OLED (Organic Light Emitting Diode) display panel, preparation method thereof and display device

Abstract

The invention provides an OLED display panel and a preparation method thereof and a display device.The OLED display panel comprises a light-emitting layer and a filter layer, the filter layer comprises color filter films, the color filter films comprise at least two of a red filter film, a green filter film and a blue filter film, and the color filter films are arranged between the light-emitting layer and the filter layer. A retaining wall with a sandwich structure is arranged between two adjacent color filter films with different colors, and the upper layer, the middle layer and the lower layer of the retaining wall with the sandwich structure are limited, so that the color filter films with at least two different colors are alternately arranged in the filter layer; according to the OLED display panel, the problems that the RGB three-color visual angle light-emitting proportion of an existing OLED display panel is poor in consistency and the visual angle color cast is increased can be effectively solved, and the obtained OLED display panel has high light-emitting color purity.

Description

Technical Field

[0001] The present invention belongs to the field of display technology, and in particular relates to an OLED display panel and a preparation method thereof, as well as a display device. Background Art

[0002] Organic light-emitting display devices, namely organic light-emitting diodes (OLEDs), have become a current research hotspot due to their lightness, thinness, power saving and other characteristics, as well as many incomparable advantages over liquid crystal displays.

[0003] Color filter is a key component for organic light-emitting display devices to achieve color display. Color filter is an optical filter that can accurately select a small range of light waves to pass through, and reflect other undesirable bands, thereby presenting different colors through the different light bands transmitted by different color sub-pixels, and presenting the desired color by controlling the light transmission intensity of different color sub-pixels.

[0004] At present, color filters are usually installed on the light-emitting side of the display panel so that the human eye can receive saturated light of a certain color. The basic structure of the color filter includes a glass substrate, a black matrix, a color layer and a protective layer; among them, the main function of the black matrix is ​​to block stray light between sub-pixels, improve the color purity of the color filter, and expand the color gamut; however, the existing black matrix materials cannot have both low reflectivity and high optical concentration, and will also cause environmental pollution. At the same time, the existence of the black matrix will make the preparation process of the display panel more complicated.

[0005] Therefore, there is an urgent need to develop an OLED display panel that can replace the existing black matrix. Summary of the invention

[0006] The present invention provides an OLED display panel and a preparation method thereof, and a display device, wherein a light shielding area in the OLED display panel adopts a material different from a black matrix, thereby solving the problems of the prior art.

[0007] According to one aspect of the present invention, there is provided an OLED display panel, the OLED display panel comprising a light emitting layer and a light filter layer;

[0008] The light-emitting layer includes at least two of a red light-emitting unit, a blue light-emitting unit and a green light-emitting unit;

[0009] The filter layer includes a color filter film;

[0010] The color filter film includes at least two of a red filter film, a green filter film and a blue filter film;

[0011] At least two color filter films of different colors are alternately arranged in the filter layer, and a retaining wall with a sandwich structure is arranged between two adjacent color filter films of different colors, and the retaining wall is composed of the color filter films;

[0012] Along the direction from the filter layer to the light-emitting layer, the retaining wall comprises an upper layer, a middle layer and a lower layer which are arranged in sequence;

[0013] The upper layer and the lower layer have the same color, the upper layer and the middle layer have different colors, and the upper layer has a color different from at least one of the two adjacent color filter films of different colors on both sides of the retaining wall;

[0014] At least one of the upper layer and the lower layer is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall, and the middle layer is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall;

[0015] Along the direction from the filter layer to the light-emitting layer, the thickness of the middle layer is greater than the thickness of the upper layer, and the thickness of the middle layer is greater than the thickness of the lower layer;

[0016] In the direction from the color filter film on one side of the retaining wall to the color filter film on the other side of the retaining wall, the width of the middle layer is the same as the width of the lower layer, and the width of the middle layer is the same as or different from that of the upper layer.

[0017] According to another aspect of the present invention, a method for preparing an OLED display panel is provided, the method for preparing an OLED display panel comprising:

[0018] Providing a light-emitting layer, wherein the light-emitting layer is a multi-layer stacked structure, comprising at least an OLED anode, an OLED device light-emitting stacked composite film layer, a cathode, a thin film encapsulation layer, and a planarization layer;

[0019] A filter layer is formed on the light-emitting layer to obtain the OLED display panel.

[0020] According to another aspect of the present invention, a display device is provided, wherein the display device comprises the OLED display panel as described above.

[0021] Compared with the prior art, the OLED display panel provided by the present invention is provided with a retaining wall with a sandwich structure between two adjacent color filter films of different colors. On the one hand, the retaining wall with a sandwich structure can achieve the effect of a black matrix, effectively block stray light between sub-pixels, thereby improving the color purity of RGB and expanding the color gamut; on the other hand, by limiting the retaining wall with a sandwich structure to be composed of color filter films of two different colors, and the colors of the upper and lower layers are the same, which are different from the color of the middle layer, and the colors of the upper and lower layers are different from the colors of at least one of the two color filter films of different colors adjacent to the two sides of the retaining wall, and at the same time, the thickness of the middle layer is greater than the thickness of the upper and lower layers, thereby effectively improving the problems of poor consistency of RGB three-color viewing angle light output ratio and increased visual color angular deviation of the OLED display panel existing in the existing filter film overlapping technology, so that the obtained OLED display panel has higher luminous color purity. In addition, the sandwich structure retaining wall can reduce the step difference between color filters of different colors, and thus form a highly close retaining wall at the adjacent side positions. The consistency of the RGB three-color viewing angle light output ratio of the OLED display panel formed based on this is effectively improved, which improves the large viewing angle color deviation problem of the existing display panel and improves the display effect.

[0022] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a schematic diagram of a conventional OLED display panel;

[0025] Figure 2 This is a simulation test chart of the tri-color stimulus values ​​of two OLED display panels;

[0026] Figure 3 is a schematic diagram of an OLED display panel provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0029] Figure 6 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0030] Figure 7 yes Figure 1 and Figure 3 Simulation test chart of tri-color stimulus values ​​of two OLED display panels;

[0031] Figure 8 is a comparative schematic diagram of OLED display panels with retaining walls of different widths provided in an embodiment of the present invention;

[0032] Fig. 9 is a comparative schematic diagram of OLED display panels with retaining walls of different shapes provided by an embodiment of the present invention;

[0033] Fig.10 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0034] Fig.11 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0035] Fig.12 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0036] Fig.13 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0037] Fig.14 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0038] Fig.15 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention;

[0039] Fig.16 It is a schematic diagram of a method for preparing an OLED display panel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] Figure 1 is a schematic diagram of a conventional OLED display panel, such as Figure 1 In the cross-sectional structure of the OLED display panel 100 shown, the OLED display panel 100 at least includes a light-emitting layer 101 and a filter layer 102; wherein the light-emitting layer 101 includes a blue light-emitting unit 111, a red light-emitting unit 112, and a green light-emitting unit 113; the filter layer 102 is arranged corresponding to the light-emitting layer 101, and specifically, the filter layer 102 includes a blue filter film 121, a red filter film 122, and a green filter film 123, and a light-shielding area 103 is provided between two adjacent filter films of different colors. The light-shielding area 103 is formed by partially overlapping the blue filter film 121 and the red filter film 122, and the formation of the light-shielding area 103 mentioned here refers to selecting the same material as the color filter film to form the light-shielding area 103. It can be understood that in other embodiments, the light shielding area of ​​the OLED display panel 100 can be formed by partially overlapping the blue filter film and the green filter film, or the light shielding area of ​​the OLED display panel 100 can be formed by partially overlapping the red filter film and the green filter film. In this embodiment, the light shielding area 103 is formed by partially overlapping the blue filter film 121 and the red filter film 122 as an example for description.

