comprising the display panel described in the first aspect.

[0016] In a fourth aspect, based on the same inventive concept, a method for manufacturing a color filter substrate is also provided, comprising:

[0017] providing a substrate;

[0018] forming a color filter layer on the base substrate;

[0019] forming a buffer layer on the color filter layer, wherein the buffer layer includes a high refractive index region and a low refractive index region;

[0020] A black matrix is ​​formed on the buffer layer, wherein the opening area of ​​the black matrix is ​​located in the high refractive index area, and the non-opening area of ​​the black matrix is ​​located in the low refractive index area.

[0021] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] Embodiments of the present invention provide a color filter substrate, display panel, and display device, wherein the color filter substrate comprises: a base substrate; a color filter layer disposed on one side of the base substrate; a buffer layer disposed on a side of the color filter layer away from the base substrate; the buffer layer comprising a high refractive index region and a low refractive index region; a black matrix disposed on a side of the buffer layer away from the base substrate; the opening region of the black matrix is ​​located in the high refractive index region, and the non-opening region of the black matrix is ​​located in the low refractive index region. In embodiments of the present invention, by disposing a buffer layer between the black matrix and the color filter layer, a display panel manufactured using the color filter substrate can position the black matrix closer to the TFT array substrate, so that light emitted from one side of the TFT array substrate is not blocked or absorbed by the black matrix. At the same time, when light is incident from the high refractive index region to the low refractive index region, total reflection occurs, ensuring that the light can be emitted from the color filter layer at the corresponding pixel position, avoiding light leakage and effectively improving the light output efficiency of the display panel.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0025] Figure 1 This is a schematic structural diagram of a display panel in the prior art;

[0026] Figure 2 Schematic diagram of the structure of a color filter substrate in an embodiment of the present invention;

[0027] Figure 3 For use Figure 2 A schematic structural diagram of a display panel of a color filter substrate shown;

[0028] Figure 4 for Figure 3 A schematic diagram of a light path away from a display panel to improve light extraction efficiency;

[0029] Figure 5 Schematic diagram of the principle of determining the angle between the interface and the surface of the black matrix in an embodiment of the present invention;

[0030] Figure 6 The figure is a flow chart of a method for manufacturing a color filter substrate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0032] Through analysis, it is found that in existing display panels, the transmittance of the black matrix is ​​basically zero. After the TFT array substrate of the display panel emits light, part of the light incident on the black matrix is ​​almost blocked or absorbed by the black matrix. Therefore, the light emitted by the TFT array substrate of the display panel is not fully utilized. For example, please refer to the top emission OLED display panel. Figure 1 ,exist Figure 1 The structure of the display panel 100 of the prior art solution includes a color filter substrate 10 and a TFT array substrate 20, which are encapsulated by an encapsulating adhesive 30. The color filter substrate 10 includes a base substrate 11, a color filter layer 12 disposed on the base substrate 11, and a black matrix 13 disposed on the side of the color filter layer 12 away from the base substrate 11. The TFT array substrate 20 includes a base substrate 21, a pixel structure layer 22 disposed on the base substrate 21, and a pixel defining layer 23 for separating pixels. The pixel structure layer 22 includes a plurality of pixel light-emitting units, each corresponding one-to-one to the color resist units of the color filter layer 12. Light I emitted by the pixel light-emitting units on one side of the TFT array substrate 20 can pass through the color filter layer 12 of the color filter substrate 10 and the base substrate 11. However, light II at a large angle (angle perpendicular to the direction of the display panel 100) can be blocked and absorbed by the black matrix 13 due to its impact on the black matrix 13, resulting in loss, ultimately resulting in a low light output efficiency of the display panel 100.

[0033] In this embodiment, a color filter substrate is provided. By setting a buffer layer between the black matrix and the cover glass, the distance between the black matrix and the cover glass is increased, so that the large-angle light emitted by the display panel will not be blocked by the black matrix; at the same time, the color filter layer provided has a high refractive index area and a low refractive index area. The interface between the high refractive index area and the low refractive index area is located between the opening area and the non-opening area of ​​the black matrix, so that the light originally blocked by the black matrix can be incident on the interface. When the light is emitted from the high refractive index area to the low refractive index area, total reflection can occur at the interface to avoid light leakage, and the light emitted by the TFT array substrate can be emitted more from the opening area, significantly improving the light output rate of the display panel. It can be effectively applied to LCD display panels, top-emitting OLED display panels, and bottom-emitting OLED display panels, etc. In order to make the concept of the present invention easier to understand, it is further explained through specific embodiments below.

