Display panel and display device

Abstract

A display panel includes: a back plate; the plurality of light emitting devices are positioned on the back plate; the light-emitting device comprises a first electrode and a second electrode which are oppositely arranged, and the first electrode is closer to the back plate than the second electrode; the light extraction layer is positioned on the light emitting sides of the plurality of light emitting devices; the light extraction layer is configured to allow the circularly polarized light in the first rotation direction to pass through and reflect the circularly polarized light in the second rotation direction; the first rotating direction is different from the second rotating direction; and an anti-reflection layer on the light extraction layer, the anti-reflection layer is configured to allow the circularly polarized light in the first rotation direction to pass through.

Description

Display panel and display device Technical Field

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

[0002] OLED (Organic Light-Emitting Diode) display devices have been listed as a next-generation display technology with great development prospects due to their advantages such as thinness, lightness, wide viewing angle, active luminescence, continuously adjustable luminous color, low cost, fast response speed, low energy consumption, low driving voltage, wide operating temperature range, simple production process, high luminous efficiency and flexible display.

[0003] Summary of the Invention

[0004] In one aspect, a display panel is provided, comprising: a backplane, a plurality of light-emitting devices, a light extraction layer, and an anti-reflection layer. The plurality of light-emitting devices are located on the backplane. The light-emitting devices include a first electrode and a second electrode disposed opposite each other, with the first electrode being closer to the backplane than the second electrode. The light extraction layer is located on the light-emitting side of the plurality of light-emitting devices. The light extraction layer is configured to allow circularly polarized light of a first rotational direction to pass through and to reflect circularly polarized light of a second rotational direction; the first rotational direction and the second rotational direction are different. The anti-reflection layer is located on the light extraction layer; the anti-reflection layer is configured to allow circularly polarized light of the first rotational direction to pass through.

[0005] In some embodiments, the transmittance of the light extraction layer to the light emitted by the light emitting device is greater than or equal to 35%, and / or the reflectivity of the light extraction layer to the light emitted by the light emitting device is greater than or equal to 35%.

[0006] In some embodiments, the material of the light extraction layer includes at least one cholesteric liquid crystal material; when the material of the light extraction layer includes at least two cholesteric liquid crystal materials, the helical pitches of the at least two cholesteric liquid crystals are unequal.

[0007] In some embodiments, when the material of the light extraction layer includes at least two cholesteric liquid crystals, the light extraction layer includes: at least two sub-light extraction layers stacked in sequence; the at least two sub-light extraction layers include: a first light extraction layer and a second light extraction layer; the pitch of the cholesteric liquid crystal in the first light extraction layer is not equal to the pitch of the cholesteric liquid crystal in the second light extraction layer.

[0008] In some embodiments, when the material of the light extraction layer includes at least two cholesteric liquid crystals, the at least two cholesteric liquid crystals include a first liquid crystal and a second liquid crystal; the first liquid crystal is uniformly distributed in the light extraction layer, the second liquid crystal is uniformly distributed in the light extraction layer, and the distribution density of the first liquid crystal in the light extraction layer is equal to the distribution density of the second liquid crystal in the light extraction layer.

[0009] In some embodiments, when the material of the light extraction layer includes at least two cholesteric liquid crystals, in the light extraction layer, the pitches of the cholesteric liquid crystals corresponding to light emitting devices with different luminous colors are unequal.

[0010] In some embodiments, the anti-reflection layer includes at least a quarter wave plate and a polarizing layer; the quarter wave plate is located between the polarizing layer and the light extraction layer; and the transmittance of the polarizing layer to visible light is greater than or equal to 40%.

[0011] In some embodiments, the anti-reflection layer further includes a light absorbing layer; the light absorbing layer is stacked with a quarter wave plate or a polarizing layer and is configured to absorb light with a wavelength below 450 nm.

[0012] In some embodiments, the display panel further includes: a defining layer located between the back panel and the light extraction layer; the defining layer has a plurality of second openings; wherein the plurality of light-emitting devices include a plurality of red light-emitting devices, a plurality of green light-emitting devices and a plurality of blue light-emitting devices; the plurality of second openings include: a plurality of red openings for setting red light-emitting devices, a plurality of green openings for setting green light-emitting devices, and a plurality of blue openings for setting each blue light-emitting device; the area of ​​the orthographic projection of the red openings on the back panel is less than or equal to the area of ​​the orthographic projection of the green openings on the back panel.

[0013] In some embodiments, a ratio of an area of ​​an orthographic projection of the blue opening on the backplane to an area of ​​an orthographic projection of the red opening on the backplane is γ, and 1.0≤γ≤2.6.

[0014] In some embodiments, the sum of the areas of the orthographic projections of all blue openings in the display area of ​​the display panel on the backplane is less than or equal to 10% of the area of ​​the display area.

[0015] In some embodiments, the ratio of the sum of the areas of the orthographic projections of all the second openings in the display area of ​​the display panel on the back plate to the area of ​​the display area is in a range of 10% to 70%.

[0016] In some embodiments, an angle between a sidewall of the second opening and a plane where the back plate is located is less than or equal to 35°.

[0017] In some embodiments, the display panel further includes: a light-shielding layer disposed between the plurality of light-emitting devices and the light extraction layer; the light-shielding layer having a plurality of first openings; and an orthographic projection of a light-emitting device on the back panel having an overlapping area with an orthographic projection of the first opening on the back panel.

[0018] In some embodiments, the display panel has a first area and a second area, and an angle between a sidewall of at least one first opening in the first area and a plane where the back plate is located is different from an angle between a sidewall of at least one first opening in the second area and the plane where the back plate is located.

[0019] In some embodiments, the display panel further includes: a defining layer located between the back plate and the light shielding layer; the defining layer has a plurality of second openings; and along a direction perpendicular to the plane where the back plate is located, a second opening is arranged opposite to a first opening.

[0020] In some embodiments, the display panel has a third region and a fourth region, and an angle between a sidewall of at least one second opening in the third region and a plane where the back plate is located is different from an angle between a sidewall of at least one second opening in the fourth region and the plane where the back plate is located.

[0021] In some embodiments, the orthographic projection of the second opening on the back plate is located within the range of the orthographic projection of the first opening on the back plate that is directly opposite to the second opening.

[0022] In some embodiments, an angle between a sidewall of the first opening and a plane where the back plate is located is greater than an angle between a sidewall of the second opening and a plane where the back plate is located.

[0023] In some embodiments, an angle between a sidewall of the first opening and a plane where the back plate is located is smaller than an angle between a sidewall of the second opening and a plane where the back plate is located.

[0024] In some embodiments, the material of the defining layer includes a light-absorbing material, and / or the material of the light-shielding layer includes a light-absorbing material, and the absorbance of the light-absorbing material to visible light is greater than or equal to 0.5.

[0025] In some embodiments, the maximum distance between the boundary line of the orthographic projection of the second opening on the back panel and the boundary line of the orthographic projection of the first opening opposite to the second opening on the back panel is less than or equal to 1 / 3 of the maximum size of the orthographic projection of the second opening on the back panel.

[0026] In some embodiments, the display panel further includes: an optical covering layer located between the plurality of light-emitting devices and the light extraction layer; and an encapsulation layer located between the optical covering layer and the light extraction layer and in contact with the optical covering layer; wherein the difference between the refractive index of the optical covering layer and the refractive index of the encapsulation layer is greater than or equal to 0.1.

[0027] In some embodiments, the encapsulation layer includes at least three stacked sub-encapsulation layers; and the refractive index of at least two of the at least three sub-encapsulation layers is greater than or equal to 1.65.

[0028] In some embodiments, the at least three sub-encapsulation layers include a first sub-encapsulation layer, a second sub-encapsulation layer, and a third sub-encapsulation layer; the first sub-encapsulation layer contacts the optical cover layer, the material of the first sub-encapsulation layer is an inorganic material, the second sub-encapsulation layer is an organic material, and the material of the third sub-encapsulation layer is an inorganic material; the first sub-encapsulation layer includes a fourth sub-encapsulation layer and a fifth sub-encapsulation layer that are stacked.

[0029] In some embodiments, a refractive index of the fourth sub-encapsulation layer is different from a refractive index of the fifth encapsulation layer.

[0030] In some embodiments, the display panel further includes a touch function layer located between the encapsulation layer and the light extraction layer.

[0031] On the other hand, a display device is provided, comprising: a display panel according to any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below should be considered schematic diagrams and are not intended to limit the actual dimensions, etc., of the products involved in the embodiments of the present disclosure.

[0033] FIG1 is a schematic diagram of a display device according to some embodiments of the present disclosure;

[0034] FIG2A is a structural diagram of a display panel according to one implementation manner;

[0035] FIG2B is a schematic diagram illustrating a changing process of light emitted by a light-emitting device in a display panel entering an anti-reflection structure according to one implementation manner;

[0036] FIG3 is a structural diagram of a display panel according to some embodiments of the present disclosure;

[0037] 4 is a schematic diagram illustrating a process in which light emitted by a light-emitting device in a display panel is incident on a light extraction layer and an anti-reflection layer according to some embodiments of the present disclosure;

[0038] FIG5 is a schematic diagram of testing the reflectivity of a light extraction layer according to some embodiments of the present disclosure;

[0039] FIG6 is a graph showing the relationship between the reflectivity of a light extraction layer and the wavelength of incident light according to some embodiments of the present disclosure;

[0040] FIG7A is a structural diagram of another display panel according to some embodiments of the present disclosure;

[0041] FIG7B is a structural diagram of another display panel according to some embodiments of the present disclosure;

[0042] FIG7C is a structural diagram of another display panel according to some embodiments of the present disclosure;

[0043] FIG7D is a structural diagram of another display panel according to some embodiments of the present disclosure;

[0044] FIG8 is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0045] FIG9A is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0046] FIG9B is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0047] FIG10A is a structural diagram of another display panel according to some embodiments of the present disclosure;

[0048] FIG10B is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0049] FIG11 is a structural diagram of a light shielding layer and a defining layer according to some embodiments of the present disclosure;

[0050] FIG12 is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0051] FIG13 is a structural diagram of a defining layer and a light-emitting device according to some embodiments of the present disclosure;

[0052] FIG14 is a structural diagram of yet another display panel according to some embodiments of the present disclosure;

[0053] FIG15A is a structural diagram of an encapsulation layer according to some embodiments of the present disclosure;

[0054] FIG15B is a structural diagram of another encapsulation layer according to some embodiments of the present disclosure;

[0055] FIG. 16 is a structural diagram of yet another display panel according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0056] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0057] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0058] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0059] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0060] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0061] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0062] As used herein, "perpendicular" and "equal" include the conditions described and conditions similar to the conditions described, where the range of the similar conditions is within an acceptable deviation range, where the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, that the difference between the two equalities is less than or equal to 5% of either.

[0063] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0064] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0065] As shown in FIG1 , some embodiments of the present disclosure provide a display device 1. The display device 1 can be any display device that displays either motion (e.g., video) or fixed (e.g., still images) and whether text or images. More specifically, it is expected that the display device of the embodiments described can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigation systems, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of jewelry), etc.

[0066] In some embodiments, as shown in FIG1 , the display device 1 includes a display panel 10. The display panel 10 has a display area AA.

[0067] Exemplarily, the display panel 10 may be an OLED (Organic Light Emitting Diode) display panel or a QLED (Quantum-dot Light Emitting Diode) display panel.

[0068] The following description will be made by taking the display panel 10 as an OLED display panel as an example.

[0069] Exemplarily, the display device 1 further includes: a frame, a display driver IC (Integrated Circuit) and other electronic components.

[0070] For example, the display panel 10 is located within a frame, which can provide support for the display panel 10 and protect it from external damage such as bumps. The display panel 10 is electrically connected to a display driver IC, receiving display signals transmitted by the display driver IC and displaying images under the control of the display signals.

[0071] 2A , the display panel 10 includes a back panel 20 and a plurality of light emitting devices 30 disposed on the back panel 20. The plurality of light emitting devices 30 are disposed in a display area.

[0072] In Figure 2A, X represents a first direction, Y represents a second direction, and Z represents a third direction. Both the first direction X and the second direction Y are parallel to the plane of the backplane 20, and the first direction X and the second direction Y may be perpendicular to each other. The third direction Z is perpendicular to the plane of the backplane 20, or is the thickness direction of the backplane 20.

[0073] For example, the backplane 20 has a first surface 20A, and a plurality of light-emitting devices 30 are located on the first surface 20A. The plurality of light-emitting devices 30 may be in direct contact with the first surface 20A (for example, no other film layer is disposed between the light-emitting devices 30 and the first surface 20A), or may be in non-contact with the first surface 20A (for example, a film layer is disposed between the light-emitting devices 30 and the first surface 20A to separate the two).

