Display panel, manufacturing method thereof, and display device

Abstract

The present application discloses a display panel, a method for preparing the same, and a display device, comprising a stacked substrate, a sensor layer, a functional film layer, a light-shielding layer, and a display layer. The sensor layer is provided with a plurality of photosensitive elements; the functional film layer is configured to receive incident light and convert the incident light into linearly polarized light for emission; the light-shielding layer is provided with a plurality of imaging holes, through which the linearly polarized light is incident on the photosensitive elements. The functional film layer can extinct natural light reaching the sensor layer, thereby effectively reducing interference light entering the sensor layer and improving fingerprint recognition accuracy. By adding a chiral liquid crystal layer to the functional film layer, the extinction ratio and light intensity of the display panel can be effectively increased, significantly improving the clarity and contrast of fingerprint imaging.

Description

Technical Field

[0001] The present application generally relates to the field of display technology, and specifically relates to a display panel and a manufacturing method thereof, and a display device. Background Art

[0002] Currently, the market is demanding an increasingly high screen-to-body ratio for consumer products like mobile phones. Traditional fingerprint collection methods, which require a separate space, are no longer able to meet market demands. Under-screen fingerprint recognition has become a key implementation method because it can be integrated into the panel without occupying additional panel space. Under-screen fingerprint recognition primarily includes capacitive, ultrasonic, and optical methods, with optical being the most widely used, particularly in the OLED display industry.

[0003] In the existing technology, OLED is mainly used as the light source. The light emitted by OLED is reflected when it reaches the skin of the finger on the surface of the touch screen, forming reflected light that propagates toward the photosensitive element below the touch screen. The photosensitive element receives the reflected light and then generates a fingerprint image based on the reflected light, thereby achieving the purpose of fingerprint recognition.

[0004] For photosensitive elements, it is obvious that the higher the panel's transmittance, the stronger the light intensity it receives, which is more conducive to fingerprint recognition. However, since fingerprints are highly transparent, if the photosensitive element can only obtain light intensity information, it is difficult to obtain a clear and high-contrast fingerprint image. In this case, it is necessary to further increase the panel's transmittance to enhance the light intensity, but this requirement is difficult to achieve, or it is costly and difficult to achieve. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a display panel and a manufacturing method thereof, and a display device that can improve the recognition accuracy of under-screen fingerprint recognition.

[0006] In a first aspect, the present application provides a display panel, comprising a stacked substrate, a sensor layer, a functional film layer, a light shielding layer, and a display layer, wherein:

[0007] A plurality of photosensitive elements are provided on the sensor layer;

[0008] The functional film layer is used to receive incident light and convert the incident light into linearly polarized light before emitting it;

[0009] The light shielding layer is provided with a plurality of imaging holes, and the linearly polarized light is incident on the photosensitive element through the imaging holes.

[0010] Optionally, the functional film layer includes a linear polarizing layer and / or a quarter-wave plate layer, and the linear polarizing layer is arranged on a side close to the sensor layer; the optical axis of the quarter-wave plate layer forms an angle of 45° with the absorption axis of the linear polarizing layer, and the optical axis of the quarter-wave plate layer is parallel to the plane where the substrate is located.

[0011] Optionally, the functional film layer includes a chiral liquid crystal layer disposed on a side close to the light-shielding layer, and the chiral liquid crystal layer is configured to reflect light of a first rotating direction and transmit light of a second rotating direction.

[0012] Optionally, the peak wavelength of the reflected light of the chiral liquid crystal layer is equal to four times the phase difference of the quarter-wave plate layer.

[0013] Optionally, the second polarized light is converted into the linearly polarized light after being incident on the quarter-wave plate layer, and the polarization direction of the linearly polarized light is perpendicular to the absorption axis of the linear polarizing layer.

[0014] Optionally, a plurality of light-emitting elements are provided on the display layer, and the orthographic projections of the light-emitting elements on the substrate do not overlap with the orthographic projections of the imaging holes on the substrate; the orthographic projections of the imaging holes on the substrate are within the orthographic projection range of the photosensitive elements on the substrate.

[0015] Optionally, the display layer includes an electrode layer electrically connected to the light-emitting element, and the electrode layer is a semi-transmissive and semi-reflective material.

