Display panel and display device

Abstract

The application discloses a display panel and a display device. The display panel comprises an array substrate, a light-emitting layer, a liquid crystal reflection layer and a circularly polarized layer arranged on the array substrate in sequence. The light-emitting layer comprises a plurality of light-emitting units with different light-emitting colors. The liquid crystal reflection layer comprises a plurality of liquid crystal reflection units corresponding to the plurality of light-emitting units one by one and arranged in the same layer. The circularly polarized layer is configured to convert linearly polarized light and circularly polarized light of a first rotation direction into each other. Each liquid crystal reflection unit is configured to selectively reflect circularly polarized light of a second rotation direction, and the first rotation direction and the second rotation direction are opposite. The center wavelength of the reflection spectrum of each liquid crystal reflection unit is located within the emission spectrum of the corresponding light-emitting unit, and the half-peak width of the reflection spectrum of each liquid crystal reflection unit is less than or equal to 60 nanometers. The application can effectively improve the white-state brightness on the basis of inhibiting the reflectivity of the panel, thereby reducing the power consumption of the panel and prolonging the service life of the panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a display panel and a display device. Background Technology

[0002] In Organic Light-Emitting Diode (OLED) displays, circular polarizer (POL) technology is typically used to eliminate interference from external ambient light, reduce screen reflection, and achieve a black level effect. This POL is composed of a linear polarizer and a quarter-wave plate (QWP). Its working principle is to change the polarization state of ambient light, so that the polarization direction of external incident light, after being reflected by the metal electrodes inside the display, is orthogonal to the transmission axis of the linear polarizer, thus being effectively absorbed, significantly reducing screen reflectivity, and improving contrast and black level effect. However, while absorbing external ambient light, the POL also blocks more than 50% of the light emitted from the OLED device. This requires the OLED device to be driven with a higher current to achieve the target brightness, leading to increased power consumption and affecting the product's energy efficiency and lifespan.

[0003] As an alternative, Color Filter on Encapsulation (COE) technology has been proposed, aiming to eliminate the need for polarizers by directly integrating a color filter onto the encapsulation layer to achieve anti-reflection. However, COE technology suffers from relatively high screen reflectivity and poor black-state performance.

[0004] Therefore, improving the energy efficiency and display effect of OLED displays while ensuring good anti-reflective performance has become an important direction for the development of current display technology. Summary of the Invention

[0005] This application provides a display panel and a display device that can effectively improve white brightness while suppressing panel reflectivity, thereby reducing panel power consumption and extending panel lifespan.

[0006] To achieve the above objectives, according to a first aspect of this application, a display panel is provided, comprising: Array substrate; A light-emitting layer is disposed on one side of the array substrate and includes multiple light-emitting units with different light-emitting colors; A liquid crystal reflective layer is disposed on the side of the light-emitting layer away from the array substrate, and includes a plurality of liquid crystal reflective units that correspond one-to-one with the plurality of light-emitting units and are disposed on the same layer; A circular polarizing layer is disposed on the side of the liquid crystal reflective layer opposite to the light-emitting layer, and is configured to convert linearly polarized light and circularly polarized light of a first rotation direction into each other; Each of the liquid crystal reflective units is configured to selectively reflect circularly polarized light with a second rotation direction, wherein the first rotation direction and the second rotation direction are opposite; the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and the half-width at half maximum (FWHM) of the reflection spectrum of each liquid crystal reflective unit is less than or equal to 60 nanometers.

[0007] Optionally, the half-width at half maximum (WHM) of the reflection spectrum of each liquid crystal reflective unit ranges from 20 nanometers to 60 nanometers.

[0008] Optionally, the plurality of light-emitting units include a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit; the peak wavelength of the emission spectrum of the first light-emitting unit is greater than the peak wavelength of the emission spectrum of the second light-emitting unit, and the peak wavelength of the emission spectrum of the second light-emitting unit is greater than the peak wavelength of the emission spectrum of the third light-emitting unit. The plurality of liquid crystal reflective units include a first liquid crystal reflective unit, a second liquid crystal reflective unit, and a third liquid crystal reflective unit, which are respectively disposed in one-to-one correspondence with the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit; The ratio of the half-width at half maximum (WHM) of the reflection spectrum of the first liquid crystal reflective unit to the half-width at half maximum (WHM) of the reflection spectrum of the second liquid crystal reflective unit is in the range of 0.8 to 3, and / or the ratio of the half-width at half maximum (WHM) of the reflection spectrum of the third liquid crystal reflective unit to the half-width at half maximum (WHM) of the reflection spectrum of the second liquid crystal reflective unit is in the range of 0.8 to 3.

[0009] Optionally, the first light-emitting unit is a red light-emitting unit, the second light-emitting unit is a green light-emitting unit, and the third light-emitting unit is a blue light-emitting unit; The center wavelength range of the reflection spectrum of the first liquid crystal reflective unit is 625nm to 650nm, and / or the center wavelength range of the reflection spectrum of the second liquid crystal reflective unit is 530nm to 550nm, and / or the center wavelength range of the reflection spectrum of the third liquid crystal reflective unit is 450nm to 460nm.

[0010] Optionally, the thickness of the first liquid crystal reflective unit is greater than the thickness of the second liquid crystal reflective unit, and the thickness of the second liquid crystal reflective unit is greater than the thickness of the third liquid crystal reflective unit. And / or, the material of the liquid crystal reflective layer includes cholesteric liquid crystal, and the thickness of any one of the liquid crystal reflective units is greater than or equal to five times the pitch of the corresponding cholesteric liquid crystal.

[0011] Optionally, the projection of each light-emitting unit along the thickness direction of the display panel is located within the projection of the corresponding liquid crystal reflecting unit along the thickness direction of the display panel; The ratio of the projected area of ​​each liquid crystal reflective unit along the thickness direction of the display panel to the projected area of ​​the corresponding light-emitting unit along the thickness direction of the display panel is greater than 1 and less than or equal to 1.5.

[0012] Optionally, two liquid crystal reflective units, which are arranged adjacent to each other and have different light-emitting colors, are arranged in abutment or partially overlap.

[0013] Optionally, the two liquid crystal reflective units respectively provided for the two light-emitting units that are different in color from the light-emitting units and are arranged adjacently include a first liquid crystal reflective unit and a second liquid crystal reflective unit; The first liquid crystal reflective unit includes a first liquid crystal reflective main body and a first liquid crystal reflective overlapping part made of the same material. The second liquid crystal reflective unit includes a second liquid crystal reflective main body and a second liquid crystal reflective overlapping part made of the same material. The first liquid crystal reflective main body and the second liquid crystal reflective main body are made of different materials. The first liquid crystal reflective overlapping part and the second liquid crystal reflective overlapping part are located between the first liquid crystal reflective main body and the second liquid crystal reflective main body and are stacked. Alternatively, the first liquid crystal reflective unit includes a first liquid crystal reflective main portion and a liquid crystal reflective overlapping portion, and the second liquid crystal reflective unit includes a second liquid crystal reflective main portion and the liquid crystal reflective overlapping portion. The first liquid crystal reflective main portion and the second liquid crystal reflective main portion are made of different materials, and the liquid crystal reflective overlapping portion is made of the materials of the first liquid crystal reflective main portion and the second liquid crystal reflective main portion.

[0014] Optionally, the first rotation direction is left-handed, the second rotation direction is right-handed, and the circular polarizing layer is a left-handed circular polarizing layer; or, the first rotation direction is right-handed, the second rotation direction is left-handed, and the circular polarizing layer is a right-handed circular polarizing layer.