[0034] See also Figure 2 and Figure 3 In one embodiment of the present invention, a color filter substrate 210 is provided, comprising: a base substrate 211, a color filter layer 212, a buffer layer 213, and a black matrix 214. The color filter layer 212 is disposed on one side of the base substrate 211, and the buffer layer 213 is disposed on a side of the color filter layer 212 away from the base substrate 211. The buffer layer 213 includes a high refractive index region 213a and a low refractive index region 213b. The black matrix 214 is disposed on a side of the buffer layer 213 away from the base substrate 211. The opening region of the black matrix 214 is located on the surface of the high refractive index region 213a, and the non-opening region of the black matrix 214 is located on the surface of the low refractive index region 213b. The light generated by the display panel 200 manufactured using the color filter substrate 210 can be not blocked by the black matrix 214 and enter the high refractive index area 213a, and then emitted from the high refractive index area 213a to the interface. The light can be totally reflected at the interface, so that the light corresponding to each opening area can be emitted more from the opening area, thereby improving the light extraction efficiency of the display panel 200. Figure 4 shown.

[0035] The substrate 211 may be made of substrate glass or a flexible transparent substrate.

[0036] The color filter layer 212 can be formed on the base substrate 211 by spin coating, exposure and / or development. Specifically, the color filter layer 212 can include a plurality of color resist units, including a red color resist unit, a blue color resist unit, and a green color resist unit.

[0037] The TFT array substrate 220 corresponding to the color filter substrate 210 may include a base substrate 221, a pixel structure layer, and a pixel definition layer; the pixel structure layer includes a plurality of pixel light-emitting units, and these color resistance units correspond one-to-one to the pixel light-emitting units of the TFT array substrate 220 for manufacturing the display panel 200, such as Figure 3 shown.

[0038] The buffer layer 213 can also be formed by spin coating, exposure, and / or development processes. It covers the color filter layer 212. In the specific manufacturing process, the high refractive index region 213a of the buffer layer 213 can be formed first, and then the low refractive index region 213b can be formed. This ensures that the low refractive index region 213b with a smaller unit volume is more stable and prevents the low refractive index region 213b from collapsing or falling off. In this embodiment, the high refractive index region 213a has a higher refractive index than the low refractive index region 213b, that is, the terms high and low are relative.

[0039] In some implementations, the width of the longitudinal cross-section of the low-refractive-index region 213b decreases from the side closest to the black matrix 214 to the side closest to the substrate 211; the longitudinal cross-section is the cross-section between any two adjacent color-resist units and perpendicular to the substrate 211. In other words, in some implementations, the cross-sectional area of ​​the low-refractive-index region 213b decreases from the side closest to the black matrix 214 to the side closest to the substrate 211; the cross-section is the cross-section between any two adjacent color-resist units and parallel to the surface of the substrate 211. This structural shape can effectively increase the angle of incidence of incident light, which is light incident on the interface in the buffer layer 213 from a direction away from the substrate 211, and thus increase the probability of total internal reflection.

[0040] Furthermore, the aforementioned longitudinal cross section may be a trapezoid. Of course, in other implementations, the shape of the longitudinal cross section may also be a rectangle, a square, etc.; or other irregular quadrilaterals.

[0041] In some embodiments, the thickness of the buffer layer 213 can be controlled to be 0.5um to 5um. This can prevent the thickness of the buffer layer 213 from being too thin, and the black matrix 214 cannot be well separated from the surface of the color filter layer 212. The black matrix 214 still blocks the incident light, which is not conducive to improving the light output rate of the display panel 200 manufactured based on the color filter substrate 210; at the same time, it avoids the buffer layer 213 from being too thick, which leads to the risk of the buffer layer 213 easily falling off during the manufacturing process, thereby improving the manufacturing yield; the display panel 200 finally manufactured also has better reliability. In order to further improve the stability of the buffer layer 213 and ensure that the incident light can be fully reflected as much as possible at the interface, the angle between the interface of the high refractive index region 213a and the low refractive index region 213b and the black matrix 214 can be set in the range of 65° to 90°.

[0042] Of course, in other implementations, the angle between the interface and the surface of the black matrix 214 can be calculated based on the refractive index of the high-refractive-index region 213a and the refractive index of the low-refractive-index region 213b. Ultimately, this angle can satisfy the requirement that the incident angle of the incident light is greater than a predetermined critical angle, which is the angle at which total internal reflection occurs when the light enters the low-refractive-index region 213b from the high-refractive-index region 213a. Furthermore, the refractive index of the encapsulant between the color filter substrate 210 and the TFT array substrate 220 can be considered in the calculation to further improve the accuracy of the angle.