[0043] At the same large viewing angle, Figure 1 As shown in FIG. 1 , the blue light (B) emitted by the blue light emitting unit 111 has an emission angle less than or equal to φ B The blue light of the blue light emitting unit 111 will not be blocked by the shading area 103 outside the blue filter film 121, so these small-angle blue lights can pass through the blue filter film 121 and be directly emitted normally. B Most of the blue light is blocked by the red filter film 122 in the light shielding area 103 outside the blue filter film 121, so the large-angle blue light is mostly absorbed by the light shielding area 103 and cannot be emitted.

[0044] Similarly, if Figure 1As shown in FIG. 1 , the green light (G) emitted by the green light emitting unit 113 has an emission angle less than or equal to φ G The green light can be emitted directly through the green filter film 123, and the emission angle is greater than φ G Most of the green light is absorbed by the red filter film 122 and the blue filter film 121 in the light shielding area 103 around the green filter film 123 and cannot be emitted.

[0045] For the red light emitting unit 122, Figure 1 As shown in FIG, the red light (R) emitted by the red light emitting unit 122 has an emission angle less than or equal to φ R The red light of the red light emitting unit 122 is mainly emitted through the red filter film 122, and a part of the red light is emitted into the red filter film 122 in the light shielding area 103 outside the red filter film 122. However, the red filter film 122 in the light shielding area 103 will not block it. Therefore, the emission angle of the red light emitting unit 122 is less than or equal to φ R The red light can basically be emitted normally, and the emission angle is greater than φ R Most of the red light is absorbed by the blue filter film 121 in the light shielding area 103 around the red filter film 122 and cannot be emitted.

[0046] At the same wide viewing angle, the blue light emission angle φ of the blue light emitting unit 111 is B is approximately equal to the emission angle φ of the green light of the green light emitting unit 113 G , the emission angle φ of the green light of the green light emitting unit 113 G is smaller than the emission angle φ of the red light of the red light emitting unit 122 R .

[0047] Obviously, under the same wide viewing angle, the light emission angle φ of the red light emitting unit 122 in the OLED display panel 100 is R Correspondingly, the red light emitted from the OLED display panel 100 is the largest as a whole, which makes the difference between the blue light emission amount and the green light emission amount and the red light emission amount in the OLED display panel 100 relatively large. There is a problem of poor consistency in the RGB three-color viewing angle light output ratio of the OLED display panel 100, resulting in the problem of red color in the OLED display panel 100 at a large viewing angle.

[0048] In order to better verify the above issues, Figure 1 The three-color stimulus values ​​of the traditional OLED display panel were simulated and tested. The simulation test diagram of the three-color stimulus values ​​obtained by the test is shown in the figure below. Figure 2As shown. The traditional OLED display panel uses the traditional black matrix (BM) as a barrier between two adjacent filter films of different colors. The blocking area 103 formed by the color blocking overlapping technology is defined as CBM, and the CBM structure is used to replace the traditional black matrix (BM) structure. The tristimulus values ​​are a representation of the degree of stimulation of the three primary colors that cause the human retina to perceive a certain color. The tristimulus values ​​include X value, Y value and Z value, where the X value represents the amount of red stimulation, the Y value represents the amount of green stimulation, and the Z value represents the amount of blue stimulation.

[0049] Figure 2 This is a simulation test chart of the tri-color stimulus values ​​of two OLED display panels. Figure 2 The solid line represents Figure 1 The three-color stimulation values ​​of the OLED display panel 100 based on the CBM structure are shown, and the dotted line represents the three-color stimulation values ​​of the conventional OLED display panel based on the BM structure. Figure 2 In the coordinate system, the horizontal axis represents the viewing angle (unit: °), and the vertical axis represents the stimulus value (unit: Nor).

[0050] Figure 2 Middle, red solid line CBM-X characterization Figure 1 The green solid line CBM-Y represents the X value of the OLED display panel 100 based on the CBM structure, and the blue solid line CBM-Z represents the Z value of the OLED display panel 100 .

[0051] Figure 2 In the figure, the red dotted line represents the X value of the traditional OLED display panel based on the BM structure, the green dotted line represents the Y value of the traditional OLED display panel, and the blue dotted line represents the Z value of the traditional OLED display panel.

[0052] from Figure 2 It can be clearly seen that at a wide viewing angle, such as -40° or +40°, the blue solid line CBM-Z, the red solid line CBM-X and the green solid line CBM-Y corresponding to the OLED display panel 100 have large differences, among which the red solid line CBM-X, i.e., the X value, is the largest, and the blue solid line CBM-Z, i.e., the Z value, is the smallest. Figure 2 The simulation result shows that as the viewing angle increases, the Z value of the OLED display panel 100 decreases rapidly, and the X value and the Z value gradually separate in the viewing angle.

[0053] The larger the stimulus value, the greater the contribution of the corresponding color component in visual matching. Figure 2Among them, the red solid line CBM-X corresponding to the OLED display panel 100 has the largest X value, indicating that the red light (R) of the OLED display panel 100 makes a greater contribution in visual matching. Correspondingly, the OLED display panel 100 may have a problem of red color in the large viewing angle picture.

[0054] It can be seen from this that Figure 2 The conclusion drawn from the simulation test of the tristimulus values Figure 1 confirms the problem of red color in the large viewing angle picture of the structure

[0055] In fact, the problems existing in the above OLED display panel 100 are common problems of this type of display panel that uses two overlapping color filter films as the barrier wall. Because after using two overlapping color filter films to form a light-shielding area, there will inevitably be a large step difference between the color filter films of different colors, and then barrier walls with different heights will be formed at adjacent side positions. Refer to Figure 1 As shown, the side wall height (which can also be called the thickness) of the blue color filter film 121 corresponding to the blue light emitting unit 111 is Hb, the side wall height of the red color filter film 122 corresponding to the red light emitting unit 112 is Hr, and the side wall height of the green color filter film 123 corresponding to the green light emitting unit 113 is Hg, Hb = Hg < Hr. In practice, Hb in the OLED display panel 100 is about 1.2 μm, and Hr is about 0.4 μm. The side wall is the barrier wall at the adjacent side position of the color filter film. Then, during the light output process of the light passing through the color filter film, different color lights will inevitably encounter different degrees of side wall effects, resulting in a poor consistency of the RGB three-color viewing angle light output ratio of the OLED display panel 100.

[0056] To solve the above problems of the OLED display panel 100, the present invention provides a new type of OLED display panel to solve the above technical problems. The following will specifically describe several specific structures of the OLED display panel provided by the present invention with reference to the drawings.

