Display panel and display device

Abstract

The invention provides a display panel and a display device. The display panel comprises a substrate and a plurality of light-emitting units arranged on the substrate, each light-emitting unit comprises an anode, a functional part and a light-emitting part, the thickness of the light-emitting part in a middle area is larger than that of the light-emitting part in an edge area, and the thickness of the functional part in the middle area is smaller than that of the functional part in the edge area; the thickness of the light-emitting part of the light-emitting unit in the middle area is larger than the thickness of the light-emitting part in the edge area, namely, the light-emitting part is in the convex shape to compensate for the concave function part, the flatness of the surface of the side, away from the substrate, of the light-emitting part is improved, the uniformity of a film layer is improved, the performance of the display device is improved, and the service life of the display device is prolonged.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] Organic Light-Emitting Diode (OLED) is a new type of current-type semiconductor light-emitting device that displays light by controlling the carriers of the device and exciting organic materials.

[0003] In the current inkjet printing process of OLED display panels, the "coffee ring" phenomenon often occurs when ink droplets are drying. That is, the solvent at the contact line at the edge of the ink droplet evaporates faster during the drying process, forming a capillary flow from the inside to the outside, thereby bringing the solute to the contact line for precipitation and forming a film that is thick around the edges and thin in the middle, which in turn leads to poor uniformity of the film and reduces the performance and service life of the display device. Summary of the invention

[0004] The present application provides a display panel and a display device to improve the technical problem of poor uniformity of film layers in existing display panels.

[0005] To solve the above-mentioned problems, the technical solutions provided by this application are as follows:

[0006] The present application proposes a display panel, which includes a base substrate and a plurality of light-emitting units arranged on the base substrate; wherein the light-emitting units include:

[0007] an anode, disposed on one side of the substrate;

[0008] A functional portion is disposed on a side of the anode away from the substrate;

[0009] A light emitting portion, disposed on a side of the functional portion away from the base substrate;

[0010] The thickness of the light-emitting portion of the light-emitting unit in the middle region is greater than that in the edge region, and the thickness of the functional portion of the light-emitting unit in the middle region is less than that in the edge region.

[0011] Optionally, the light emitting portion includes a first surface away from the substrate, and the functional portion includes a second surface away from the substrate;

[0012] The difference between the maximum distance and the minimum distance between the first surface and the substrate is smaller than the difference between the maximum distance and the minimum distance between the second surface and the substrate.

[0013] Optionally, the functional part includes a hole injection part and a hole transport part provided between the hole injection part and the light emitting part;

[0014] The thickness of the hole injection portion in the middle region is smaller than the thickness of the hole injection portion in the edge region, and the thickness of the hole transport portion in the middle region is different from the thickness of the hole transport portion in the edge region.

[0015] Optionally, the thickness of the hole transport portion in the middle area is greater than the thickness of the hole transport portion in the edge area, and the difference between the thickness of the hole transport portion in the middle area and the thickness of the edge area is less than the difference between the thickness of the light-emitting portion in the middle area and the thickness of the edge area.

[0016] Optionally, the display panel further includes:

[0017] A first pixel definition portion, disposed on one side of the base substrate, wherein the first pixel definition portion includes a plurality of first pixel openings corresponding to the plurality of light emitting units;

[0018] A second pixel definition portion, disposed on a side of the first pixel definition portion away from the base substrate, the second pixel definition portion comprising a plurality of second pixel openings corresponding to the plurality of first pixel openings;

[0019] The hole injection portion is located in the corresponding first pixel opening, and at least a portion of the hole transport portion is located in the first pixel opening.

[0020] Optionally, a difference between a maximum distance and a minimum distance between the first surface of the display panel and the base substrate in a middle area is smaller than a difference between a maximum distance and a minimum distance between the first surface of the display panel and the base substrate in an edge area.

[0021] Optionally, the plurality of light-emitting units include a first color light-emitting unit, a second color light-emitting unit and a third color light-emitting unit, the light-emitting wavelength of the first color light-emitting unit is greater than the light-emitting wavelength of the second color light-emitting unit, and the light-emitting wavelength of the second color light-emitting unit is greater than the light-emitting wavelength of the third color light-emitting unit;

[0022] The thickness of the first color light-emitting unit is greater than the thickness of the second color light-emitting unit, and the thickness of the second color light-emitting unit is greater than or equal to the thickness of the third color light-emitting unit.