[0074] For example, the backplane 20 may include a plurality of pixel circuits, and the plurality of pixel circuits may be electrically connected in a one-to-one correspondence with the plurality of light emitting devices 30. The light emitting devices 30 may emit light under the control of control signals transmitted by the pixel circuits.

[0075] There are many structures of pixel circuits, which can be selected and set according to actual needs. For example, the structure of the pixel circuit may include "6T1C", "7T1C", "6T2C" or "7T2C" structures. Here, "T" represents a transistor (for example, FIG. 12 shows a transistor T), and the number before "T" represents the number of transistors. "C" represents a storage capacitor, and the number before "C" represents the number of storage capacitors.

[0076] For example, the light emitting device 30 may be an OLED light emitting device. Exemplarily, the light emitting device 30 may emit natural light NL.

[0077] Natural light is evenly distributed in all directions. The light emitting device 30 can emit light of different wavelengths, such as red light, blue light, green light, etc. The above red light, blue light, and green light are all natural light.

[0078] Exemplarily, the light emitting device 30 includes a first electrode and a second electrode disposed opposite to each other, and a light emitting layer located between the first electrode and the second electrode. The first electrode is closer to the back plate 20 than the second electrode.

[0079] For example, the light-emitting layer emits light under the action of the electric field provided by the first electrode and the second electrode. For example, the first electrode is located on the first surface of the back plate 20, and the second electrode is located on the side of the first electrode 31 away from the back plate 20. For example, the first electrode can be one of the anode and the cathode, and the second electrode can be the other of the anode and the cathode, and the present disclosure is not limited to this. For example, the first electrode is the anode; the second electrode is the cathode. It can be understood that the display panel 10 includes multiple conductive layers, such as a pixel conductive layer for forming a pixel circuit and a conductive layer for forming the first electrode of the light-emitting device. When the external environment where the display panel is located is relatively bright (it can also be said to be in a bright field of view), the light from the external environment will be incident on the interior of the display panel, reflected on the above-mentioned multiple conductive layers, and then emitted from the light-emitting side of the display panel, resulting in a significant reduction in the contrast of the display panel, affecting the display effect of the display panel.

[0080] Therefore, in one implementation, as shown in FIG2A , an anti-reflection structure 50 ′ is provided on the light-emitting side of a plurality of light-emitting devices 30 . The anti-reflection structure 50 ′ can reduce the reflectivity of the display panel to external light and improve the contrast of the display panel under bright viewing fields. The anti-reflection structure 50 ′ generally includes a phase conversion structure 51 ′ and a linear polarizer 52 ′. The linear polarizer 52 ′ can transmit light parallel to the transmission axis of the linear polarizer 52 ′. Specifically, reference can be made to the schematic diagram of the light change process shown in FIG2B . However, the light emitted by the light-emitting device 30 will be incident on the linear polarizer 52 ′ of the above-mentioned anti-reflection structure 50 ′, and at least 50% of the light will be absorbed and consumed by the anti-reflection structure 50 ′ (this part of the light is not shown in FIG2B ), and the remaining light can be emitted through the anti-reflection structure 50 ′, thereby causing the brightness of the image displayed by the display panel to drop sharply, increasing the power consumption of the display panel and the display device, and reducing the display life.

[0081] To address this technical problem, some embodiments of the present disclosure provide a display panel. As shown in FIG3 , the display panel 10 may include: a backplane 20, a plurality of light-emitting devices 30 disposed on the backplane 20, a light extraction layer 40, and an anti-reflection layer 50. For the structures of the backplane 20 and the light-emitting devices 30, reference may be made to the description of the above embodiments.

[0082] FIG4 is a simple schematic diagram illustrating a light change process after light emitted by the light emitting device 30 in the display panel provided by some embodiments of the present disclosure passes through the light extraction layer 40 and the anti-reflection layer 50 in sequence.

[0083] In some examples, the light extraction layer 40 is located on the light-emitting side of the plurality of light-emitting devices 30. The light extraction layer 40 is configured to allow circularly polarized light CL1 of a first handedness to pass through, and to reflect circularly polarized light CL2 of a second handedness, where the first handedness and the second handedness are different. The anti-reflection layer 50 is configured to allow circularly polarized light CL1 of the first handedness to pass through.

[0084] Exemplarily, the light extraction layer 40 has a modulation effect on the light incident thereon, and can modulate the natural light NL or the light emitted by the light emitting device 30 into circularly polarized light CL.

[0085] A polarization characteristic experiment is conducted on the light emitted through the light extraction layer 40. For example, a quarter wave plate, a polarizer and a receiver are sequentially arranged on one side of the light extraction layer 40, and the light is incident from the side of the light extraction layer away from the quarter wave plate. The polarizer is rotated with the light path as the axis to perform a polarization cross extinction test. The results show that the brightness of the light received by the receiver is different under different rotation directions of the polarizer. And among the light received by the receiver, the ratio of the brightness value of the light with the highest brightness to the brightness value of the light with the lowest brightness is greater than 5. In other words, the light transmitted from the light extraction layer 40 has circular polarization characteristics. Exemplarily, the above-mentioned light extraction layer 40 also has a screening effect on light. The light extraction layer 40 has a rotation direction, which can transmit light with a rotation direction opposite to that of the light extraction layer 40 and reflect light with the same rotation direction as that of the light extraction layer 40.

[0086] Illustratively, the circularly polarized light CL includes circularly polarized light CL1 of a first rotation direction and circularly polarized light CL2 of a second rotation direction.

[0087] The first and second handedness directions may be opposite, for example, the first handedness direction may be clockwise, and the circularly polarized light CL1 of the first handedness direction is right-handed circularly polarized light, and the second handedness direction may be counterclockwise, and the circularly polarized light CL2 of the second handedness direction is left-handed circularly polarized light.

[0088] For another example, the first handedness may be counterclockwise, and the circularly polarized light CL1 of the first handedness is left-handed circularly polarized light. The second handedness may be clockwise, and the circularly polarized light CL2 of the second handedness is right-handed circularly polarized light.

[0089] The handedness of the light extraction layer 40 is, for example, opposite to the first handedness, so that the light extraction layer 40 can selectively transmit the circularly polarized light CL1 of the first handedness. The handedness of the light extraction layer 40 is, for example, opposite to the second handedness, so that the light extraction layer 40 can selectively reflect the circularly polarized light CL2 of the second handedness.

[0090] In FIG4 , the circularly polarized light CL1 of the first hand direction is left-handed circularly polarized light, and the circularly polarized light CL2 of the second hand direction is right-handed circularly polarized light.

[0091] In some examples, an anti-reflection layer 50 is located on the light extraction layer 40. The anti-reflection layer 50 is located on the side of the light extraction layer 40 away from the backplane. The anti-reflection layer 50 is used to reduce the reflectivity of the display panel 10 to external light, thereby improving the contrast of the display panel 10 and the display device 1, and enhancing the display effect.

[0092] Exemplarily, the anti-reflection layer 50 can also convert circularly polarized light into linearly polarized light. For example, the anti-reflection layer 50 converts circularly polarized light CL1 of a first rotation direction into linearly polarized light, and the polarization direction of the linearly polarized light is parallel to the transmission axis of the anti-reflection layer 50, so that the anti-reflection layer 50 can transmit the circularly polarized light CL1 of the first rotation direction.

[0093] Exemplarily, the light-emitting device 30 in the display panel 10 emits natural light, which is incident on the light extraction layer 40 and converted by the light extraction layer 40 into circularly polarized light CL1 of a first rotation direction and circularly polarized light CL2 of a second rotation direction. The light extraction layer 40 transmits the circularly polarized light CL1 of the first rotation direction and reflects the circularly polarized light CL2 of the second rotation direction.

[0094] Among them, the circularly polarized light CL1 of the first rotation direction that passes through the light extraction layer 40 can be incident on the anti-reflection layer 50 and emitted through the anti-reflection layer 50. The circularly polarized light CL2 of the second rotation direction is reflected by the light extraction layer 40 to the light emitting device 30, reflected by the conductive layer in the light emitting device 30 (for example, the conductive layer where the first electrode mentioned above is located, and of course, it can also be the conductive layer where the second electrode is located) and changes its rotation direction, for example, from counterclockwise to clockwise, and then enters the light extraction layer 40 again, and then can pass through the light extraction layer 40 to enter the anti-reflection layer 50, and then emit through the anti-reflection layer 50. As a result, the vast majority of the light emitted by the light emitting device 30 can be emitted through the light extraction layer 40 and the anti-reflection layer 50, thereby improving the display brightness of the display panel 10 and reducing the power consumption of the display panel. The embodiments of the present disclosure provide a display panel 10. By sequentially disposing a light extraction layer 40 and an anti-reflection layer 50 on a side of the light-emitting device 30 away from the backplane, the light extraction layer 40 can convert light emitted by the light-emitting device 30 and incident on the light extraction layer 40 into circularly polarized light CL1 of a first hand and circularly polarized light CL2 of a second hand. The light extraction layer 40 transmits the circularly polarized light CL1 of the first hand and reflects the circularly polarized light CL2 of the second hand. The reflected circularly polarized light CL2 of the second hand enters the light-emitting device 30, is reflected again by the first electrode or the second electrode in the light-emitting device 30, and its hand is changed before entering the light extraction layer 40 again. Since the circularly polarized light CL2 of the second rotation direction has changed its rotation direction and converted into the circularly polarized light of the first rotation direction, it can be emitted through the light extraction layer 40, and then continue to move forward and enter the anti-reflection layer 50, and is converted by the anti-reflection layer 50 into linear polarized light parallel to the light transmission axis direction of the anti-reflection layer 50, thereby allowing the circularly polarized light of the first rotation direction to be emitted through the anti-reflection layer 50. As a result, the display panel 10 can utilize the light extraction layer 40 to effectively utilize the light emitted by the light-emitting device 30, thereby improving the light extraction efficiency of the light-emitting device 30, so that about 80% of the light emitted by the light-emitting device 30 can pass through the light extraction layer 40 and the anti-reflection layer 50 and be emitted. Compared with the above-mentioned implementation method in which about 50% of the light emitted by the light-emitting device 30 is absorbed by the anti-reflection layer 50 and causes loss, the display panel provided by the embodiment of the present disclosure can reduce the loss caused by a part of the light emitted by the light-emitting device 30 being absorbed by the anti-reflection layer 50, thereby improving the display brightness of the display panel 10, reducing the power consumption of the display panel 10 and the display device 1, and improving the display life of the display panel 10 and the display device 1.

[0095] Furthermore, the anti-reflection layer 50 can prevent the transmission of circularly polarized light CL2 of the second hand. For example, if circularly polarized light CL2 of the second hand is incident on the anti-reflection layer 50, since the polarization direction of the circularly polarized light CL2 of the second hand is perpendicular to the transmission axis of the anti-reflection layer 50, it cannot pass through the anti-reflection layer 50. As a result, once external light enters the anti-reflection layer 50, the anti-reflection layer 50 blocks some of the light from passing through, thereby preventing this light from entering the interior of the light-emitting device and being reflected by the conductive layer therein, thereby improving the anti-reflection capability of the display panel.

[0096] In some examples, the transmittance of the light extraction layer 40 to the light emitted by the light emitting device 30 (which may be simply referred to as the transmittance of the light extraction layer 40 ) is greater than or equal to 35%.

[0097] For example, the transmittance of the light extraction layer 40 to the light emitted by the light emitting device is 35%, 40%, 50%, 60% or 70%.

[0098] In other examples, the reflectivity of the light extraction layer 40 to the light emitted by the light emitting device 30 (which may be simply referred to as the reflectivity of the light extraction layer 40 ) is greater than or equal to 35%.

[0099] For example, the reflectivity of the light extraction layer 40 to the light emitted by the light emitting device 30 is 35%, 42%, 50%, 60% or 75%.

[0100] In some other examples, the light extraction layer 40 has a transmittance greater than or equal to 35% for light emitted by the light-emitting device 30, and a reflectance greater than or equal to 35% for light emitted by the light-emitting device 30. It is understood that the sum of the transmittance and reflectance of the light extraction layer 40 for light emitted by the light-emitting device 30 is no greater than 100%. For example, the transmittance of the light extraction layer 40 for light emitted by the light-emitting device 30 is less than 50%, and the reflectance of the light extraction layer 40 for light emitted by the light-emitting device 30 is less than 50%.

[0101] By adopting the above-mentioned setting method, the transmittance and / or reflectivity of the light extraction layer 40 can be higher, the utilization rate of light by the light extraction layer 40 can be improved, the loss of light emitted by the light-emitting device 30 by the light extraction layer 40 can be reduced, and the loss of light emitted by the light-emitting device 30 can be reduced, which is beneficial to reducing the power consumption of the display panel 10 and the display device 1.