[0057] Figure 3 is a schematic diagram of an OLED display panel provided by an embodiment of the present invention. As Figure 3 shown, the OLED display panel 200 is different from Figure 1 the OLED display panel 100 shown

[0058] As Figure 3In the cross-sectional structure of the OLED display panel 200 shown, the OLED display panel 200 at least includes a light-emitting layer 201 and a filter layer 202; the light-emitting layer 201 includes at least two of a blue light-emitting unit 211, a red light-emitting unit 212 and a green light-emitting unit 213; the filter layer 202 includes a color filter film; the color filter film includes at least two of a blue filter film 221, a red filter film 222 and a green filter film 223; at least two color filter films of different colors are alternately arranged in the filter layer 202, and a retaining wall 203 with a sandwich structure is arranged between two adjacent color filter films of different colors, and the retaining wall 203 is composed of color filter films; along the direction from the filter layer 202 to the light-emitting layer 201 ( Figure 3 The retaining wall 203 includes an upper layer 231, an intermediate layer 232 and a lower layer 233 which are arranged in sequence; the upper layer 231 and the lower layer 233 have the same color, the upper layer 231 and the intermediate layer 232 have different colors, and the color of the upper layer 231 is different from the color of at least one of the two adjacent color filter films of different colors on both sides of the retaining wall 203; at least one of the upper layer 231 and the lower layer 233 is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall 203, and the intermediate layer 232 is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall 203; along the direction from the filter layer 202 to the light-emitting layer 201, the thickness Hz of the intermediate layer 232 is greater than the thickness Hs of the upper layer 231, and the thickness Hz of the intermediate layer 232 is greater than the thickness Hx of the lower layer 233; along the direction from the color filter film on one side of the retaining wall 203 to the color filter film on the other side of the retaining wall 203 ( Figure 3 The width Wz of the middle layer 232 is the same as the width of the lower layer 233 , and the width Ws of the middle layer 232 and the upper layer 231 are the same or different.

[0059] In this embodiment, the OLED display panel 200 includes a light-emitting layer 201. The light-emitting layer 201 may include a blue light-emitting unit 211, a red light-emitting unit 212, and a green light-emitting unit 213, and the blue light-emitting unit 211, the red light-emitting unit 212, and the green light-emitting unit 213 are alternately arranged in the light-emitting layer 201. In other embodiments, the light-emitting layer may also include light-emitting units of two different colors, for example, the light-emitting layer includes red light-emitting units and green light-emitting units alternately arranged, but is not limited thereto.

[0060] The OLED display panel 200 includes a filter layer 202 corresponding to the light-emitting layer 201, and the filter layer 202 is arranged on the light-emitting side of the light-emitting layer 201. The optional filter layer 202 includes a blue filter film 221, a red filter film 222, and a green filter film 223 that are alternately arranged. The blue filter film 221, the red filter film 222, and the green filter film 223 are alternately arranged in the filter layer 202. The blue light emitted by the blue light-emitting unit 211 is emitted through the blue filter film 221, the red light emitted by the red light-emitting unit 212 is emitted through the red filter film 222, and the green light emitted by the green light-emitting unit 213 is emitted through the green filter film 223. It can be understood that the light-emitting units in the light-emitting layer are arranged corresponding to the color filter films in the filter layer. For example, the light-emitting layer includes red light-emitting units and green light-emitting units that are alternately arranged, and correspondingly, the filter layer includes a red filter film arranged corresponding to the red light-emitting unit and a green filter film arranged corresponding to the green light-emitting unit. Hereinafter, the red light of the OLED display panel 200 refers to the red light emitted by the red light emitting unit 212 , the green light of the OLED display panel 200 refers to the green light emitted by the green light emitting unit 213 , and the blue light of the OLED display panel 200 refers to the blue light emitted by the blue light emitting unit 211 .

[0061] A retaining wall 203 having a sandwich structure is provided between two adjacent color filter films of different colors in the filter layer 202. The retaining wall 203 is composed of color filter films. Figure 3 In the embodiment, the retaining wall 203 is formed by partially overlapping a blue filter film 221 and a red filter film 222, wherein the upper layer 231 and the lower layer 233 are both formed by using a blue filter film 221, and the middle layer 232 is formed by using a red filter film 222. However, the invention is not limited thereto, and other different structures will be described in subsequent embodiments, which will not be described in detail here. In the embodiment, the structure is described by taking the upper layer 231 using a blue filter film 221 and the middle layer 232 using a red filter film 222 as an example. The retaining wall 203 described herein as being composed of a color filter film means that the retaining wall 203 can be prepared using the same material as the color filter film. Therefore, in this embodiment, any one of the upper layer 231 and the lower layer 233 can be formed of the same material as the blue filter film 221 , and the middle layer 232 can be formed of the same material as the red filter film 222 .

[0062] The color of the upper layer 231 is different from the color of at least one of the two adjacent color filters of different colors on both sides of the retaining wall 203. In this embodiment, when the two adjacent color filters are respectively the red filter film 222 and the green filter film 223, the color of the upper layer 231 of the retaining wall 203 between the two is different from the color of either color filter film. When one of the two adjacent color filters is the blue filter film 221, the color of the upper layer 231 of the retaining wall 203 between the two is the same as the color of the blue filter film 221.

[0063] At least one of the upper layer 231 and the lower layer 233 is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall 203, and the middle layer 232 is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall 203. In this embodiment, when one of the two adjacent color filter films is a red filter film 222, the color of the middle layer 232 of the retaining wall 203 between the two is the same as the color of the red filter film 222, and the middle layer 232 of the retaining wall 203 is directly connected to the adjacent red filter film 222 of the same color. Specifically, the same material as the red filter film 222 can be selected to form the middle layer 232, so the red filter film 222 and the middle layer 232 can be directly manufactured through a single patterning process during preparation. When one of the two adjacent color filters is a blue filter 221, the lower layer 233 of the retaining wall 203 between the two is directly connected to the adjacent blue filter 221 of the same color. Specifically, the lower layer 233 can be formed of the same material as the blue filter 221. Therefore, the blue filter 221 and the lower layer 233 can be directly manufactured through a single patterning process. In the present invention, the single patterning process refers to a process of forming a desired layer structure through a single coating, exposure, and development process.

[0064] Figure 4 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention, and Figure 3 The difference is that Figure 4 When one of the two adjacent color filter films is a blue filter film 221 , the upper layer 231 of the retaining wall 203 between the two is directly connected to the adjacent blue filter film 221 of the same color.

[0065] Figure 5 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention, and Figure 3 The difference is that Figure 5 When one of the two adjacent color filters is a blue filter 221 , any one of the upper layer 231 and the lower layer 233 of the retaining wall 203 between the two is directly connected to the adjacent blue filter 221 of the same color.

[0066] Figure 6is a schematic diagram of another OLED display panel provided by an embodiment of the present invention, and Figure 3 The difference is that Figure 6 When one of the two adjacent color filters is a blue filter 221 , the upper layer 231 of the retaining wall 203 between the two is directly connected to the adjacent blue filter 221 of the same color, and at the same time, the lower layer 233 of the retaining wall 203 is directly connected to the adjacent blue filter 221 of the same color.

[0067] It can be understood that since the materials of the color filter films of different colors in the filter layer 202 are different, the preparation processes are also different. During the preparation process, the thinnest color filter film can be preferentially formed in the filter layer area just above the corresponding light-emitting unit opening as the lower layer 233, and then the color filter films of other colors are formed in sequence as the middle layer 232, and then the upper layer 231 is formed. The upper layer 231 and the lower layer 233 of the retaining wall 203 are limited to the same color, which not only simplifies the preparation process, but also only uses two colors of color filter films to form the retaining wall 203, and can also ensure that the overall thickness of the retaining wall 203 is not too thick. If the thickness of the retaining wall 203 is too thick, it will limit the light output at the viewing angle, reduce the viewing angle brightness, and the process is complicated, which will lead to a decrease in product yield.

[0068] Continue to refer Figure 3 , along the direction from the filter layer 202 to the light-emitting layer 201, i.e., the F2 direction, the thickness Hz of the middle layer 232 is greater than the thickness Hs of the upper layer 231, and the thickness Hz of the middle layer 232 is greater than the thickness Hx of the lower layer 233. In this embodiment, a thicker color filter film is used as the middle layer 232 of the retaining wall 203, and a thinner color filter film is used as the upper layer 231 and the lower layer 233 of the retaining wall 203, which is conducive to thinning the retaining wall 203 and reducing the height of the retaining wall 203, thereby increasing the emission angle of the light-emitting unit, and correspondingly, increasing the light emission amount of the light-emitting unit.

