CN117135971A

CN117135971A - Display panel, preparation method and display device

Info

Publication number: CN117135971A
Application number: CN202310223314.7A
Authority: CN
Inventors: 汪博
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-02-28
Filing date: 2023-02-28
Publication date: 2023-11-28

Abstract

The embodiment of the application provides a display panel, a preparation method and a display device, relates to the technical field of display, and can improve the brightness of the display panel. The display panel includes a substrate; a pixel defining layer on the substrate; the pixel defining layer includes a plurality of first openings; a plurality of light emitting elements respectively located in the plurality of first openings; a brightness enhancing structure at a side of the pixel defining layer facing away from the substrate; the brightness enhancement structure comprises a brightness enhancement layer, a shielding structure and a plurality of color resistors; the brightness enhancement layer comprises a plurality of second openings, and projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively; the color resistors are respectively positioned in the second openings; the plurality of color resists at least comprises a plurality of red, green and blue color resists; the projection of the shielding structure on the substrate is positioned between the projections of the adjacent two second openings on the substrate and is used for shielding ambient light from entering the display panel; the refractive index of the brightness enhancing layer is smaller than the refractive index of the color resistance.

Description

Display panel, preparation method and display device

Technical Field

The application relates to the technical field of display, in particular to a display panel, a preparation method and a display device.

Background

An important component of an electronic device for realizing a display function is a display panel. The display panel generally includes an organic light emitting diode (OrganicLightEmittingDiode, OLED) display panel, a liquid crystal display panel (Liquid Crystal Display, LCD), and the like.

The OLED display panel has the advantages of self-luminescence, wide viewing angle, high contrast, low energy consumption, light weight, thin thickness, easy bending and the like, and is widely applied to straight-panel terminal equipment or folding terminal equipment of mobile phones, flat-panel cameras, digital cameras, notebook computers and the like.

However, the current OLED display panel generally has a problem of low brightness.

Disclosure of Invention

In order to solve the technical problems, the application provides a display panel, a preparation method and a display device. The brightness of the display panel can be improved.

In a first aspect, an embodiment of the present application provides a display panel including a substrate; a pixel defining layer on the substrate; the pixel defining layer includes a plurality of first openings; the light-emitting elements are respectively positioned in the first openings and at least comprise a plurality of red light-emitting elements, a plurality of green light-emitting elements and a plurality of blue light-emitting elements; a brightness enhancing structure at a side of the pixel defining layer facing away from the substrate; the brightness enhancement structure comprises a brightness enhancement layer, a shielding structure and a plurality of color resistors; the brightness enhancement layer comprises a plurality of second openings, and projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively; the color resistors are respectively positioned in the second openings; the plurality of color resistances at least comprise a plurality of red color resistances, a plurality of green color resistances and a plurality of blue color resistances, the plurality of red color resistances respectively correspond to the plurality of red light-emitting elements, the plurality of green color resistances respectively correspond to the plurality of green light-emitting elements, and the plurality of blue color resistances respectively correspond to the plurality of blue light-emitting elements; the projection of the shielding structure on the substrate is positioned between the projections of the adjacent two second openings on the substrate and is used for shielding ambient light from entering the display panel; wherein, the refractive index of the brightness enhancement layer is smaller than the refractive index of the color resistance.

The setting of color resistance both can absorb ambient light and reduce reflectivity, can also make the light that light emitting component sent send smoothly simultaneously, and this light behind the color resistance for luminous spectrum is narrower, and the display color gamut is wider, promotes display panel's display effect. The shielding structure is positioned between two adjacent second openings, so that shielding of light rays emitted by the light-emitting element is avoided, meanwhile, ambient light can be shielded, the reflectivity is reduced, when the display panel is in a screen-off state, an integral black effect can be achieved, and compared with the arrangement of the polaroid, the reflectivity is reduced, and the display panel provided by the embodiment of the application is lighter and thinner and has low cost. Further, through setting up luminance enhancement layer, and set up the colour resistance in the opening of luminance enhancement layer, wherein, the refracting index of luminance enhancement layer is less than the refracting index of colour resistance, and in this way, when the light that the luminescent element sent shines on the interface of colour resistance and luminance enhancement layer, refraction takes place, and after light enters into high material from the low material that rolls over promptly, can take place the deflection, and then makes the light of wide angle gather to the low angle, reaches total reflection spotlight effect to promote display panel's luminance. That is, the display panel provided by the embodiment of the application can not only avoid reflection of ambient light, but also improve the color gamut and the brightness.

In some possible implementations, the projections of the color resists of at least two colors on the substrate overlap, and the overlapping areas are located in the projections of the pixel defining layer on the substrate to form the shielding structure, that is, the shielding structure does not need to be formed separately, so that the arrangement avoids reflection of ambient light, improves the color gamut and the brightness, and can simplify the process steps.

Illustratively, color resists, which may be two adjacent colors, extend onto the pixel defining layer to form a masking structure; the color resists of any two colors can be arranged on the pixel limiting layer to form a shielding structure.

In some possible implementations, the projections of the red color resistor, the green color resistor and the blue color resistor on the substrate are overlapped, and the overlapped areas are located in the projection of the pixel defining layer on the substrate to form the shielding structure, that is, the shielding structure is not required to be formed separately, so that the arrangement is realized, the reflection of ambient light is avoided, the color gamut and the brightness are improved, and meanwhile, the process steps are simplified.

In some possible implementations, the shielding structure includes a black matrix, the black matrix includes a plurality of third openings, the brightness enhancing layer is disposed on a side of the black matrix facing away from the pixel defining layer, and projections of the plurality of second openings on the substrate are respectively located in projections of the plurality of third openings on the substrate. The reflection of ambient light is avoided through the black matrix, and the shielding effect is good.

In some possible implementations, the thickness of the brightness enhancing layer is greater than or equal to 1.5um and less than or equal to 3.5um in a direction perpendicular to the substrate.

The thickness of the brightness enhancement layer is not too small, so that the uniformity of the coating of the brightness enhancement layer is not affected, namely the thickness uniformity of the brightness enhancement layer is not affected, the size of the black matrix is not affected due to the fact that the thickness of the brightness enhancement layer is large, and the display effect is further affected.