[0102] For example, the display panel includes some light-emitting devices 30 for emitting blue light. These light-emitting devices 30 can be referred to as blue light-emitting devices. When the wavelength of light emitted by the blue light-emitting devices and incident on the light extraction layer 40 is within the range of 440 nm to 470 nm, the reflectivity of the light extraction layer 40 is greater than or equal to 35% in at least one 10 nm interval within this range.

[0103] It is understood that light with a wavelength in the range of 440nm to 470nm is generally blue light. In other words, the reflectivity of the light extraction layer 40 on at least part of the blue light emitted by the light emitting device 30 is greater than or equal to 35%.

[0104] For example, the reflectivity of the light extraction layer 40 for blue light with a wavelength between 440 nm and 450 nm emitted by the light emitting device 30 is greater than or equal to 35%. Of course, the wavelength range can also be 445 nm to 455 nm, 450 nm to 460 nm, 455 nm to 465 nm, or 460 nm to 470 nm.

[0105] For example, the display panel includes some light-emitting devices 30 for emitting green light. These light-emitting devices 30 can be referred to as blue light-emitting devices. When the wavelength of light emitted by the green light-emitting devices and incident on the light extraction layer 40 is within the range of 510 nm to 540 nm, the reflectivity of the light extraction layer 40 is greater than or equal to 35% in at least one 10 nm interval within this range.

[0106] It is understood that light with a wavelength in the range of 510 nm to 540 nm is generally green light. In other words, the reflectivity of the light extraction layer 40 on at least part of the green light emitted by the light emitting device 30 is greater than or equal to 35%.

[0107] For example, the reflectivity of the light extraction layer 40 for green light with a wavelength between 510 nm and 520 nm emitted by the light emitting device 30 is greater than or equal to 35%. Of course, the wavelength range can also be 515 nm to 525 nm, 520 nm to 530 nm, 525 nm to 535 nm, or 530 nm to 540 nm.

[0108] For example, the display panel includes some light-emitting devices 30 that emit red light. These light-emitting devices 30 can be referred to as blue light-emitting devices. When the wavelength of light emitted by the red light-emitting devices and incident on the light extraction layer 40 is within the range of 610 nm to 645 nm, the reflectivity of the light extraction layer 40 is greater than or equal to 35% in at least one 10 nm interval within this range.

[0109] It is understood that light with a wavelength in the range of 610 nm to 645 nm is generally red light. In other words, the reflectivity of the light extraction layer 40 for at least part of the red light is greater than or equal to 35%.

[0110] For example, the reflectivity of the light extraction layer 40 for red light with a wavelength between 620 nm and 630 nm emitted by the light emitting device 30 is greater than or equal to 35%. Of course, the wavelength range can also be 615 nm to 625 nm, 625 nm to 635 nm, 630 nm to 640 nm, or 635 nm to 645 nm.

[0111] In this way, it can be ensured that the reflectivity of the light extraction layer 40 to light within different wavelength ranges emitted by the light-emitting device 30 is roughly the same, thereby ensuring that the brightness of light of different colors emitted by the display panel 10 is roughly the same, and it can also reduce the probability of color deviation in the case of white light formed by the combination of light emitted by multiple light-emitting devices.

[0112] The inventors conducted experiments on the reflectivity of the light extraction layer 40 within different wavelength ranges. As shown in Figure 5, a full-band light absorption layer was set on one side of the light extraction layer 40 and the anti-reflection layer 50. The reflectivity of the light extraction layer 40 to light within different wavelength ranges was obtained by testing, and the graph was obtained as Figure 6.

[0113] As can be seen from Figure 6, the average reflectivity of the light extraction layer 40 to light in the visible light range is greater than or equal to 35%. Therefore, the display panel 10 provided by the above-mentioned embodiment of the present disclosure can utilize the light extraction layer 40 to improve the utilization rate of the light emitted by the light-emitting device 30, thereby improving the brightness of the display panel 10 and reducing the power consumption of the display panel 10 and the display device 1.

[0114] As shown in Figure 6, when the wavelength of light incident on the light extraction layer 40 is in the range of 430nm to 460nm, the reflectivity of the light extraction layer 40 is greater than 35%. When the wavelength of light incident on the light extraction layer 40 is in the range of 520nm to 530nm, the reflectivity of the light extraction layer 40 is greater than 35%. When the wavelength of light incident on the light extraction layer 40 is in the range of 620nm to 630nm, the reflectivity of the light extraction layer 40 is greater than 35%.

[0115] In some embodiments, the material of the light extraction layer 40 includes cholesteric liquid crystal.

[0116] Exemplarily, cholesteric liquid crystal can convert incident light into circularly polarized light, and can transmit circularly polarized light with a direction opposite to its own, such as circularly polarized light CL1 with a first rotation direction; and reflect circularly polarized light with the same rotation direction as its own, such as circularly polarized light CL2 with a second rotation direction.

[0117] By adopting the above-mentioned setting method, the screening efficiency of the light extraction layer 40 can be improved, so that more circularly polarized light can pass through the light extraction layer 40 and be emitted, and more circularly polarized light can be reflected by the light extraction layer 40 and then pass through the light-emitting device 30 to enter the light extraction layer 40 again and be emitted, thereby improving the utilization rate of the light emitted by the light-emitting device 30, improving the luminous brightness of the display panel 10, reducing the power consumption of the display panel 10, and improving the service life of the display panel 10 and the display device 1.

[0118] It is understood that the display panel 10 has a display area, which is the area of ​​the display panel 10 used to display images. The light extraction layer 40 composed of cholesteric liquid crystals covers the entire display area of ​​the display panel 10. In this way, light emitted by the multiple light-emitting devices 30 in the display panel can all pass through the cholesteric liquid crystals before being emitted, thereby improving the utilization rate of the light emitted by the light-emitting devices 30 and reducing the power consumption of the display panel 10.

[0119] Cholesteric liquid crystals have multiple layers of molecules. The arrangement direction of each layer of molecules is the same, but the arrangement directions of the molecules in the adjacent layers are slightly rotated, stacked into a spiral structure. Cholesteric liquid crystals have a microscopic spiral structure. When the arrangement direction of one layer of molecules rotates 360 degrees and then returns to the original direction, the distance between the two layers with exactly the same molecular arrangement is called the pitch of the cholesteric liquid crystal. Cholesteric liquid crystals are generally ester compounds formed by reacting cholesterol as the main raw material with certain organic acids (such as oleic acid, benzoic acid, nonanoic acid, etc.).

[0120] For example, cholesteric liquid crystals with different helical pitches can reflect light of different wavelengths. In other words, cholesteric liquid crystals with different helical pitches can selectively reflect light of different wavelengths.

[0121] There are many ways to set the light extraction layer in the display panel, which can be set according to actual needs, and the present disclosure does not limit this.

[0122] 7A to 7D , the material of the light extraction layer 40 includes at least one cholesteric liquid crystal. When the material of the light extraction layer 40 includes at least two cholesteric liquid crystals, the helical pitches of the at least two cholesteric liquid crystals are unequal.

[0123] In some examples, as shown in FIG7A , the material of the light extraction layer 40 includes a cholesteric liquid crystal. That is, the helical pitches of the cholesteric liquid crystals in the light extraction layer 40 are substantially uniform. The helical pitches of the cholesteric liquid crystals in the light extraction layer 40 are within a relatively small size range, or the helical pitches of the cholesteric liquid crystals in the light extraction layer 40 are all of the same size.

[0124] The cholesteric liquid crystal has a high reflectivity and transmittance for light within a certain wavelength range emitted by the plurality of light emitting devices 30 .

[0125] For example, when the pitch of the cholesteric liquid crystal is the first size, the light extraction layer 40 formed by the cholesteric liquid crystal has a high reflectivity and transmittance only for the red light emitted by the light-emitting device, thereby improving the light extraction efficiency of the red light-emitting device. For another example, when the pitch of the cholesteric liquid crystal is the second size, the light extraction layer 40 formed by the cholesteric liquid crystal has a high reflectivity and transmittance only for the green light emitted by the light-emitting device, thereby improving the light extraction efficiency of the green light-emitting device. For another example, when the pitch of the cholesteric liquid crystal is the third size, the light extraction layer 40 formed by the cholesteric liquid crystal has a high reflectivity and transmittance only for the blue light emitted by the light-emitting device, thereby improving the light extraction efficiency of the blue light-emitting device. In this way, the light extraction layer 40 can have a high reflection or transmittance for light within a certain wavelength range, thereby improving the brightness of the light within this wavelength range. The above-mentioned first size, second size, and third size are not equal.

[0126] In other examples, as shown in Figure 7B, when the material of the light extraction layer 40 includes at least two cholesteric liquid crystals, the light extraction layer 40 includes: at least two sub-light extraction layers stacked in sequence; the at least two sub-light extraction layers include: a first light extraction layer 41 and a second light extraction layer 42; the pitch of the cholesteric liquid crystal in the first light extraction layer 41 is not equal to the pitch of the cholesteric liquid crystal in the second light extraction layer 42.

[0127] For example, as shown in FIG7B , the light extraction layer 40 includes a first light extraction layer 41, a second light extraction layer 42, and a third light extraction layer 43, which are stacked in sequence. The helical pitch of the cholesteric liquid crystal in the first light extraction layer 41, the helical pitch of the cholesteric liquid crystal in the second light extraction layer 42, and the helical pitch of the cholesteric liquid crystal in the third light extraction layer 43 are not equal.

[0128] There are many corresponding relationships between the pitch of the cholesteric liquid crystal in the first light extraction layer 41, the pitch of the cholesteric liquid crystal in the second light extraction layer 42, and the pitch of the cholesteric liquid crystal in the third light extraction layer 43 and the wavelength of red light, green light, and blue light. They can be selected and set as needed, and the present disclosure does not impose any restrictions on this.

[0129] For example, the helical pitch of the cholesteric liquid crystal in the first light extraction layer 41 corresponds to the wavelength of red light, and the cholesteric liquid crystal in the first light extraction layer 41 can reflect light with a red wavelength. The helical pitch of the cholesteric liquid crystal in the second light extraction layer 42 corresponds to the wavelength of green light, and the cholesteric liquid crystal in the second light extraction layer 42 can reflect light with a green wavelength. The helical pitch of the cholesteric liquid crystal in the third light extraction layer 43 corresponds to the wavelength of blue light, and the cholesteric liquid crystal in the third light extraction layer 43 can reflect light with a blue wavelength.

[0130] For example, the helical pitch of the cholesteric liquid crystal in the first light extraction layer 41 corresponds to the wavelength of green light, and the cholesteric liquid crystal in the first light extraction layer 41 can reflect light with a green wavelength. The helical pitch of the cholesteric liquid crystal in the second light extraction layer 42 corresponds to the wavelength of red light, and the cholesteric liquid crystal in the second light extraction layer 42 can reflect light with a red wavelength. The helical pitch of the cholesteric liquid crystal in the third light extraction layer 43 corresponds to the wavelength of blue light, and the cholesteric liquid crystal in the third light extraction layer 43 can reflect light with a blue wavelength.

[0131] Therefore, the light extraction layer 40 can reflect light of different colors or different wavelengths emitted by multiple light-emitting devices 30, so that the reflection of light by the light extraction layer 40 can be accurately controlled, the utilization rate of light emitted by the light-emitting device 30 can be improved, and the brightness of light of different colors emitted by the light-emitting device 30 can be adjusted to be roughly the same, thereby reducing the probability of color deviation of the white light synthesized by the interaction of light of different colors.

[0132] In some further examples, as shown in Figure 7C, when the material of the light extraction layer 40 includes at least two cholesteric liquid crystals, the at least two cholesteric liquid crystals include a first liquid crystal and a second liquid crystal; the first liquid crystal is uniformly distributed in the light extraction layer, the second liquid crystal is uniformly distributed in the light extraction layer, and the distribution density of the first liquid crystal in the light extraction layer 40 is approximately equal to the distribution density of the second liquid crystal in the light extraction layer 40.

[0133] Exemplarily, the material of the light extraction layer 40 includes at least two cholesteric liquid crystal materials with different helical pitches. At different locations in the light extraction layer 40, the at least two cholesteric liquid crystals with different helical pitches are evenly distributed, or in other words, the distribution density of the at least two cholesteric liquid crystals with different helical pitches at different locations in the light extraction layer 40 is approximately the same. For example, a blending process can be used to blend the at least two cholesteric liquid crystals with different helical pitches to prepare the light extraction layer.