[0069] The color filter film on one side of the retaining wall 203 points to the direction of the color filter film on the other side of the retaining wall 203 ( Figure 3 The width Wz of the middle layer 232 is the same as the width of the lower layer 233, and the width Wz of the middle layer 232 is the same as or different from the width Ws of the upper layer 231. In this embodiment, Wz=Ws can be selected. However, it is not limited to this. In other embodiments, the width of the upper layer of the retaining wall can be different from the width of the middle layer.

[0070] At the same large viewing angle, Figure 3 As shown in FIG. 1 , the red light emitted by the red light emitting unit 212 has an emission angle less than or equal to θ RThe red light of the red light emitting unit 212 will not be blocked by the retaining wall 203 outside the red filter film 222, so these small-angle red lights can pass through the red filter film 222 and be directly emitted normally. R The red light will at least be blocked by the upper layer 231 in the retaining wall 203 outside the red filter film 222. Since the upper layer 231 is made of blue filter film material, the blue upper layer 231 will block most of the red light so that it cannot be emitted. Therefore, these large-angle red lights are mostly absorbed by the retaining wall 203 and cannot be emitted.

[0071] Similarly, if Figure 3 As shown in FIG. 1 , the green light emitted by the green light emitting unit 213 has an emission angle less than or equal to θ G The green light can be emitted directly through the green filter film 223, and the emission angle is greater than θ G Most of the green light will be absorbed by the retaining wall 203 outside the green filter film 223 and cannot be emitted.

[0072] As for the blue light emitting unit 211, Figure 3 As shown in FIG. 1 , the blue light emitted by the blue light emitting unit 211 has an emission angle less than or equal to θ B The blue light of the blue light emitting unit 221 is mainly emitted through the blue filter film 221, and a part of the blue light is emitted into the upper layer 231 of the retaining wall 203 outside the blue filter film 221. However, the upper layer 231 of the blue light emitting unit 221 in the retaining wall 203 does not block the blue light. Therefore, the emission angle of the blue light emitting unit 221 is less than or equal to θ. B The blue light can basically be emitted normally, and the emission angle is greater than θ B Most of the blue light is absorbed by the middle layer 232 in the retaining wall 203 outside the blue filter film 221 and cannot be emitted.

[0073] At the same wide viewing angle, the emission angle θ of the green light of the green light emitting unit 213 is G is approximately equal to the emission angle θ of the red light of the red light emitting unit 212 R , the emission angle θ of the blue light of the blue light emitting unit 211 B Greater than the emission angle θ of the red light of the red light emitting unit 212 R .

[0074] Obviously, under the same wide viewing angle, the light emission angle θ of the red light emitting unit 212 in the OLED display panel 200 is R is approximately equal to the emission angle θ of the green light of the green light emitting unit 213 G , so that the viewing angle light emission ratios of the R and G colors of the OLED display panel 200 tend to be consistent, thereby improving the consistency of the viewing angle light emission ratios of the R and G colors of the OLED display panel 200.

[0075] Under the same wide viewing angle, the light emission angle θ of the red light emitting unit 212 in the OLED display panel 200 is R is smaller than the emission angle θ of the blue light of the blue light emitting unit 211 B , so that the viewing angle light output ratio of the blue color B of the OLED display panel 200 is improved.

[0076] Figure 2 In the OLED display panel 100 using two layers of color filter films as the shading area 103, the Z value decreases rapidly, the Z value is smaller than the X value, and the X value and the Z value are gradually separated and contrasted in the viewing angle, and the difference between the two is relatively large.

[0077] In this embodiment, the viewing angle light emission ratios of the R and G colors of the OLED display panel 200 tend to be consistent, and the viewing angle light emission ratio of the blue B of the OLED display panel 200 is increased, thereby reducing the difference in the viewing angle light emission ratios of R and B in the OLED display panel 200, making the viewing angle light emission ratios of the RGB three colors tend to be consistent, thereby improving the consistency of the viewing angle light emission ratios of the RGB three colors of the OLED display panel 200, improving the problem of reddish color in the large viewing angle picture of the OLED display panel 200, and reducing the visual color deviation. Effective solution Figure 1 The OLED display panel 100 shown has problems such as inconsistent light emission ratios at different viewing angles and increased visual color deviation.

[0078] In order to further illustrate that the OLED display panel 200 provided by the present invention can improve the consistency of the RGB three-color viewing angle light output ratio and reduce the color deviation of the viewing angle, Figure 3 The three-color stimulus values ​​of the OLED display panel 200 are simulated and tested, and the simulation test diagram of the three-color stimulus values ​​is shown in FIG. Figure 7 shown.

[0079] Figure 7 yes Figure 1 and Figure 3 The simulation test chart of the three-color stimulus values ​​of the two OLED display panels. Figure 7 The solid line represents Figure 1 The three-color stimulus values ​​of the OLED display panel 100 are shown, and the dotted line represents Figure 3 The tristimulus values ​​of the OLED display panel 200 are shown.

[0080] from Figure 7It can be clearly seen that at a wide viewing angle, such as -60° or +60°, the differences between the blue dotted line 203-Z, the red dotted line 203-X and the green dotted line 203-Y corresponding to the OLED display panel 200 are small, while the differences between the blue solid line CBM-Z, the red solid line CBM-X and the green solid line CBM-Y corresponding to the OLED display panel 100 are large. By comparison, it can be seen that the difference between the X value corresponding to the red dotted line 203-X in the OLED display panel 200 and the Z value corresponding to the blue dotted line 203-Z is reduced, and the Z value corresponding to the blue dotted line 203-Z is greater than the Z value corresponding to the blue solid line CBM-Z in the OLED display panel 100. Therefore, according to Figure 7 It can be seen that the red light output of the OLED display panel 200 is reduced, the blue light output is increased, and the difference in the output of red light and blue light is reduced. Therefore, the consistency of the RGB three-color viewing angle light output ratio of the OLED display panel 200 is better than that of the OLED display panel 100, which improves the problem of red color in the wide viewing angle picture of the OLED display panel 100. The OLED display panel 200 can reduce the visual color deviation.

[0081] From this we can see that Figure 7 The conclusion drawn from the simulation test of the three-color stimulus values ​​confirms Figure 3 The structure is better than Figure 1 The structure solves the problem of reddish color in wide viewing angle images and improves the consistency of the RGB three-color light output ratio.

[0082] In fact, in the above-mentioned OLED display panel 200, two color filter films are overlapped to form a sandwich structure retaining wall 203, and the thickness of the upper layer 231 is relatively small, so the step difference between the color filter films of different colors can be reduced, thereby forming a retaining wall 203 with a close height at adjacent lateral positions.

[0083] Figure 1 In the OLED display panel 100, the side wall height of the blue filter film 121 corresponding to the blue light emitting unit 111 is about 1.2 μm, the side wall height of the red filter film 122 corresponding to the red light emitting unit 112 is about 0.4 μm, and the side wall height difference between the two different color filter films is about 0.8 μm.

[0084] refer to Figure 3As shown, the side wall height (also referred to as thickness) of the blue filter film 221 corresponding to the blue light emitting unit 211 is Hz+Hx, the side wall height of the red filter film 222 corresponding to the red light emitting unit 212 and the side wall height of the green filter film 223 corresponding to the green light emitting unit 213 are both Hs+Hz+Hx, and the thickness Hs of the upper layer 231 is relatively small. In the optional OLED display panel 200, Hz+Hx is about 1.2μm, and Hs is about 0.4μm. Obviously, the side wall height difference between the blue filter film 221 and the red filter film 222 is about 0.4μm, which is Figure 1 compared to, Figure 3 The step difference between the color filters of different colors in the OLED display panel 200 is effectively reduced. Then, when the light passes through the color filter film, the side wall effect degree area encountered by the light of different colors is relatively close, thereby improving the consistency of the RGB three-color viewing angle light output ratio of the OLED display panel 200, and further improving the color deviation problem of the viewing angle.