[0023] Optionally, the difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area of ​​the first color light-emitting unit and the substrate is greater than the difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area of ​​the second color light-emitting unit and the substrate;

[0024] The difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area to the base substrate in the second color light-emitting unit is greater than the difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area to the base substrate in the third color light-emitting unit.

[0025] Optionally, a difference between a maximum spacing and a minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the first color light-emitting unit is greater than a difference between a maximum spacing and a minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the second color light-emitting unit;

[0026] The difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the second color light-emitting unit is greater than the difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the third color light-emitting unit.

[0027] Optionally, a difference between a maximum distance and a minimum distance between the first surface of the light-emitting portion in the first color light-emitting unit and the substrate is greater than a difference between a maximum distance and a minimum distance between the first surface of the light-emitting portion in the second color light-emitting unit and the substrate;

[0028] The difference between the maximum distance and the minimum distance from the first surface of the light-emitting portion in the second color light-emitting unit to the base substrate is greater than the difference between the maximum distance and the minimum distance from the first surface of the light-emitting portion in the third color light-emitting unit to the base substrate.

[0029] Optionally, a difference between a maximum distance and a minimum distance between the first surface and the substrate is in a range of 0 to 10 nm.

[0030] The present application also proposes a display device, which includes the above-mentioned display panel.

[0031] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0033] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0034] Figure 1 A schematic diagram of a first structure of a display panel provided in an embodiment of the present application;

[0035] Figure 2 A film layer diagram of a display panel provided in an embodiment of the present application;

[0036] Figure 3 A second schematic structural diagram of a display panel provided in an embodiment of the present application;

[0037] Figure 4 for Figure 3 Cross-sectional view of part of the membrane layer in the middle section MM;

[0038] Figure 5a for Figure 3 Thickness distribution diagram of the functional part in the middle section MM;

[0039] Figure 5b for Figure 3 Thickness distribution diagram of the luminous part in the middle section MM;

[0040] Figure 5c for Figure 3 Distribution diagram of the sum of the thickness of the functional part and the light-emitting part in the middle section MM;

[0041] Figure 6 for Figure 3 Cross-sectional view of part of the membrane layer in the middle section NN. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0043] See also Figures 1 to 6The present application proposes a display panel 100, which includes a base substrate 10 and a plurality of light-emitting units PL arranged on the base substrate 10, wherein the light-emitting unit PL includes an anode AN, a functional portion HL and a light-emitting portion EL.

[0044] In this embodiment, the anode AN is disposed on one side of the base substrate 10 , the functional portion HL is disposed on the side of the anode AN away from the base substrate 10 , and the light emitting portion EL is disposed on the side of the functional portion HL away from the base substrate 10 .

[0045] In this embodiment, the thickness of the light emitting portion EL of the light emitting unit PL in the middle region is greater than that in the edge region, and the thickness of the functional portion HL of the light emitting unit PL in the middle region is less than that in the edge region.

[0046] In the current OLED display panel process, the materials of the hole transport layer 405, the hole injection layer 404 and the light-emitting layer 402 in the light-emitting device layer 40 are all prepared by inkjet printing. When the ink droplets are drying, they are often accompanied by the occurrence of a coffee ring phenomenon, that is, the thin film formed by the hole transport layer 405, the hole injection layer 404 and the light-emitting layer 402 is thick around and thin in the middle, which leads to poor uniformity of the thin film; however, the present application makes the thickness of the light-emitting portion EL of the light-emitting unit PL in the middle area greater than the thickness of the light-emitting portion EL in the edge area, which is equivalent to the present application making the film thickness of the light-emitting portion EL in the middle area larger and the film thickness of the edge area smaller, and the light-emitting portion EL is convex to compensate for the concave functional portion HL, so as to improve the flatness of the surface of the light-emitting portion EL away from the substrate 10, thereby improving the uniformity of the film layer and thus improving the performance and service life of the display device.

[0047] It should be noted that the edge region of the light emitting unit PL refers to the peripheral region of each light emitting unit PL, and the middle region of the light emitting unit PL refers to the region of each light emitting unit PL except the peripheral region.

[0048] The technical solution of the present application is now described in conjunction with specific embodiments.