In some possible implementations, when the shielding structure includes a black matrix, the thickness of the brightness enhancing layer is greater than the thickness of the black matrix to facilitate the preparation of each film layer.

In some possible implementations, the refractive index of the brightness enhancing layer is greater than or equal to 1.4 and less than or equal to 1.55. In this way, the choice of material for the brightness enhancing layer 1323 is facilitated.

In some possible implementations, the brightness enhancing layer includes a photoresist, etc., and may be selected by those skilled in the art according to the actual situation.

In some possible implementations, the brightness enhancement layer includes a red brightness enhancement unit, a green brightness enhancement unit, and a blue brightness enhancement unit, each including a plurality of second openings; the red brightness enhancement units surround the red resistors, the green brightness enhancement units surround the green resistors, and the blue brightness enhancement units surround the blue resistors; the refractive index of the red brightness enhancing unit is larger than that of the green brightness enhancing unit, and the refractive index of the green brightness enhancing unit is larger than that of the blue brightness enhancing unit. Therefore, the luminous brightness of each area of the display panel tends to be consistent, and the display uniformity of the display panel is facilitated. In addition, since the plurality of red resistors correspond to a red brightness enhancement unit, the plurality of green resistors correspond to a green brightness enhancement unit, and the plurality of blue resistors correspond to a blue brightness enhancement unit, the arrangement of the brightness enhancement units of one color can be realized by one mask, and the process steps are simplified.

In some possible implementations, the display panel further includes a planarization layer on a side of the brightness enhancement structure facing away from the substrate, where the planarization layer has a planarization function to facilitate placement of a subsequent structure (e.g., a cover plate).

In a second aspect, embodiments of the present application provide a display device, which includes the display panel of the first aspect, and has the same advantageous effects, and particularly, can be seen from the effects of the first aspect.

In a third aspect, an embodiment of the present application provides a method for manufacturing a display panel, where the method for manufacturing a display panel includes: providing a substrate; forming a pixel defining layer on a substrate; forming a plurality of first openings on the pixel defining layer; forming a plurality of light emitting elements within the plurality of first openings; forming a brightness enhancement structure on one side of the pixel defining layer, which is away from the substrate, wherein the brightness enhancement structure comprises a brightness enhancement layer, a shielding structure and a plurality of color resistors; the brightness enhancement layer comprises a plurality of second openings, and projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively; the color resistors are respectively positioned in the second openings; the plurality of color resistances at least comprises a plurality of red color resistances, a plurality of green color resistances and a plurality of blue color resistances; the projection of the shielding structure on the substrate is positioned between the projections of the adjacent two second openings on the substrate and is used for shielding ambient light from entering the display panel; wherein, the refractive index of the brightness enhancement layer is smaller than the refractive index of the color resistance.

In some possible implementations, forming a brightness enhancement structure on a side of the pixel defining layer facing away from the substrate includes: forming a brightness enhancement layer on one side of the pixel defining layer away from the substrate; forming a plurality of second openings on the brightness enhancement layer, wherein projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively; forming a plurality of red resistors, a plurality of green resistors and a plurality of blue resistors on one side of the brightness enhancement layer, which is away from the substrate, respectively; the red color resistors, the green color resistors and the blue color resistors are respectively located in the second openings, projections of the color resistors of at least two colors on the substrate are overlapped, and the overlapped areas are located in projections of the pixel limiting layer on the substrate to form a shielding structure, namely, the shielding structure is not required to be formed independently.

In some possible implementations, forming a brightness enhancement structure on a side of the pixel defining layer facing away from the substrate includes: forming a black matrix on a side of the pixel defining layer facing away from the substrate; forming a plurality of third openings on the black matrix to form a shielding structure, wherein projections of the plurality of first openings on the substrate are respectively positioned in projections of the plurality of third openings on the substrate; forming a brightness enhancement layer on one side of the black matrix facing away from the substrate; forming a plurality of second openings on the brightness enhancement layer, wherein the projections of the second openings on the substrate are respectively positioned in the projections of the third openings on the substrate; forming a plurality of red resistors, a plurality of green resistors and a plurality of blue resistors on one side of the brightness enhancement layer, which is away from the substrate, respectively; the red color resistors, the green color resistors and the blue color resistors are respectively located in the second openings, namely, shielding structures are not required to be formed independently, the arrangement is performed, reflection of ambient light is avoided, the color gamut and the brightness are improved, and meanwhile, the process steps can be simplified.

Drawings

Fig. 1 is a schematic structural diagram of a display device according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a display panel according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of another display panel according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of another display panel according to an embodiment of the present application;

fig. 5 is a film layer structure diagram of a display panel according to an embodiment of the present application;

FIG. 6 is a diagram illustrating a structure of a film layer of a display panel according to an embodiment of the present application;

fig. 7 is a positional relationship diagram of a black matrix and a brightness enhancing layer according to an embodiment of the present application;

fig. 8 is a positional relationship diagram of a black matrix and a brightness enhancing layer according to another embodiment of the present application;

fig. 9 is a film layer structure diagram of another display panel according to an embodiment of the present application;

fig. 10 is a diagram showing a positional relationship between a black matrix and a brightness enhancing layer according to an embodiment of the present application;

FIG. 11 is a view angle brightness contrast chart of the related art provided by the embodiment of the present application and simulated by the embodiment of the present application;

fig. 12 is a flowchart of a method for manufacturing a display panel according to an embodiment of the present application;

fig. 13a is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

Fig. 13b is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

FIG. 13c is a schematic diagram of a process for fabricating a display panel according to an embodiment of the present application;

FIG. 13d is a schematic diagram of a process for fabricating a display panel according to an embodiment of the present application;

fig. 13e is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

FIG. 13f is a schematic diagram of a process for fabricating a display panel according to an embodiment of the present application;

FIG. 13g is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

FIG. 13h is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

FIG. 13i is a schematic diagram of a process for manufacturing a display panel according to an embodiment of the present application;

FIG. 14 is a diagram illustrating a structure of a film layer of a display panel according to an embodiment of the present application;

fig. 15 is a film structure diagram of another display panel according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone.