[0085] It should be noted that, in this embodiment, parameters such as thickness and width of each layer in the retaining wall 203 are not fixed values, nor are there specific requirements, and can be adjusted according to actual product demand.

[0086] Optional materials for the red filter film include phthalocyanine red and / or azo red; materials for the green filter film include phthalocyanine green and / or azo green; materials for the blue filter film include any one of aluminum phthalocyanine, phthalocyanine blue and azo blue, or a combination of at least two of them.

[0087] Compared with the prior art, the OLED display panel provided by the present invention is provided with a retaining wall with a sandwich structure between two adjacent color filter films of different colors. On the one hand, the retaining wall with a sandwich structure can achieve the effect of a black matrix, effectively block stray light between sub-pixels, thereby improving the color purity of RGB and expanding the color gamut; on the other hand, by limiting the retaining wall with a sandwich structure to be composed of color filter films of two different colors, and the colors of the upper and lower layers are the same, which are different from the color of the middle layer, and the colors of the upper and lower layers are different from the colors of at least one of the two color filter films of different colors adjacent to the two sides of the retaining wall, and at the same time, the thickness of the middle layer is greater than the thickness of the upper and lower layers, thereby effectively improving the problems of poor consistency of RGB three-color viewing angle light output ratio and increased visual color angular deviation of the OLED display panel existing in the existing filter film overlapping technology, so that the obtained OLED display panel has higher luminous color purity. In addition, the sandwich structure retaining wall can reduce the step difference between color filters of different colors, and thus form a highly close retaining wall at the adjacent side positions. The consistency of the RGB three-color viewing angle light output ratio of the OLED display panel formed based on this is effectively improved, which improves the large viewing angle color deviation problem of the existing display panel and improves the display effect.

[0088] In the retaining wall, the width of the upper layer can be set to D, and the thickness of the middle layer can be set to Hz, then D≥0.894×Hz. In order to make the light emission consistency of the OLED display panel better, the width of the upper layer of the retaining wall can be limited.

[0089] Figure 8 is a comparative schematic diagram of OLED display panels with retaining walls of different widths provided by an embodiment of the present invention, such as Figure 8 As shown, the thickness of the middle layer 232 of the retaining wall 203 is relatively large. If the width of the retaining wall 203 is too narrow, the influence on the light with a color different from that of the middle layer 232 will be small, but the influence on the light with the same color as that of the middle layer 232 will be large.

[0090] In this embodiment, the color of the middle layer 232 of the optional retaining wall 203 is the same as the color of the red filter film 222. Based on this, if the width of the retaining wall 203 is too narrow (such as the width is Da), then at the same large viewing angle θ R1 Under, large viewing angle θ R1 The red light may be emitted from the middle layer 232 of the baffle 203, and the large viewing angle θ R1 The blue light and green light will not be emitted from the baffle 203, which makes the OLED display panel 200 have a reddish color problem at a large viewing angle. Increasing the width of the baffle 203 can improve the color deviation problem at a large viewing angle. For example, if the width of the baffle 203 is increased to D, then at the same large viewing angle θ R1 Under, large viewing angle θ R1 The red light, green light and blue light will not be emitted from the blocking wall 203, thereby improving the color shift problem of the large viewing angle of the OLED display panel 200.

[0091] The width D of the retaining wall 203 will be specifically analyzed below. Here, the width of the upper layer 231 of the retaining wall 203 is assumed to be D, where D is the width of the upper layer 231 facing the middle layer 232.

[0092] Along the F1 direction, the width of the upper layer 231 is D, and along the F2 direction, the thickness of the middle layer 232 of the retaining wall 203 is Hz, tanθ R0 =D / Hz. The emission angle is less than θ R0 Most of the light can be emitted from the area defined by the retaining wall 203, and the emission angle is greater than or equal to θ R0 The light is completely blocked by the blocking wall 203 and cannot be emitted from the blocking wall 203. R1 Greater than θ R0 . Large viewing angle θ R1 The blue light is blocked by the middle layer 232 of the retaining wall 203 and cannot be emitted. R1 The green light and the red light are blocked by the lower layer 233 of the blocking wall 203 and cannot be emitted.

[0093] The critical angle of total reflection refers to the angle of incidence when light is incident from a denser medium (a medium with a larger refractive index) into a less dense medium (a medium with a smaller refractive index). When the incident angle increases to a certain angle, the refraction angle reaches 90°. At this time, the corresponding incident angle is the critical angle of total reflection. When the incident angle is greater than the critical angle of total reflection, the light will no longer enter the less dense medium, but will be completely reflected back to the denser medium. In the OLED display panel 200, the side of the filter layer 202 facing away from the light-emitting layer 201 is the air medium Air, the refractive index of air is 1, and the refractive index of the filter layer 202 is greater than 1. Therefore, the filter layer 202 is a denser medium, and the air medium Air is a less dense medium.

[0094] Assume that the critical angle of total reflection of the red light emitted by the red light emitting unit 212 is θ R2 It can be understood that the emission angle of the red light emitting unit 212 is less than or equal to θ R2 The red light emitted by the red light emitting unit 212 has an emission angle greater than θ R2 The red light, due to the incident angle is greater than the critical angle of total reflection θ R2 , so there is total reflection, making the emission angle greater than θ R2 The red light will not be emitted from the filter layer 202 to the air medium Air, but will be completely reflected back into the filter layer 202. R2 The red light is reflected back into the filter layer 202 by the light-emitting side of the filter layer 202, which will interfere with other color lights.

[0095] In order to avoid interference between light rays, a baffle 203 is required to prevent the light rays from having an angle greater than θ. R2 The red light is blocked to prevent the emission angle from being greater than θ R2 The red light is incident on the light-emitting side of the filter layer 202 and is totally reflected.

[0096] Design θ R0 Greater than θ R2 .

[0097] It is known that the exit angle is less than θ R0 Most of the light can be emitted from the area defined by the retaining wall 203, and the emission angle is greater than or equal to θ R0 The light is completely blocked by the blocking wall 203 and cannot be emitted from the blocking wall 203. R0 The minimum value is equal to θ R2 , then the exit angle is less than θ R2 Most of the light can be emitted from the area defined by the retaining wall 203, and the emission angle is greater than or equal to θ R2 The light will be blocked by the blocking wall 203 and cannot be emitted from the blocking wall 203.

[0098] Therefore, the design θ R0 Greater than θ R2 , it can be achieved that the exit angle of the retaining wall 203 is greater than the critical angle of total reflection θ R2 The red light is effectively blocked to prevent the angle greater than the critical angle of total reflection θ R2 The wide-viewing angle red light is incident on the light-emitting side of the filter layer 202 and is totally reflected.

[0099] The refractive index of the material of the color filter is usually greater than 1.5. According to the law of refraction, the critical angle of total reflection of red light is θ R2 <41.8°. Specifically, from the law of refraction, sinθ R2 / sinθ air =1 / n r ,θ R2 is the incident angle of red light, θ air is the refraction angle of the light from the filter layer 202 into the air, 1 is the refractive index of air, n r is the refractive index of the red filter film 222. R2 is the critical angle of total reflection of red light, so θ air is 90°, then sinθ air =1, the refractive index n of the red filter film 222 r >1.5, then we can get sinθ R2 =1 / n r <1 / 1.5, calculate θ R2 <41.8°.