[0015] According to a second aspect of this application, a display device is provided, the display device comprising the display panel described in the foregoing embodiments.

[0016] In the display panel and display device provided in this application, by sequentially distributing a liquid crystal reflective layer and a circular polarizing layer on the light-emitting side of the light-emitting layer, the circular polarizer can realize the mutual conversion between linearly polarized light and circularly polarized light with a first rotation direction (e.g., one of left-hand rotation and right-hand rotation). At the same time, each liquid crystal reflective unit in the liquid crystal reflective layer can selectively reflect circularly polarized light with a second rotation direction (e.g., the other of left-hand rotation and right-hand rotation). On the one hand, the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and each liquid crystal reflective unit is configured to selectively reflect circularly polarized light of the second rotation direction. This allows circularly polarized light of a specific wavelength emitted by the light-emitting unit to pass through the corresponding liquid crystal reflective unit and the circular polarizer. Furthermore, at least a portion of the circularly polarized light of the second rotation direction in the specific wavelength emitted by the light-emitting unit can be converted into circularly polarized light of the first rotation direction after being reflected sequentially by the corresponding liquid crystal reflective unit and the metal layer inside the display panel. This allows the light that could not be emitted originally to pass through the corresponding liquid crystal reflective unit and the circular polarizer layer again, thereby efficiently improving the light extraction efficiency of the display panel. This, in turn, helps to improve the white brightness of the display panel, reduce the power consumption of the display panel, and extend the lifespan of the display panel. On the other hand, since each liquid crystal reflective unit is configured to selectively reflect circularly polarized light with a second rotation direction, and the half-width of the reflection spectrum of each liquid crystal reflective unit is less than or equal to 60 nanometers, when ambient light is incident on the display panel, the liquid crystal reflective units in the liquid crystal reflective layer selectively reflect only the circularly polarized light with a second rotation direction and a half-width of less than or equal to 60 nanometers in the incident light, effectively reducing the reflection of ambient light and thus suppressing the increase in the reflectivity of the display panel to ambient light.

[0017] Therefore, by narrowing the reflection spectrum of the liquid crystal reflective units in the liquid crystal reflective layer, this application can balance the reflectivity and light emission efficiency of the display panel, effectively improve the white state brightness while suppressing the panel reflectivity, thereby reducing panel power consumption and extending panel life.

[0018] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0020] Figure 1This is a schematic cross-sectional view of an exemplary OLED display panel provided in this application; Figure 2 yes Figure 1 The diagram shows the optical path of the emitted light from the OLED display panel. Figure 3 It is incident to Figure 1 The diagram shows the optical path of natural light from an OLED display panel. Figure 4 This is a schematic cross-sectional view of another exemplary OLED display panel provided in this application; Figure 5 This is a schematic cross-sectional view of a display panel provided in an embodiment of this application; Figure 6 This is a schematic diagram of another cross-sectional structure of the display panel provided in an embodiment of this application; Figure 7 This is a schematic diagram of the absorption axis and the phase difference lag axis of the left circular polarizer provided in the embodiments of this application; Figure 8 This is a schematic diagram of the absorption axis and the phase difference lag axis of the right circular polarizer provided in the embodiments of this application; Figure 9 yes Figure 5 and Figure 6 The diagram shows the optical path of the emitted light from the display panel. Figure 10 It is incident to Figure 5 and Figure 6 A schematic diagram of the optical path of natural light from the display panel shown. Figure 11 This is a reflection spectrum of the liquid crystal reflective layer provided in the embodiments of this application; Figure 12 This is a schematic diagram of the light emission from the liquid crystal reflective layer provided in the embodiments of this application; Figure 13 This is a schematic diagram of a cross-sectional structure of a liquid crystal reflective layer provided in an embodiment of this application.

[0021] Explanation of reference numerals in the attached figures: 1. Display panel; 2. Array substrate; 3. Light-emitting layer; 3a. First light-emitting unit; 3b. Second light-emitting unit; 3c. Third light-emitting unit; 4. Liquid crystal reflective layer; 41. First liquid crystal reflective unit; 41a. First liquid crystal reflective main body; 41b. First liquid crystal reflective overlapping part; 42. Second liquid crystal reflective unit; 42a. Second liquid crystal reflective main body; 42b. Second liquid crystal reflective overlapping part; 43. Third liquid crystal reflective unit; 44. Liquid crystal reflective overlapping part; 45. Filler layer; 5. Encapsulation layer; 6. Circular polarizer layer; 6a. Quarter-wave plate; 6b. Linear polarizer; 7. Protective cover plate; 8. Adhesive layer; 10. Color filter; 11. Low-reflection film. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0023] like Figure 1 As shown, an exemplary OLED display panel includes, from bottom to top, an array substrate 2, a light-emitting layer 3, an encapsulation layer 5, a protective cover plate 7, an adhesive layer 8, a quarter-wave plate (QWP) 6a, and a linear polarizer (POL) 6b.

[0024] like Figure 2 As shown, taking the transmission axis direction of the linear polarizer 6b as 0° as an example, when natural light is incident on the surface of the display panel, the natural light first passes through the linear polarizer 6b and is converted into linearly polarized light vibrating in the 0° direction (referred to as 0° polarized light). This 0° polarized light continues to pass through the quarter-wave plate 6a and is converted into left-hand circularly polarized light (referred to as left circularly polarized light). After entering the interior of the OLED display panel and being reflected by the metal layer, the polarization direction of the left circularly polarized light changes, converting into right-hand circularly polarized light (referred to as right circularly polarized light). This right circularly polarized light passes through the quarter-wave plate 6a again and is converted into linearly polarized light vibrating in the 90° direction (referred to as 90° polarized light). Since the vibration direction of this 90° polarized light is orthogonal to the transmission axis direction of the linear polarizer 6b, it cannot pass through the linear polarizer 6b and is thus effectively blocked. Through the above structure, the reflectivity of ambient light on the surface of the display panel can be significantly reduced, improving the display contrast.

[0025] like Figure 3As shown, the light emitted by the OLED device in the light-emitting layer 3 is decomposed into two polarization components after passing through the quarter-wave plate 6a: linearly polarized light vibrating along the 0° direction and linearly polarized light vibrating along the 90° direction. Only the linearly polarized light vibrating along the 0° direction can pass through the linear polarizer 6b, while the linearly polarized light vibrating along the 90° direction is absorbed or blocked by the linear polarizer 6b. Therefore, the light extraction efficiency of the display panel is theoretically only about 50%, and may be even lower in practice. Because a large amount of emitted light is lost, the overall light extraction efficiency of the display panel decreases. To achieve the target brightness, a higher driving current is required, which increases panel power consumption and adversely affects the product's energy efficiency and device lifespan.

[0026] To improve the light emission efficiency of display panels, a polarizer-less technology has been proposed. For example... Figure 4 As shown, with Figure 1 The difference in the OLED display panel shown lies in the fact that this technology eliminates the polarizer on the light-emitting side of the traditional display module and instead sets a color filter 10 and a low-reflection film 11 on the light-emitting side to reduce ambient light reflection and improve light extraction efficiency. However, this solution still has certain shortcomings. On the one hand, introducing the color filter 10 and the low-reflection film 11 adds extra process steps, thereby increasing production difficulty and process complexity; on the other hand, the ability of this structure to suppress ambient light reflection is still limited, resulting in a relatively high average reflectivity of the screen, poor black-state display effect, and thus affecting display contrast.