[0043] See also Figure 5For example, taking the display panel 200 applied to the OLED type as an example, a color resist unit of the color filter substrate 210 corresponds to a pixel light-emitting unit 222a. For the sake of convenience, the first target point A is defined as the light-emitting point at the outermost edge of the pixel light-emitting unit 222a; the second target point B belongs to the point set on the interface F corresponding to the pixel light-emitting unit 222a that is farthest from the base substrate 211 (the point set can exclude the point on the surface of the low refractive index region 213b), and the second target point B is the point in the point set farthest from the first target point A. When determining the size of the angle, it is sufficient to ensure that the angle between a beam of incident light III from the first target point A to the second target point B and the interface F is greater than the critical angle. First, the incident angle of the incident light III entering the high refractive index region 213a can be determined based on the vertical distance between the first target point A and the buffer layer 213, and the distance between the first target point A and the second target point B. Next, based on the refractive index of the encapsulant and the refractive index of the high refractive index region 213a, the exit angle (α) of the incident light III after passing through the interface H between the encapsulant and the high refractive index region 213a can be calculated. Then, based on the exit angle and the critical angle (β) at which total reflection occurs at the interface F, the angle range between the interface F and the surface of the black matrix 214 can be determined. The critical angle can be determined by the refractive index of the high refractive index region 213a and the refractive index of the low refractive index region 213b. In some implementations, θ≤α+β, θ is the angle between the interface F and the surface of the black matrix 214, α is the exit angle of the incident light III after passing through the interface between the encapsulant and the high refractive index region 213a, and β is the critical angle. In this way, the incident light III from the pixel unit can be almost totally reflected at the interface F, thereby improving the light output rate of the display panel 200 while effectively avoiding light leakage.

[0044] In some implementations, the refractive index of the high-refractive-index region 213a can be set within a range of 1.7 to 2, while the refractive index of the low-refractive-index region 213b can be set within a range of 1.3 to 1.5. This ensures that the thickness of other structures is not affected after the buffer layer 213 is manufactured, effectively accommodating the thickness requirements of the existing display panel 200. Specifically, the material of the high-refractive-index region 213a can include one or more of a sulfur-containing epoxy resin, an epoxy resin containing multiple benzene rings, a silicon-containing resin material, molybdenum trioxide, and titanium dioxide; while the material of the low-refractive-index region 213b can include silicon nitride and / or silicon dioxide. All of these material choices can effectively meet the aforementioned refractive index requirements.

[0045] The black matrix 214 can also be formed on the buffer layer 213 through processes such as spin coating, exposure, and / or development. An opening region of the black matrix 214, whose orthographic projection on the color filter layer 212 corresponds to a color resist unit, allows light emitted by the pixel light-emitting unit to pass through the opening region. The non-opening region of the black matrix 214 is located on the surface of the low-refractive-index region 213b and cooperates with the low-refractive-index region 213b to shield light from adjacent pixel light-emitting units.

[0046] It should be noted that, in addition to the structural layers described above, the color filter substrate 210 may also include a planarization layer covering the black matrix 214 and other commonly used functional structural layers. For details, please refer to the commonly used functional film layer designs in the prior art, which will not be described in detail in this embodiment.

[0047] It is understandable that the display panel 200 provided in the embodiment of the present invention includes: a TFT array substrate 220 and the color film substrate 210 described in any of the aforementioned embodiments, and the side of the color film substrate 210 on which the black matrix 214 is provided is bonded to the light-emitting side of the TFT array substrate 220. Specifically, the encapsulation and bonding can be performed using a sealing adhesive 310. It is understandable that when the display panel 200 is an LCD type display panel 200, when the TFT array substrate 220 and the color film substrate 210 are encapsulated, a liquid crystal layer is filled between the TFT array substrate 220 and the color film substrate 210. When the display panel 200 is an OLED type display panel 200, the light-emitting side of the TFT array substrate 220 can be bonded to the color film substrate 210 after the sealing adhesive 310 is applied to the color film substrate 210.

[0048] Based on the same inventive concept, a display device is provided in another embodiment of the present invention. The display device includes the display panel 200 in the foregoing embodiment.