[0100] θ R0 Greater than θ R2 ,θ R2 <41.8°. Design θ R0 The minimum value can be 41.8°.

[0101] When θ R0 When the minimum value of is 41.8°, it means that only red light with an emission angle less than 41.8° can be emitted from the area defined by the retaining wall 203, while red light with an emission angle greater than or equal to 41.8° will be completely blocked by the retaining wall 203 and cannot be emitted from the retaining wall 203. R0 The minimum value of can be 41.8°, so that the retaining wall 203 can block the emission angle greater than θ R2 The red light is emitted.

[0102] D / Hz=tanθ R0 ≥tan41.8°=0.894, that is, D≥0.894×Hz, the retaining wall 203 can block the emission angle greater than θ R2 The red light is prevented from emitting from the retaining wall 203.

[0103] According to the above relationship, the minimum value of the width D of the upper layer 231 of the retaining wall 203 is 0.894×Hz, which can effectively avoid the problem of larger viewing angle light emission due to insufficient width of the upper layer 231 of the retaining wall 203, avoid total reflection, and reduce interference between sub-pixels.

[0104] The cross-sectional shape of the upper layer can be a regular trapezoid; let the angle between the light emitted from the side close to the upper layer and the direction perpendicular to the filter layer be θ B1 , the angle between the hypotenuse of the right trapezoid and the direction perpendicular to the filter layer is θ S , then θ S ≥θ B1 θ S <41.8°.

[0105] Fig. 9 is a comparative schematic diagram of OLED display panels with retaining walls of different shapes provided by an embodiment of the present invention, such as Fig. 9 As shown, the upper layer 231 of the retaining wall 203 can be designed as a regular trapezoid, which can improve the consistency of the light emission ratio of the three colors of RGB at the same viewing angle. The cross-sectional shape of the upper layer 231 can be a regular trapezoid; let the angle between the light emitted from the side close to the upper layer 231 and the direction perpendicular to the filter layer 203 be θ B1 The angle between the hypotenuse of the right trapezoid and the direction perpendicular to the filter layer 203 is θ S , then θ S ≥θ B1 θ S <41.8°.

[0106] like Fig. 9 As shown, the color of the upper layer 231 of the retaining wall 203 is blue, so the angle of emission of the blue light emitting unit 211 is less than or equal to θ B1 The blue light can be emitted smoothly. However, the same emission angle θ B1 When the cross-sectional shape of the upper layer 231 of the retaining wall 203 is a rectangle, the red light and the green light cannot be emitted. Specifically, the angle of emission of the red light emitting unit 212 is less than or equal to θ X The red light can be emitted smoothly, and the angle of the green light emitting unit 213 is less than or equal to θ X The green light can be emitted smoothly, θ X Less than θ B1 This will result in the angle θ B1 In this case, the red light and green light emitted from the entire OLED display panel 200 are relatively less, and the blue light is relatively more, which will also cause the problem of increased visual color deviation. The blue light output ratio is higher than the red light and green light, resulting in inconsistent light output ratios of the three colors RGB in the OLED display panel 200.

[0107] In order to solve this problem, the cross-sectional shape of the upper layer 231 of the retaining wall 203 is further defined as a regular trapezoid, and the angle between the hypotenuse of the regular trapezoid and the direction perpendicular to the filter layer 203 is set to θ S , limiting the light with a smaller angle than this angle to be emitted through the upper layer 231 of the retaining wall 203 at a large viewing angle, and designing θ S ≥θ B1 And θ S <41.8°.

[0108] If the emission angle of red light is equal to that of green light, and the emission angle of green light is equal to that of blue light, then the light emission ratio consistency of the three colors RGB in the OLED display panel 200 can be improved. Based on this, the shape of the upper layer 231 of the retaining wall 203 can be designed as a regular trapezoid, and the angle between the hypotenuse of the regular trapezoid and the direction perpendicular to the filter layer 203 is θ S θ S Greater than or equal to θ B1 .

[0109] When the upper layer 231 of the retaining wall 203 is a regular trapezoid, θ S Greater than or equal to θ B1 , so that the same exit angle θ B1 When θ is 0, the blue light emitted by the blue light emitting unit 211 can be emitted smoothly, the red light emitted by the red light emitting unit 212 can be emitted smoothly, and the green light emitted by the green light emitting unit 213 can be emitted smoothly. B1 Greater than θ X Obviously, in the OLED display panel 200, the light emission ratios of blue light, green light and red light are close, which improves the consistency of the light emission ratios of the three colors of RGB.

[0110] If θ S Greater than or equal to 41.8°, since 41.8° is greater than the critical angle of total reflection of red light, the large-viewing angle red light with an emission angle equal to or greater than 41.8° may not be blocked by the upper layer 231 of the baffle 203, resulting in total reflection and interference to other sub-pixels. S If the angle of the red light is less than 41.8°, the red light with an emission angle exceeding 41.8° will be blocked by the upper layer 231 of the regular trapezoid and will not be emitted to the light-emitting side of the filter layer 203 .

[0111] A transparent filling layer may be provided in the groove formed between two adjacent retaining walls. The material of the optional transparent filling layer includes an inorganic transparent material, which is any one of transparent silicon nitride, transparent silicon oxide and transparent silicon oxynitride or a combination of at least two thereof; or, the material of the transparent filling layer includes an organic transparent material, which is any one of transparent epoxy resin, transparent acrylate, transparent phenolic resin and transparent polysiloxane resin or a combination of at least two thereof; or, the material of the transparent filling layer includes a filter material of the same color as the color filter film in contact, which includes any one of square acid, phthalocyanine, perylene amide and azo organic dyes or a combination of at least two thereof. The material of the optional transparent filling layer includes a filter material of the same color as the color filter film in contact, and the concentration of the filter material in the transparent filling layer is lower than the concentration of the filter material in the color filter film in contact.

[0112] Optionally, in a groove formed between two adjacent retaining walls, the color filter film is located between the transparent filling layer and the light-emitting layer.

[0113] Fig.10 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. Further, in order to ensure that the flatness of the prepared OLED display panel 200 is higher and the preparation is more convenient, as Fig.10 As shown, a transparent filling layer 205 may be further provided at the concave portion of one side of the retaining wall 203. Specifically, the blue filter film 221 is directly connected to the lower layer 233 and is relatively thin. The transparent filling layer 205 is provided on the blue filter film 221, that is, the blue filter film 221 is located between the transparent filling layer 205 and the light-emitting layer 201. In this way, the light-emitting side of the concave portion of the retaining wall 203 corresponding to the blue light-emitting unit 211, the light-emitting side of the red filter film 222 corresponding to the red light-emitting unit 212, and the light-emitting side of the green filter film 223 corresponding to the green light-emitting unit 213 can be substantially flush.

[0114] Optionally, in the groove formed between two adjacent retaining walls, the transparent filling layer is located between the color filter film and the light-emitting layer.

[0115] Fig.11 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. Further, in order to ensure that the flatness of the prepared OLED display panel 200 is higher and the preparation is more convenient, as Fig.11As shown, a transparent filling layer 205 may also be provided at a concave portion on one side of the retaining wall 203. Specifically, the blue filter film 221 is directly connected to the upper layer 231. To prevent the blue filter film 221 from collapsing, a transparent filling layer 205 is first provided at the concave portion of the retaining wall 203 corresponding to the blue light emitting unit 211, and then the blue filter film 221 is provided on the transparent filling layer 205, that is, the transparent filling layer 205 is located between the blue filter film 221 and the light emitting layer 201. In this way, the light emitting side of the concave portion of the retaining wall 203 corresponding to the blue light emitting unit 211, the light emitting side of the red filter film 222 corresponding to the red light emitting unit 212, and the light emitting side of the green filter film 223 corresponding to the green light emitting unit 213 can be substantially flush.