[0027] In order to balance the reflectivity and light emission efficiency of the display panel, and to effectively improve the white brightness of the display panel while suppressing the reflectivity, thereby reducing panel power consumption and extending panel life, this application improves the structure of the display panel.

[0028] like Figure 5 and Figure 6 As shown, this application embodiment provides a display panel 1, which includes an array substrate 2, a light-emitting layer 3, a liquid crystal reflective layer 4, and a circular polarizing layer 6. The light-emitting layer 3 is disposed on one side of the array substrate 2 and includes multiple light-emitting units with different emitting colors (e.g., the first light-emitting unit 3a, the second light-emitting unit 3b, and the third light-emitting unit 3c hereinafter). The liquid crystal reflective layer 4 is disposed on the side of the light-emitting layer 3 away from the array substrate 2 and includes multiple liquid crystal reflective units (e.g., the first liquid crystal reflective unit 4a, the second liquid crystal reflective unit 4b, and the third liquid crystal reflective unit 4c) that correspond one-to-one with the multiple light-emitting units and are disposed on the same layer. The circular polarizing layer 6 is disposed on the side of the liquid crystal reflective layer 4 away from the light-emitting layer 3 and is configured to convert linearly polarized light and circularly polarized light with a first rotation direction to each other.

[0029] Each liquid crystal reflective unit is configured to selectively reflect circularly polarized light with a second rotation direction, the first rotation direction and the second rotation direction being opposite. The center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and the reflection spectrum of each liquid crystal reflective unit is less than or equal to 60 nanometers.

[0030] It should be noted that the circularly polarized light in the embodiments of this application can be simply referred to as circularly polarized light, and the linearly polarized light can be simply referred to as linearly polarized light.

[0031] Specifically, the array substrate 2 includes a substrate layer and a driving circuit layer. The substrate layer can be a glass substrate or a flexible substrate, such as a polyimide substrate. The driving circuit layer includes a thin-film transistor array for driving pixels and related wiring structures.

[0032] In some embodiments, the light-emitting unit may be an organic light-emitting diode (OLED) pixel unit, and each light-emitting unit may include a first electrode, a second electrode, and a light-emitting functional layer located between the first electrode and the second electrode.

[0033] It should be noted that the first electrode and / or the second electrode are configured to reflect the incident circularly polarized light and simultaneously reverse the rotation of the circularly polarized light. For example, left-handed circularly polarized light incident on the first electrode and / or the second electrode is converted into right-handed circularly polarized light after reflection, or right-handed circularly polarized light incident on the first electrode and / or the second electrode is converted into left-handed circularly polarized light after reflection.

[0034] Understandably, the first electrode or the second electrode is electrically connected to the driving circuit in the array substrate 2.

[0035] In some embodiments, the first electrode is the anode and the second electrode is the cathode, or vice versa.

[0036] In one specific embodiment, the light-emitting functional layer may include one or more of a hole injection layer, a hole transport layer, a light-emitting material layer, an electron transport layer, and an electron injection layer. At least two of the multiple light-emitting units emit different colors; for example, the multiple light-emitting units may include a red light-emitting unit (R), a green light-emitting unit (G), and a blue light-emitting unit (B), but are not limited thereto.

[0037] Understandably, the red, green, and blue light-emitting units are configured to emit red, green, and blue light, respectively. The color of the light emitted by the light-emitting units of the light-emitting layer 3 is not limited to this.

[0038] Specifically, such as Figure 5 and Figure 6 As shown, the multiple liquid crystal reflective units in the liquid crystal reflective layer 4 correspond one-to-one with the multiple light-emitting units, and the multiple liquid crystal reflective units in the liquid crystal reflective layer 4 are arranged in the same layer.

[0039] In some embodiments, the liquid crystal reflective unit may be formed of a cholesteric liquid crystal (CLC) material with selective reflective properties, whose internal helical structure can selectively reflect circularly polarized light in a specific direction of rotation.

[0040] It is understandable that the cholesteric liquid crystal materials of the multiple liquid crystal reflective units corresponding to multiple light-emitting units of different emission colors are different, so that each liquid crystal reflective unit has the effect of selective transmission and selective reflection of light emitted by its corresponding light-emitting unit.

[0041] Specifically, the circular polarizing layer 6 is configured to convert linearly polarized light and circularly polarized light of the first rotation direction into each other. This means that the circular polarizing layer 6 can convert linearly polarized light incident on the circular polarizer 6 into circularly polarized light of the first rotation direction for emission, or it can convert circularly polarized light of the first rotation direction incident on the circular polarizer 6 into linearly polarized light for emission.

[0042] In one specific embodiment, such as Figure 5 and Figure 6 As shown, the circular polarizing layer 6 may include a linear polarizer 6b and a quarter-wave plate 6a, wherein the quarter-wave plate 6a is disposed between the liquid crystal reflective layer 4 and the linear polarizer 6b. Linearly polarized light can be converted into circularly polarized light after passing through the quarter-wave plate 6a, while the first-axis circularly polarized light from the liquid crystal reflective layer 4 can be converted into linearly polarized light after passing through the quarter-wave plate 6a.

[0043] For example, when the first rotation direction is left-handed and the second rotation direction is right-handed, the circular polarizing layer 6 is a left-handed circular polarizer. In this case, natural light passing through the circular polarizing layer 6 can be converted into left-handed circularly polarized light. Alternatively, when the first rotation direction is right-handed and the second rotation direction is left-handed, the circular polarizing layer 6 is a right-handed circular polarizer. In this case, natural light passing through the circular polarizing layer 6 can be converted into right-handed circularly polarized light.

[0044] Understandably, the liquid crystal material in the multiple liquid crystal reflective units of the liquid crystal reflective layer 4 is chiral liquid crystal (specifically, CLC), and the liquid crystal rotation direction of the multiple liquid crystal reflective units is consistent. When the liquid crystal material of the liquid crystal reflective layer 4 is right-handed liquid crystal, the liquid crystal reflective unit can selectively reflect right-handed circularly polarized light whose half-width at half-maximum (HWHM) matches the HWHM of the reflection spectrum of the liquid crystal reflective unit (e.g., less than or equal to 60 nm), while other light rays can pass through. In this case, the circularly polarized layer 6 is a left-handed circularly polarizer. Conversely, when the liquid crystal material of the liquid crystal reflective layer 4 is left-handed liquid crystal, the liquid crystal reflective unit can selectively reflect left-handed circularly polarized light whose HWHM matches the HWHM of the reflection spectrum of the liquid crystal reflective unit (e.g., less than or equal to 60 nm), while other light rays can pass through. In this case, the circularly polarized layer 6 is a right-handed circularly polarizer.

[0045] It should be noted that the liquid crystal reflective layer 4 in this embodiment uses a CLC material with a narrow reflectance spectrum, so that the liquid crystal reflective unit only reflects circularly polarized light with a half-width of less than or equal to 60 nm in the second rotation direction, while circularly polarized light with a first rotation direction and circularly polarized light with a half-width of greater than 60 nm in the second rotation direction can both pass through the corresponding liquid crystal reflective unit.

[0046] like Figure 7 As shown, the absorption axis of the left circular polarizer is at 0°, and the angle between the phase difference lag axis and the absorption axis is 45°; Figure 8 As shown, the absorption axis of the right circular polarizer is 90°, and the angle between the phase difference lag axis and the absorption axis is 45°.