[0134] Taking the above-mentioned light extraction layer 40 as an example, which includes three cholesteric liquid crystals, the three cholesteric liquid crystals of different pitches are a first liquid crystal, a second liquid crystal, and a third liquid crystal. For example, the first liquid crystal has a high reflectivity and transmittance for red light emitted by the light-emitting device, thereby reflecting or transmitting the red light; the second liquid crystal has a high reflectivity and transmittance for green light emitted by the light-emitting device, thereby reflecting or transmitting the green light; and the third liquid crystal has a high reflectivity and transmittance for blue light emitted by the light-emitting device, thereby reflecting or transmitting the blue light. Thus, the light extraction layer can be used to precisely control the light emitted by the light-emitting device, thereby improving the light extraction efficiency of the light-emitting device and adjusting the brightness of the different colors of light emitted by the light-emitting device to be approximately the same, thereby reducing the probability of color cast in the white light synthesized by the interaction of different colors of light.

[0135] In some other examples, as shown in FIG7D , when the material of the light extraction layer 40 includes at least two cholesteric liquid crystals, the pitches of the cholesteric liquid crystals corresponding to the light emitting devices 30 with different luminous colors in the light extraction layer 40 are not equal.

[0136] Exemplarily, the light extraction layer 40 may include multiple first light extraction portions 401, multiple second light extraction portions 402, and multiple third light extraction portions 403. The cholesteric liquid crystals in the first light extraction portions 401, the second light extraction portions 402, and the third light extraction portions 403 have different helical pitches. Each first light extraction portion 401 corresponds to a red light-emitting device 301. This means that the orthographic projection of a red light-emitting device 301 on the backplane 20 is within the orthographic projection range of a first light extraction portion 401 on the backplane 20. Light emitted by the red light-emitting device 301 is projected onto the corresponding first light extraction portion 401, enabling the first light extraction portion 401 to reflect or transmit the red light emitted by the red light-emitting device 301. Each second light extraction portion 402 corresponds to a green light-emitting device 302. That is, the orthographic projection of a green light-emitting device 302 on the back panel 20 is within the orthographic projection range of a second light extraction portion 402 on the back panel 20. Light emitted by the green light-emitting device 302 is projected onto the corresponding second light extraction portion 402, thereby enabling the second light extraction portion 402 to reflect or transmit the red light emitted by the green light-emitting device 302. A third light extraction portion 403 corresponds to a blue light-emitting device 303. That is, the orthographic projection of a blue light-emitting device 303 on the back panel 20 is within the orthographic projection range of a third light extraction portion 403 on the back panel 20. Light emitted by the blue light-emitting device 303 is projected onto the corresponding third light extraction portion 403, thereby enabling the third light extraction portion 403 to reflect or transmit the red light emitted by the blue light-emitting device 303.

[0137] For example, in the light extraction layer 40, the helical pitches of the cholesteric liquid crystals corresponding to the light-emitting devices 30 emitting the same light color can be approximately the same. The helical pitches of the cholesteric liquid crystals in the multiple first light extraction portions 401 are approximately the same. The helical pitches of the cholesteric liquid crystals in the multiple second light extraction portions 402 are approximately the same. The helical pitches of the cholesteric liquid crystals in the multiple third light extraction portions 403 are approximately the same. "Approximately the same" means that the helical pitches of the cholesteric liquid crystals at different positions are equal, or that the difference between the helical pitches of the cholesteric liquid crystals at different positions is less than or equal to 5% of the minimum helical pitch of the cholesteric liquid crystals.

[0138] When the pitch of the cholesteric liquid crystal matches the wavelength of light emitted by the light emitting device, the cholesteric liquid crystal can selectively reflect and transmit light, and the reflectivity and transmittance of the light are relatively high.

[0139] Since the wavelengths of light emitted by different light-emitting devices are different, the above-mentioned setting can enable the cholesteric liquid crystals in the parts of the light extraction layer 40 corresponding to different light-emitting devices 30 to accurately transmit or reflect light of different wavelengths, thereby accurately regulating the transmittance and reflectivity of the light extraction layer for light of different wavelengths emitted by different light-emitting devices 30, thereby improving the utilization rate of light emitted by different light-emitting devices 30, and adjusting the brightness of light of different colors emitted by the light-emitting devices to be roughly the same, thereby reducing the probability of color cast in the white light synthesized by the interaction of light of different colors.

[0140] In some examples, the display panel 10 further includes: a first connection layer located on the side of the light extraction layer 40 close to the anti-reflection layer 50 , and / or a second connection layer located on the side of the light extraction layer 40 away from the anti-reflection layer 50 .

[0141] Exemplarily, both the first connecting layer and the second connecting layer function as adhesives: the first connecting layer is used to connect the anti-reflection layer 50 and the light extraction layer 40 , and the second connecting layer is used to connect the light extraction layer 40 and the light emitting device 30 .

[0142] In some embodiments, as shown in FIG. 7A , the anti-reflection layer 50 includes at least a quarter wave plate and a polarizing layer 52 . The quarter wave plate is located between the polarizing layer 52 and the light extraction layer 40 .

[0143] In some examples, the quarter-wave plate causes a phase delay of (2n-1)λ / 4 on light incident thereon, where λ is the wavelength of the incident light, for example, λ ranges from 520 nm to 570 nm, and n is a positive integer, for example, n=1, 2, 3, etc.

[0144] Of course, when the wavelength λ of the incident light is in the range of 460 nm to 630 nm, the quarter wave plate can also cause the light incident thereon to have a phase delay of (2n-1)λ / 4.

[0145] Exemplarily, as shown in FIG. 4 , the circularly polarized light passing through the light extraction layer 40 is converted into linearly polarized light by the quarter wave plate after entering the quarter wave plate.

[0146] In some examples, the polarizing layer 52 can transmit light parallel to its transmission axis and reflect light perpendicular to its transmission axis. This can reduce the amount of light entering the display panel 10 and reduce the reflection of external light by the conductive layer within the display panel 10, thereby improving the contrast of the display panel 10. Furthermore, the display panel 10 can emit light with a uniform polarization state, thus preventing haloing.

[0147] In some embodiments, the transmittance of the polarizing layer 52 to visible light is greater than or equal to 40%.

[0148] For example, the transmittance of the polarizing layer 52 may be 40%, 45%, 52%, 62% or 75%.

[0149] By adopting the above configuration, the light loss of the polarizing layer 52 can be reduced, the light extraction efficiency of the display panel 10 can be improved, the light loss can be reduced, and the power consumption of the display panel 10 and the display device 1 can be reduced.

[0150] In some embodiments, as shown in FIG8 , the anti-reflection layer 50 further includes a light absorbing layer 53 . The light absorbing layer 53 is stacked with the quarter wave plate or the polarizing layer 52 .

[0151] For example, the light absorbing layer 53 may be located between the quarter wave plate and the polarizing layer 52 , or the light absorbing layer 53 may be located on the side of the quarter wave plate away from the polarizing layer 52 , or the light absorbing layer 53 may be located on the side of the polarizing layer 52 away from the quarter wave plate.

[0152] Exemplarily, the light absorbing layer 53 is used to absorb light with a wavelength below 450 nm, for example, light with a wavelength of 445 nm, 440 nm, or 435 nm.

[0153] Light with a wavelength below 450nm is generally short-wave blue light.

[0154] By adopting the above-mentioned setting method, the light absorbing layer 53 can be used to absorb the short-wave blue light filtered by the light extraction layer 40, thereby preventing the short-wave blue light from being emitted from the display panel and preventing the short-wave blue light from entering the human eye and causing damage to the human eye. In this way, the display panel 10 and the display device 1 can have an eye protection function.

[0155] In some embodiments, as shown in FIG9A , the display panel 10 further includes a light shielding layer 60 disposed between the plurality of light-emitting devices 30 and the light extraction layer 40. The light shielding layer 60 has a plurality of first openings 61. The orthographic projection of a light-emitting device 30 on the backplane 20 overlaps with the orthographic projection of the first opening 61 on the backplane 20.

[0156] Here, the orthographic projection of a light emitting device 30 on the back plate 20 refers to the orthographic projection of the effective light emitting area of ​​the light emitting device 30 on the back plate 20. The effective light emitting area of ​​the light emitting device 30 is the area defined by the second opening in the defining layer of the light emitting device 30.

[0157] For example, light emitted by a light emitting device 30 is incident on the area corresponding to the corresponding first opening 61 .

[0158] Exemplarily, the orthographic projection of the light emitting device 30 on the back plate 20 is located within the orthographic projection range of the first opening 61 on the back plate 20 .

[0159] The light shielding layer 60 can absorb or block the light incident thereon, preventing the light from passing through, thereby achieving a light shielding effect, and the first openings 61 on the light shielding layer 60 can allow a portion of the light emitted by the corresponding light emitting device 30 to pass through. For example, multiple light emitting devices 30 correspond to multiple first openings 61 on a one-to-one basis.

[0160] By adopting the above-mentioned arrangement, the light with a large viewing angle (the light with a large viewing angle here refers to the light with a large angle between the emission direction of the light and the normal of the back plate 20, for example, the angle is greater than 45°) emitted by each light emitting device 30 can be blocked by the light shielding layer 60, thereby avoiding crosstalk between the light emitted by adjacent light emitting devices 30, thereby improving the display effect of the display panel 10. Moreover, the setting of the light shielding layer 60 can also reduce the reflection effect of the display panel on external light, so that the display panel 10 has a higher contrast in a bright field of view, thereby improving the display effect of the display panel 10. In addition, the display panel 10 can also emit light with a smaller viewing angle, so that the brightness of the image displayed by the display panel 10 viewed by the user at a smaller viewing angle is larger, and the brightness of the display image viewed by the user at other viewing angles is smaller, thereby making the display panel 10 have a certain anti-peeping function. It is understandable that in different areas of the display panel, the angles between the sidewalls of the first opening 61 in the light shielding layer 60 and the plane where the back plate 20 is located can be equal or unequal.

[0161] In some examples, as shown in FIG9B , the display panel 10 has a first region R1 and a second region R2. An included angle α1 between the sidewall of the at least one first opening 61 in the first region R1 and the plane where the back plate 20 is located is different from an included angle α2 between the sidewall of the at least one first opening 61 in the second region R2 and the plane where the back plate 20 is located.

[0162] For example, the first region R1 and the second region R2 may be adjacent to each other or may not be adjacent to each other.

[0163] For example, when the display panel 10 is a full-screen display panel including an under-screen camera (FDC), the first region R1 of the display panel 10 is the display area directly opposite the camera, and the second region R2 is the display area excluding the first region R1. An angle α1 between the sidewalls of the plurality of first openings 61 located in the first region R1 and the plane of the back plate 20 is set to be smaller than an angle α2 between the sidewalls of at least one first opening 61 located in the second region R2 and the plane of the back plate 20. This allows the light shielding layer 60 to block less light incident on the camera through the first region R1, thereby allowing the camera to receive sufficient external light to achieve the camera function.

[0164] For example, when the display panel 10 is applied to a transparent display panel, the size of the angle α1 between the side wall of at least one first opening 61 located in the first area R1 and the plane where the back panel 20 is located, and the angle α2 between the side wall of at least one first opening 61 located in the second area R2 and the plane where the back panel 20 is located can be set according to actual conditions.

[0165] By adopting the above setting, the first openings 61 in different areas of the display panel 10 can be designed differently, so that the light output of different areas of the display panel 10 can be adjusted to ensure that the light output of different areas of the display panel 10 is roughly the same, thereby ensuring the display effect of the display panel 10.

[0166] In some embodiments, as shown in FIG. 9A , the angle α between the sidewall of the first opening 61 and the plane where the back plate 20 is located is an acute angle.

[0167] For example, the angle between the sidewall of the first opening 61 and the plane where the back plate 20 is located may be 25°, 30°, 35°, 37° or 40°.

[0168] By adopting the above-mentioned setting method, it is possible to avoid a large angle between the side wall of the first opening 61 and the plane where the back plate 20 is located, which makes it easy to pierce the entire light extraction layer 40 located on the light-shielding layer 60, and facilitate the preparation of the light extraction layer 40 and the anti-reflection layer 50 located on the light-shielding layer 60.

[0169] In some examples, as shown in FIG. 9A , the display panel 10 further includes a planar layer 601 located on a side of the light shielding layer 60 away from the back plate 20 .

[0170] For example, the side of the flat layer 601 away from the back plate 20 is a flat surface, and the light extraction layer 40 is disposed on the flat surface, thereby facilitating the preparation of the light extraction layer 40 .

[0171] In some embodiments, as shown in FIG. 10A , the display panel 10 further includes a defining layer 70 located between the back plate 20 and the light shielding layer 60 .

[0172] In some examples, the defining layer 70 has a plurality of second openings 71 , and along a direction perpendicular to the plane where the back plate 20 is located, one second opening 71 is disposed opposite to one first opening 61 .