The terms first and second and the like in the description and in the claims of embodiments of the application, are used for distinguishing between different objects and not necessarily for describing a particular sequential order of objects. For example, the first target object and the second target object, etc., are used to distinguish between different target objects, and are not used to describe a particular order of target objects.

In embodiments of the application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In the description of the embodiments of the present application, unless otherwise indicated, the meaning of "a plurality" means two or more. For example, the plurality of processing units refers to two or more processing units; the plurality of systems means two or more systems.

The display device provided by the embodiment of the application can be an electronic device including a display panel, such as a mobile phone, a notebook computer, a tablet personal computer, a personal digital assistant (personal digital assistant, PDA for short), a vehicle-mounted computer, a television, intelligent wearable equipment (such as an intelligent watch, an intelligent bracelet, an intelligent head-mounted display, intelligent glasses), intelligent household equipment and the like, and the embodiment of the application does not limit the specific form of the display device. For convenience of explanation, the display device is a mobile phone.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a display device according to an embodiment of the present application. As shown in fig. 1, the mobile phone 100 includes a display module 10, a rear cover (also referred to as a battery cover) 20, and a center 30.

It will be appreciated that in fig. 1, the handset 100 is in the form of a rectangular flat plate. In other alternative embodiments, the shape of the display device may also be square flat plate, circular flat plate, oval flat plate, etc. Of course, the display device may also be a folding display device (such as a folding mobile phone), and the like.

The display module 10 includes a cover plate 11 and a display panel (not shown) disposed along a stack. The cover plate 11 protects the display panel, for example. The display panel includes, for example, an OLED display panel, and it should be noted that the type of the display panel is not limited thereto, and those skilled in the art may select the display panel according to the actual situation, and the following examples are given by taking the display panel as an OLED display panel.

The rear cover 20 is located on a side of the display panel facing away from the cover plate 11, wherein the material of the rear cover 20 may include, for example, a light-impermeable material such as plastic, a plain skin, glass fiber, etc.; light-transmitting materials such as glass may also be included. The material of the rear cover 20 is not limited in the embodiment of the present application.

The middle frame 30 is located between the cover plate 11 and the rear cover 20, and the middle frame 30 includes an annular exterior member 31 and a support member (not shown) located within the annular exterior member 31 and located between the display panel and the rear cover 20. The cover plate 11, the annular exterior member 31, and the rear cover 20 may enclose a receiving cavity. The accommodating cavity is internally provided with a display panel, a printed circuit board (Printed Circuit Board, PCB), a flexible circuit board (Flexible Printed Circuit, FPC), a battery, a System on Chip (SoC) arranged on the PCB, an application processor (Application Processor, AP) and other structures (not shown in the figure), and the structures in the accommodating cavity are supported by the support member of the middle frame 30. The display module 10 is disposed on a support member, and the display panel is supported by the support member.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a display panel according to an embodiment of the application. As shown in fig. 2, the display panel 12 includes, for example, a display area AA and a non-display area NAA. In the display area AA, the data lines 121 and the scan lines 122 are disposed to intersect to define a plurality of sub-pixel areas, and sub-pixels 123 are disposed in the sub-pixel areas. The plurality of sub-pixels 123 are arranged in an array, for example. The non-display area NAA is provided with a driving chip 124, and the driving chip 124 includes a plurality of data output pins 1241. A plurality of data output pins 1241 are coupled to the plurality of data lines 121 in a one-to-one correspondence. The SoC transmits a control signal to the driving chip 124, and the internal circuit of the driving chip 124 processes the control signal to generate a data signal, and the data signal is transmitted to the data line 121 through the data output pin 1241, so as to write the data signal to the sub-pixel 123 through the data line 121.

Or, referring to fig. 3, fig. 3 is a schematic structural diagram of another display panel according to an embodiment of the application. As shown in fig. 3, a multiplexing circuit 125 is further disposed in the non-display area NAA, and the multiplexing circuit 125 includes a plurality of multiplexing units 1251. An input of a multiplexing unit 1251 is coupled to a data output pin 1241, and an output of the multiplexing unit 1251 may be coupled to at least two data lines 121, for example. The SoC transmits a control signal to the driving chip 124, and the internal circuit of the driving chip 124 processes the control signal to generate a data driving signal, and the data driving signal is transmitted to the multiplexing unit 1251 through the data output pin 1241, so as to write the data signal to the sub-pixel 123 through the multiplexing unit 1251. The provision of multiplexing circuits 125 may reduce the number of data output pins 1241.

The following examples are described by taking, as an example, the case where the multiplexing circuit 125 is not provided in the non-display area NAA.

It should be noted that the driving chip 124 may be disposed on the display panel 12 or may not be disposed on the display panel 12, which is not limited in the embodiment of the present application.

With continued reference to fig. 1, 2 or 3, in the non-display area NAA, a shift register 126 is further provided, where the shift register 126 includes a plurality of cascaded shift register units, and a scan signal output 1261 of each stage of shift register units is coupled to a scan line 122 corresponding to a row of sub-pixels 123. The internal circuit of the driving chip 124 processes the control signal and generates a scan driving signal. The scan driving signal is transmitted to the shift register 126 to generate a scan signal, and is transmitted to the scan line 122 through the scan signal output terminal 1261 of the shift register unit. The number of shift registers 126 may be one, as shown in fig. 1-3, and a set of cascaded shift registers 126 is disposed on one side of the display area AA. Optionally, referring to fig. 4, fig. 4 is a schematic structural diagram of another display panel according to an embodiment of the present application. As shown in fig. 4, the number of shift registers 126 may be two, two sets of cascaded shift registers 126 are respectively located in non-display areas NAA disposed opposite to each other on two sides of the display area AA, the scan signal output ends 1261 of the two sets of shift registers 126 located in the non-display areas NAA are coupled through a scan line 122, and the shift registers 126 coupled with the same scan line 122 synchronously output scan signals to the scan line 122 through the scan signal output ends 1261. In this way, the voltage drop on the scan line 122 can be avoided from affecting the display effect of the display panel.