[0016] Optionally, the functional layer further includes a total reflection layer arranged on a side of the chiral liquid crystal layer close to the functional film layer, the total reflection layer includes a plurality of light-transmitting holes, and the orthographic projections of the light-transmitting holes on the base substrate at least cover the orthographic projections of the imaging holes on the base substrate.

[0017] In a second aspect, the present application provides a method for manufacturing a display panel, for manufacturing any of the above display panels, the method comprising:

[0018] providing a substrate;

[0019] forming a functional film layer on the base substrate, the functional film layer comprising one or more of a first liquid crystal layer, a second liquid crystal layer, and a third liquid crystal layer, wherein the first liquid crystal layer forms a linear polarizing layer after alignment and curing, the second liquid crystal layer forms a quarter-wave plate layer after alignment and curing, and the third liquid crystal layer forms a chiral liquid crystal layer after alignment and curing;

[0020] A light shielding layer and a display layer are sequentially formed on the functional film layer.

[0021] In a third aspect, the present application provides a display device comprising any display panel as described above.

[0022] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0023] The display panel provided in the embodiment of the present application can perform extinction processing on the natural light reaching the sensor layer through the functional film layer, thereby effectively reducing the interference light entering the sensor layer and improving the accuracy of fingerprint recognition; by adding a chiral liquid crystal layer in the functional film layer, the extinction ratio and light intensity of the display panel can be effectively improved, which can greatly improve the clarity and contrast of fingerprint imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0025] Figure 1 A schematic structural diagram of a display panel provided in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of light rays of a display panel provided in an embodiment of the present application;

[0027] Figure 3 A schematic structural diagram of another display panel provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of light rays of another display panel provided in an embodiment of the present application;

[0029] Figure 5 A schematic structural diagram of another display panel provided in an embodiment of the present application;

[0030] Figure 6 A schematic structural diagram of another display panel provided in an embodiment of the present application;

[0031] Figure 7 A schematic diagram of light rays of another display panel provided in an embodiment of the present application;

[0032] Figure 8 A flow chart of a method for manufacturing a display panel provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0034] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] Research has found that when the light received by the photosensitive element is linearly polarized, that is, has a large extinction ratio, better image clarity can be achieved. However, compared to existing display panels, the light reflected from the finger, after passing through the entire OLED module, is affected by multiple refractions. By the time it reaches the photosensitive element, it is already in an unpolarized state close to natural light, meaning its extinction ratio is 0.

[0036] Please see Figure 1 The present application provides a display panel, comprising a stacked base substrate 100, a sensor layer 200, a functional film layer 300, a light shielding layer 400, and a display layer 500, wherein:

[0037] The sensor layer 200 is provided with a plurality of photosensitive elements 1;

[0038] The functional film layer 300 is used to receive incident light and convert the incident light into linearly polarized light before emitting it;

[0039] A plurality of imaging holes 2 are provided on the light shielding layer 400 , and the linearly polarized light is incident on the photosensitive element 1 through the imaging holes 2 .

[0040] In one embodiment of the present application, the functional film layer 300 includes a linear polarizing layer 3 or a quarter wave plate layer 4 (λ / 4). The linear polarizing layer 3 is an optical film material that converts natural light into polarized light. The linear polarizing layer 3 only allows light with a polarization direction parallel to the transmission axis of the linear polarizing layer 3 to pass through, while filtering out light that vibrates perpendicular to the transmission axis (i.e., along the absorption axis). Figure 2 The function of the quarter-wave plate layer 4 is similar to that of the linear polarizer layer. When light passes through the wave plate from a normal incidence direction, the phase difference between the ordinary light (o light) and the extraordinary light (e light) is equal to π / 2 or an odd multiple thereof, which can convert the natural light into linearly polarized light.

[0041] In the embodiment of the present application, the functional film layer 300 is arranged between the light-shielding layer 400 and the sensor layer 200, so that the light reaching the sensor layer 200 can be extinct, thereby effectively reducing the interference light entering the sensor layer 200. Since an imaging hole 2 with a through hole is provided on the light-shielding layer 400, the imaging hole 2 is light-transmissive and can illuminate the light reflected back from the fingerprint onto the photosensitive element 1. By utilizing the principle of through hole (pinhole imaging), the shape of the fingerprint can be presented on the photosensitive element 1, so that it can be recognized by the photosensitive element 1, which can greatly improve the clarity and contrast of the fingerprint imaging.