[0047] Specifically, the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum range of the corresponding light-emitting unit. For example, when the emission peak wavelength of the light-emitting unit is located in a certain band, the center wavelength of the reflection spectrum of its corresponding liquid crystal reflective unit can be set within that band, thereby improving the utilization efficiency of light energy. At the same time, the half-width at half-maximum (WHM) of the reflection spectrum of each liquid crystal reflective unit can be less than or equal to 60 nanometers, giving the liquid crystal reflective unit a narrow reflection spectrum. This allows it to reflect only circularly polarized light in the second rotation direction within that WHM range, thereby suppressing the increase in reflectivity.

[0048] It should be noted that the full name of the half-width at half maximum (FWHM) of the reflectance spectrum described in the embodiments of this application is the width at half the peak intensity of a reflectance spectrum.

[0049] Specifically, the cholesteric liquid crystal molecules in the liquid crystal reflective unit are flattened and arranged in layers. Molecules within each layer are parallel to each other, with their long axes parallel to the layer plane. The orientation vectors (directions of the long axes) of molecules in different layers differ slightly. The long axes of molecules in adjacent layers gradually rotate around a helical axis, eventually rotating by 2... It then returns to its initial direction, forming a pitch P (the length of one period of the helical structure). Due to the anisotropy of liquid crystals (ordinary refractive index n... o Unusual optical refractive index n e Unlike other liquid crystal reflective cells, this spiral arrangement allows the liquid crystal reflective unit to produce Bragg reflection of incident light at specific wavelengths (similar to Bragg diffraction in crystals, with enhanced reflection when the phase-matching condition is met). The center wavelength of the reflection spectrum of the liquid crystal reflective unit... for: ; Where, n e The unusual optical refractive index of a liquid crystal (the refractive index when the direction of light vibration is perpendicular to the helical surface), n oP represents the ordinary refractive index of the liquid crystal (the refractive index when the direction of light vibration is parallel to the helical surface), and P represents the pitch of the helical structure of the cholesteric liquid crystal. This indicates the angle of incidence (the angle between the incident light and the helical axis).

[0050] The full width at half maximum (FWHM) of the reflection spectrum of a liquid crystal reflective cell. satisfy: ; in, .

[0051] Specifically, the following will take the first rotation direction as left-handed and the second rotation direction as right-handed as examples to explain in detail the working principle of the embodiment of this application in which the liquid crystal reflective layer 4 improves the transmittance performance of the panel and in which the liquid crystal reflective layer 4 reflects narrow-spectrum circularly polarized light to suppress the increase in reflectivity.

[0052] In one specific embodiment, the full width at half maximum (FWHM) of the reflection spectrum of each liquid crystal reflective unit is in the range of 20 nm to 60 nm. That is, the liquid crystal reflective unit only reflects circularly polarized light of the second rotation direction with a FWHM of 20 nm to 60 nm, while circularly polarized light of the first rotation direction and circularly polarized light of the second rotation direction with a FWHM not in the range of 20 nm to 60 nm can pass through the corresponding liquid crystal reflective unit.

[0053] By controlling the full width at half maximum (FWHM) of the reflection spectrum of the liquid crystal reflective unit within the range of 20 to 60 nanometers, the unit can reflect only light within the target wavelength band, thus avoiding excessive reflection of non-target wavelengths. Compared to broadband reflective structures, this structure reduces ineffective reflection of ambient light in the display panel, lowers the average reflectivity, and improves black levels and ambient light contrast. Simultaneously, because the liquid crystal reflective unit only reflects circularly polarized light of a specific wavelength and direction, other light can pass through and be effectively emitted, reducing light energy loss during emission and increasing effective light transmittance. In white mode, more light generated by different color emitting units can directly pass through the display panel, increasing overall white brightness and reducing the driving power required to achieve the target brightness. Furthermore, a narrower FWHM reduces the mutual influence between different color wavelengths, minimizing the misreflection of adjacent wavelengths and improving the spectral purity of each color channel, thus enhancing color performance. With the combined action of multiple liquid crystal reflective units, it is possible to balance ambient light suppression capability and panel light emission efficiency, achieving a balance between low reflectivity and high brightness.

[0054] like Figure 9As shown, during the operation of the display panel 1, the light emitted by the light-emitting unit (e.g., the first light-emitting unit 3a) includes circularly polarized light components with different rotation directions. Left-circularly polarized light can pass through the corresponding liquid crystal reflecting unit (e.g., the first liquid crystal reflecting unit 41) and be emitted outwards, while right-circularly polarized light with a half-width between 20nm and 60nm is reflected back to the light-emitting layer 3 by the liquid crystal reflecting unit. The reflected right-circularly polarized light, after being reflected by a metal layer (e.g., an electrode layer) inside the display panel 1 during propagation, has its rotation direction reversed and transforms into left-circularly polarized light. When this light reaches the liquid crystal reflecting layer 4 again, it can pass through the corresponding liquid crystal reflecting unit and then sequentially through a quarter-wave plate 6a and a linear polarizer 6b before being emitted outwards. Through the above-mentioned light reflection and polarization state conversion process, the light energy that might otherwise be lost can be reused, thereby improving the overall light extraction efficiency of the display panel 1.

[0055] Therefore, by setting a liquid crystal reflective layer 4 above the light-emitting layer 3 and cooperating with a circular polarizing layer 6, circularly polarized light with different rotation directions can selectively pass through and reflect inside the panel, realizing the recycling of light. While maintaining a low ambient reflectivity, the white brightness of the display panel 1 is significantly improved, which helps to reduce the power consumption of the display panel 1 and extend the service life of the device.

[0056] It should be noted that, although the right-circularly polarized light with a full width at half maximum (FWHM) outside the range of 20nm to 60nm can pass through the corresponding liquid crystal reflective unit, this portion of right-circularly polarized light cannot pass through the circular polarizer and therefore cannot be emitted for display.

[0057] like Figure 10 As shown, when ambient natural light is incident on the light-emitting surface of the display panel 1, the 0° polarized light in the natural light passes through the linear polarizer 6b and is converted into left-hand circularly polarized light by the quarter-wave plate 6a. This left-hand circularly polarized light passes through the corresponding liquid crystal reflective unit (e.g., the first liquid crystal reflective unit 41), and after being reflected by the metal layer (e.g., the electrode layer) inside the display panel 1 during propagation, its rotation direction is reversed and it is converted into right-hand circularly polarized light. Since the half-width at half-maximum (WHM) of the reflection spectrum of the liquid crystal reflective unit is 20nm to 60nm, only the portion of the right-hand circularly polarized light with a WHM of 20nm to 60nm is reflected back to the light-emitting layer 3 by the corresponding liquid crystal reflective unit, while the other portion of the right-hand circularly polarized light passes through the liquid crystal reflective layer 4. Among them, the portion of the right-hand circularly polarized light that passes through the liquid crystal reflective layer 4 is converted into 90° polarized light by the quarter-wave plate 6a and cannot pass through the linear polarizer 6b with the 0° transmission axis. The right-circularly polarized light with a narrow reflection spectrum that is reflected back to the light-emitting layer 3 is reflected again by the metal layer (e.g., the electrode layer) inside the display panel 1, and its rotation direction is reversed and it becomes left-circularly polarized light, so that it can pass through the corresponding liquid crystal reflection unit, quarter-wave plate 6a and linear polarizer 6b in sequence.

[0058] Understandably, this application embodiment selects chiral liquid crystal with a narrow reflectance spectrum as the material of the liquid crystal reflective unit, so that the liquid crystal reflective unit only reflects circularly polarized light with a half-width in the range of 20nm to 60nm in the second rotation direction, which effectively reduces the amount of circularly polarized light that can be reflected, thereby suppressing the increase in reflectivity and helping to balance the reflection and transmission performance of the display panel 1.