Referring to fig. 5, fig. 5 is a film layer structure diagram of a display panel according to an embodiment of the present application. As shown in fig. 5, the display panel 12 includes a substrate 127, a pixel circuit layer 128 on the substrate 127, and a light emitting layer 129 on a side of the pixel circuit layer 128 facing away from the substrate 127.

Illustratively, the substrate 127 may be flexible or rigid, for example, formed of any suitable insulating material having flexibility for blocking oxygen and moisture, preventing moisture or impurities from diffusing through the substrate 127 into the interior of the display panel 12.

The pixel circuit layer 128 may include a plurality of pixel driving circuits 1281, and each pixel driving circuit 1281 includes a plurality of (e.g., including seven) thin film transistors (Thin Film Transistor, TFTs) 1282 for driving light emitting elements 1290 (described below) in the light emitting layer 129 to emit light. As shown in fig. 5, the structure of the present embodiment is illustrated by taking a top gate thin film transistor as an example, and the pixel circuit layer 128 of the display panel 12 specifically includes an active layer 12811 on a substrate 127; a gate insulating layer 128b located on a side of the active layer 12811 facing away from the substrate 127; a gate electrode 12812 of the thin film transistor 1282 on a side of the gate insulating layer 128b facing away from the substrate 127, for example, the scan line is disposed in the same layer as the gate electrode 12812; an interlayer insulating layer 128c located on a side of the gate electrode 12812 facing away from the substrate 127, wherein the interlayer insulating layer 128c may be formed of an inorganic layer of silicon oxide or silicon nitride or the like; a source electrode 12813 and a drain electrode 12814 of the thin film transistor 1282 on a side of the interlayer insulating layer 128c facing away from the substrate 127, wherein the source electrode 1283 and the drain electrode 1284 are electrically connected (or bonded) to a source region and a drain region of the active layer 12811, respectively, through contact holes formed by selectively removing the gate insulating layer 128b and the interlayer insulating layer 128c, for example, the data lines are disposed in the same layer as the source electrode 12813 and the drain electrode 12814 of the thin film transistor 1282; a passivation layer 128d on the source electrode 12813 and the drain electrode 12814 of the thin film transistor 1282. The structure and materials of preparation of the further pixel circuit layer 128 are not further illustrated here.

The light emitting layer 129 includes a pixel defining layer 1291, an anode 1292, a light emitting functional layer 1293, and a transparent cathode layer 1294. The pixel defining layer 1291 may be formed of an organic material such as Polyimide (PI), polyamide, benzocyclobutene (BCB), acryl resin, or phenol resin, or an inorganic material such as SiNx. The pixel defining layer 1291 includes a plurality of first openings 1295, and the anode 1292, the light emitting functional layer 1293, and the transparent cathode layer 1294 defined by the first openings 1295 may be formed into a light emitting element 1290 (i.e., shown in a dashed line frame in fig. 5) for light emitting display of the display panel by filling the light emitting functional layer 1293 at least partially in the first openings 1295, wherein the light emitting functional layer 1293 includes a red light emitting functional layer, a green light emitting functional layer, and a blue light emitting functional layer, each light emitting element 1290 is capable of emitting light of different colors according to the different light emitting functional layers 1293, that is, the light emitting element 1290 corresponding to the red light emitting functional layer (i.e., red light emitting element) emits red light, and the light emitting element 1290 corresponding to the green light emitting functional layer (i.e., green light emitting element) emits green light, and the light emitting element 1290 corresponding to the blue light emitting element emits blue light. The arrangement of the first openings 1295 in the pixel defining layer 1291 isolates the plurality of light emitting elements 1290 from each other, avoiding interference of light rays from the light emitting elements 1290. Anodes 1292 of the light emitting elements 1290 are electrically connected to the pixel driving circuits 1281 in a one-to-one correspondence, wherein one pixel driving circuit 1281 is electrically connected to the anode 1292 of one light emitting element 1290, and the pixel driving circuit 1281 and the corresponding light emitting element 1290 form one sub-pixel 123. When the pixel driver circuit 1281 drives the light-emitting element 1290 electrically connected thereto to emit light, a plurality of sub-pixels perform display of a screen in common.

With continued reference to fig. 5, in some embodiments, display panel 12 further includes an encapsulation layer 130 on a side of light-emitting layer 129 facing away from substrate 127 for protecting light-emitting functional layer 1293 from water and oxygen.

With continued reference to fig. 5, in some embodiments, the display panel 12 further includes a touch layer 131 located on a side of the encapsulation layer 130 facing away from the substrate 127, so as to implement a touch function of the display panel 12. It should be noted that, the setting position of the touch layer 131 is not limited thereto, and the setting position of the touch layer 131 is similar to the prior art, and specific reference may be made to the prior art, and details thereof are not repeated here.

In order to improve brightness and color saturation of a display panel, the display panel provided by the embodiment of the application not only comprises the structure, but also comprises a brightness improving structure on one side of the pixel limiting layer away from the substrate, wherein the brightness improving structure comprises a brightness improving layer, a shielding structure and a plurality of color resistors. The brightness enhancement layer comprises a plurality of second openings, and a plurality of color resistors are respectively positioned in the second openings; the plurality of color resistors at least comprise a plurality of red color resistors, a plurality of green color resistors and a plurality of blue color resistors, wherein the plurality of red color resistors correspond to a plurality of light-emitting elements comprising red light-emitting functional layers, the plurality of green color resistors correspond to a plurality of light-emitting elements comprising green light-emitting functional layers, and the plurality of blue color resistors correspond to a plurality of light-emitting elements comprising blue light-emitting functional layers. The setting of color resistance both can absorb ambient light and reduce reflectivity, can also make the light that light emitting component sent send smoothly simultaneously, and this light behind the color resistance for luminous spectrum is narrower, and the display color gamut is wider, promotes display panel's display effect. The shielding structure is positioned between two adjacent second openings, so that shielding of light rays emitted by the light-emitting element is avoided, meanwhile, ambient light can be shielded, the reflectivity is reduced, when the display panel is in a screen-off state, an integral black effect can be achieved, and compared with the arrangement of the polaroid, the reflectivity is reduced, and the display panel provided by the embodiment of the application is lighter and thinner and has low cost. Further, through setting up luminance enhancement layer, and set up the colour resistance in the opening of luminance enhancement layer, wherein, the refracting index of luminance enhancement layer is less than the refracting index of colour resistance, and in this way, when the light that the luminescent element sent shines on the interface of colour resistance and luminance enhancement layer, refraction takes place, and after light enters into high material from the low material that rolls over promptly, can take place the deflection, and then makes the light of wide angle gather to the low angle, reaches total reflection spotlight effect to promote display panel's luminance. That is, the display panel provided by the embodiment of the application can not only avoid reflection of ambient light, but also improve the color gamut and the brightness.