[0173] For example, an orthographic projection of a second opening 71 on the back plate 20 has an overlapping area with an orthographic projection of a first opening 61 on the back plate 20 .

[0174] Since one first opening 61 corresponds to one light emitting device 30 and one second opening 71 is disposed opposite to one first opening 61 , one second opening 71 is also disposed corresponding to one light emitting device 30 .

[0175] It is understandable that, in different areas of the display panel 10 , the angles between the sidewalls of the plurality of second openings 71 in the defining layer 70 and the plane where the back plate 20 is located may be equal or unequal.

[0176] In some examples, as shown in FIG10B , the display panel 10 has a third region R3 and a fourth region R4. An included angle β1 between the sidewall of the at least one second opening 71 in the third region R3 and the plane where the back plate 20 is located is not equal to an included angle β2 between the sidewall of the at least one second opening 71 in the fourth region R4 and the plane where the back plate 20 is located.

[0177] For example, the angle β1 between the sidewall of at least one second opening 71 in the third region R3 and the plane of the back plate 20 is greater than the angle β2 between the sidewall of at least one second opening 71 in the fourth region R4 and the plane of the back plate 20 .

[0178] With the above-mentioned setting, for example, when the display panel 10 is a full-screen display or a transparent display panel or a double-sided display panel, the second openings 71 in different areas of the display panel 10 can be designed differently, so that the light output of different areas of the display panel 10 can be adjusted to ensure that the light output of different areas of the display panel 10 is roughly the same, thereby ensuring the display effect of the display panel 10.

[0179] In the same area of ​​the display panel 10, such as the third area R3 mentioned above, the relationship between the angle α between the side wall of the first opening 61 and the plane where the back panel 20 is located, and the angle β between the side wall of the second opening 71 and the plane where the back panel 20 is located can be set according to actual needs, and the embodiments of the present disclosure are not limited to this.

[0180] In some examples, as shown in FIG. 10A , an angle α between the sidewall of the first opening 61 and the plane where the back plate 20 is located is greater than an angle β between the sidewall of the second opening 71 and the plane where the back plate 20 is located.

[0181] With the above-mentioned setting, the shading layer 60 having the first opening 61 can be used to block the light emitted at a larger angle from the light-emitting device 30, so that the light emission angle of the display panel 10 is smaller, so that the user can view the display screen at a smaller viewing angle, while the brightness of the display screen viewed by the user at a larger viewing angle is smaller, or the user cannot view the display screen at a larger viewing angle, so that the display panel 10 can achieve better anti-peeping function, especially when the display panel is used for vehicle-mounted display.

[0182] In other examples, the angle α between the sidewall of the first opening 61 and the plane where the back plate 20 is located is smaller than the angle β between the sidewall of the second opening 71 and the plane where the back plate 20 is located.

[0183] With the above-mentioned arrangement, the light-shielding layer 60 having the first opening 61 blocks less light at a larger angle emitted by the light-emitting device 30, thereby making the light emission angle of the display panel 10 larger, so that the user can view the display image at different viewing angles. Therefore, when the display panel is in an outdoor environment or other environmental conditions, the display panel can enable more users at different viewing angles to view the display image, thereby achieving a good display effect.

[0184] In some other examples, the angle α between the sidewall of the first opening 61 and the plane where the back plate 20 is located is equal to the angle β between the sidewall of the second opening 71 and the plane where the back plate 20 is located.

[0185] 12 , the light emitting device 30 includes at least a light emitting layer 33 . One light emitting layer 33 is located in at least one second opening 71 .

[0186] For example, the light emitting layer 33 is located in the second opening 71 . In another example, a portion of the light emitting layer 33 is located in the second opening 71 , another portion of the light emitting layer 33 overlaps the defining layer 70 , and two adjacent light emitting layers 33 are disconnected.

[0187] Exemplarily, the defining layer 70 separates the light emitting layers 33 of adjacent light emitting devices 30 , thereby reducing the probability of crosstalk between large-angle light emitted by the light emitting devices 30 .

[0188] As shown in FIG. 10A , illustratively, the angle β between the sidewall of the second opening 71 and the plane where the back plate 20 is located is less than or equal to 35°.

[0189] For example, the angle β between the sidewall of the second opening 71 and the plane where the back plate 20 is located can be 20°, 25°, 27°, 32° or 35°.

[0190] By adopting the above-mentioned setting method, the flatness of the film layer formed on the defining layer 70 (such as the second electrode 32 mentioned below) can be ensured, and the angle between the side wall of the second opening 71 and the plane where the back plate 20 is located is avoided to be too large, resulting in the disconnection of the film layer, thereby improving the stability and accuracy of the signal transmitted by the film layer and improving the display effect of the display panel 10.

[0191] In some embodiments, the material of the defining layer 70 includes a light absorbing material, and / or the material of the light shielding layer 70 includes a light absorbing material.

[0192] In some examples, the material of the defining layer 70 includes a light-absorbing material, so that the portion of light emitted by the light-emitting device 30 that is incident on the defining layer 70 can be absorbed by the defining layer 70 .

[0193] In other examples, the material of the light shielding layer 60 includes a light-absorbing material. Thus, the light shielding layer 60 can absorb light at large angles, preventing this portion of light from being emitted, thereby mitigating or even preventing crosstalk between light emitted by adjacent light-emitting devices 30. Furthermore, the user can view the image displayed on the display panel 10 at a narrow viewing angle, thereby providing the display panel 10 with a certain degree of privacy protection.

[0194] In some other examples, the material of the definition layer 70 includes a light absorbing material, and the material of the light shielding layer 60 includes a light absorbing material.

[0195] For example, the material of the defining layer 70 and the material of the light shielding layer 60 may be the same.

[0196] By adopting the above-mentioned setting method, the defining layer 70 or the light-shielding layer 60 formed by the light-absorbing material can be used to slow down or even avoid the crosstalk between the light emitted by adjacent light-emitting devices 30, and enable the user to view the image displayed by the display panel 10 at a smaller viewing angle (for example, at a roughly straight-on viewing angle), thereby giving the display panel 10 and the display device 1 a certain anti-peeping function.

[0197] In some embodiments, the light absorbing material has an absorbance greater than or equal to 0.5.

[0198] For example, the absorbance represents the degree of light absorption per unit thickness of the material. An absorbance greater than or equal to 50% means that the intensity of light decreases by at least 50% after passing through each micron of the light-absorbing material.

[0199] For example, the absorbance of the light absorbing material is 50%, 60%, 80%, 90% or 100%.

[0200] By setting the absorbance of the light-absorbing material within the above range, the defining layer 70 or the light-shielding layer 60 can be used to absorb large-angle, different-color light emitted by adjacent light-emitting devices 30, thereby slowing down or avoiding the crosstalk between the different-color light, thereby improving the display effect of the display panel 10 and the display device 1.

[0201] In some embodiments, as shown in FIG. 10A and FIG. 11 , the orthographic projection of the second opening 71 on the back plate is located within the orthographic projection range of the first opening 61 on the back plate that is directly opposite to the second opening 71 .

[0202] Illustratively, the boundary line of the orthographic projection of the second opening 71 on the back plate 20 is located within the boundary line of the orthographic projection of the first opening 61 on the back plate 20 directly opposite to the second opening 71 , and there is a certain distance between the two boundary lines.

[0203] For example, in the orthographic projection onto the plane where the light extraction layer 40 is located, the orthographic projection of the defining layer 70 covers the orthographic projection of the light shielding layer 60 .

[0204] The above arrangement can avoid the phenomenon that the light shielding layer 60 blocks or absorbs more light incident through the second opening 71 of the defining layer 70 and weakens the light intensity of the outgoing light, thereby improving the brightness of the display panel 10 and reducing the power consumption of the display panel 10 and the display device 1.

[0205] In some embodiments, as shown in Figure 10A, the maximum spacing L between the boundary line of the orthographic projection of the second opening 71 on the back panel 20 and the boundary line of the orthographic projection of the first opening 61 opposite to the second opening 71 on the back panel 20 is less than or equal to 1 / 3 of the maximum size of the orthographic projection of the second opening 71 on the back panel 20.

[0206] For example, the maximum distance L between the boundary line of the orthographic projection of the second opening 71 on the back panel 20 and the boundary line of the orthographic projection of the first opening 61 opposite to the second opening 71 on the back panel 20 is 1 / 3, 2 / 7, 1 / 4, 2 / 9 or 1 / 5 of the maximum size of the orthographic projection of the second opening 71 on the back panel 20.

[0207] Since the angle between the side wall of the first opening 61 and the plane where the back plate 20 is located is an acute angle rather than a right angle, the orthographic projection of the first opening 61 on the back plate 20 is two contour lines, which are an outer contour line and an inner contour line, wherein the inner contour line is located within the outer contour line. The boundary line of the orthographic projection of the first opening 61 on the back plate 20 refers to the inner contour line of the orthographic projection of the first opening 61 on the back plate 20. Similarly, since the angle between the side wall of the second opening 71 and the plane where the back plate 20 is located is an acute angle rather than a right angle, the orthographic projection of the second opening 71 on the back plate 20 is two contour lines, which are an outer contour line and an inner contour line, wherein the inner contour line is located within the outer contour line. The boundary line of the orthographic projection of the second opening 71 on the back plate 20 refers to the inner contour line of the orthographic projection of the second opening 71 on the back plate 20.

[0208] There is a certain distance between any two points on the boundary line of the orthographic projection of the first opening 61 on the back plate 20. The "maximum distance" mentioned above refers to the distance between the two points on the boundary line of the orthographic projection of the first opening 61 on the back plate 20 that are opposite the second opening 71, with the largest distance between them.

[0209] For example, the shapes of the orthographic projection of the second opening 71 on the back plate 20 may be various and may be selected according to actual conditions, and the present disclosure does not impose any limitation thereto.

[0210] For example, the shape of the orthographic projection of the second opening 71 on the back plate 20 can be a hexagon, a rectangle, etc. Taking the shape of the orthographic projection of the second opening 71 on the back plate 20 as a hexagon as an example, the maximum size of the orthographic projection of the second opening 71 on the back plate 20 can be the size of the longest diagonal of the hexagon.

[0211] By adopting the above-mentioned setting method, the shading layer 60 can not only have a certain shielding effect on the light emitted by each light-emitting device 30, reducing the crosstalk between the light emitted by adjacent light-emitting devices, but also enable the light emitted by the light-emitting device 30 with a larger viewing angle to be emitted from the first opening 61 of the shading layer 60, meeting the user's need to view the display screen of the display panel 10 within a larger viewing angle range, so that the user can normally view the screen displayed by the display panel at a side viewing angle (or the brightness of the screen displayed by the display panel at a side viewing angle is higher), so that the display panel can realize a shared display, avoiding the shading layer 60 blocking or absorbing light within a larger angle range, resulting in a narrow viewing angle for the user or a low display brightness at a large viewing angle, thereby avoiding affecting the viewing experience at a side viewing angle.

[0212] It is understood that the light emitting device 30 may be a top-emitting device, which emits light toward a side away from the back plate 20. The following description takes the first electrode 31 as an anode and the second electrode 32 as a cathode as an example.

[0213] For example, as shown in FIG12 , in the above-mentioned light emitting device 30 , the material of the second electrode 32 may be a semi-transparent material or a transparent material, and the reflectivity of the first electrode 31 is greater than or equal to 85%.

[0214] For example, the second electrode 32 may transmit at least a portion of light incident on a surface thereof.

[0215] Exemplarily, the reflectivity of the first electrode 31 to light within the visible wavelength range is in the range of 85% to 95%. Thus, the first electrode 31 can be used to reflect as much light as possible from the light emitting device 30, thereby improving the light extraction efficiency of the light emitting device 30.

[0216] For example, the reflectivity of the first electrode 31 may be 85%, 90%, 92%, 94%, or 95%.

[0217] For example, the light-emitting layer 33 emits natural light under the voltage provided by the first electrode 31 and the second electrode 32. A portion of the light emitted by the light-emitting layer 33 can be emitted through the second electrode 32. Another portion of the light emitted by the light-emitting layer 33 can be reflected by the first electrode 31 and then incident on the second electrode 32 and emitted. Furthermore, the circularly polarized light CL2 of the second handedness reflected by the light extraction layer 40 will also pass through the second electrode 32 and the light-emitting layer 33 before being incident on the first electrode 31. There, the handedness direction is changed by the first electrode 31 and reflected to the second electrode 32. Thereafter, the light will pass through the second electrode 32 again before being incident on the light extraction layer 40 again and being emitted through the light extraction layer 40.