[0049] See also Figure 1 , the display panel 100 includes a display area AA and a non-display area NA disposed adjacent to the display area AA. Optionally, the non-display area NA surrounds the display area AA, so that the display area AA is surrounded by the non-display area NA. The display area AA is an area in the display panel 100 for performing a display function, and a plurality of sub-pixels PX are disposed therein to realize the display function. The non-display area NA may be a frame area of ​​the display panel 100, and a functional component may be disposed therein to assist the sub-pixels PX in the display area AA to perform display.

[0050] See also Figure 1The lower side of the display area AA is provided with a binding terminal, which can be connected to an external circuit, and transmits the signal input by the external circuit to the data line, thereby driving the display panel 100 to display the picture. For example, the binding terminal can be bound and connected to a chip or a flip chip film, etc., to provide power and driving signals for the display panel 100.

[0051] See also Figure 2 The display panel 100 may include a base substrate 10, an array layer 20 disposed on the base substrate 10, a pixel layer 30 disposed on the array layer 20, a light-emitting functional layer 40 and an encapsulation layer 50, a color filter layer 60 disposed on the encapsulation layer 50, and a cover layer 70 disposed on the color filter layer 60.

[0052] In this embodiment, the material of the base substrate 10 may be glass, quartz, polyimide or other materials; for example, when the display panel 100 is a flexible panel, the material of the base substrate 10 may be a flexible material such as polyimide, or may be composed of a stacked film layer of a flexible material and an inorganic material; when the display panel 100 is a rigid panel, the material of the base substrate 10 may be a rigid material such as glass or quartz.

[0053] In this example, see Figure 2 The array layer 20 may include a plurality of thin film transistors, which may be of an etch-stop type, a back-channel etch type, or may be divided into a bottom-gate thin film transistor, a top-gate thin film transistor, etc. according to the position of the gate electrode and the active layer AS, without any specific limitation. For example, Figure 2 The thin film transistor shown in the figure is a top-gate thin film transistor, which may include an active layer AS arranged on the base substrate 10, a first gate insulating layer 202 arranged on the active layer AS, a first gate layer GE1 arranged on the first gate insulating layer 202, a second gate insulating layer 203 arranged on the first gate layer GE1, a second gate layer GE2 arranged on the second gate insulating layer 203, a first interlayer insulating layer 204 arranged on the second gate layer GE2, a second interlayer insulating layer 205 arranged on the first interlayer insulating layer 204, a first source-drain layer SD1 arranged on the second interlayer insulating layer 205, a third interlayer insulating layer 201 arranged on the first source-drain layer SD1, a first planar layer 206 arranged on the third interlayer insulating layer 201, a second source-drain layer SD2 arranged on the first planar layer 206, a second planar layer 207 arranged on the second source-drain layer SD2, and a third planar layer 208 arranged on the second planar layer 207.

[0054] It should be noted that the number of source and drain layers can be set according to the requirements of wiring space. For example, the source and drain layers of the present application can be two layers. At the same time, the number of gate layers can be set according to the requirements of wiring space and capacitance. For example, the gate layers of the present application can be two layers.

[0055] It should be noted that the first gate insulating layer 202, the second gate insulating layer 203, the first interlayer insulating layer 204, the second interlayer insulating layer 205 and the third interlayer insulating layer 201 can all be inorganic materials composed of elements such as nitrogen, silicon, oxygen, and aluminum, for example, a single layer or multiple layers of stacked inorganic film layers composed of one of silicon nitride, silicon oxide, and aluminum oxide.

[0056] It should be noted that the leveling layer of the present application is provided to ensure the flatness of the film layer, and the number of leveling layers is set according to the flatness requirement. For example, the leveling layer of the present application can be three flat layers.

[0057] See also Figure 2 The pixel layer 30 may include a first pixel definition portion 310 and a second pixel definition portion 320 . The first pixel definition portion 310 is disposed on a side of the third flat layer 208 away from the base substrate 10 , and the second pixel definition portion 320 is disposed on a surface of the first pixel definition portion 310 away from the base substrate 10 .