The specific structure of the display panel including the brightness enhancing structure and the forming process are described below in detail. The following examples are not to be construed as limiting the application.

In an example, referring to fig. 6 and fig. 7, fig. 6 is a film layer structure diagram of a display panel according to another embodiment of the present application, and fig. 7 is a positional relationship diagram of a black matrix and a brightness enhancing layer according to an embodiment of the present application, where, in fig. 7, for clearly showing a positional relationship between the black matrix and the brightness enhancing layer, fig. 7 illustrates an example in which a projection size of the black matrix on a substrate is larger than a projection size of the brightness enhancing layer on the substrate, and the positional relationship diagrams of the black matrix and the brightness enhancing layer in the following examples are the same, which will not be repeated. As shown in fig. 6 and 7, the display panel 12 further includes a brightness enhancing structure 132, the brightness enhancing structure 132 includes a shielding structure 1321, the shielding structure 1321 includes a black matrix 1322, the black matrix 1322 includes a plurality of third openings 13221, the plurality of third openings 13221 respectively correspond to the plurality of light emitting elements 1290, so as to expose the light emitting elements 1290, avoid shielding the light emitted by the light emitting elements 1290, and a region of the black matrix 1322 where the third openings 13221 are not disposed can shield ambient light to reduce reflectivity.

It should be noted that, the plurality of third openings 13221 respectively correspond to the plurality of light emitting elements 1290, that is, the projections of the plurality of third openings 13221 on the substrate 127 respectively overlap with the projections of the plurality of light emitting elements 1290 on the substrate 127; alternatively, the projections of the plurality of third openings 13221 onto the substrate 127 are respectively located within the projection overlap of the plurality of light-emitting elements 1290 onto the substrate 127; alternatively, the projections of the plurality of third openings 13221 onto the substrate 127 overlap with the projections of the plurality of light-emitting elements 1290 onto the substrate 127, respectively.

With continued reference to fig. 6 and 7, the brightness enhancing structure 132 further includes a brightness enhancing layer 1323 on a side of the black matrix 1322 facing away from the substrate 127, the brightness enhancing layer 1323 covering the black matrix 1322 and the third opening 13221. The brightness enhancing layer 1323 includes a plurality of second openings 13231, wherein projections of the plurality of second openings 13231 on the substrate 127 are respectively located in projections of the plurality of third openings 13221 on the substrate 127, that is, the third openings 13221 are disposed around the second openings 13221, so that the brightness enhancing structure 132 covers sidewalls of the third openings 13221 opened by the black matrix 1322.

With continued reference to fig. 6, the brightness enhancing structure 132 further includes a plurality of Color resists 1324, wherein the Color resists 1324 are also referred to as Color Filters (CF), the plurality of Color resists are respectively located in the plurality of second openings 13231, and a projection of each Color resist 1324 on the substrate 127 covers the third opening 13221 corresponding thereto. The plurality of color resistors 1324 at least comprise a plurality of red color resistors 1324r, a plurality of green color resistors 1324g and a plurality of blue color resistors 1324b, the plurality of red color resistors 1324r respectively correspond to the plurality of red light emitting elements 1290, the plurality of green color resistors 1324g respectively correspond to the plurality of green light emitting elements 1290, the plurality of blue color resistors 1324b respectively correspond to the plurality of blue light emitting elements 1290, the arrangement of the color resistors 1324 can absorb ambient light to reduce the reflectivity, meanwhile, the light emitted by the light emitting elements 1290 can be emitted smoothly, after passing through the color resistors 1324, the light emitting spectrum is narrower, the display color gamut is wider, and the display effect of the display panel 12 is improved.

In addition, the refractive index of the brightness enhancement layer 1323 is smaller than the refractive index of the color resist 1324. In this way, when the light emitted by the light emitting element 1290 irradiates the interface between the color resistor 1324 and the brightness enhancing layer 1323, refraction occurs, that is, after the light enters the high-refraction material from the low-refraction material, the light with a large angle is deflected, so that the light with a large angle is converged towards a small angle (as indicated by a thick arrow in fig. 6), and the total reflection condensing effect is achieved, so as to enhance the brightness of the display panel.

In summary, the embodiment of the present application can not only avoid the reflection of ambient light, but also enhance the color gamut and the brightness by providing the brightness enhancing structure 132 in the display panel 12.

It should be noted that, the above examples are described by taking the shape of the first opening 1295, the second opening 13231 and the third opening 13221 as circles as an example, but the embodiments of the present application are not limited thereto, and those skilled in the art may set the sizes and positions of the first opening 1295, the second opening 13231 and the third opening 13221 according to practical situations, and may correspondingly change the sizes and positions of the first opening 1295, the second opening 13231 and the third opening 13221 according to practical situations on the basis of satisfying the above requirements, and the size and positions of the first opening 1295, the second opening 13231 and the third opening 13221 are determined by the arrangement manner of the sub-pixels, as shown in fig. 8, where fig. 8 is a positional relationship diagram of a black matrix and a brightness enhancing layer according to another embodiment of the present application.

The refractive index of the brightness enhancing layer 1323 and the refractive index of the color resist 1324 are not limited to those of the brightness enhancing layer 1323 and the color resist 1324, so long as the display effect and the brightness of the display panel can be enhanced.