[0059] Research has revealed that the embodiments of this application are similar to... Figure 1 Compared to the display panel shown, the embodiment of this application, by providing a liquid crystal reflective layer 4, can increase the light transmittance of the display panel 1 from 42% to 60% or more, effectively improving the energy efficiency of the display panel 1.

[0060] In this embodiment, by sequentially distributing a liquid crystal reflective layer 4 and a circular polarizing layer 6 on the light-emitting side of the light-emitting layer 3, the circular polarizer can achieve mutual conversion between linearly polarized light and circularly polarized light of a first rotation direction (e.g., one of left-handed and right-handed rotation). At the same time, each liquid crystal reflective unit in the liquid crystal reflective layer 4 can selectively reflect circularly polarized light of a second rotation direction (e.g., the other of left-handed and right-handed rotation).

[0061] On the one hand, the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and each liquid crystal reflective unit is configured to selectively reflect circularly polarized light of the second rotation direction, so that circularly polarized light of a specific wavelength band emitted by the light-emitting unit can pass through the corresponding liquid crystal reflective unit and the circular polarizer. At least part of the circularly polarized light of the second rotation direction in the light of the specific wavelength band emitted by the light-emitting unit can be converted into circularly polarized light of the first rotation direction after being reflected by the corresponding liquid crystal reflective unit and the metal layer inside the display panel 1 in sequence. This allows the light that could not be emitted in the first place to pass through the corresponding liquid crystal reflective unit and the circular polarizer layer 6 again, thereby efficiently improving the light emission efficiency of the display panel 1, which in turn helps to improve the white brightness of the display panel 1, reduce the power consumption of the display panel 1, and extend the life of the display panel 1.

[0062] On the other hand, since each liquid crystal reflective unit is configured to selectively reflect circularly polarized light with a second rotation direction, and the half-width of the reflection spectrum of each liquid crystal reflective unit is less than or equal to 60 nanometers, when ambient light is incident on the display panel 1, the liquid crystal reflective units in the liquid crystal reflective layer 4 selectively reflect only the circularly polarized light with a second rotation direction in the incident light with a half-width of less than or equal to 60 nanometers, effectively reducing the reflection of ambient light and thus suppressing the increase in the reflectivity of the display panel 1 to ambient light.

[0063] Therefore, by narrowing the reflection spectrum of the liquid crystal reflective unit in the liquid crystal reflective layer 4, the reflectivity and light emission efficiency of the display panel 1 can be balanced. This can effectively improve the white state brightness while suppressing the panel reflectivity, thereby reducing panel power consumption and extending panel life.

[0064] In some embodiments, when viewed in the thickness direction of the display panel 1, the projection of each light-emitting unit along the thickness direction of the display panel 1 lies entirely within the projection range of the corresponding liquid crystal reflecting unit along the thickness direction of the display panel 1. That is, as... Figure 12 As shown, the liquid crystal reflective unit covers the corresponding light-emitting unit on the plane, thereby ensuring that the light emitted by the light-emitting unit can be effectively controlled by the corresponding liquid crystal reflective unit, which is beneficial to improve the display brightness of the display panel 1 while improving the viewing angle range of the display panel 1.

[0065] In some embodiments, the projected area of ​​each liquid crystal reflective unit along the thickness direction of the display panel 1 is greater than the projected area of ​​the corresponding light-emitting unit along the thickness direction of the display panel 1, and the area ratio of the two is greater than 1 and less than or equal to 1.5.

[0066] By making the projected area of ​​the liquid crystal reflective unit larger than that of the light-emitting unit to a certain extent, it is possible to ensure that the light from the light-emitting unit is completely covered by the liquid crystal reflective unit within a wider viewing angle range, while avoiding pixel crosstalk or resolution degradation caused by an excessively large reflective unit size. When the area ratio is controlled between 1 and 1.5, a good balance can be achieved between light utilization efficiency, viewing angle range, display uniformity, and pixel density.

[0067] In some embodiments, such as Figure 5 and Figure 6 As shown, the plurality of light-emitting units include a first light-emitting unit 3a, a second light-emitting unit 3b, and a third light-emitting unit 3c. The peak wavelength of the emission spectrum of the first light-emitting unit 3a is greater than the peak wavelength of the emission spectrum of the second light-emitting unit 3b, and the peak wavelength of the emission spectrum of the second light-emitting unit 3b is greater than the peak wavelength of the emission spectrum of the third light-emitting unit 3c.

[0068] Correspondingly, the plurality of liquid crystal reflective units include a first liquid crystal reflective unit 41, a second liquid crystal reflective unit 42, and a third liquid crystal reflective unit 43, which are respectively disposed in a one-to-one correspondence with the first light-emitting unit 3a, the second light-emitting unit 3b, and the third light-emitting unit 3c. The ratio of the half-width at half-maximum (WHM) of the reflection spectrum of the first liquid crystal reflective unit 41 to the WHM of the reflection spectrum of the second liquid crystal reflective unit 42 is in the range of 0.8 to 3, and / or the ratio of the WHM of the reflection spectrum of the third liquid crystal reflective unit 43 to the WHM of the reflection spectrum of the second liquid crystal reflective unit 42 is in the range of 0.8 to 3.

[0069] In some embodiments, the ratio of the half-width at half-maximum (WHM) of the reflection spectrum of the first liquid crystal reflective unit 41 to that of the second liquid crystal reflective unit 42 ranges from 0.8 to 1.2, and / or the ratio of the WHM of the reflection spectrum of the third liquid crystal reflective unit 43 to that of the second liquid crystal reflective unit 42 ranges from 0.8 to 1.2. This scheme can make the reflection bandwidths of each color channel closer, thereby helping to balance display effect and optical efficiency.

[0070] In one specific embodiment, the first light-emitting unit 3a is a red light-emitting unit configured to emit red light; the second light-emitting unit 3b is a green light-emitting unit configured to emit green light; and the third light-emitting unit 3c is a blue light-emitting unit configured to emit blue light. Correspondingly, the liquid crystal reflective unit corresponding to the red light-emitting unit is denoted as R-CLC, the liquid crystal reflective unit corresponding to the green light-emitting unit is denoted as G-CLC, and the liquid crystal reflective unit corresponding to the blue light-emitting unit is denoted as B-CLC.

[0071] In some embodiments, the reflection spectrum of the liquid crystal reflective layer 4 is as follows: Figure 11 As shown. It should be noted that, Figure 11 The vertical axis in the figure refers to the reflectivity of the liquid crystal reflective unit to a specific light wave, while the reflectivity of the display panel described in the embodiments of this application refers to the average reflectivity of the visible light range, i.e., the visual reflectivity ρv.

[0072] like Figure 11 As shown, the center wavelength of the reflection spectrum of R-CLC is located in the red light band, the center wavelength of the reflection spectrum of G-CLC is located in the green light band, and the center wavelength of the reflection spectrum of B-CLC is located in the blue light band.