[0058] It should be noted that since the light-emitting layer 402 of the present application is prepared using an inkjet printing process, in order to reduce the accuracy of inkjet printing, the first pixel definition portion 310 of the present application may include a plurality of first pixel dams 311 that are staggered horizontally and vertically, and the first pixel dams 311 that are staggered horizontally and vertically enclose a plurality of pixel openings corresponding to sub-pixels. The second pixel definition portion 320 includes a plurality of second pixel dams 321 in a horizontal or vertical direction, and the plurality of sub-pixels between two adjacent second pixel dams 321 have the same color, so that in the inkjet printing process, the plurality of sub-pixels between two adjacent second pixel dams 321 can be printed simultaneously along the direction of the second pixel dams 321, thereby reducing the accuracy of inkjet printing and improving the process efficiency.

[0059] In this embodiment, since the second pixel dam 321 mainly serves to isolate sub-pixels of different colors, the thickness of the second pixel dam 321 of the present application can be greater than the thickness of the first pixel dam 311, that is, the thickness of the first pixel definition portion 310 of the present application is less than the thickness of the second pixel definition portion 320.

[0060] It should be noted that the materials of the first planar layer 206 , the second planar layer 207 , the third planar layer 208 , the first pixel defining portion 310 and the second pixel defining portion 320 may all be positive organic materials.

[0061] See also Figure 2The light-emitting functional layer 40 may include an anode layer 401 disposed on the third flat layer 208, a light-emitting layer 402 disposed on the anode layer 401, and a cathode layer 403 disposed on the light-emitting layer 402. The anode layer 401 includes a plurality of anodes corresponding to the pixel openings one by one, and the light-emitting layer 402 may include a plurality of light-emitting portions EL corresponding to the plurality of anodes one by one.

[0062] It should be noted that the light-emitting functional layer 40 also includes a hole injection layer 404 and a hole transport layer 405 arranged between the anode layer 401 and the light-emitting layer 402, and an electron injection layer 406 and an electron transport layer 407 arranged between the cathode layer 403 and the light-emitting layer 402, that is, the hole transport layer 405 includes a plurality of hole transport parts 405a, and the hole injection layer 404 includes a plurality of hole injection parts 404a, and the hole injection parts 404a and the hole transport parts 405a constitute the functional part HL.

[0063] It should be noted that the electron injection layer 406 and the electron transport layer 407 are formed by evaporation process, so the electron injection layer 406 and the electron transport layer 407 of the present application will not have the coffee ring phenomenon. Figure 4 The electron injection portion 406 a of the electron injection layer 406 and the electron transport portion 407 a of the electron transport layer 407 are relatively flat film layers.

[0064] See also Figure 2 The encapsulation layer 50 covers the pixel layer 30 and continuously covers multiple pixel openings and multiple light-emitting portions; the encapsulation layer 50 includes a first inorganic encapsulation layer 501, an organic encapsulation layer 502, and a second inorganic encapsulation layer 503 which are sequentially stacked.

[0065] In this embodiment, the first inorganic encapsulation layer 501 and / or the second inorganic encapsulation layer 503 extend from the display area AA to the non-display area NA, and the first inorganic encapsulation layer 501 and / or the second inorganic encapsulation layer 503 overlap the retaining wall structure, and the organic encapsulation layer 502 extends to the non-display area NA and is terminated at the retaining wall structure.

[0066] See also Figure 2 The color filter layer 60 includes a plurality of color resists 610 and light shielding units 620 disposed on both sides of the color resists 610 , and one color resist 610 corresponds to one light-emitting portion.

[0067] See also Figure 2 The cover layer 70 is disposed on a side of the color filter layer 60 away from the base substrate 10 . The cover layer 70 may be a glass cover or may be formed directly on the color filter layer 60 .

[0068] It should be noted that the display panel 100 of the present application may further include a touch layer (not shown), and the touch layer may be disposed between the encapsulation layer 50 and the cover layer 70 .

[0069] It should be noted that, since the third flat layer 208 is disposed on the second flat layer 207 , the third flat layer 208 is disposed to further adjust the flatness of the film layer. Therefore, the thickness of the third flat layer 208 of the present application can be less than the thickness of the second flat layer 207 and the first flat layer 206 .

[0070] See also Figure 3 The light-emitting functional layer 40 may include a plurality of light-emitting units PL, which are arranged in an array on the display panel 100 , and the plurality of light-emitting units PL include a first color light-emitting unit PLr, a second color light-emitting unit PLg, and a third color light-emitting unit PLb.