[0042] In which, a plurality of light-emitting elements 6 are arranged on the display layer 500, and the orthographic projection of the light-emitting element 6 on the substrate does not overlap with the orthographic projection of the imaging hole 2 on the base substrate 100; the orthographic projection of the imaging hole 2 on the base substrate 100 is located within the orthographic projection range of the photosensitive element 1 on the base substrate 100.

[0043] The shape of the imaging aperture 2 is not limited in the embodiments of the present application and may be circular, square, rectangular, etc. Furthermore, the formation method of the imaging aperture 2 is not limited in the embodiments of the present application. In some embodiments, the imaging aperture 2 is formed by forming an opening in the light-shielding layer 400 for light to pass through. The light-shielding layer 400 is made of a resin material or an opaque metal material such as molybdenum (Mo). In other embodiments, the light-through hole is formed through a transparent layer and a light-shielding layer 400 is provided on the upper and lower surfaces of the transparent layer or on the intermediate interface of the transparent layer.

[0044] It should be noted that the diameter of the imaging aperture 2 must meet the pinhole diameter requirements of the pinhole imaging principle. For example, the diameter of the imaging aperture 2 can be set to 6 μm to 20 μm. Specifically, the diameter of the imaging aperture 2 can be set to 6 μm, 10 μm, or 20 μm. In actual applications, the specific value of the diameter of the imaging aperture 2 needs to be designed and determined based on the actual application environment and is not limited here.

[0045] Through further research, a linear polarizing layer 3 (or a quarter-wave plate layer 4) is added between the photosensitive element 1 and the imaging pinhole layer. Since the light reaching the linear polarizing layer 3 is already in a non-polarized state close to natural light, after passing through the linear polarizing layer, it is converted into linearly polarized light. Then, although the light reaching the photosensitive element 1 at this time has a high extinction ratio (the specific value is determined by the polarization degree of the linear polarizing layer 3, such as 20dB for a polarization degree of 99% and 30dB for a polarization degree of 99.9%), the light intensity loss will reach more than 50%, such as Figure 2 That is to say, the extinction ratio and intensity cannot achieve a good state at the same time.

[0046] In order to further optimize the extinction ratio and light intensity, such as Figure 3 As shown, the functional film layer 300 in the present application includes a chiral liquid crystal layer 5 disposed on a side close to the light shielding layer 400 , and the chiral liquid crystal layer 5 is used to reflect light of a first rotating direction and transmit light of a second rotating direction.

[0047] It should be noted that the chiral liquid crystal molecules in the chiral liquid crystal layer 5 are liquid crystal molecules with chiral centers. Chiral liquid crystal molecules are characterized by the presence of carbon atoms with asymmetric chiral centers within their molecular structure. The presence of chiral centers creates a helical structure in these liquid crystal molecules, which imparts numerous optical properties not possessed by conventional liquid crystal molecules, such as the ability to selectively reflect light of a fixed wavelength and direction. In the present embodiment, the chiral liquid crystal layer 5 is described using a cholesteric liquid crystal as an example.

[0048] Based on the direction of the helix, cholesteric liquid crystal films are classified as left-handed cholesteric liquid crystal and right-handed cholesteric liquid crystal. Left-handed cholesteric liquid crystal exhibits left-handed circular polarization, while right-handed cholesteric liquid crystal exhibits right-handed circular polarization. When cholesteric liquid crystal is distributed in a planar texture state, it exhibits selective reflection properties. Left-handed circular polarization reflects left-handed circularly polarized light with a wavelength close to the cholesteric liquid crystal helical pitch, while allowing right-handed circularly polarized light and light of other wavelengths to pass through. Right-handed circular polarization reflects right-handed circularly polarized light with a wavelength close to the cholesteric liquid crystal helical pitch, while allowing left-handed circularly polarized light and light of other wavelengths to pass through.

[0049] Cholesteric liquid crystals contain many layers of molecules. Each layer has the same orientation, but the orientations of adjacent layers are slightly rotated, forming a spiral structure. When the molecular arrangement rotates 360° and then returns to its original orientation, the distance between the two layers with exactly the same molecular arrangement is called the pitch of the cholesteric liquid crystal. The pitch can be altered by adding chiral agents to the cholesteric liquid crystal as needed.