[0073] The inventors discovered through research that the full width at half maximum (FWHM) of the reflectance spectrum of G-CLC (which can be simply referred to as the reflectance bandwidth) is strongly correlated with the average reflectance of the display panel 1. Therefore, during the design process, G-CLC can be used as a reference for reflectance measurement. The CLC's reflectance spectrum full width at half maximum (FWHM) is set to a relatively small range to effectively reduce ambient light reflection; while R... CLC and B The half-width at half maximum (FWHM) of the reflection spectrum of CLC can be appropriately greater than G. The full width at half maximum (FWHM) of the reflection spectrum of CLC. Taking into account the stability of the reflection hue and the differences in lifetime of different color emitting units, R... CLC and B The full width at half maximum (FWHM) of the CLC's reflectance spectrum is controlled to G. The half-width at half-maximum (WHM) of the CLC reflection spectrum is 0.8 to 3 times that of the CLC. By rationally adjusting the reflection bandwidth of each liquid crystal reflective unit, the light output of different color light-emitting units can be optimized and matched while ensuring low reflectivity. For example, the lifespan of blue light-emitting units is relatively short. By appropriately increasing the WHM of the B-CLC reflection spectrum, the transmittance of blue light can be improved, thereby reducing the driving power consumption of blue light-emitting units while achieving the same display brightness, and thus extending their lifespan.

[0074] In one specific embodiment, the half-width at half-maximum (WHM) of the reflectance spectra of R-CLC and B-CLC is 60 nm, and the WHM of the reflectance spectrum of G-CLC is 20 nm. With this configuration, while maintaining a low average reflectance of the display panel 1, the power consumption requirements of the red and blue light-emitting units can be effectively reduced, thereby extending their lifespan and improving the overall display performance of the panel.

[0075] In one specific embodiment, the full width at half maximum (FWHM) of the reflection spectra of R-CLC, G-CLC, and B-CLC can also be the same. For example, when the FWHM of the reflection spectra of R-CLC, G-CLC, and B-CLC is 30 nm, the reflectance of R-CLC, G-CLC, and B-CLC at the center wavelength of their respective reflection spectra is less than or equal to 40%, the average reflectance of display panel 1 is 7%, and the white state brightness of display panel 1 is above 120%.

[0076] This application investigated the effect of the full width at half maximum (FWHM) of the reflectance spectra of R-CLC, G-CLC, and B-CLC on the average reflectance and white-state brightness of the display panel 1 through Examples 1 to 5. The results are shown in Table 1.

[0077] Specifically, in Examples 1 to 5, the light-emitting layer 3 is composed of R-OLED, G-OLED, and B-OLED, and the liquid crystal reflective layer 4 is composed of R-CLC, G-CLC, and B-CLC. The only difference between Examples 1 to 5 is the value of the full width at half maximum (FWHM). For example, in Example 1, the FWHM of the reflectance spectra of R-CLC, G-CLC, and B-CLC is 20 nm; in Example 2, the FWHM of the reflectance spectra of R-CLC, G-CLC, and B-CLC is 30 nm; in Example 3, the FWHM of the reflectance spectra of R-CLC, G-CLC, and B-CLC is 40 nm; in Example 4, the FWHM of the reflectance spectra of R-CLC, G-CLC, and B-CLC is 50 nm; and in Example 5, the FWHM of the reflectance spectra of R-CLC, G-CLC, and B-CLC is 60 nm.

[0078] Specifically, the half-width at half maximum (WHM) of the reflectance spectra in Table 1 was obtained using a UV-Vis spectrophotometer. The testing method included: instrument warm-up, baseline calibration, placement of the sample to be tested, spectral scanning and acquisition, and calculation of the WHM (the software automatically found the maximum reflectance, and the plate height threshold = 0.5XTmax, corresponding to the WHM peak).

[0079] Specifically, the average reflectance in Table 1 was obtained using a Konica Minolta CM-2600d or CM-26d spectrophotometer (reflectance meter). Before measurement, the sample to be tested (liquid crystal reflective layer) was flatly attached to the surface of a black acrylic plate to eliminate interference from background transmitted light on the reflectance measurement. During measurement, the spectral reflectance data of the sample were collected under a D65 standard light source, and the final reflectance value obtained is the total internal reflection value including specular reflection components.

[0080] Specifically, the white-state brightness in Table 1 was obtained using a Konica Minolta CS-410 colorimeter. During testing, the sample to be tested (liquid crystal reflective layer) was flatly attached to the surface of the display screen, and brightness data was collected and recorded while the screen displayed a completely white image. It can be understood that the white-state brightness in Table 1 is relative data obtained using brightness data obtained from a display screen without a liquid crystal reflective layer displaying a completely white image as a baseline.

[0081] Table 1

[0082] As shown in Table 1, by controlling the half-width of the reflection spectrum of the liquid crystal reflective layer 4 of the display panel 1 within the range of 20nm to 60nm, the average reflectivity of the display panel 1 can be kept low, and the white brightness of the display panel 1 can be effectively improved.

[0083] It should be noted that the full width at half maximum (FWHM) of the reflectance spectra of R-CLC, G-CLC, and B-CLC can be adjusted according to various requirements such as reflectance, white state brightness, reflectance hue, and the lifetime of the luminescent material.

[0084] In some embodiments, the center wavelength range of the reflection spectrum of the first liquid crystal reflective unit 41 is 625 nm to 650 nm.

[0085] In some embodiments, the center wavelength range of the reflection spectrum of the second liquid crystal reflective unit 42 is 530 nm to 550 nm.

[0086] In some embodiments, the center wavelength range of the reflection spectrum of the third liquid crystal reflective unit 43 is 450 nm to 460 nm.

[0087] By setting the center wavelength of the reflection spectrum of each liquid crystal reflection unit within the emission spectrum range of the corresponding light-emitting unit, the circularly polarized light with a specific rotation direction generated by different color light-emitting units can be effectively reflected and reused, thereby improving the light extraction efficiency of each color sub-pixel and helping to improve the overall light utilization rate and display brightness of the display panel 1.

[0088] In some embodiments, the peak wavelength of the emission spectrum of the first light-emitting unit 3a is greater than the peak wavelength of the emission spectrum of the second light-emitting unit 3b, and the peak wavelength of the emission spectrum of the second light-emitting unit 3b is greater than the peak wavelength of the emission spectrum of the third light-emitting unit 3c. The thickness of the first liquid crystal reflective unit 41 is greater than the thickness of the second liquid crystal reflective unit 42, and the thickness of the second liquid crystal reflective unit 42 is greater than the thickness of the third liquid crystal reflective unit 43, to adapt to the reflection requirements of different center wavelengths.

[0089] In one specific embodiment, the material of the liquid crystal reflective layer 4 includes cholesteric liquid crystal. To ensure that the liquid crystal reflective unit has high selective reflection efficiency, the thickness of any liquid crystal reflective unit is greater than or equal to five times the pitch (P) of the corresponding cholesteric liquid crystal. For example, the thickness of any one of R-CLC, G-CLC, and B-CLC is greater than or equal to five times the pitch (P) of the corresponding cholesteric liquid crystal, for example, about 1.5 micrometers or more, thereby improving the reflection capability of circularly polarized light with a specific rotation direction and further improving the light utilization efficiency of the display panel 1.

[0090] In some embodiments, such as Figure 5 As shown, two adjacent light-emitting units (e.g., the first light-emitting unit 3a and the second light-emitting unit 3b) of different colors alight together have two corresponding liquid crystal reflective units (e.g., the first liquid crystal emitting unit 41 and the second liquid crystal reflective unit 42) that alight against each other. In other words, two adjacent liquid crystal reflective units used for selectively reflecting different colors of light alight against each other to form a continuous reflective structure.

[0091] By making adjacent liquid crystal reflective units abut against each other, the ineffective area between liquid crystal reflective units can be reduced, the space utilization of the overall structure can be improved, and the light emitted by the light-emitting unit is less likely to leak from the gap between two adjacent liquid crystal reflective units when it enters the corresponding liquid crystal reflective unit, thereby increasing the light extraction efficiency.