[0071] In this embodiment, the first color light emitting cells PLr, the second color light emitting cells PLg and the third color light emitting cells PLb may be arranged cyclically along the row direction, and the colors of each column of light emitting cells PL are the same, and the second pixel dam 321 may be disposed between two adjacent columns of light emitting cells PL.

[0072] In this embodiment, the emission wavelength of the first color light-emitting unit PLr is greater than the emission wavelength of the second color light-emitting unit PLg, and the emission wavelength of the second color light-emitting unit PLg is greater than the emission wavelength of the third color light-emitting unit PLb; for example, the first color light-emitting unit PLr emits red light, the second color light-emitting unit PLg emits green light, and the third color light-emitting unit PLb emits blue light.

[0073] In this embodiment, due to the different colors of the light emitting units PL, different thicknesses of the cavity length need to be designed to improve the luminous purity of a specific color, and the light emitting unit PL emitting red light requires the largest cavity length thickness, the light emitting unit PL emitting green light requires the second largest cavity length thickness, and the light emitting unit PL emitting blue light requires the smallest cavity length thickness. For example, see Figure 6 , the present application can make the thickness of the first color light-emitting unit PLr greater than the thickness of the second color light-emitting unit PLg, and the thickness of the second color light-emitting unit PLg greater than or equal to the thickness of the third color light-emitting unit PLb.

[0074] See also Figure 4 , Figure 3 A cross-sectional view of part of the membrane layer in the middle section MM, and Figure 4 The light emitting cell PL shown in FIG. 4 may be any one of the first color light emitting cell PLr, the second color light emitting cell PLg, and the third color light emitting cell PLb.

[0075] In this embodiment, the light-emitting portion EL includes a first surface ELa away from the side of the base substrate 10, and the functional portion HL includes a second surface HLa away from the side of the base substrate 10. The difference L1 between the maximum spacing and the minimum spacing between the first surface ELa and the base substrate 10 is smaller than the difference L2 between the maximum spacing and the minimum spacing between the second surface HLa and the base substrate 10.

[0076] See also Figure 5a to Figure 5c , the horizontal axis x in the attached figure is the different positions of the corresponding film layer, and the vertical axis x is the thickness of the corresponding film layer. Since the functional part HL is formed by inkjet printing technology, and the coffee ring phenomenon appears when the printed ink droplets dry, the second surface HLa of the functional part HL of the present application is a concave surface. For the thickness distribution diagram of the functional part HL at different positions, please refer to the attached Figure 5a The thickness of the light emitting portion EL in the middle region of the present invention is greater than the thickness of the light emitting portion EL in the edge region. For the thickness distribution diagram of the light emitting portion EL at different positions, please refer to the attached Figure 5b That is, the surface of the light emitting portion EL in contact with the functional portion HL is a convex surface, and since the thickness distribution of the light emitting portion EL and the thickness distribution of the functional portion HL compensate each other, the flatness of the first surface ELa of the light emitting portion EL is improved. For the distribution diagram of the distance between the first surface ELa and the anode at different positions in the light emitting portion EL, please refer to the attached Figure 5c The curve c.

[0077] In this embodiment, since the thickness distribution of the light-emitting part EL and the thickness distribution of the functional part HL compensate each other, the flatness of the first surface ELa of the light-emitting part EL is improved. Therefore, the difference L1 between the maximum spacing and the minimum spacing from the first surface ELa to the base substrate 10 of the present application can range from 0 to 10 nm.

[0078] In this embodiment, a difference L2 between a maximum distance and a minimum distance between the second surface HLa and the base substrate 10 may range from 30 nm to 50 nm.

[0079] It should be noted that when performing the drying process of the light-emitting portion EL, the present application can achieve a convex light-emitting portion EL by adjusting the temperature of the upper and lower plates in the drying device, the height of the rectifier plate, and the exhaust speed.

[0080] In this embodiment, the thickness of the hole injection portion 404a in the middle region is smaller than that in the edge region, and the thickness of the hole transport portion 405a in the middle region is different from that in the edge region.