[0050] The following is a detailed description of the implementation of the fingerprint recognition function of the present invention in conjunction with specific embodiments. It should be noted that this embodiment is only for better explanation of the present invention, but does not limit the present invention.

[0051] Example 1

[0052] like Figure 3 As shown, the functional film layer 300 includes a chiral liquid crystal layer 5 and a linear polarizer layer 3 or a quarter-wave plate layer 4 located on a side of the chiral liquid crystal layer 5 close to the sensor layer 200. The chiral liquid crystal layer 5 is configured to reflect one of left-handed circularly polarized light and right-handed circularly polarized light and transmit the other, for example, to reflect light of a first rotating direction and transmit light of a second rotating direction.

[0053] Natural light emitted by the OLED device is modulated into circularly polarized light by the chiral liquid crystal layer 5. In this embodiment, left-handed cholesteric liquid crystal is used as an example. After passing through the chiral liquid crystal layer 5, the natural light is incident on the linear polarization layer, where the second-handed light (right-handed circularly polarized light) is converted to linearly polarized light for output; or it is incident on the quarter-wave plate layer 4, where the circularly polarized light passing through the liquid crystal layer is converted to linearly polarized light for output due to phase retardation.

[0054] It can be understood that in the embodiment of the present application, when the functional film layer 300 only includes the chiral liquid crystal layer 5 and the quarter-wave plate layer 4, the circularly polarized light will ideally be completely converted into linearly polarized light after passing through the quarter-wave plate, but in reality the output light may be an elliptically polarized light with a large major-minor axis ratio. However, compared with the functional film layer 300 in which only a linear polarization layer is provided, the extinction ratio and light intensity can be effectively improved; in addition, compared with the structure of Example 2, one optical film layer can be omitted, but the extinction ratio will also decrease to a certain extent. In specific applications, the choice should be made according to the needs.

[0055] In the embodiment of the present application, the display layer 500 includes an electrode layer 7 electrically connected to the light emitting element 6. The electrode layer 7 is a semi-transmissive and semi-reflective material. In the embodiment of the present application, the electrode layer 7 can be an anode or a cathode, which is not limited in the present application.

[0056] Exemplarily, the display layer 500 includes a cathode, a light-emitting layer, an anode, and an encapsulation layer 600, which are sequentially stacked on the side of the functional film layer 300 away from the base substrate 100. The cathode is a transflective material. For example, the cathode may include a transflective layer formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a mixture thereof, and prepared by vacuum deposition.

[0057] Figure 4 A schematic diagram of light modulation is shown in the figure. Natural light can be considered as a collection of 50% left-handed circularly polarized light and 50% right-handed circularly polarized light. After the natural light passes through the chiral liquid crystal layer 5, 50% of the left-handed circularly polarized light (first rotating direction light) is reflected, and 50% of the right-handed circularly polarized light (second rotating direction light) can pass through. After reflection, the 50% left-handed circularly polarized light reaches the semi-transparent and semi-reflective cathode, and is reflected again by the cathode to form right-handed circularly polarized light and is incident on the chiral liquid crystal layer 5 and emitted; the right-handed circularly polarized light that passes through the linear polarization layer or quarter-wave plate layer 4 becomes linearly polarized light and is incident on the photosensitive element 1.

[0058] It is understood that the cathode of the present embodiment, which uses a semi-transparent and semi-reflective material, can reflect the first-handed light reflected by the chiral liquid crystal layer 5. While there is a certain amount of light intensity loss in this process, it is expected that a transmittance of >70% can be achieved. Therefore, compared to a functional film layer 300 having only a linear polarization layer, the clarity and contrast of fingerprint imaging can be greatly improved. In some embodiments, to improve the reflection effect of the first-handed light reflected by the chiral liquid crystal layer 5, the present application may also use a total reflection layer 8 as described in Example 2. The total reflection layer 8 can reflect the left-handed light reflected from the chiral liquid crystal layer 5 to the greatest extent possible, thereby further increasing the transmittance of light. This will be described in detail below.