[0218] By adopting the above-mentioned setting method, the transmittance of the second electrode 32 can be higher, and the reflectivity of the first electrode 31 can be higher, thereby reducing the loss of light emitted by the light-emitting device 30 when it is incident on the first electrode 31 or the second electrode 32, thereby improving the utilization rate of the light emitted by the light-emitting layer 33, reducing the light consumption of the light-emitting device 30, and thereby improving the display brightness of the display panel 10 and the display device 1, and reducing the power consumption of the display panel 10 and the display device 1.

[0219] In some examples, the material of the first electrode 31 is a material with a relatively high work function, which is beneficial for improving the light extraction efficiency of the light emitting device 30 .

[0220] Exemplarily, the first electrode 31 may be formed of a multi-layer composite film. The multi-layer film may include a metal oxide material and a metal material, such as a composite film of Ag (Argentum) and ITO (Indium Tin Oxide), or a composite film of Ag and IZO (Indium Zinc Oxide). The thickness of the metal material may range from 80 nm to 200 nm, and the thickness of the metal oxide material may range from 5 nm to 10 nm.

[0221] For example, the material of the second electrode 32 may be a single metal, such as Mg (Magnesium), Ag, or Al (Aluminum).

[0222] For example, the second electrode 32 may be made of a metal alloy, such as a magnesium-silver alloy (Mg-Ag). When the second electrode 32 is made of a magnesium-silver alloy, the mass ratio of magnesium to silver in the magnesium-silver alloy ranges from 1:9 to 3:7. The second electrode 32 composed of this metal alloy has a transmittance of 50% to 60% for light with a wavelength of 530 nm.

[0223] For another example, the material of the second electrode 32 may also be a transparent metal oxide material, such as ITO, IZO, IGZO (Indium Gallium Zinc Oxide), etc.

[0224] Exemplarily, the colors of the light emitted by the multiple light emitting devices 30 may be the same or different.

[0225] In some examples, the plurality of light emitting devices 30 may include a plurality of red light emitting devices 301, a plurality of green light emitting devices 302, and a plurality of blue light emitting devices 303. The red light emitting devices 301 emit red light, the green light emitting devices 302 emit green light, and the blue light emitting devices 303 emit blue light.

[0226] In some examples, as shown in FIG12 , the light-emitting device 30 further includes a hole injection layer 34 (HIL), a hole transport layer 35 (HTL), and an electron blocking layer 36 (EBL) sequentially stacked on the first electrode 31 .

[0227] For example, the hole injection layer 34 is used to reduce the potential barrier of hole injection and improve the efficiency of hole injection. The hole injection layer 34 can be a single layer film made of materials such as HATCN (Hexaazatriphenylenehexacarbonitrile) and CuPc (Copper Phthalocyanine). The hole injection layer 34 may also be formed by p-doping a hole transport material, such as NPB (N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine), F4TCNQ (2-[4-(dicyanomethylidene)-2,3,5,6-tetrafluorocyclohexa-2,5-dien-1-ylidene]propanedinitrile, 2,3,5,6-tetrafluoro-7,7′,8,8′-tetracyanodimethyl-p-benzoquinone), TAPC (4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline], 4,4′-cyclohexylbis[N,N-di(4-methylphenyl)aniline), or MnO3 (manganese trioxide). The p-doping concentration ranges from 0.5% to 10%. The thickness of the hole injection layer 34 ranges from 5 nm to 20 nm. For example, the thickness of the hole injection layer 34 may be 5 nm, 10 nm, 12 nm, 15 nm, or 20 nm.

[0228] For example, the hole injection layers 34 of different light-emitting devices 30 are interconnected to form an integrated structure, thereby simplifying the manufacturing process of the light-emitting device 30 .

[0229] Exemplarily, the hole transport layer 35 is used to transport holes. The material of the hole transport layer 35 may include a carbazole material, etc., which can increase the hole mobility. The highest occupied molecular orbital (HOMO) energy level of the material of the hole transport layer 35 must be within the range of -5.2eV to -5.6eV. The hole transport layer 35 can be formed using an evaporation process. The thickness of the hole transport layer 35 ranges from 100nm to 200nm.

[0230] For example, the highest occupied molecular orbital energy level of the material of the hole transport layer 35 may be −5.2 eV, −5.3 eV, −5.4 eV, −5.5 eV, or −5.6 eV.

[0231] For example, the hole transport layers 35 of different light-emitting devices 30 are interconnected to form an integrated structure, thereby simplifying the manufacturing process of the light-emitting device 30 .

[0232] For example, the electron blocking layer 36 can transfer holes to the light-emitting layer 33 and can also block electrons and excitons.

[0233] Exemplarily, the thickness of the electron blocking layer 36 in the red light-emitting device 301 ranges from 40 nm to 60 nm, the thickness of the electron blocking layer 36 in the green light-emitting device 302 ranges from 15 nm to 30 nm, and the thickness of the electron blocking layer 36 in the blue light-emitting device 303 ranges from 1 nm to 10 nm.

[0234] For example, the thickness of the electron blocking layer 36 in the red light-emitting device 301 can be 40 nm, 43 nm, 47 nm, 52 nm, or 60 nm. The thickness of the electron blocking layer 36 in the green light-emitting device 302 can be 15 nm, 17 nm, 22 nm, 28 nm, or 30 nm. The thickness of the electron blocking layer 36 in the blue light-emitting device 303 ranges from 1 nm, 3 nm, 5 nm, 7 nm, or 10 nm. Thus, the luminous efficiency of the red light-emitting device 301, the green light-emitting device 302, and the blue light-emitting device 303 can be adjusted by using electron blocking layers 36 of different thicknesses, so that the luminous efficiency of the red light-emitting device 301, the green light-emitting device 302, and the blue light-emitting device 303 tends to be consistent, which helps to improve the display life of the display panel.

[0235] Exemplarily, the material of the light-emitting layer 33 includes at least a host material and a dopant material. For example, the dopant material can be a fluorescent material, a delayed fluorescent material, or a phosphorescent material.

[0236] The host material itself has poor luminescence performance, but good film-forming properties, and can be mixed with other materials with excellent luminescence performance. The guest material itself has excellent luminescence performance, but poor film-forming properties. Therefore, when the host material and the guest material doped therein are used together as the light-emitting layer materials, because the host material includes molecules in a highly excited energy state, and these highly excited energy state molecules can transfer their energy to the guest material, this can change the wavelength of the light emitted by the light-emitting layer, and at the same time, can improve the luminescence efficiency of the light-emitting device 30, resulting in excellent luminescence performance of the light-emitting device 30.

[0237] For example, the thickness of the light-emitting layer 33 in the red light-emitting device 301 is in the range of 25 nm to 40 nm, the thickness of the light-emitting layer 33 in the green light-emitting device 302 is in the range of 25 nm to 40 nm, and the thickness of the light-emitting layer 33 in the blue light-emitting device 303 is in the range of 15 nm to 25 nm.

[0238] In some examples, as shown in FIG12 , the light-emitting device 30 further includes: a hole blocking layer 37 (HBL), an electron transport layer 38 (ETL), and an electron injection layer 39 (EIL), which are sequentially stacked on the light-emitting layer 33 (EML).

[0239] Exemplarily, the hole blocking layer 37 is used to transport electrons to the light emitting layer 33 and block holes and excitons. The thickness of the hole blocking layer 37 ranges from 2 nm to 10 nm.

[0240] For example, the thickness of the hole blocking layer 37 may be 2 nm, 4 nm, 6 nm, 8 nm, or 10 nm.

[0241] Exemplarily, the electron transport layer 38 is used to transport electrons. Materials for the electron transport layer 38 include thiophene, imidazole, or azine derivatives, and lithium quinoline. The electron transport layer 38 can be prepared by blending thiophene, imidazole, or azine derivatives with lithium quinoline. The mass percentage of lithium quinoline in the material of the electron transport layer 38 ranges from 30% to 70%. The thickness of the electron transport layer 38 ranges from 20 nm to 40 nm.

[0242] For example, the thickness of the electron transport layer 38 may be 20 nm, 24 nm, 32 nm, 38 nm, or 40 nm.

[0243] For example, the electron transport layers 38 of different light-emitting devices 30 are interconnected to form an integrated structure, thereby simplifying the manufacturing process of the light-emitting device 30 .

[0244] Exemplarily, the electron injection layer 39 is used to lower the potential barrier of electron injection, improve the efficiency of electron injection, and thus improve the light extraction efficiency of the light emitting device 30 .

[0245] For example, materials for electron injection layer 39 include LiF (Lithium Fluoride), LiQ (Lithium Quinolin-8-olate), Yb (Ytterbium), and Ca (Calcium). Electron injection layer 39 can be formed using an evaporation process. The thickness of electron injection layer 39 ranges from 0.5 nm to 2 nm.

[0246] For example, the thickness of the electron injection layer 39 may be 0.5 nm, 0.7 nm, 1.2 nm, 1.8 nm, or 2 nm.

[0247] It can be understood that Figures 12, 14 and 16 only illustrate the relative position relationship of the hole injection layer 34, hole transport layer 35, electron blocking layer 36, light-emitting layer 33, hole blocking layer 37, electron transport layer 38 and electron injection layer 39 in the above-mentioned light-emitting device 30, and do not represent their relative thickness relationship. The specific thickness can be referred to the description in the above example.

[0248] In some embodiments, as shown in FIG13 , the plurality of second openings 71 include: a plurality of red openings 711 for arranging red light-emitting devices 301, a plurality of green openings 712 for arranging green light-emitting devices 302, and a plurality of blue openings 713 for arranging respective blue light-emitting devices 303. The area of ​​the orthographic projection of the red openings 711 on the backplane is less than or equal to the area of ​​the orthographic projection of the green openings 712 on the backplane.

[0249] Exemplarily, the size of the second opening 71 is equal to the light emitting area of ​​the corresponding red light emitting device 301, green opening 712 or blue light emitting device 303. That is, the light emitting area of ​​the red light emitting device 301 is less than or equal to the light emitting area of ​​the green light emitting device 302.

[0250] When the red light emitted by multiple red light-emitting devices 301, the green light emitted by multiple green light-emitting devices 302, and the blue light emitted by multiple blue light-emitting devices 303 are combined to produce white light, the above-described arrangement can ensure that the color purity of the white light produced by the multiple light-emitting devices is high, thereby reducing the probability of color cast on the image displayed by the display panel 10 and improving the contrast and display quality of the display panel 10. The different light-emitting areas can also be used to coordinate the light-emitting lifespans of the red light-emitting devices 301, the green light-emitting devices 302, and the blue light-emitting devices 303. For example, the light-emitting lifespans of the red light-emitting devices 301, the green light-emitting devices 302, and the blue light-emitting devices 303 can be made substantially the same, thereby increasing the service life of the light-emitting devices 30 and the display panel 10.

[0251] In some embodiments, the ratio of the area of ​​the orthographic projection of the blue opening 713 on the back plate 20 to the area of ​​the orthographic projection of the red opening 711 on the back plate 20 is γ, where 1.0≤γ≤2.6. Correspondingly, the ratio of the light-emitting area of ​​the blue light-emitting device 303 to the light-emitting area of ​​the red light-emitting device 301 is also γ, where 1.0≤γ≤2.6.

[0252] For example, the ratio of the area of ​​the orthographic projection of the blue opening 713 on the back plate 20 to the area of ​​the orthographic projection of the red opening 711 on the back plate 20 is 2.6, 2.4, 2.3, 2.0, 1.6 or 1.0.

[0253] By adopting the above-mentioned setting method, the ratio of the light-emitting area of ​​the blue light-emitting device 303 and the light-emitting area of ​​the red light-emitting device 301 can be within an appropriate range, so that the purity of the white light synthesized by the combination of the light emitted by the blue light-emitting device 303, the light emitted by the red light-emitting device 301, and the light emitted by the green light-emitting device 302 is higher, so that the color purity of the white light emitted by the display panel 10 is higher, and the service life of the light-emitting device 30 and the display panel 10 is extended to a certain extent.

[0254] In some embodiments, the sum of the areas of the orthographic projections of all the blue openings 713 in the display area on the back plate 20 is less than or equal to 10% of the area of ​​the display area of ​​the display panel 10 .

[0255] For example, the sum of the orthographic projection areas of the plurality of blue openings 713 on the back plate 20 is 10%, 9%, 8%, 7%, or 6% of the area of ​​the display region of the display panel 10. In this case, the pixel density (Pixels Per Inch, PPI) may be greater than or equal to 400, for example, the pixel density may be 400, 420, 600, etc.

[0256] Since the luminous efficiency of the light-emitting layer 33 in the green light-emitting device 302 is relatively low, the above-mentioned method can improve the color deviation problem caused by the difference in luminous efficiency of the blue light-emitting device 303, the red light-emitting device 301 and the green light-emitting device 302. For example, when the display panel needs to display a white picture, the reddish or bluish color of the displayed white can be improved, thereby improving the display effect of the display panel.