[0081] See also Figure 4Since the hole injection part 404a has a coffee ring phenomenon, the hole injection part 404a of the present application is a concave film layer, and in order to improve the uniformity of the film layer of the hole injection part 404a, the present application can make the thickness of the hole transport part 405a in the middle area greater than the thickness of the hole transport part 405a in the edge area, which is equivalent to setting the hole transport part 405a as a convex film layer; but since the average thickness of the hole injection part 404a is less than the average thickness of the hole transport part 405a, the coffee ring effect of the hole injection part 404a is weaker than the coffee ring effect of the hole transport part 405a, so even if the hole transport part 405a is set as a convex film layer, the difference between the thickness of the hole transport part 405a in the middle area and the thickness of the edge area is less than the difference between the thickness of the hole injection part 404a in the middle area and the thickness of the edge area, that is, the functional part HL composed of the hole transport part 405a and the hole injection part 404a is still a concave film layer.

[0082] In this embodiment, the difference between the thickness of the hole transport portion 405a in the middle area and the thickness of the edge area is smaller than the difference between the thickness of the light-emitting portion EL in the middle area and the thickness of the edge area; that is, since the film layer of the hole transport portion 405a cannot compensate for the concave film of the hole injection portion 404a, the light-emitting portion EL of the present application has a greater thickness in the middle area to compensate for the concave film layer of the functional portion HL.

[0083] Alternatively, the present application can set the hole transport part 405a to be a concave film layer. At the same time, since the average thickness of the hole injection part 404a is less than the average thickness of the hole transport part 405a, the difference between the thickness of the hole transport part 405a in the middle area and the thickness of the edge area is greater than the difference between the thickness of the hole injection part 404a in the middle area and the thickness of the edge area, that is, the functional part HL formed by the hole transport part 405a and the hole injection part 404a is still a concave film layer.

[0084] See also Figure 3 The first pixel definition portion 310 includes a plurality of first pixel openings HL1 corresponding to the plurality of light-emitting units PL, the second pixel definition portion 320 includes a plurality of second pixel openings HL2 corresponding to the plurality of first pixel openings HL1, the hole injection portion 404a is located in the corresponding first pixel opening HL1, and at least a portion of the hole transport portion 405a is located in the first pixel opening HL1.

[0085] In the present embodiment, in the same column of light-emitting units PL, there is only a first pixel defining portion 310 with a smaller thickness between adjacent light-emitting units PL, so the printed material forming the light-emitting portion EL can flow across the first pixel defining portion 310; and in order to reduce the difference between the thickness of the functional portion HL in the middle area and the thickness of the edge area, the present application can adjust the thickness of the first pixel defining portion 310. For example, the present application can reduce the thickness of the first pixel defining portion 310 so that part of the hole transport portion 405a can cross the first pixel defining portion 310 and flow into the adjacent light-emitting unit PL to reduce the coffee ring effect of the hole transport portion 405a.

[0086] Since different color light-emitting units PL need to be designed with different thickness of cavity length, the thickness of light-emitting units PL of different colors is different, and the thickness of the cavity length can be adjusted by adjusting the thickness of the hole transport layer 405, the hole injection layer 404, the light-emitting layer 402, the electron transport layer 407, the electron injection layer 406 or the cavity length adjustment layer; secondly, the larger the volume of ink in the inkjet printing process, the more obvious the coffee ring effect, and the greater the difference in film thickness between the edge area and the middle area.

[0087] For example, since the thickness of the first color light-emitting unit PLr is greater than that of the second color light-emitting unit PLg, and the thickness of the second color light-emitting unit PLg is greater than that of the third color light-emitting unit PLb, the thickness of the functional part HL of the first color light-emitting unit PLr of the present application can be greater than that of the functional part HL of the second color light-emitting unit PLg, and the thickness of the functional part HL of the second color light-emitting unit PLg can be greater than that of the functional part HL of the third color light-emitting unit PLb, and the coffee ring effect is positively correlated with the film thickness, that is, the film uniformity of the second surface HLa in the functional part HL of the first color light-emitting unit PLr is worse than the film uniformity of the second surface HLa in the functional part HL of the second color light-emitting unit PLg, and the film uniformity of the second surface HLa in the functional part HL of the second color light-emitting unit PLg is worse than the film uniformity of the second surface HLa in the functional part HL of the third color light-emitting unit PLb.

[0088] Therefore, the difference between the maximum spacing and the minimum spacing between the second surface HLa in the middle area of ​​the functional part HL in the first color light-emitting unit PLr of the present application is greater than the difference between the maximum spacing and the minimum spacing between the second surface HLa in the middle area of ​​the functional part HL in the second color light-emitting unit PLg and the substrate 10; at the same time, the difference between the maximum spacing and the minimum spacing between the second surface HLa in the middle area of ​​the functional part HL in the second color light-emitting unit PLg and the substrate 10 is greater than the difference between the maximum spacing and the minimum spacing between the second surface HLa in the middle area of ​​the functional part HL in the third color light-emitting unit PLb and the substrate 10.