[0059] In some embodiments, the chiral liquid crystal layer 5 can also reflect a fixed wavelength range. If the wavelength of the incident light matches the helical pitch of the cholesteric liquid crystal, the cholesteric liquid crystal allows incident light with the same chirality to pass through and reflects incident light with the opposite chirality. If the wavelength of the incident light does not match the helical pitch of the cholesteric liquid crystal, the cholesteric liquid crystal allows all incident light to pass through. Therefore, the reflection or transmission of incident light can be changed by adjusting the helical pitch.

[0060] The peak wavelength λ of the light reflected by the chiral liquid crystal layer 5 is max =n avg *P, where n avg is the average refractive index of the liquid crystal, and P is the pitch of the helical structure. The spectral width of the reflected light is △λ = △n*P, where △n is the difference between the refractive indices of ordinary and extraordinary light.

[0061] For example, n avg The peak wavelength λ of the reflected light of the chiral liquid crystal layer 5 can be limited to between 1.2 and 1.8, Δn is between 0 and 0.2, and the pitch P is between 0 and 3 μm. max The value range is 550±20nm. The spectral width Δλ of the reflected light of the chiral liquid crystal layer 5 is in the range of 450 to 650nm.

[0062] In one embodiment of the present application, the quarter-wave plate layer 4 can be implemented by a liquid crystal layer, wherein the liquid crystal of the quarter-wave plate layer 4 is a uniaxial liquid crystal, and the optical axis of the quarter-wave plate layer 4 is parallel to the plane where the base substrate 100 is located.

[0063] The peak wavelength of light reflected by the chiral liquid crystal layer 5 is equal to four times the phase difference of the quarter-wave plate layer 4 (i.e., the phase difference of the quarter-wave plate layer 4 * 4 = the peak wavelength of light reflected by the chiral liquid crystal layer 5). This ensures the transmittance of light emitted by the light-emitting element 6 in the display panel, thereby improving or even avoiding the problems of color variation and / or life degradation that may occur in the display module while maintaining the luminous efficiency of the light-emitting element 6 and the display quality of the display panel. The light transmittance of the light-regulating layer in the preset wavelength range is greater than or equal to 90%.

[0064] The display panel may include a cover plate 900, an optical adhesive 800, a polarizer 700 and a display layer 500 stacked in sequence, wherein the polarizer 700 is located between the optical adhesive 800 and the display layer 500, and the cover plate 900 is used to protect the polarizer 700 and the display surface layer; the optical adhesive 800 is used to bond the cover plate 900 and the polarizer 700 to avoid ghosting caused by a gap between the glass cover plate 900 and the circular polarizer; the light emitted from the display layer 500 is processed by the polarizer 700 and then emitted from the cover plate 900.

[0065] It should be noted that the display panel contains various reflective structures (e.g., pixel drive circuits and anodes). Based on this, when ambient light is irradiated from the light-emitting side of the display panel to the interior of the display panel, the reflective structures are likely to reflect the ambient light, thereby adversely affecting the display effect of the display device. Therefore, in some of the above examples, by providing a functional film layer 300 in the display panel, the circular polarizing layer formed by the functional film layer 300 and the linear polarizer 700 can be used to prevent at least a portion of the reflected ambient light from being emitted outside the display panel, thereby improving the display effect of the display panel.

[0066] It is understandable that each structure in the display panel is pursuing a lower thickness. However, due to the large thickness of the circular polarizing layer and the low light transmittance, in some other embodiments, COE (CF on EL, forming a color film layer on the thin film encapsulated organic electroluminescent element 6) and the like can also be used. It includes a plurality of filter units and a black matrix; wherein, the plurality of filter units are arranged in an array; the black matrix separates the plurality of filter units. On the one hand, the plurality of filter units and the black matrix can be used to improve the light transmittance of the display panel while preventing at least a portion of the reflected light of the external ambient light from being emitted outside the display panel, thereby improving the display effect of the display device and reducing the power consumption of the display device; at the same time, since the thickness of the color filter layer is small, the thickness of the display panel can be greatly reduced.

[0067] Example 2

[0068] like Figure 5 As shown, the functional film layer 300 includes a chiral liquid crystal layer 5, a quarter-wave plate layer 4, and a linear polarizer layer 3 located on the side of the chiral liquid crystal layer 5 close to the sensor layer 200, with the quarter-wave plate layer 4 located between the chiral liquid crystal layer 5 and the linear polarizer layer 3. The chiral liquid crystal layer 5 is configured to reflect one of left-handed circularly polarized light and right-handed circularly polarized light and transmit the other, for example, to reflect light of a first rotating direction and transmit light of a second rotating direction.