[0092] For example, in one specific embodiment, multiple light-emitting units are arranged periodically in the order of red, green, and blue light-emitting units. The liquid crystal reflective unit corresponding to the red light-emitting unit is denoted as R-CLC, the liquid crystal reflective unit corresponding to the green light-emitting unit is denoted as G-CLC, and the liquid crystal reflective unit corresponding to the blue light-emitting unit is denoted as B-CLC. Adjacent R-CLCs and G-CLCs are directly abutted against each other, as are adjacent G-CLCs and B-CLCs, and adjacent R-CLCs and B-CLCs, forming a continuous reflective area in the planar direction. In this structure, since there are essentially no significant gaps between adjacent liquid crystal reflective units, brightness loss caused by light entering ineffective areas can be effectively avoided. It also helps to reduce pixel pitch, increase the pixel density of the display panel 1, and further improve the display resolution.

[0093] In other embodiments, such as Figure 6 and Figure 13 As shown, two adjacent light-emitting units with different emission colors are respectively arranged with two liquid crystal reflective units that partially overlap. By forming an overlapping structure in a local area between adjacent liquid crystal reflective units, a continuous and larger reflection area can be formed between adjacent light-emitting units, thereby reducing light loss in the boundary area and improving the overall light utilization efficiency.

[0094] In one specific embodiment, such as Figure 13 As shown, two liquid crystal reflective units, corresponding to two adjacent light-emitting units with different emission colors, include a first liquid crystal reflective unit 41 and a second liquid crystal reflective unit 42. The first liquid crystal reflective unit 41 includes a first liquid crystal reflective main body portion 41a and a first liquid crystal reflective overlapping portion 41b, both made of the same material. The second liquid crystal reflective unit 42 includes a second liquid crystal reflective main body portion 42a and a second liquid crystal reflective overlapping portion 42b, both made of the same material. The first liquid crystal reflective main body portion 41a and the second liquid crystal reflective main body portion 42a are made of different materials, and the first liquid crystal reflective overlapping portion 41b and the second liquid crystal reflective overlapping portion 42b are located between the first liquid crystal reflective main body portion 41a and the second liquid crystal reflective main body portion 42a, and are stacked along the thickness direction of the display panel 1.

[0095] The first liquid crystal reflective overlapping portion 41b and the second liquid crystal reflective overlapping portion 42b are stacked in the thickness direction of the display panel 1, thereby forming a stacked reflective structure between adjacent liquid crystal reflective units. Through this structural design, the liquid crystal reflective layers 4 of different materials work synergistically in the overlapping area, which can effectively reflect or control the light from different light-emitting units, which helps to reduce light loss between adjacent light-emitting units and improve the overall light extraction efficiency.

[0096] It should be noted that the higher the surface flatness of the CLC layer, the more complete the periodicity of its spiral structure and the fewer defects. Bragg reflection is very sensitive to the periodicity of the structure; a flat surface can significantly reduce scattering and reflection losses, resulting in greater reflected light intensity and higher reflection efficiency at specific wavelengths. Furthermore, in display applications, a flat CLC layer provides more uniform reflection or transmission characteristics, avoiding localized light intensity differences or haze caused by surface unevenness, thereby improving display contrast and overall brightness. In addition, improved surface flatness helps maintain the consistent alignment of the spiral axes within the CLC layer (fewer misalignments or tilts), thus improving the consistency of optical performance at different viewing angles (such as the uniformity of reflected color and intensity). Therefore, when two adjacent liquid crystal reflective units are overlapped, it is necessary to improve the surface flatness of each liquid crystal reflective unit through structural improvements.

[0097] In some embodiments, when the liquid crystal reflective layer 4 includes R-CLC, G-CLC and B-CLC, since the thickness of R-CLC is greater than the thickness of G-CLC, and the thickness of G-CLC is greater than the thickness of B-CLC, in order to improve the surface flatness of R-CLC, G-CLC and B-CLC, resin (e.g. UV-curable resin) can be used to fill the liquid crystal reflective layer 4 to reduce the step difference before coating CLC.

[0098] For example, B-CLC and R-CLC can be coated so that the edge of R-CLC overlaps the edge of B-CLC. Since the thickness of R-CLC is greater than that of B-CLC, the overlapping area has little impact on the surface smoothness of R-CLC. Then, a UV-cured resin can be applied to a predetermined area of ​​G-CLC, curing it to form a filler layer 45. G-CLC is then coated onto the filler layer 45, raising the overall height of G-CLC and reducing the step difference between G-CLC and R-CLC. This ensures that the surface smoothness of G-CLC is not affected when the edge of G-CLC overlaps the edge of R-CLC. Therefore, the surface smoothness of R-CLC, G-CLC, and B-CLC is all guaranteed.

[0099] Of course, the above is only an illustrative example, and the application order of R-CLC, G-CLC and B-CLC is not limited in this application embodiment.

[0100] In another specific embodiment, such as Figure 6 and Figure 12As shown, the first liquid crystal reflective unit 41 includes a first liquid crystal reflective main body portion 41a and a liquid crystal reflective overlapping portion 44, and the second liquid crystal reflective unit 42 includes a second liquid crystal reflective main body portion 42a and a liquid crystal reflective overlapping portion 44. The first liquid crystal reflective main body portion 41a and the second liquid crystal reflective main body portion 42a are made of different materials, and the liquid crystal reflective overlapping portion 44 is made of the same material as the first liquid crystal reflective main body portion 41a and the second liquid crystal reflective main body portion 42a. It can be understood that the overlapping area of ​​the first liquid crystal reflective unit 41 and the second liquid crystal reflective unit 42 has the optical properties of both materials. By setting the shared liquid crystal reflective overlapping portion 44, a transition area can be formed between adjacent liquid crystal reflective units, making each part of the liquid crystal reflective layer 4 flat, thereby reducing the interface light loss between different reflective structures, and avoiding the negative optical effects caused by poor surface flatness of the liquid crystal reflective unit, which is beneficial to further improving the overall light utilization rate of the light-emitting unit array and the display effect of the display panel 1.

[0101] Of course, in other embodiments, the two liquid crystal reflective units that are respectively arranged with two light-emitting units of different colors and adjacent to each other can also be arranged at intervals. In this case, the liquid crystal reflective layer has a limited effect on balancing the reflectivity and white brightness of the display panel.

[0102] In some embodiments, the display panel 1 further includes an encapsulation layer 5 disposed between the light-emitting layer 3 and the liquid crystal reflective layer 4. The encapsulation layer 5 may be a thin film encapsulation layer 5, such as including a first inorganic encapsulation layer 5, an organic encapsulation layer 5 and a second inorganic encapsulation layer 5 stacked sequentially, but is not limited thereto.

[0103] In some embodiments, the display panel 1 further includes a protective cover plate 7 disposed on the side of the liquid crystal reflective layer 4 opposite to the light-emitting layer 3. The protective cover plate 7 can be a glass cover plate or an ultra-thin glass cover plate, but is not limited thereto.

[0104] In some embodiments, an adhesive layer 8 is provided between the circular polarizer and the glass cover plate. The adhesive layer 8 may be selected from pressure-sensitive adhesive layers or optical adhesive layers, but is not limited thereto.

[0105] This application also provides a display device, which includes the display panel 1 described in the above embodiments.