In some embodiments, the refractive index of the brightness enhancing layer 1323 is, for example, greater than or equal to 1.4 and less than or equal to 1.55. The color resistance 1324 is, for example, greater than or equal to 1.6. In this way, the choice of material for the brightness enhancement layer 1323 and the material for the color resist 1324 is facilitated.

As for the material of the brightness enhancing layer 1323, the material of the brightness enhancing layer 1323 is not limited in the embodiment of the present application, and may be selected by those skilled in the art according to practical situations. Illustratively, the brightness enhancing layer 1323 includes photoresist or the like.

As for the thickness of the brightness enhancing layer 1323, the thickness of the brightness enhancing layer 1323 is not limited in the embodiment of the present application, and may be set by those skilled in the art according to practical situations.

In some embodiments, the thickness H1 of the brightness enhancing layer 1323 is greater than or equal to 1.5um and less than or equal to 3.5um in a direction perpendicular to the substrate 127. The thickness of the brightness enhancing layer 1323 is not too small, so that the uniformity of the coating of the brightness enhancing layer 1323 is not affected, namely, the thickness uniformity of the brightness enhancing layer 1323 is not affected, and the size of the black matrix 1322 is not affected due to the larger thickness of the brightness enhancing layer 1323, so that the display effect is not affected.

In this case, the thickness of the brightness enhancing layer 1323 is greater than that of the black matrix 1322, facilitating the preparation of each film layer.

In addition, with continued reference to fig. 6, the display panel 12 further includes a planarization layer 133 on a side of the brightness enhancing structure 132 facing away from the substrate 127, and the planarization layer has a planarization function to facilitate the placement of a subsequent structure (e.g., the cover plate 11).

In consideration of the fact that the luminous efficiency of the luminous layers with different colors is different, the display effect of the display panel is further affected. Therefore, referring to fig. 9 and 10, fig. 9 is a film layer structure diagram of another display panel according to an embodiment of the present application, and fig. 10 is a positional relationship diagram of a black matrix and a brightness enhancing layer according to an embodiment of the present application. As shown in fig. 9 and 10, the luminance improving layer 1323 includes a red luminance improving unit 13232, a green luminance improving unit 13233, and a blue luminance improving unit 13234, and each of the red luminance improving unit 13232, the green luminance improving unit 13233, and the blue luminance improving unit 13234 includes a plurality of second openings 13231; the red brightness enhancing units 13232 surround the red resistors 1324r, the green brightness enhancing units 13233 surround the green resistors 1324g, and the blue brightness enhancing units 13234 surround the blue resistors 1324b. Wherein the refractive index of the red brightness enhancing unit 13232 is larger than the refractive index of the green brightness enhancing unit 13233, and the refractive index of the green brightness enhancing unit 13233 is larger than the refractive index of the blue brightness enhancing unit 13234.

This is because the blue light emitting element corresponding to the blue light emitting functional layer has the lowest light emitting efficiency, and the red light emitting element corresponding to the red light emitting functional layer has the highest light emitting efficiency. The refractive index of the blue brightness enhancement unit 13234 corresponding to the blue light emitting element with the lowest light emitting efficiency is the lowest, so that light with more angles is converged towards a small angle, and the brightness enhancement effect of the area corresponding to the blue light emitting element is the best, so that the light emitting brightness of each area of the display panel tends to be consistent, and the display uniformity of the display panel is facilitated. In addition, since the plurality of red resistors 1324r corresponds to a red brightness enhancement unit 13232, the plurality of green resistors 1324g corresponds to a green brightness enhancement unit 13233, and the plurality of blue resistors 1324b corresponds to a blue brightness enhancement unit 13234, the arrangement of the brightness enhancement units of one color can be realized by one mask, and the process steps are simplified.

It should be noted that the shape of the red brightness enhancing unit is not limited thereto, and those skilled in the art can set the red brightness enhancing unit according to practical situations, so long as the red brightness enhancing unit can encircle each red resistor 1324 r.

In order to explain the display panel provided by the application in detail, the brightness of the display panel can be improved, and the display panel is explained below by comparing with the related art.

Fig. 11 is a view angle brightness comparison chart of the related art and the simulation of the embodiment of the present application, wherein the abscissa represents the view angle, the ordinate represents the brightness improvement percentage, the solid line represents the brightness curve of the display panel of the present application (the display panel including the brightness improvement structure), and the dotted line represents the brightness curve of the display panel of the related art (the display panel including the polarizer).

As shown in fig. 11, comparing the optical simulation results of the display panel of the related art with that of the embodiment of the present disclosure, it is found that part of the light incident at a large angle to the interface between the brightness enhancement layer with low refractive index and the color resistor with high refractive index emits total reflection, so that the light deflects toward the normal direction, the effect of converging the light is achieved, and the brightness of the display panel is enhanced. For example, the brightness at the 0-degree viewing angle is improved by 30%, and the brightness improvement effect of the scheme can be further optimized by optimizing the transmittance of the color resistance material.

Therefore, through simulation, the brightness of the display panel provided by the embodiment of the application is improved under the common viewing angle of the user.

The above description is given by taking an example of a display panel as an example, and is intended to express all the improvements in luminance of the display panel of the present disclosure. The percentage of brightness improvement at each viewing angle is not limited thereto.

The embodiment of the application also provides a preparation method of the display panel, which is used for preparing the display panel in the above content, has the same beneficial effects, and the detailed content which is not described in detail in the embodiment can refer to the embodiment of the display panel. The method of manufacturing the display panel is described below with reference to the display panel shown in fig. 6.

As shown in fig. 12, the manufacturing method of the display panel may be implemented by:

s101, forming a pixel circuit layer on a substrate and forming an anode.

Referring to fig. 13a, each of the film layers of the pixel circuit layer 128 is sequentially formed on the substrate 127, and the structure of each film layer may be referred to as above (the description of the structure of fig. 6 is given), and the forming process of each film layer is similar to the prior art, and may be referred to in detail in the prior art, and will not be repeated here. Then, a plurality of anodes 1292 are formed on a side of the pixel circuit layer 128 facing away from the substrate, and the plurality of anodes 1292 are electrically connected to the pixel driving circuits 1281 in the plurality of pixel circuit layers 128 in a one-to-one correspondence.