[0069] In this embodiment of the present application, the quarter-wave plate layer 4 serves as a polarizing layer, and the linear polarizing layer 3 serves as an analyzing layer. After the second-handed light enters the quarter-wave plate layer 4, it is converted into the linearly polarized light. The polarization direction of the linearly polarized light is perpendicular to the absorption axis of the linear polarizing layer 3.

[0070] In this embodiment of the present application, the chiral liquid crystal layer 5, quarter-wave plate layer 4, and linear polarizer layer 3 must satisfy a certain optical matching relationship. The helical structure of the chiral liquid crystal layer 5 must be aligned with the optical axis of the quarter-wave plate layer 4 and the absorption axis of the linear polarizer layer 3. This means that the vibration direction of the linearly polarized light generated by the second chiral light entering the quarter-wave plate is perpendicular to the absorption axis of the linear polarizer layer 3. In this embodiment of the present application, the optical axis of the quarter-wave plate layer 4 forms a 45° angle with the absorption axis of the linear polarizer layer 3, and the optical axis of the quarter-wave plate layer 4 is parallel to the plane of the substrate 100.

[0071] Natural light emitted by the OLED device is modulated into circularly polarized light by the chiral liquid crystal layer 5. In this embodiment, left-handed cholesteric liquid crystal is used as an example for illustrative purposes. After passing through the chiral liquid crystal layer 5, the natural light is incident on the quarter-wave plate layer 4. This circularly polarized light, which passes through the liquid crystal layer, is converted to linearly polarized light through phase retardation and then emitted to the linear polarization layer. The linear polarization layer and the quarter-wave plate layer 4 have the same polarization direction, allowing the linearly polarized light to be emitted from the linear polarization layer to the photosensitive element 1.

[0072] In a specific implementation, in the embodiment of the present invention, the photosensitive element 1 may include a CCD photosensitive image sensor or a CMOS photosensitive image sensor. Of course, the photosensitive detector may also be any other photosensitive image sensor capable of fingerprint recognition, which is not specifically limited here.

[0073] In the embodiments of this application, Figure 6 As shown, the functional layer also includes a total reflection layer 8 arranged on the side of the chiral liquid crystal layer 5 close to the functional film layer 300. In the embodiment of the present application, the total reflection layer 8 can reflect the left-handed light reflected from the chiral liquid crystal layer 5 to the maximum extent, thereby further increasing the transmittance of light.

[0074] The total reflection layer 8 includes a plurality of light-transmitting holes 9, the orthographic projections of the light-transmitting holes 9 on the base substrate 100 at least overlapping the orthographic projections of the imaging holes 2 on the base substrate 100. The orthographic projections of the light-transmitting holes 9 on the base substrate 100 may overlap with the orthographic projections of the imaging holes 2 on the base substrate 100. In a specific implementation, the light-transmitting holes 9 are circular and concentric with the corresponding imaging holes 2. Of course, in other embodiments, to improve the reflection effect, the size of the light-transmitting holes 9 may be slightly larger than the size of the imaging holes 2. For example, the total reflection layer 8 may be formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or mixtures thereof, and may be prepared by vacuum deposition.

[0075] Figure 7A light modulation schematic diagram is shown in the figure. After the natural light passes through the chiral liquid crystal layer 5, 50% of the left-handed circularly polarized light (first rotating direction light) is reflected, and 50% of the right-handed circularly polarized light (second rotating direction light) can pass through. The 50% left-handed circularly polarized light reaches the total reflection layer 8 after reflection, and is reflected again by the total reflection layer 8 to form right-handed circularly polarized light and is incident on the chiral liquid crystal layer 5 and emitted; the right-handed circularly polarized light that passes through the quarter-wave plate layer 4 becomes linearly polarized light and is incident on the linear polarization layer. The linear polarized light passes through the linear polarization layer and is incident on the photosensitive element 1.

[0076] like Figure 8 As shown, the present application also provides a method for preparing a display panel, for preparing any of the above display panels, the method comprising:

[0077] S01. Provide a base substrate 100.