[0049] It should be noted that the display panel 200 and display device can be applied to, but not limited to, monitors, mobile phones, televisions, laptop computers, and in-car computers. Furthermore, the relevant structures and beneficial effects of the display panel 200 and display device in the above-mentioned embodiment have been described in the aforementioned embodiment of the color filter substrate 210 and will not be repeated here.

[0050] See also Figure 6 Based on the same inventive concept, another embodiment of the present invention further provides a method for manufacturing a color filter substrate, the method comprising:

[0051] Step S10: providing a substrate;

[0052] Step S20: forming a color filter layer on the base substrate;

[0053] Step S30: forming a buffer layer on the color filter layer, wherein the buffer layer includes a high refractive index region and a low refractive index region;

[0054] Step S40: forming a black matrix on the buffer layer, wherein the opening area of ​​the black matrix is ​​located in the high refractive index area, and the non-opening area of ​​the black matrix is ​​located in the low refractive index area.

[0055] In the above steps S10-S40, the specific process of manufacturing the color filter layer, the buffer layer and the black matrix can be completed using existing technologies. The structure and functional effects of the manufactured color filter substrate can be found in the relevant description of the above embodiments, and will not be repeated in this embodiment.

[0056] In summary, the color filter substrate and the color filter substrate provided in the embodiments of the present invention can effectively improve the light extraction efficiency of a display panel manufactured using the color filter substrate.

[0057] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0058] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0059] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed herein may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0060] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments. For example, in the claims below, any of the claimed embodiments may be used in any combination.

[0061] It should be noted that the above embodiments illustrate rather than limit the invention, and that a person skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

Claims

1. A color film substrate, characterized in that: include: substrate; A color filter layer is provided on one side of the base substrate; A buffer layer is provided on a side of the color filter layer away from the base substrate; the buffer layer includes a high refractive index region and a low refractive index region; a black matrix, disposed on a side of the buffer layer away from the base substrate; an opening area of ​​the black matrix is ​​located on the surface of the high refractive index area, and a non-opening area of ​​the black matrix is ​​located on the surface of the low refractive index area; The color filter layer includes multiple color resist units; the width of the longitudinal section of the low refractive index area decreases from the side close to the black matrix to the side close to the base substrate; the longitudinal section is a section between any two adjacent color resist units and perpendicular to the base substrate.

2. The color film substrate according to claim 1, wherein: The longitudinal section is trapezoidal.

3. The color film substrate according to claim 1, wherein: An included angle between the interface between the high refractive index region and the low refractive index region and the black matrix is ​​65° to 90°.

4. The color film substrate according to claim 1, wherein: The angle between the interface between the high refractive index region and the low refractive index region and the surface of the black matrix satisfies: The incident angle of the incident light is greater than a preset critical angle; the incident light is the light incident on the interface from a direction away from the substrate, and the critical angle is the angle at which the light is totally reflected from the high refractive index area to the low refractive index area.

5. The color film substrate according to claim 1, wherein: The refractive index range of the high refractive index region is 1.7 to 2; the refractive index range of the low refractive index region is 1.3 to 1.

5.

6. The color film substrate according to claim 1, wherein: The thickness of the buffer layer ranges from 0.5um to 5um.

7. The color film substrate according to claim 1, wherein: The material of the high refractive index region includes one or more of sulfur-containing epoxy resin, epoxy resin containing multiple benzene rings, silicon-containing resin material, molybdenum trioxide and titanium dioxide; the material of the low refractive index region includes silicon nitride and / or silicon dioxide.

8. A display panel, characterized in that: include: A TFT array substrate and the color film substrate according to any one of claims 1 to 7, wherein a surface of the color film substrate on which the black matrix is ​​provided is laminated to a light-emitting side of the TFT array substrate.

9. A display device, characterized in that: The display panel comprises the display panel according to claim 8.

10. A method for manufacturing a color filter substrate, characterized in that: include: providing a substrate; forming a color filter layer on the base substrate; forming a buffer layer on the color filter layer, wherein the buffer layer includes a high refractive index region and a low refractive index region; forming a black matrix on the buffer layer, wherein the opening area of ​​the black matrix is ​​located in the high refractive index area, and the non-opening area of ​​the black matrix is ​​located in the low refractive index area; The color filter layer forms a plurality of color resist units; the width of the longitudinal section of the low refractive index region decreases from the side close to the black matrix to the side close to the base substrate; the longitudinal section is a section between any two adjacent color resist units and is perpendicular to the base substrate.

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