[0257] In some embodiments, the ratio of the sum of the areas of the orthographic projections of all the second openings 71 in the display area on the back plate 20 to the area of ​​the display area of ​​the display panel 10 is in a range of 10% to 70%.

[0258] For example, the ratio of the sum of the areas of the orthographic projections of the plurality of second openings 71 on the back plate 20 to the area of ​​the display region of the display panel 10 may be 10%, 30%, 50%, 60% or 70%.

[0259] By setting the range of the sum of the projection areas of the above-mentioned multiple second openings 71 on the back panel, the sum of the light-emitting areas of the multiple light-emitting devices 30 can be limited, so that the sum of the light-emitting areas of the multiple light-emitting devices 30 can be larger, which can improve the display brightness of the display panel 10 and reduce the power consumption of the display panel 10 and the display device 1.

[0260] The inventor tested the brightness and power consumption of the display panel 10 in the above-mentioned embodiment of the present disclosure. Specifically, the orthographic projection area of ​​the red opening 711 on the back panel 20 was set to 153 μm, the orthographic projection area of ​​the green opening 712 on the back panel 20 was set to 275 μm, and the orthographic projection area of ​​the blue opening 713 on the back panel 20 was 275 μm. The orthographic projection area of ​​the blue opening 713 on the back panel 20 was 11% of the area of ​​the display area of ​​the display panel 10, and the pixel density was 463. The brightness and power consumption of a display panel without a light extraction layer and a light shading layer in an implementation method were taken as a reference value of 100%, and the changes in the brightness of light of different colors and the changes in the power consumption of the display panel in the display panel provided with a light extraction layer 40 and a light shading layer 60 were calculated, and Table 1 was obtained. Table 1 is shown below.

[0261] For the convenience of description, a display panel without a light extraction layer and a light shielding layer in one implementation is set as display panel P1, and a display panel with a light extraction layer and a light shielding layer in this disclosure is set as display panel P2.

[0262] The indentation value L in Table 1 represents the distance between the boundary line of the orthographic projection of the first opening 61 of the light shielding layer 60 on the back plate 20 and the boundary line of the orthographic projection of the second opening 71 of the corresponding defining layer 70 on the back plate 20. The power consumption in Table 1 was obtained under the conditions of a white light brightness of 500 nits and a color coordinate of (0.31, 0.32).

[0263] Table 1

[0264] As can be seen from Table 1, compared with the display panel P1, the brightness of the light emitted by the display panel P2 provided in the embodiment of the present disclosure is greatly improved. Specifically, when the color coordinates of the light emitted by the display panel P1 are approximately the same as the color coordinates of the light emitted by the display panel P2, compared with the display panel P1, the brightness of the red light emitted by the display panel P2 is increased by about 52%, the brightness of the green light is increased by about 38%, and the brightness of the blue light is increased by about 29%. After adjusting the white balance, when the color coordinates are (0.31, 0.32) and the luminous brightness is 500 nits, the power consumption of the display panel P2 is reduced by about 26.2% (26.2% = 1-73.8%) compared with the display panel P1. Therefore, using the display panel provided in the embodiment of the present disclosure for display can greatly reduce power consumption.

[0265] The inventors also tested the luminescence of various display panels P2 with different indentation values ​​L. Specifically, the orthographic projection area of ​​the red opening 711 on the backplane 20 in each display panel P2 was set to 153 μm, the orthographic projection area of ​​the green opening 712 on the backplane 20 was set to 275 μm, and the orthographic projection area of ​​the blue opening 713 on the backplane 20 was set to 275 μm. The orthographic projection area of ​​the blue opening 713 on the backplane 20 was set to 11% of the display area of ​​the display panel 10, and the pixel density was 463. Taking the power consumption of display panel P1 as a reference value of 100%, the power consumption, reflectivity, and side-view brightness loss rate of display panel P2 were obtained, as shown in Table 2.

[0266] In Table 2, the reflectivity of display panels P1 and P2 was measured at an incident wavelength of 530 nm. The side-view brightness loss rate refers to the ratio of the difference between the brightness of the display panel at a normal viewing angle and the brightness of the display panel at a side viewing angle of 30° to the brightness of the display panel at a normal viewing angle.

[0267] Table 2

[0268] As shown in Table 2, when the indentation value L is 2μm, 3μm, and 4μm, the power consumption of display panel P2 remains essentially unchanged, decreasing by approximately 26.2%. The brightness of display panel P2 also remains essentially unchanged (not shown in Table 2). Therefore, the size of the indentation value L has little effect on the brightness and power consumption of display panel P2. As the indentation value L decreases, the reflectivity of the display panel gradually decreases, and the anti-reflection capability of the display panel becomes stronger. Therefore, setting a smaller indentation value L can improve the anti-reflection capability of the display panel.

[0269] As can be seen from Table 2, compared with the side view brightness loss rate of 32% of the display panel P1, the side view brightness loss rates of the display panel P2 provided by the embodiment of the present disclosure are 35%, 39%, and 45%, all of which are greater than the above 32%. It can be seen that compared with the display panel P1, the side view brightness loss rate of the display panel P2 is improved, so that the display panel has a better anti-peeping function. And as the indentation value L decreases, the side view brightness loss rate of the display panel P2 gradually increases. The lower the brightness of the display screen viewed by the user within the side view angle of the display panel P2, the better the anti-peeping effect of the display panel P2. In particular, when the indentation value L is 2μm, the side view brightness loss rate of the display panel P2 reaches about 45%, which makes the display panel have a good anti-peeping effect.

[0270] The inventors also investigated the effect of the aperture ratio of the display panel (the aperture ratio here is the ratio of the area of ​​the positive projection of the red opening, green opening or blue opening on the back panel to the area of ​​the display area of ​​the display panel) on the power consumption, brightness and service life of the display panel. Different aperture ratios were set and the power consumption, brightness and service life of the display panel were obtained through testing, and Table 3 was obtained.

[0271] In Table 3, the R aperture ratio represents the aperture ratio of the red opening, the G aperture ratio represents the aperture ratio of the green opening, the B aperture ratio represents the aperture ratio of the blue opening, and R / G / B represents the ratio of the aperture ratio of the red opening to the aperture ratio of the green opening and the aperture ratio of the blue opening. The power consumption of the display panel is measured under the conditions of color coordinates of (0.31, 0.32) and luminous brightness of 500 nits. The total aperture ratio represents the ratio of the sum of the areas of the positive projections of the multiple second openings (multiple red openings, multiple green openings and multiple blue openings) on the backplane to the area of ​​the display area of ​​the display panel. Examples 1 to 8 represent display panels with different aperture ratios provided by the present disclosure, and Reference Examples 1 to 2 are display panels that do not contain a light extraction layer and a light shielding layer.

[0272] As can be seen from Table 3, the display panel in Reference Example 1 is not provided with a light extraction layer and a light shielding layer, while the display panel in Example 1 is provided with a light extraction layer and a light shielding layer. The display panel in Reference Example 1 and the display panel in Example 1 have the same total aperture ratio and power consumption. The brightness of the display panel in Example 1 is 680 nits, while the brightness of the display panel in Reference Example 1 is 500 nits. The brightness of the display panel in Example 1 is increased by approximately 36% compared to the brightness of the display panel in Reference Example 1. Therefore, the display panel provided by the present disclosure effectively improves the display brightness of the display panel by providing a light extraction layer and a light shielding layer without changing the aperture ratio and power consumption.

[0273] Table 3

[0274] As shown in Table 3, compared with Reference Example 2, the total aperture ratio of the display panel in Example 2 decreased by 6.5% (6.5% = 24.5% - 18%). However, the luminance, power consumption, and lifespan of the display panel in Reference Example 2 are the same as those in Example 2. Therefore, without sacrificing the power consumption and lifespan of the display panel, the display panel provided by the present disclosure can significantly reduce the total aperture ratio of the display panel, thereby utilizing the saved space to achieve a higher resolution of the display panel.

[0275] As shown in Table 3, the ratio of the R aperture ratio to the G aperture ratio of the display panel in Example 2, the ratio of the R aperture ratio to the G aperture ratio of the display panel in Example 4, and the ratio of the R aperture ratio to the G aperture ratio of the display panel in Example 4 were set equal, while the ratio of the B aperture ratio to the R aperture ratio of the display panel in Example 2 was 2.1, which was greater than the ratio of the B aperture ratio to the R aperture ratio of the display panel in Example 4 (1.5) and also greater than the ratio of the B aperture ratio to the R aperture ratio of the display panel in Example 5 (1.3). The brightness and lifespan of the display panels were then tested. Compared to Example 2, the brightness of the display panels in Examples 4 and 5 decreased slightly, while the lifespan of the display panels was significantly improved. In Example 3, the ratio of the B aperture ratio to the R aperture ratio of the display panel was 2.7, which was greater than 2.6. The lifespan of the display panel dropped below 90%, and the brightness of the display panel also decreased. Therefore, the display panel provided in the embodiment of the present disclosure sets the ratio of the area of ​​the blue opening's orthographic projection on the back panel to the area of ​​the red opening's orthographic projection on the back panel to be less than or equal to 2.6, which can improve the display brightness of the display panel and also increase the display life.

[0276] As shown in Table 3, compared with Example 2, the R aperture ratio of the display panel in Example 7 is larger, and the R aperture ratio in Example 7 is close to the G aperture ratio. However, the lifespan of the display panel in Example 7 (90%) is reduced compared to Example 2 (100%), but the reduction is small and within an acceptable range. Therefore, it can be predicted that if the R aperture ratio of the display panel is further increased, the lifespan of the display panel will continue to decrease. Therefore, in the embodiments of the present disclosure, the area of ​​the orthographic projection of the red opening on the backplane is set to be less than or equal to the area of ​​the orthographic projection of the green opening on the backplane, which can ensure that the display panel has a longer lifespan and higher display brightness.

[0277] In some embodiments, as shown in FIG14 , the display panel 10 further includes an optical cover layer 80 located between the plurality of light-emitting devices 30 and the light extraction layer 40, and an encapsulation layer 90 located between the optical cover layer 80 and the light extraction layer 40 and in contact with the optical cover layer 80. The encapsulation layer 90 can encapsulate and protect the light-emitting devices 30.

[0278] For example, the optical cover layer 80 may be made of a light-transmitting material. Of course, the encapsulation layer 90 may also be light-transmitting. This ensures that light emitted by the light-emitting device 30 can pass through the encapsulation layer 90 and the optical cover layer 90 and enter the light-shielding layer 60.

[0279] Exemplarily, the difference between the refractive index of the optical cover layer 80 and the refractive index of the encapsulation layer 90 is greater than or equal to 0.1.

[0280] For example, the difference between the refractive index of the optical cover layer 80 and the refractive index of the encapsulation layer 90 may be 0.1, 0.15, 0.2, 0.5, or 0.6.

[0281] When light emitted by the light-emitting device 30 passes through the optical cover layer 80 and enters the encapsulation layer 90, because the refractive index of the optical cover layer 80 is greater than that of the encapsulation layer 90, the encapsulation layer 90 has a certain convergence effect on the light, thereby reducing the loss of light emitted by the light-emitting device, improving the luminous efficiency of the light-emitting device 30, and further improving the display brightness of the display panel, thereby increasing the display life. In addition, when the display panel is used in an anti-peeping scenario, the viewing angle of the light emitted by each light-emitting device 30 can be controlled within a smaller viewing angle range by adjusting the difference between the refractive index of the optical cover layer 80 and the refractive index of the encapsulation layer 90, thereby enhancing the anti-peeping effect of the display panel to a certain extent.

[0282] For example, the optical cover layer 90 may include at least two sub-cover layers stacked in sequence. The refractive indices of the two adjacent sub-cover layers are different. This can reduce the reflectivity of the display panel 10 to external light, thereby improving the anti-reflection capability of the display panel 10.

[0283] In some embodiments, as shown in FIG15A , the encapsulation layer 90 includes at least three stacked sub-encapsulation layers, wherein at least two of the at least three sub-encapsulation layers have a refractive index greater than or equal to 1.65.

[0284] In some examples, the material of the sub-encapsulation layer includes an organic material or an inorganic material. The materials of the three sub-encapsulation layers can be organic material, inorganic material, and organic material in that order. Alternatively, as shown in FIG15A , the materials of the three sub-encapsulation layers can be inorganic material, organic material, and inorganic material in that order.

[0285] The sub-encapsulation layer composed of the inorganic material can be formed by chemical vapor deposition (CVD), and the sub-encapsulation layer composed of the organic material can be formed by ink jet printing (IJP).