[0078] S02. A functional film layer 300 is formed on the base substrate 100. The functional film layer 300 includes one or more of a first liquid crystal layer, a second liquid crystal layer, and a third liquid crystal layer. The first liquid crystal layer forms a linear polarizing layer 3 after alignment and curing, the second liquid crystal layer forms a quarter-wave plate layer 4 after alignment and curing, and the third liquid crystal layer forms a chiral liquid crystal layer 5 after alignment and curing.

[0079] S03 , forming a light shielding layer 400 and a display layer 500 in sequence on the functional film layer 300 .

[0080] In the present application, the base substrate 100 is a rigid substrate or a flexible substrate, wherein the material of the rigid substrate can be transparent glass, transparent plastic, etc., and the material of the flexible substrate can be polymer materials such as polyimide (PI), polyethersulfone (PES), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyarylate (PAR), and glass fiber reinforced plastic (FRP).

[0081] In the present application, the functional film layer 300 can be formed using a one-shot film-forming technology. For example, the functional film layer 300 includes a chiral liquid crystal layer 5, a quarter-wave plate layer 4, and a linear polarizer layer 3. Specifically, the cholesteric liquid crystal layer is formed using a one-shot film-forming technology, the quarter-wave plate layer 4 is formed using a one-shot film-forming technology, and the linear polarizer is formed using a one-shot film-forming technology. This can reduce manufacturing difficulty and cost.

[0082] For example, the chiral liquid crystal layer 5 is formed by coating a mixture of helical liquid crystal molecules containing photopolymerizable properties and a characteristic direction chiral agent, and then photocuring to form the chiral liquid crystal layer 5 having a specific chiral direction; or, the chiral liquid crystal layer 5 is formed by directly coating a polymer material with fixed chiral characteristics; or, the chiral liquid crystal layer 5 is formed by bonding a pre-prepared cholesteric liquid crystal film to the optical matching layer.

[0083] In an exemplary embodiment of the present application, the preparation process of the chiral liquid crystal layer 5 can be to form the chiral liquid crystal layer 5 with a specific chiral direction through photocuring, specifically, including: coating the alignment layer → pre-curing → main curing → alignment → post-drying → coating the liquid crystal material → low-temperature drying the solvent → UV curing.

[0084] It should be noted that in the embodiment of the present application, the alignment layer is an alignment structure for forming the orientation of the chiral liquid crystal layer 5, and the material of the alignment layer is selected from a substance with alignment ability. For example, a PI alignment layer. The PI alignment layer has an anchoring effect on the liquid crystal molecules, and can make the liquid crystals align according to the angle between the side chains and the main chain in the polymer molecules in the PI liquid, that is, the direction of the pretilt angle. For example, it can include: coating, photolithography, exposure, development, baking and rubbing alignment processes. Of course, other methods in the prior art can also be used to achieve liquid crystal orientation, and this application is not limited to this.

[0085] Specifically, the liquid crystal material of the chiral liquid crystal layer 5 is a polymerizable liquid crystal composition, which includes a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion enhancer, and a polymerizable liquid crystal compound.

[0086] The purpose of the low-temperature solvent drying is to remove the solvent from the cholesteric liquid crystal solution while retaining the cholesteric liquid crystal molecules in the cholesteric liquid crystal solution; the purpose of the UV (ultraviolet light) curing is to solidify the cholesteric liquid crystal molecules into a film. The baking method can include various methods. Exemplarily, the baking method is a low-temperature baking method, wherein the temperature of the low-temperature baking is below 95°C.

[0087] Similarly, the linear polarizing layer 3 can be obtained through the following process flow: "coating a polyimide alignment layer → curing → UV irradiation for alignment → low-temperature drying → coating a dichroic dye and polymerizable liquid crystal mixture → low-temperature solvent removal → UV irradiation for curing." The quarter-wave plate layer 4 can be obtained through the following process flow: "coating a polyimide alignment layer → curing → UV irradiation for alignment → low-temperature drying → coating a polymerizable liquid crystal → low-temperature solvent removal → UV irradiation for curing." For specific implementation, the process flow for the chiral liquid crystal layer 5 can be referenced and will not be detailed here.