S102, forming a pixel limiting layer on one side of the anode, which is away from the substrate, and forming a plurality of first openings on the pixel limiting layer.

Referring to fig. 13b, a pixel defining layer 1291 is formed on a side of the anode 1292 facing away from the substrate 127, and a plurality of first openings 1295 are formed in the pixel defining layer 1291, wherein the plurality of first openings 1295 correspond to the plurality of anodes 1292, respectively, to expose the plurality of anodes 1292.

S103, forming a light-emitting functional layer on one side of the anode, which is away from the substrate.

Referring to fig. 13c, a light-emitting functional layer 1293 is prepared on a side of the anode 1292 facing away from the substrate 127 by using a vacuum thermal evaporation process, where the light-emitting functional layer 1293 includes a light-emitting layer and a common layer (not shown in the figure), and the specific film structure of the light-emitting functional layer can be referred to in the prior art, and will not be described herein. Wherein, common layer and luminescent layer respectively use general Metal Mask (Common Metal Mask, CMM) and Fine Metal Mask (FMM).

S104, forming a cathode layer, a packaging layer and a touch layer on one side of the light-emitting functional layer, which is away from the substrate, in sequence.

Referring to fig. 13d, after the evaporation process, a cathode layer 1294 is formed on the side of the light-emitting functional layer 1293 facing away from the substrate 127, and an anode 1290, the light-emitting functional layer 1293 and the cathode layer 1294 together form a light-emitting element 1290. A stacked encapsulation layer 130 of an inorganic layer (e.g., siN), an organic layer, and an inorganic layer (e.g., siN) is then prepared on the side of the cathode layer 1294 facing away from the substrate 127 using a chemical vapor deposition (Chemical Vapor Deposition, CVD) and Inkjet printing (IJP) process.

Then, a CVD and Photo process (mainly comprising photoresist coating, exposure and development) is used to prepare a touch layer (Touch On Encapsulation, TOE) 131 on the side of the encapsulation layer 130 facing away from the substrate 127.

S105, forming a black matrix on one side of the touch control layer, which is away from the substrate, and exposing and developing the black matrix to form a third opening.

Referring to fig. 13e, after a Black Matrix (BM) 1322 with a thickness of 0.5-2 um is coated on a side of the touch layer 131 facing away from the substrate 127 by using a Photo process (including photoresist coating, exposing and developing), an exposing and developing process is performed directly above the light emitting element 1290 to form a third opening 13221, so as to avoid shielding light emitted by the light emitting element 1290.

S106, coating a brightness enhancement layer on one side of the black matrix, which is away from the substrate.

Referring to fig. 13f, a brightness enhancing layer 1323 having a thickness of 1.5-3.5 um and a refractive index of 1.4-1.55 is coated on a side of the black matrix 1322 facing away from the substrate 127, wherein the coated brightness enhancing layer 1323 covers the black matrix 1322 and the third opening 13221, and the thickness of the brightness enhancing layer 1323 is greater than that of the black matrix 1322.

S107, forming a plurality of second openings on the brightness enhancement layer.

Referring to fig. 13g, a plurality of second openings 13231 are formed on the brightness enhancing layer 1323, wherein the size of the second openings 13231 is smaller than the size of the third openings 13221, i.e., the projection of the second openings 13231 onto the substrate 127 is within the projection of the third openings 13221 onto the substrate 127.

S108, forming a color resistor in the third opening.

Referring to fig. 13h, a Photo process is used to form a patterned plurality of color resists 1324 within the third openings 13221. The plurality of color resistors 1324 at least include a plurality of red color resistors 1324r, a plurality of green color resistors 1324g, and a plurality of blue color resistors 1324b, the plurality of red color resistors 1324r respectively correspond to the plurality of red light emitting elements 1290, the plurality of green color resistors 1324g respectively correspond to the plurality of green light emitting elements 1290, and the plurality of blue color resistors 1324b respectively correspond to the plurality of blue light emitting elements 1290.

S109, forming a planarization layer on one side of the color resistor, which is away from the substrate.

Referring to fig. 13i, a planarization layer 133 is coated on the side of the color resist 1324 facing away from the substrate 127 using a coating process.

In yet another example, referring to fig. 14, fig. 14 is a film layer diagram of yet another display panel according to an embodiment of the present application. As shown in fig. 14, unlike the above example, the brightness enhancing structure 128 does not include a black matrix, the adjacent two-color resists 1324 overlap, i.e., the projections of the adjacent two-color resists 1324 on the substrate 127 overlap, and the overlapping region is located within the projection of the pixel defining layer 1291 on the substrate 127, and the overlapping region of the adjacent two-color resists 1324 forms the shielding structure 1321.

For example, when the ambient light enters the red color resist 1324, only the red light remains, and the red light is not transmitted through the green color resist 1324, so the ambient light cannot enter the display panel 12 after passing through the two overlapped colors of color resists 1324, that is, the ambient light is blocked to reduce the reflectivity, which is the same as the black matrix 1322 in the above example, and the blocking structure 1321 is not required to be formed while the color resist 1324 is formed, and the black matrix is not required to be separately arranged.

The manufacturing process of the display panel in this example is similar to the above example, except that the black matrix is not formed in step S104, but the brightness enhancing layer is directly formed, which is specifically referred to the above example and will not be repeated here.

In yet another example, referring to fig. 15, fig. 15 is a film layer diagram of another display panel according to an embodiment of the present application. As shown in fig. 15, unlike the second example, the color resistances 1324 of three colors overlap, that is, the projections of the red color resistance 1324r, the green color resistance 1324g, and the blue color resistance 1324b on the substrate 127 overlap, and the overlapping region is located within the projection of the pixel defining layer 1291 on the substrate 127, the region where the color resistances 1324 of three colors overlap forms the shielding structure 1321.