[0286] The above-mentioned inorganic material may be a silicon-containing inorganic material, and the silicon-containing inorganic material may be at least one of silicon oxide SiO2, silicon nitride SiNx and silicon oxynitride SiON. The organic material may be a polymer such as an acrylic-based polymer, a silicon-based polymer, etc. The sub-encapsulation layer formed by the inorganic material has good water and oxygen barrier properties, which can prevent external water and oxygen from affecting the organic materials in the light-emitting device (such as the material of the light-emitting layer). The sub-encapsulation layer formed by the organic material can well absorb and disperse the stress between the layers, and avoid cracks in the sub-encapsulation layer formed by the dense inorganic material, which reduces the barrier properties to water and oxygen. Thus, the above-mentioned encapsulation layer 90 can protect the light-emitting device 30, avoid the intrusion of water and oxygen, thereby increasing the service life of the light-emitting device, thereby increasing the service life of the display panel and the display device.

[0287] Exemplarily, as shown in Figure 15A, when the at least three sub-encapsulation layers included in the encapsulation layer 90 include a first sub-encapsulation layer 91, a second sub-encapsulation layer 92 and a third sub-encapsulation layer 93, the material of the second sub-encapsulation layer 92 is an organic material, the material of the first sub-encapsulation layer 91 is an inorganic material, and the orthographic projection of the second sub-encapsulation layer 92 on the backplane 20 is within the range of the orthographic projection of the first sub-encapsulation layer 91 on the backplane 20.

[0288] For example, the refractive index of the first sub-encapsulation layer 91 and the refractive index of the second sub-encapsulation layer 92 are both greater than 1.65.

[0289] For another example, the refractive index of the first sub-encapsulation layer 91 , the refractive index of the second sub-encapsulation layer 92 , and the refractive index of the third sub-encapsulation layer 93 are all greater than 1.65.

[0290] With the above arrangement, the package layer 90 can be used to adjust the emission angle of the light emitted by the light emitting device 30 , and most of the light emitted by the light emitting device 30 can be emitted through the package layer 90 .

[0291] Exemplarily, as shown in FIG15B , the first sub-encapsulation layer 91 is in contact with the optical cover layer 80 , and the first sub-encapsulation layer 91 includes a fourth sub-encapsulation layer 94 and a fifth sub-encapsulation layer 95 that are stacked.

[0292] For example, the material of the fourth sub-encapsulation layer 94 is different from the material of the fifth sub-encapsulation layer 95 .

[0293] For another example, the material of the fourth sub-encapsulation layer 94 is the same as the material of the fifth sub-encapsulation layer 95 .

[0294] Exemplarily, the refractive index of the fourth sub-encapsulation layer 94 is different from the refractive index of the fifth sub-encapsulation layer 95 .

[0295] For example, the refractive index of the fourth sub-encapsulation layer 94 is smaller than that of the fifth sub-encapsulation layer 95 , or the refractive index of the fourth sub-encapsulation layer 94 is greater than that of the fifth sub-encapsulation layer 95 .

[0296] By adopting the above-mentioned setting method, the fourth sub-packaging layer 94 and the fifth sub-packaging layer 95 with different refractive indices can be used to adjust the light emitted by the light-emitting device 30, so that most of the light emitted by the light-emitting device 30 is emitted in a direction perpendicular to the display panel, which is beneficial to improving the light extraction efficiency of the light-emitting device 30 and is beneficial to the display panel to realize the anti-peek function.

[0297] In some embodiments, as shown in FIG. 16 , the display panel 10 further includes a touch function layer 96 located between the encapsulation layer 90 and the light extraction layer 40 .

[0298] For example, the touch function layer 96 may be located between the first planar layer 601 and the encapsulation layer 90 .

[0299] It is understandable that the touch function layer 96 may have a variety of structures, which can be selected and set according to actual conditions, and the present disclosure does not limit this.

[0300] For example, the touch function layer 96 can be an FSLOC (Flexible Single-Layer On Cell) structure or an FMLOC (Flexible Multi-Layer On Cell) structure. The FMLOC structure uses a metal grid electrode layer on the display panel's package driver backplane to achieve touch control, eliminating the need for an external TSP (Touch Screen Panel). This reduces the thickness of the display panel, improves yield, and reduces costs.

[0301] For example, the touch function layer may include multiple touch drive electrodes and multiple touch sensing electrodes. The touch drive electrodes can emit low-voltage, high-frequency signals, and the touch sensing electrodes receive these signals, forming a stable capacitance between the two. A user's touch causes different capacitance changes between the touch drive electrodes and the touch sensing electrodes, thereby achieving the corresponding touch operation.

[0302] Thus, the touch function layer 96 can be used to enable the display panel 10 to implement touch operation. In addition, the anti-reflection layer 50 can be used to reduce the light incident on the touch function layer 96, thereby avoiding affecting the working state of the touch function layer 96.

[0303] It can be understood that the beneficial effects that can be achieved by the display devices provided in some embodiments of the present disclosure are the same as the beneficial effects that can be achieved by the display panels provided in some of the above embodiments, and will not be repeated here.

[0304] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A display panel, comprising: Back panel; A plurality of light emitting devices are located on the back panel; The light emitting device comprises a first electrode and a second electrode arranged opposite to each other, wherein the first electrode is closer to the back plate than the second electrode; A light extraction layer is located at the light output side of the plurality of light emitting devices; the light extraction layer is configured to allow circularly polarized light of a first hand direction to pass through and reflect circularly polarized light of a second hand direction; the first hand direction is different from the second hand direction; And, an anti-reflection layer is located on the light extraction layer; the anti-reflection layer is configured to allow the circularly polarized light of the first hand direction to pass through.

2. The display panel according to claim 1, wherein: The transmittance of the light extraction layer to the light emitted by the light emitting device is greater than or equal to 35%, and / or the reflectivity of the light extraction layer to the light emitted by the light emitting device is greater than or equal to 35%.

3. The display panel according to claim 1 or 2, wherein: The material of the light extraction layer includes at least one cholesteric liquid crystal material; In the case where the material of the light extraction layer includes at least two cholesteric liquid crystals, the at least two cholesteric liquid crystals have unequal helical pitches.

4. The display panel according to claim 3, wherein: In the case where the material of the light extraction layer includes at least two cholesteric liquid crystals, The light extraction layer includes: at least two sub-light extraction layers stacked in sequence; the at least two sub-light extraction layers include: a first light extraction layer and a second light extraction layer; the pitch of the cholesteric liquid crystal in the first light extraction layer is not equal to the pitch of the cholesteric liquid crystal in the second light extraction layer.

5. The display panel according to claim 3, wherein: In the case where the material of the light extraction layer includes at least two cholesteric liquid crystals, The at least two cholesteric liquid crystals include a first liquid crystal and a second liquid crystal; the first liquid crystal is uniformly distributed in the light extraction layer, the second liquid crystal is uniformly distributed in the light extraction layer, and the distribution density of the first liquid crystal in the light extraction layer is approximately equal to the distribution density of the second liquid crystal in the light extraction layer.

6. The display panel according to claim 3, wherein: In the case where the material of the light extraction layer includes at least two types of cholesteric liquid crystals, in the light extraction layer, the pitches of the cholesteric liquid crystals corresponding to the light emitting devices having different luminescent colors are unequal.

7. The display panel according to any one of claims 1 to 6, wherein the anti-reflection layer comprises at least a quarter wave plate and a polarizing layer; the quarter wave plate is located between the polarizing layer and the light extraction layer; and the transmittance of the polarizing layer to visible light is greater than or equal to 40%.

8. The display panel according to claim 7, wherein: The anti-reflection layer also includes a light absorbing layer; the light absorbing layer is stacked with the 1 / 4 wave plate or the polarizing layer and is used to absorb light with a wavelength below 450nm.

9. The display panel according to any one of claims 1 to 8, further comprising: a defining layer between the backplane and the light extraction layer; The defining layer has a plurality of second openings; Wherein, the plurality of light emitting devices include a plurality of red light emitting devices, a plurality of green light emitting devices and a plurality of blue light emitting devices; The plurality of second openings include: a plurality of red openings for arranging red light emitting devices, a plurality of green openings for arranging green light emitting devices, and a plurality of blue openings for arranging respective blue light emitting devices; The area of ​​the orthographic projection of the red opening on the back panel is less than or equal to the area of ​​the green opening on the back panel The area of ​​the orthographic projection of .

10. The display panel according to claim 9, wherein: The ratio of the area of ​​the orthographic projection of the blue opening on the back plate to the area of ​​the orthographic projection of the red opening on the back plate is γ, and 1.0≤γ≤2.

6.

11. The display panel according to claim 9 or 10, wherein: The sum of the areas of the orthographic projections of all the blue openings in the display area of ​​the display panel on the backplane is less than or equal to 10% of the area of ​​the display area.

12. The display panel according to any one of claims 9 to 11, wherein: The ratio of the sum of the areas of the orthographic projections of all the second openings in the display area of ​​the display panel on the back plate to the area of ​​the display area is in a range of 10% to 70%.

13. The display panel according to any one of claims 9 to 12, wherein: An angle between a side wall of the second opening and a plane where the back plate is located is less than or equal to 35°.

14. The display panel according to any one of claims 1 to 13, further comprising: A light shielding layer disposed between the plurality of light emitting devices and the light extraction layer; The light shielding layer has a plurality of first openings; An orthographic projection of one of the light emitting devices on the back plate has an overlapping area with an orthographic projection of the first opening on the back plate.

15. The display panel according to claim 14, wherein: The display panel has a first area and a second area; An angle between a side wall of at least one first opening in the first region and a plane where the back plate is located is not equal to an angle between a side wall of at least one first opening in the second region and a plane where the back plate is located.

16. The display panel according to claim 14 or 15, further comprising: a defining layer between the back plate and the light shielding layer; The defining layer has a plurality of second openings; Along a direction perpendicular to the plane where the back plate is located, a second opening is arranged opposite to one of the first openings.

17. The display panel according to claim 16, wherein: The display panel has a third area and a fourth area; An angle between a side wall of at least one second opening in the third region and the plane where the back plate is located is not equal to an angle between a side wall of at least one second opening in the fourth region and the plane where the back plate is located.

18. The display panel according to claim 16 or 17, wherein: The orthographic projection of the second opening on the back plate is located within the orthographic projection range of the first opening directly opposite to the second opening on the back plate.

19. The display panel according to any one of claims 16 to 18, wherein: An angle between the side wall of the first opening and the plane where the back plate is located is greater than an angle between the side wall of the second opening and the plane where the back plate is located.

20. The display panel according to any one of claims 16 to 18, wherein: An angle between the side wall of the first opening and the plane where the back plate is located is smaller than an angle between the side wall of the second opening and the plane where the back plate is located.

21. The display panel according to any one of claims 16 to 20, wherein: The material of the defining layer includes a light-absorbing material, and / or the material of the light-shielding layer includes a light-absorbing material, and the absorbance of the light-absorbing material to visible light is greater than or equal to 0.

5.

22. The display panel according to any one of claims 16 to 21, wherein: The maximum distance between the boundary line of the orthographic projection of the second opening on the back panel and the boundary line of the orthographic projection of the first opening directly opposite to the second opening on the back panel is less than or equal to 1 / 3 of the maximum size of the orthographic projection of the second opening on the back panel.

23. The display panel according to any one of claims 1 to 22, further comprising: an optical cover layer located between the plurality of light emitting devices and the light extraction layer; and, an encapsulation layer located between the optical cover layer and the light extraction layer and in contact with the optical cover layer; Wherein, the difference between the refractive index of the optical cover layer and the refractive index of the encapsulation layer is greater than or equal to 0.

1.

24. The display panel according to claim 23, wherein: The encapsulation layer comprises at least three sub-encapsulation layers stacked in layers; The refractive index of at least two sub-encapsulation layers among the at least three sub-encapsulation layers is greater than or equal to 1.

65.

25. The display panel according to claim 24, wherein: The at least three sub-encapsulation layers include a first sub-encapsulation layer, a second sub-encapsulation layer and a third sub-encapsulation layer; the first sub-encapsulation layer is in contact with the optical cover layer, the material of the first sub-encapsulation layer is an inorganic material, the second sub-encapsulation layer is an organic material, and the material of the third sub-encapsulation layer is an inorganic material; The first sub-encapsulation layer includes a fourth sub-encapsulation layer and a fifth sub-encapsulation layer which are stacked.

26. The display panel according to claim 25, wherein: A refractive index of the fourth sub-encapsulation layer is different from a refractive index of the fifth sub-encapsulation layer.

27. The display panel according to any one of claims 23 to 26, further comprising: A touch function layer is located between the encapsulation layer and the light extraction layer.

28. A display device comprising: The display panel according to any one of claims 1 to 27.

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