[0088] Based on the same inventive concept, the present application provides a display device, including a display panel as described above. The specific structure of the display panel has been described in detail in the above embodiments and will not be repeated here. The display device in the embodiment of the present application can be a TV, or it can be a PC, a smart phone, a tablet computer, an e-book reader, an MP3 (Moving Picture Experts Group Audio Layer III, Moving Picture Experts Group Audio Layer) player, an MP4 (Moving Picture Experts Group Audio Layer IV, Moving Picture Experts Group Audio Layer) player, a portable computer, or other device with a display function.

[0089] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0090] Furthermore, 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 the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0091] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art of the present invention. The terms used herein are only for describing specific implementation purposes and are not intended to limit the present invention. Terms such as "setting" appearing in this article can mean that one component is directly attached to another component, or that one component is attached to another component through an intermediate component. Features described in this article in one embodiment can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in the other embodiment or otherwise specified.

[0092] The present invention has been described through the above embodiments, but it should be understood that the above embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Those skilled in the art will appreciate that various variations and modifications may be made based on the teachings of the present invention, and such variations and modifications fall within the scope of protection claimed in the present invention.

Claims

1. A display panel, characterized in that: It includes a base substrate, a sensor layer, a functional film layer, a light shielding layer, and a display layer that are stacked, wherein: A plurality of photosensitive elements are provided on the sensor layer; The functional film layer is used to receive incident light and convert the incident light into linearly polarized light before emitting it; the functional film layer includes a chiral liquid crystal layer arranged on a side close to the light-shielding layer, a quarter-wave plate layer and / or a linear polarizing layer arranged on a side of the chiral liquid crystal layer close to the sensor layer, and a total reflection layer arranged on a side of the chiral liquid crystal layer close to the functional film layer, wherein the total reflection layer includes a plurality of light-transmitting holes; A plurality of imaging holes are provided on the light-shielding layer, and the linearly polarized light is incident on the photosensitive element through the imaging holes. The orthographic projections of the light-transmitting holes on the base substrate at least cover the orthographic projections of the imaging holes on the base substrate.

2. The display panel according to claim 1, wherein: The linear polarizing layer is arranged on a side close to the sensor layer; the optical axis of the quarter wave plate layer forms an angle of 45° with the absorption axis of the linear polarizing layer, and the optical axis of the quarter wave plate layer is parallel to the plane where the substrate is located.

3. The display panel according to claim 1, wherein: The chiral liquid crystal layer is used for reflecting light of a first rotating direction and transmitting light of a second rotating direction.

4. The display panel according to claim 1, wherein: The peak wavelength of the reflected light of the chiral liquid crystal layer is equal to four times the phase difference of the quarter-wave plate layer.

5. The display panel according to claim 3, wherein: The second polarized light is converted into the linearly polarized light after being incident on the quarter-wave plate layer, and the polarization direction of the linearly polarized light is perpendicular to the absorption axis of the linear polarizing layer.

6. The display panel according to claim 3, wherein: A plurality of light-emitting elements are provided on the display layer, and the orthographic projections of the light-emitting elements on the substrate do not overlap with the orthographic projections of the imaging holes on the substrate; The orthographic projection of the imaging hole on the substrate is located within the orthographic projection range of the photosensitive element on the substrate.

7. The display panel according to claim 6, wherein: The display layer includes an electrode layer electrically connected to the light emitting element, and the electrode layer is made of a semi-transmissive and semi-reflective material.

8. A method for preparing a display panel, characterized in that: For preparing the display panel according to any one of claims 1 to 7, the method comprises: providing a substrate; forming a functional film layer on the base substrate, the functional film layer comprising one or more of a first liquid crystal layer, a second liquid crystal layer, and a third liquid crystal layer, wherein the first liquid crystal layer forms a linear polarizing layer after alignment and curing, the second liquid crystal layer forms a quarter-wave plate layer after alignment and curing, and the third liquid crystal layer forms a chiral liquid crystal layer after alignment and curing, the functional film layer further comprising a total reflection layer disposed on a side of the chiral liquid crystal layer close to the functional film layer, the total reflection layer comprising a plurality of light-transmitting holes; A light-shielding layer and a display layer are sequentially formed on the functional film layer. A plurality of imaging holes are provided on the light-shielding layer. The linearly polarized light is incident on the photosensitive element through the imaging holes. The orthographic projection of the light-transmitting hole on the base substrate at least covers the orthographic projection of the imaging hole on the base substrate.

9. A display device, characterized in that: The display panel comprises the display panel as described in any one of claims 1 to 7.

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