[0106] In this embodiment, by sequentially distributing a liquid crystal reflective layer 4 and a circular polarizing layer 6 on the light-emitting side of the light-emitting layer 3, the circular polarizer can achieve mutual conversion between linearly polarized light and circularly polarized light of a first rotation direction (e.g., one of left-handed and right-handed rotation). At the same time, each liquid crystal reflective unit in the liquid crystal reflective layer 4 can selectively reflect circularly polarized light of a second rotation direction (e.g., the other of left-handed and right-handed rotation). On the one hand, the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and each liquid crystal reflective unit is configured to selectively reflect circularly polarized light of the second rotation direction, so that circularly polarized light of a specific wavelength band emitted by the light-emitting unit can pass through the corresponding liquid crystal reflective unit and the circular polarizer. At least part of the circularly polarized light of the second rotation direction in the light of the specific wavelength band emitted by the light-emitting unit can be converted into circularly polarized light of the first rotation direction after being reflected by the corresponding liquid crystal reflective unit and the metal layer inside the display panel 1 in sequence. This allows the light that could not be emitted in the first place to pass through the corresponding liquid crystal reflective unit and the circular polarizer layer 6 again, thereby efficiently improving the light emission efficiency of the display panel 1, which in turn helps to improve the white brightness of the display panel 1, reduce the power consumption of the display panel 1, and extend the life of the display panel 1. On the other hand, since each liquid crystal reflective unit is configured to selectively reflect circularly polarized light with a second rotation direction, and the half-width of the reflection spectrum of each liquid crystal reflective unit is in the range of 20 nanometers to 60 nanometers, when ambient light is incident on the display panel 1, the liquid crystal reflective units in the liquid crystal reflective layer 4 selectively reflect only the circularly polarized light with a second rotation direction in the incident light whose half-width falls within the range of 20 nanometers to 60 nanometers, effectively reducing the reflection of ambient light and thus suppressing the increase in the reflectivity of the display panel 1 to ambient light.

[0107] Therefore, by narrowing the reflection spectrum of the liquid crystal reflective unit in the liquid crystal reflective layer 4, this application can balance the reflectivity and light emission efficiency of the display panel 1, and effectively improve the white state brightness of the display panel 1 while suppressing the panel reflectivity, thereby reducing panel power consumption and extending panel life.

[0108] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0109] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0110] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0111] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A display panel, characterized in that, include: Array substrate; A light-emitting layer is disposed on one side of the array substrate and includes multiple light-emitting units with different light-emitting colors; A liquid crystal reflective layer is disposed on the side of the light-emitting layer away from the array substrate, and includes a plurality of liquid crystal reflective units that correspond one-to-one with the plurality of light-emitting units and are disposed on the same layer; A circular polarizing layer is disposed on the side of the liquid crystal reflective layer opposite to the light-emitting layer, and is configured to convert linearly polarized light and circularly polarized light of a first rotation direction into each other; Each of the liquid crystal reflective units is configured to selectively reflect circularly polarized light with a second rotation direction, wherein the first rotation direction and the second rotation direction are opposite; the center wavelength of the reflection spectrum of each liquid crystal reflective unit is located within the emission spectrum of the corresponding light-emitting unit, and the half-width at half maximum (FWHM) of the reflection spectrum of each liquid crystal reflective unit is less than or equal to 60 nanometers.

2. The display panel according to claim 1, characterized in that, The full width at half maximum (FWHM) of the reflection spectrum of each liquid crystal reflective unit ranges from 20 nm to 60 nm.

3. The display panel according to claim 1, characterized in that, The plurality of light-emitting units include a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit; the peak wavelength of the emission spectrum of the first light-emitting unit is greater than the peak wavelength of the emission spectrum of the second light-emitting unit, and the peak wavelength of the emission spectrum of the second light-emitting unit is greater than the peak wavelength of the emission spectrum of the third light-emitting unit; The plurality of liquid crystal reflective units include a first liquid crystal reflective unit, a second liquid crystal reflective unit, and a third liquid crystal reflective unit, which are respectively disposed in one-to-one correspondence with the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit; The ratio of the half-width at half maximum (WHM) of the reflection spectrum of the first liquid crystal reflective unit to the half-width at half maximum (WHM) of the reflection spectrum of the second liquid crystal reflective unit is in the range of 0.8 to 3, and / or the ratio of the half-width at half maximum (WHM) of the reflection spectrum of the third liquid crystal reflective unit to the half-width at half maximum (WHM) of the reflection spectrum of the second liquid crystal reflective unit is in the range of 0.8 to 3.

4. The display panel according to claim 3, characterized in that, The first light-emitting unit is a red light-emitting unit, the second light-emitting unit is a green light-emitting unit, and the third light-emitting unit is a blue light-emitting unit; The center wavelength range of the reflection spectrum of the first liquid crystal reflective unit is 625nm to 650nm, and / or the center wavelength range of the reflection spectrum of the second liquid crystal reflective unit is 530nm to 550nm, and / or the center wavelength range of the reflection spectrum of the third liquid crystal reflective unit is 450nm to 460nm.

5. The display panel according to claim 3, characterized in that, The thickness of the first liquid crystal reflective unit is greater than the thickness of the second liquid crystal reflective unit, and the thickness of the second liquid crystal reflective unit is greater than the thickness of the third liquid crystal reflective unit; And / or, the material of the liquid crystal reflective layer includes cholesteric liquid crystal, and the thickness of any one of the liquid crystal reflective units is greater than or equal to five times the pitch of the corresponding cholesteric liquid crystal.

6. The display panel according to any one of claims 1 to 5, characterized in that, The projection of each of the light-emitting units along the thickness direction of the display panel is located within the projection of the corresponding liquid crystal reflecting unit along the thickness direction of the display panel; The ratio of the projected area of ​​each liquid crystal reflective unit along the thickness direction of the display panel to the projected area of ​​the corresponding light-emitting unit along the thickness direction of the display panel is greater than 1 and less than or equal to 1.

5.

7. The display panel according to any one of claims 1 to 5, characterized in that, Two adjacent light-emitting units with different light-emitting colors are respectively arranged with two liquid crystal reflective units that abut against each other or partially overlap.

8. The display panel according to claim 7, characterized in that, The two light-emitting units, which are of different light-emitting colors and are arranged adjacently, respectively correspond to the two liquid crystal reflective units, including a first liquid crystal reflective unit and a second liquid crystal reflective unit. The first liquid crystal reflective unit includes a first liquid crystal reflective main body and a first liquid crystal reflective overlapping part made of the same material. The second liquid crystal reflective unit includes a second liquid crystal reflective main body and a second liquid crystal reflective overlapping part made of the same material. The first liquid crystal reflective main body and the second liquid crystal reflective main body are made of different materials. The first liquid crystal reflective overlapping part and the second liquid crystal reflective overlapping part are located between the first liquid crystal reflective main body and the second liquid crystal reflective main body and are stacked. Alternatively, the first liquid crystal reflective unit includes a first liquid crystal reflective main portion and a liquid crystal reflective overlapping portion, and the second liquid crystal reflective unit includes a second liquid crystal reflective main portion and the liquid crystal reflective overlapping portion. The first liquid crystal reflective main portion and the second liquid crystal reflective main portion are made of different materials, and the liquid crystal reflective overlapping portion is made of the materials of the first liquid crystal reflective main portion and the second liquid crystal reflective main portion.

9. The display panel according to claim 1, characterized in that, The first rotation direction is left-handed, the second rotation direction is right-handed, and the circular polarizing layer is a left-handed circular polarizing layer; or, the first rotation direction is right-handed, the second rotation direction is left-handed, and the circular polarizing layer is a right-handed circular polarizing layer.

10. A display device, characterized in that, Includes the display panel as described in any one of claims 1 to 9.

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