[0116] Optionally, the groove formed between two adjacent retaining walls includes two color filter films of the same color arranged at intervals. Optionally, the color of the color filter film in the groove formed between two adjacent retaining walls is the same as the color of the upper layer, and the upper layer is directly connected to the color filter film and / or the lower layer is directly connected to the color filter film. Figure 6 As shown, the groove formed between two adjacent retaining walls 203 corresponding to the blue light emitting unit 211 includes two blue filter films 221 of the same color arranged at intervals. The blue filter film 221 on the same layer as the upper layer 231 is directly connected to the upper layer 231, and the blue filter film 221 on the same layer as the lower layer 233 is directly connected to the lower layer 233.

[0117] Optionally, a transparent filling layer is provided between two color filter films of the same color in the groove formed between two adjacent retaining walls.

[0118] Fig.12 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. Further, in order to ensure that the flatness of the prepared OLED display panel 200 is higher and the preparation is more convenient, as Fig.12 As shown, a transparent filling layer 205 can also be provided in the concave part on one side of the retaining wall 203. Specifically, the groove formed between two adjacent retaining walls 203 corresponding to the blue light emitting unit 211 includes two blue filter films 221 of the same color arranged at intervals. In order to prevent the blue filter film 221 from collapsing, a transparent filling layer 205 is provided between the two blue filter films 221 of the same color arranged at intervals. In this way, the light-emitting side of the concave part of the retaining wall 203 corresponding to the blue light emitting unit 211, the light-emitting side of the red filter film 222 corresponding to the red light emitting unit 212, and the light-emitting side of the green filter film 223 corresponding to the green light emitting unit 213 can be made substantially flush.

[0119] The material of the transparent filling layer 205 can be an inorganic transparent material or an organic transparent material.

[0120] The material of the transparent filling layer 205 can also be a filter material. Fig.10 As shown, the transparent filling layer 205 is disposed on the blue filter film 221, and the material of the transparent filling layer 205 can also be a blue filter material. The concentration of the blue filter material in the transparent filling layer 205 can be lower than the concentration of the blue filter material in the blue filter film 221 in contact with it, so that the light transmittance of the transparent filling layer 205 can be improved.

[0121] Exemplarily, the organic transparent material includes any one of transparent epoxy resin, transparent acrylate, transparent phenolic resin or transparent polysiloxane resin, or a combination of at least two of them; exemplary, the inorganic transparent material includes any one of transparent silicon nitride, transparent silicon oxide or transparent silicon oxynitride, or a combination of at least two of them; exemplary, the filter material having the same color as the lower layer of the retaining wall includes any one of square acid, phthalocyanine, perylene amide or azo organic dyes, or a combination of at least two of them.

[0122] In addition, the present invention has no special requirements on the materials of the red filter film 222, the green filter film 223 and the blue filter film 221, and conventional materials in the art may be used; illustratively, the material of the red filter film 222 includes phthalocyanine red and / or azo red, etc.; illustratively, the material of the green filter film 223 includes phthalocyanine green and / or azo green; illustratively, the material of the blue filter film 221 includes any one of aluminum phthalocyanine, phthalocyanine blue or azo blue, or a combination of at least two of them.

[0123] In fact, for the OLED display panel 200 provided in the embodiment of the present invention, there is no special restriction on the arrangement of the three different colors of the color filter films in the filter layer 203, as long as the three different colors can be alternately distributed; similarly, there is no special restriction on the colors of the upper layer 231, the middle layer 232 and the lower layer 233 in the retaining wall 203 with a sandwich structure, as long as the colors of the upper layer 231 and the lower layer 233 of the retaining wall 203 are the same, but different from the color of the middle layer 232, and the middle layer 232 is the same as the color of the color filter film on any adjacent side, the problem of color fading can be effectively solved. Figure 1 The existing OLED display panel 100 has problems such as inconsistent light output ratio and increased visual color deviation.

[0124] Fig.13 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. For example, Fig.13 In the OLED display panel 200 shown, the upper layer 231 and the lower layer 233 of the retaining wall 203 are both blue, and the color of the middle layer 232 is green. For the green filter film 223, it can be directly connected to the middle layer 232 in the adjacent retaining wall 203. For the blue filter film 221, it can be directly connected to the upper layer 231 or the lower layer 233 in the adjacent retaining wall 203.

[0125] Fig.14 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. For example, Fig.14 In the OLED display panel 200 shown, the upper layer 231 and the lower layer 233 of the retaining wall 203 are both red, and the color of the middle layer 232 is green. For the green filter film 223, it can be directly connected to the middle layer 232 in the adjacent retaining wall 203. For the red filter film 222, it can be directly connected to the upper layer 231 or the lower layer 233 in the adjacent retaining wall 203.

[0126] Other similar structures are within the protection scope of the present invention and will not be described in detail here.

[0127] Even, according to actual needs, the filter layer 203 in the OLED display panel provided by the present invention may only include two colors of color filter films, specifically Fig.15 shown. Fig.15 is a schematic diagram of another OLED display panel provided by an embodiment of the present invention. For example, Fig.15 In the OLED display panel 200 shown, the filter layer 203 includes a red filter film 222 and a blue filter film 221. The upper layer 231 and the lower layer 233 of the retaining wall 203 are both blue, and the color of the middle layer 232 is red. For the red filter film 222, it can be directly connected to the middle layer 232 in the adjacent retaining wall 203. For the blue filter film 221, it can be directly connected to the upper layer 231 or the lower layer 233 in the adjacent retaining wall 203.

[0128] The embodiment of the present invention also provides a method for preparing an OLED display panel, which can be used to prepare the OLED display panel described in any of the above embodiments. In this embodiment, the method for preparing an OLED display panel includes: providing a light-emitting layer, the light-emitting layer is a multi-film stacking structure, at least including an OLED anode, an OLED device light-emitting stacking composite film layer, a cathode, a thin film encapsulation layer, and a planarization layer; forming a filter layer on the light-emitting layer to obtain an OLED display panel.

[0129] In this specific Figure 3 Taking the OLED display panel 200 as an example, the overall process flow is described.

[0130] Fig.16 FIG. 1 is a schematic diagram of a method for preparing an OLED display panel provided by an embodiment of the present invention. Fig.16 As shown, the specific steps include:

[0131] (1) providing a substrate, and sequentially forming an OLED anode, an OLED device stacked composite film layer, a cathode, a thin film encapsulation layer, and a planarization layer on the substrate as a light-emitting layer 201, wherein the light-emitting layer 201 includes a first light-emitting region corresponding to a blue light-emitting unit 211, a second light-emitting region corresponding to a red light-emitting unit 212, and a third light-emitting region corresponding to a green light-emitting unit 213;

[0132] (2) forming a first filter area on the light-emitting layer 201 by coating, exposing and developing, wherein the first filter area includes two patterns, one of which is a pattern corresponding to the position of the lower layer 233 of the retaining wall, and the other is a pattern corresponding to the position of the blue light-emitting unit 211 in the first light-emitting area (the pattern is the blue filter film 221);

[0133] (3) forming a second filter area by coating, exposure and development, wherein the second filter area includes two patterns, one of which is a pattern corresponding to the position of the intermediate layer 232 of the retaining wall, and the other is a pattern corresponding to the position of the red light emitting unit 212 in the second light emitting area (the pattern is the red filter film 222);

[0134] (4) forming a third filter area by coating, exposure and development, wherein the third filter area is a pattern corresponding to the position of the green light emitting unit 213 in the third light emitting area (the pattern is the green filter film 223);

[0135] (5) A fourth filter area is formed by coating, exposure and development. The fourth filter area is a pattern corresponding to the position of the upper layer 231 of the retaining wall, thereby forming a filter layer 202 to obtain an OLED display panel.