[0089] Similarly, in order to compensate for the difference in film uniformity of the functional part HL, the difference between the maximum spacing and the minimum spacing between the first surface ELa and the second surface HLa in the middle area of ​​the light-emitting part EL in the first color light-emitting unit PLr of the present application is greater than the difference between the maximum spacing and the minimum spacing between the first surface ELa and the second surface HLa in the middle area of ​​the light-emitting part EL in the second color light-emitting unit PLg; and the difference between the maximum spacing and the minimum spacing between the first surface ELa and the second surface HLa in the middle area of ​​the light-emitting part EL in the second color light-emitting unit PLg is greater than the difference between the maximum spacing and the minimum spacing between the first surface ELa and the second surface HLa in the middle area of ​​the light-emitting part EL in the third color light-emitting unit PLb.

[0090] That is, it is equivalent to that the thickness of the light-emitting part EL in the middle area of ​​the first color light-emitting unit PLr of the present application is greater than the thickness of the light-emitting part EL in the middle area of ​​the second color light-emitting unit PLg, and the thickness of the light-emitting part EL in the middle area of ​​the second color light-emitting unit PLg is greater than the thickness of the light-emitting part EL in the middle area of ​​the third color light-emitting unit PLb; the present application can compensate for the uniformity of the film layer of the functional part of different color light-emitting units by making the light-emitting parts of different color light-emitting units have thickness differences in the middle area.

[0091] At the same time, since the film uniformity of the functional parts of the light-emitting units of different colors is different, after the light-emitting parts are formed, the first surfaces of the light-emitting parts in the light-emitting units of different colors also have different film uniformities; and since the film uniformity of the functional part HL of the first color light-emitting unit PLr is poor, the film uniformity of the functional part HL of the third color light-emitting unit PLb is good, and the film uniformity of the functional part HL of the second color light-emitting unit PLg is centered, the difference between the maximum spacing and the minimum spacing from the first surface ELa of the light-emitting part EL of the first color light-emitting unit PLr of the present application to the base substrate 10 is greater than the difference between the first surface ELa of the light-emitting part EL of the second color light-emitting unit PLg. The difference between the maximum spacing and the minimum spacing from the first surface ELa to the substrate 10, and the difference between the maximum spacing and the minimum spacing from the first surface ELa of the light-emitting part EL of the second color light-emitting unit PLg to the substrate 10, is greater than the difference between the maximum spacing and the minimum spacing from the first surface ELa of the light-emitting part EL of the second color light-emitting unit PLb to the substrate 10, that is, equivalent to the surface level difference of the light-emitting part EL of the first color light-emitting unit PLr is greater than the surface level difference of the light-emitting part EL of the second color light-emitting unit PLg, and the surface level difference of the light-emitting part EL of the second color light-emitting unit PLg is greater than the surface level difference of the light-emitting part EL of the third color light-emitting unit PLb.

[0092] See also Figure 3, the difference between the maximum spacing and the minimum spacing between the first surface ELa of the display panel 100 and the base substrate 10 in the middle area 101 is smaller than the difference between the maximum spacing and the minimum spacing between the first surface ELa of the display panel 100 and the base substrate 10 in the edge area 102.

[0093] The uniformity of the film layer of the light-emitting unit PL of the present application is mainly achieved by adjusting the temperature of the upper and lower plates in the drying device, the height of the rectifier plate, and the exhaust speed, etc., and due to the differences in temperature and exhaust speed in different areas of the drying device, the ink in different areas of the display panel 100 exhibits different drying rates during the drying process; for example, due to the difference in drying rate, the uniformity of the film layer in the middle area 101 of the display panel 100 of the present application can be better than the uniformity of the film layer in the edge area 102.

[0094] It should be noted that the middle area 101 of the display panel 100 refers to the central area located in the display area AA, and the edge area 102 of the display panel 100 refers to the peripheral area located in the display area AA.

[0095] It should be noted that the present application also proposes a display device, which includes the above-mentioned display panel, and the display device of the present application can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, navigator, etc.