For example, after the ambient light enters the red color resist 1324, only red light remains, and the red light is not transmitted after passing through the green color resist 1324, so the ambient light cannot enter the display panel 12 after passing through the two overlapped colors of color resist 1324, that is, the ambient light is blocked to reduce the reflectivity, and after the blue color resist 1324b is set, the effect of filtering the ambient light can be further achieved, which is the same as the effect of the black matrix 1322 in the above example, and the blocking structure 1321 can be formed without forming the color resist 1324 and without separately setting the black matrix.

The preparation process of the display panel in this example is similar to that of the second example, and specific reference may be made to the above example, and details are not repeated here.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. A display panel, comprising:

a substrate;

a pixel defining layer on the substrate; the pixel defining layer includes a plurality of first openings;

a plurality of light emitting elements respectively positioned in the first openings; the plurality of light emitting elements at least include a plurality of red light emitting elements, a plurality of green light emitting elements, and a plurality of blue light emitting elements;

a brightness enhancement structure located on a side of the pixel defining layer facing away from the substrate; the brightness enhancement structure comprises a brightness enhancement layer, a shielding structure and a plurality of color resistors;

the brightness enhancement layer comprises a plurality of second openings, and projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively;

the color resistors are respectively positioned in the second openings; the plurality of color resistances at least comprise a plurality of red color resistances, a plurality of green color resistances and a plurality of blue color resistances, the plurality of red color resistances respectively correspond to the plurality of red light-emitting elements, the plurality of green color resistances respectively correspond to the plurality of green light-emitting elements, and the plurality of blue color resistances respectively correspond to the plurality of blue light-emitting elements;

the projection of the shielding structure on the substrate is positioned between the projections of two adjacent second openings on the substrate and is used for shielding ambient light from entering the display panel;

Wherein, the refractive index of the brightness enhancement layer is smaller than the refractive index of the color resistance.

2. The display panel of claim 1, wherein projections of the color resists of at least two colors onto a substrate overlap and an overlapping region is located within a projection of the pixel defining layer onto the substrate to form the shielding structure.

3. The display panel of claim 2, wherein the projections of the red, green, and blue color resists onto a substrate all overlap, and wherein the overlapping areas are located within the projection of the pixel defining layer onto the substrate to form the shielding structure.

4. The display panel according to claim 1, wherein the shielding structure comprises a black matrix, the black matrix comprises a plurality of third openings, the brightness enhancing layer is arranged on one side of the black matrix facing away from the pixel defining layer, and projections of the plurality of second openings on the substrate are respectively located in projections of the plurality of third openings on the substrate.

5. The display panel according to any one of claims 1 to 4, wherein a thickness of the brightness enhancing layer is greater than or equal to 1.5um and less than or equal to 3.5um in a direction perpendicular to the substrate.

6. The display panel of claim 5, wherein when the shielding structure includes a black matrix, a thickness of the brightness enhancing layer is greater than a thickness of the black matrix.

7. The display panel according to claim 1, wherein the refractive index of the brightness enhancing layer is greater than or equal to 1.4 and less than or equal to 1.55.

8. The display panel of claim 7, wherein the brightness enhancing layer comprises a photoresist.

9. The display panel according to claim 1, wherein the luminance enhancement layer includes a red luminance enhancement unit, a green luminance enhancement unit, and a blue luminance enhancement unit, each of which includes a plurality of the second openings; the red brightness enhancement units encircle a plurality of red resistors, the green brightness enhancement units encircle a plurality of green resistors, and the blue brightness enhancement units encircle a plurality of blue resistors;

the refractive index of the red brightness enhancement unit is larger than that of the green brightness enhancement unit, and the refractive index of the green brightness enhancement unit is larger than that of the blue brightness enhancement unit.

10. The display panel of claim 1, further comprising a planarization layer on a side of the brightness enhancement structure facing away from the substrate.

11. A display device comprising the display panel of any one of claims 1-10.

12. A method for manufacturing a display panel, comprising:

providing a substrate;

forming a pixel defining layer on the substrate;

forming a plurality of first openings on the pixel defining layer;

forming a plurality of light emitting elements in a plurality of the first openings;

forming a brightness enhancement structure on one side of the pixel defining layer away from the substrate, wherein the brightness enhancement structure comprises a brightness enhancement layer, a shielding structure and a plurality of color resistors; the brightness enhancement layer comprises a plurality of second openings, and projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively; the color resistors are respectively positioned in the second openings; the plurality of color resistances at least comprise a plurality of red color resistances, a plurality of green color resistances and a plurality of blue color resistances; the projection of the shielding structure on the substrate is positioned between the projections of two adjacent second openings on the substrate and is used for shielding ambient light from entering the display panel; wherein, the refractive index of the brightness enhancement layer is smaller than the refractive index of the color resistance.

13. The method of claim 12, wherein forming a brightness enhancement structure on a side of the pixel defining layer facing away from the substrate, comprises:

forming a brightness enhancement layer on a side of the pixel defining layer away from the substrate;

forming a plurality of second openings on the brightness enhancement layer, wherein projections of the second openings on the substrate overlap with projections of the first openings on the substrate respectively;

forming a plurality of red resistors, a plurality of green resistors and a plurality of blue resistors on one side of the brightness enhancement layer, which is away from the substrate, respectively; the red color resistors, the green color resistors and the blue color resistors are respectively located in the second openings, projections of the color resistors of at least two colors on the substrate are overlapped, and overlapped areas are located in projections of the pixel defining layer on the substrate to form the shielding structure.

14. The method of claim 12, wherein forming a brightness enhancement structure on a side of the pixel defining layer facing away from the substrate, comprises:

forming a black matrix on one side of the pixel defining layer away from the substrate;

Forming a plurality of third openings on the black matrix to form the shielding structure, wherein projections of the first openings on the substrate are respectively positioned in projections of the third openings on the substrate;

forming a brightness enhancement layer on one side of the black matrix away from the substrate;

forming a plurality of second openings on the brightness enhancement layer, wherein the projections of the second openings on the substrate are respectively positioned in the projections of the third openings on the substrate;

forming a plurality of red resistors, a plurality of green resistors and a plurality of blue resistors on one side of the brightness enhancement layer, which is away from the substrate, respectively; the red color resistors, the green color resistors and the blue color resistors are respectively positioned in the second openings.