[0136] Furthermore, it also includes: forming a transparent filling layer by coating to eliminate the step difference between different light-emitting areas. Fig.16 As shown, the blue filter film 221 and the red filter film 222 form a step difference, and a transparent filling layer 205 can be formed on the blue filter film 221 to reduce the step difference between the first light-emitting area corresponding to the blue light-emitting unit 211, the second light-emitting area corresponding to the red light-emitting unit 212, and the third light-emitting area corresponding to the green light-emitting unit 213.

[0137] The transparent filling layer 205 may be formed after the third filter region is formed. Alternatively, the transparent filling layer 205 may be formed after the fourth filter region is formed. There is no specific limitation.

[0138] It can be seen from the above content that the color filter films in the filter layer in the preparation method can be prepared by stacking them in sequence from the side close to the light-emitting layer.

[0139] The embodiment of the present invention further provides a display device, including the OLED display panel as described in any of the above embodiments. The display device can be a display device such as an OLED display and any product or component with a display function such as a TV, a digital camera, a mobile phone, a tablet computer, etc. including these display devices.

[0140] It should be noted that, in the above embodiments, the structure of the above OLED display panel has been described in detail, and thus will not be repeated here.

[0141] The applicant declares that the present invention illustrates an OLED display panel and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned structures and process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An OLED display panel, characterized in that: The OLED display panel includes a light-emitting layer and a light filter layer; The light-emitting layer includes at least two of a red light-emitting unit, a blue light-emitting unit and a green light-emitting unit; The filter layer includes a color filter film; The color filter film includes at least two of a red filter film, a green filter film and a blue filter film; At least two color filter films of different colors are alternately arranged in the filter layer, and a retaining wall with a sandwich structure is arranged between two adjacent color filter films of different colors, and the retaining wall is composed of the color filter films; Along the direction from the filter layer to the light-emitting layer, the retaining wall comprises an upper layer, a middle layer and a lower layer which are arranged in sequence; The upper layer and the lower layer have the same color, the upper layer and the middle layer have different colors, and the upper layer has a color different from at least one of the two adjacent color filter films of different colors on both sides of the retaining wall; At least one of the upper layer and the lower layer is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall, and the middle layer is directly connected to the adjacent color filter films of the same color on both sides of the retaining wall; Along the direction from the filter layer to the light-emitting layer, the thickness of the middle layer is greater than the thickness of the upper layer, and the thickness of the middle layer is greater than the thickness of the lower layer; In the direction from the color filter film on one side of the retaining wall to the color filter film on the other side of the retaining wall, the width of the middle layer is the same as the width of the lower layer, and the width of the middle layer is the same as or different from that of the upper layer.

2. The OLED display panel according to claim 1, characterized in that: The filter layer includes a red filter film, a green filter film and a blue filter film which are alternately arranged.

3. The OLED display panel according to claim 1, characterized in that: Assume that in the retaining wall, the width of the upper layer is D, and the thickness of the middle layer is Hz, then D≥0.894×Hz.

4. The OLED display panel according to claim 1, characterized in that: The cross-sectional shape of the upper layer is a regular trapezoid; Assume that the angle between the light emitted from the side close to the upper layer and the direction perpendicular to the filter layer is θ B1 The angle between the hypotenuse of the regular trapezoid and the direction perpendicular to the filter layer is θ S , then θ S ≥θ B1 ; i S <41.8°.

5. The OLED display panel according to claim 1, characterized in that: The material of the red filter film includes phthalocyanine red and / or azo red; The material of the green filter film includes phthalocyanine green and / or azo green; The material of the blue filter film includes any one of aluminum phthalocyanine, phthalocyanine blue and azo blue, or a combination of at least two of them.

6. The OLED display panel according to claim 1, characterized in that: A transparent filling layer is also arranged in the groove formed between two adjacent retaining walls.

7. The OLED display panel according to claim 6, characterized in that: In the groove formed between two adjacent retaining walls, the color filter film is located between the transparent filling layer and the light-emitting layer.

8. The OLED display panel according to claim 6, characterized in that: In the groove formed between two adjacent retaining walls, the transparent filling layer is located between the color filter film and the light-emitting layer.

9. The OLED display panel according to claim 1, characterized in that: The groove formed between two adjacent retaining walls includes two color filter films of the same color arranged at intervals.

10. The OLED display panel according to claim 9, characterized in that: In the groove formed between two adjacent retaining walls, the color of the color filter film is the same as the color of the upper layer, the upper layer is directly connected to the color filter film and / or the lower layer is directly connected to the color filter film.

11. The OLED display panel according to claim 9, characterized in that: In the groove formed between two adjacent retaining walls, a transparent filling layer is arranged between the two color filter films of the same color.

12. The OLED display panel according to claim 6 or 11, characterized in that: The material of the transparent filling layer includes an inorganic transparent material, and the inorganic transparent material is any one of transparent silicon nitride, transparent silicon oxide and transparent silicon oxynitride, or a combination of at least two thereof; Alternatively, the material of the transparent filling layer includes an organic transparent material, and the organic transparent material is any one of transparent epoxy resin, transparent acrylate, transparent phenolic resin and transparent polysiloxane resin, or a combination of at least two thereof; Alternatively, the material of the transparent filling layer includes a filter material of the same color as the color filter film in contact therewith, and the filter material includes any one or a combination of at least two of squaric acid, phthalocyanine, perylene amide and azo organic dyes.

13. The OLED display panel according to claim 12, characterized in that: The material of the transparent filling layer includes a filter material of the same color as the color filter film in contact with it, and the concentration of the filter material in the transparent filling layer is lower than the concentration of the filter material in the color filter film in contact with it.

14. A method for preparing an OLED display panel, characterized in that: The method for preparing the OLED display panel includes: Providing a light-emitting layer, wherein the light-emitting layer is a multi-layer stacked structure, comprising at least an OLED anode, an OLED device light-emitting stacked composite film layer, a cathode, a thin film encapsulation layer, and a planarization layer; A filter layer is formed on the light-emitting layer to obtain the OLED display panel.

15. The preparation method according to claim 14, characterized in that: The preparation method comprises the following steps: The OLED anode, the OLED device stacked composite film layer, the cathode, the thin film encapsulation layer and the planarization layer are sequentially formed on the substrate to obtain the light-emitting layer; Forming a first light filtering area on the light emitting layer by coating, exposing and developing, wherein the first light filtering area comprises two patterns, one of which is a pattern corresponding to the lower layer position of the retaining wall, and the other is a pattern corresponding to the position of the first light emitting area; A second light filtering area is formed by coating, exposing and developing, wherein the second light filtering area includes two parts of graphics, one of which is a graphic corresponding to the position of the middle layer of the retaining wall, and the other is a graphic corresponding to the position of the second light emitting area; Forming a third light filtering area by coating, exposing and developing, wherein the third light filtering area is a pattern corresponding to the position of the third light emitting area; The fourth filter area is formed by coating, exposure and development, and the fourth filter area is a pattern corresponding to the upper position of the retaining wall to obtain the OLED display panel.

16. The preparation method according to claim 15, characterized in that: Also includes: A transparent filling layer is formed by coating to eliminate the step difference between different light-emitting areas.

17. A display device, characterized in that: The display device comprises the OLED display panel according to any one of claims 1 to 13.

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