[0096] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0097] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0098] In the above embodiments, the structures shown in the drawings are only schematic diagrams, and the specific structure of the display panel of the present application is mainly based on the description.

[0099] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0100] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A display panel, characterized in that: The invention comprises a base substrate and a plurality of light emitting units arranged on the base substrate; wherein the light emitting units comprise: Anodes, disposed on some of the substrates; A functional portion is disposed on a side of the anode away from the substrate; A light emitting portion, disposed on a side of the functional portion away from the base substrate; The thickness of the light-emitting portion of the light-emitting unit in the middle region is greater than that in the edge region, and the thickness of the functional portion of the light-emitting unit in the middle region is less than that in the edge region.

2. The display panel according to claim 1, characterized in that: The light emitting portion includes a first surface away from the substrate, and the functional portion includes a second surface away from the substrate; The difference between the maximum distance and the minimum distance between the first surface and the substrate is smaller than the difference between the maximum distance and the minimum distance between the second surface and the substrate.

3. The display panel according to claim 2, characterized in that: The functional part includes a hole injection part and a hole transport part provided between the hole injection part and the light emitting part; The thickness of the hole injection portion in the middle region is smaller than the thickness of the hole injection portion in the edge region, and the thickness of the hole transport portion in the middle region is different from the thickness of the hole transport portion in the edge region.

4. The display panel according to claim 3, characterized in that: The thickness of the hole transport portion in the middle area is greater than the thickness of the hole transport portion in the edge area, and the difference between the thickness of the hole transport portion in the middle area and the thickness of the edge area is less than the difference between the thickness of the light-emitting portion in the middle area and the thickness of the edge area.

5. The display panel according to claim 3, characterized in that: The display panel further includes: A first pixel definition portion, disposed on one side of the base substrate, wherein the first pixel definition portion includes a plurality of first pixel openings corresponding to the plurality of light emitting units; A second pixel definition portion, disposed on a side of the first pixel definition portion away from the base substrate, the second pixel definition portion comprising a plurality of second pixel openings corresponding to the plurality of first pixel openings; The hole injection portion is located in the corresponding first pixel opening, and at least a portion of the hole transport portion is located in the first pixel opening.

6. The display panel according to any one of claims 1 to 5, characterized in that: The plurality of light-emitting units include a first color light-emitting unit, a second color light-emitting unit and a third color light-emitting unit, the light-emitting wavelength of the first color light-emitting unit is greater than the light-emitting wavelength of the second color light-emitting unit, and the light-emitting wavelength of the second color light-emitting unit is greater than the light-emitting wavelength of the third color light-emitting unit; The thickness of the first color light-emitting unit is greater than the thickness of the second color light-emitting unit, and the thickness of the second color light-emitting unit is greater than or equal to the thickness of the third color light-emitting unit.

7. The display panel according to claim 6, characterized in that: The difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area of ​​the first color light-emitting unit and the substrate is greater than the difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area of ​​the second color light-emitting unit and the substrate; The difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area to the base substrate in the second color light-emitting unit is greater than the difference between the maximum spacing and the minimum spacing between the second surface of the functional part in the middle area to the base substrate in the third color light-emitting unit.

8. The display panel according to claim 7, characterized in that: The difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the first color light-emitting unit is greater than the difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the second color light-emitting unit; The difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the second color light-emitting unit is greater than the difference between the maximum spacing and the minimum spacing between the first surface and the second surface in the middle area of ​​the light-emitting portion in the third color light-emitting unit.

9. The display panel according to claim 7, characterized in that: The difference between the maximum distance and the minimum distance between the first surface of the light-emitting portion in the first color light-emitting unit and the base substrate is greater than the difference between the maximum distance and the minimum distance between the first surface of the light-emitting portion in the second color light-emitting unit and the base substrate; The difference between the maximum distance and the minimum distance from the first surface of the light-emitting portion in the second color light-emitting unit to the base substrate is greater than the difference between the maximum distance and the minimum distance from the first surface of the light-emitting portion in the third color light-emitting unit to the base substrate.

10. The display panel according to any one of claims 1 to 5, characterized in that: The difference between the maximum distance and the minimum distance between the first surface and the substrate is in the range of 0 to 10 nm.

11. A display device, characterized in that: The display device comprises the display panel according to any one of claims 1 to 10.

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