Display panel and display device

Abstract

The application discloses a display panel and a display device, which comprise a substrate, a microlens array layer and a grating layer; the substrate comprises a first color light emitting subunit, a second color light emitting subunit and a third color light emitting subunit; the microlens array layer comprises a first microlens subunit, a second microlens subunit and a third microlens subunit, and respectively corresponds to cover the first color light emitting subunit, the second color light emitting subunit and the third color light emitting subunit; the optical parameters of the first microlens subunit, the second microlens subunit and the third microlens subunit are different from each other; the grating layer comprises a first grating subarea, a second grating subarea and a third grating subarea, and is respectively arranged corresponding to the first color light emitting subunit, the second color light emitting subunit and the third color light emitting subunit; the grating ruling orientations of the first grating subarea, the second grating subarea and the third grating subarea are different from each other; and the application realizes the suppression of large-angle color deviation and the crosstalk of inter-pixel lateral stray light.

Description

Technical Field

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

[0002] Traditional OLED screens often incorporate microlens arrays to achieve higher efficiency and better display effects. While microlens arrays can focus light and increase brightness, they cannot suppress stray light or correct color shifts, thus failing to meet current display requirements. Summary of the Invention

[0003] The present invention provides a display panel and display device that suppresses large-angle color shift and crosstalk between pixels by lateral stray light.

[0004] In a first aspect, embodiments of the present invention provide a display panel, comprising: a substrate, a microlens array layer, and a grating layer; The substrate includes multiple light-emitting units, and each light-emitting unit includes at least a first color light-emitting subunit, a second color light-emitting subunit, and a third color light-emitting subunit; The microlens array layer is located on the light-emitting side of the substrate and includes multiple microlens units, each of which corresponds to one light-emitting unit. Each microlens unit includes a first microlens subunit, a second microlens subunit, and a third microlens subunit. The first, second, and third microlens subunits respectively cover the first, second, and third color light-emitting subunits. The optical parameters of the first, second, and third microlens subunits are different from each other. The grating layer is located on the side of the microlens array layer away from the substrate and includes multiple grating regions; each grating region corresponds to one light-emitting unit; the grating region includes a first grating sub-region, a second grating sub-region, and a third grating sub-region; the first grating sub-region, the second grating sub-region, and the third grating sub-region are respectively configured to correspond to the first color light-emitting sub-unit, the second color light-emitting sub-unit, and the third color light-emitting sub-unit; wherein the grating lines of the first grating sub-region, the second grating sub-region, and the third grating sub-region are different from each other.

[0005] Optionally, the emission wavelength of the first color light-emitting unit is greater than the emission wavelength of the second color light-emitting unit; the emission wavelength of the second color light-emitting unit is greater than the emission wavelength of the third color light-emitting unit. The focal length of the first microlens subunit is greater than that of the second microlens subunit, and the aperture of the first microlens subunit is greater than or equal to that of the second microlens subunit; the focal length of the third microlens subunit is less than that of the second microlens subunit.

[0006] Optionally, the first microlens subunit, the second microlens subunit, and the third microlens subunit are all aspherical lenses.

[0007] Optionally, the grating lines of the first grating sub-region extend along a first direction; the grating lines of the second grating sub-region extend along a second direction; wherein the first direction and the second direction intersect in the same plane and are perpendicular; The grating lines of the third grating sub-region extend along a third direction; the third direction forms a 45° angle with the first direction.

[0008] Optionally, the grating periods of the first grating sub-region, the second grating sub-region, and the third grating sub-region are less than the shortest wavelength of visible light; the grating depth is configured to produce a phase difference of π / 2 to π for the incident light.

[0009] Optionally, the grating period of the first grating sub-region, the second grating sub-region, and the third grating sub-region is 250nm to 350nm, and the grating depth is 80nm to 150nm.

[0010] Optionally, the display panel may further include a refractive index gradient matching layer; The refractive index gradient matching layer is disposed between the microlens array layer and the grating layer, and the refractive index gradient matching layer covers the microlens array layer; the refractive index of the refractive index gradient matching layer continuously increases along the direction from the microlens array layer to the grating layer.

[0011] Optionally, the refractive index of the graded-index matching layer near the microlens array layer is a first refractive index, and the refractive index of the graded-index matching layer near the grating layer is a second refractive index; wherein, the first refractive index is the same as the material refractive index of the microlens array layer, and the second refractive index is the same as the material refractive index of the grating layer; The refractive index of the graded-index matching layer continuously increases from the first refractive index to the second refractive index along the direction from the microlens array layer to the grating layer.

[0012] Optionally, the first color light-emitting unit is a red light-emitting unit, the second color light-emitting unit is a green light-emitting unit, and the third color light-emitting unit is a blue light-emitting unit.

[0013] Secondly, embodiments of the present invention provide a display device, including a display panel according to any embodiment of the present invention.

[0014] The display panel provided in this invention compensates for the refractive index differences of different wavelengths of light by setting independent microlens sub-units on each color light-emitting sub-unit and setting differentiated optical parameters according to the emitted light color. This makes the brightness attenuation curves of different emitted light colors tend to be consistent at large viewing angles, thereby suppressing color shift at large angles. Furthermore, by setting grating sub-regions with different grating line orientations on each color light-emitting sub-unit, crosstalk of lateral stray light is suppressed. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a grating structure provided in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Figure 1 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention. Figure 2 A schematic diagram of a grating structure provided in an embodiment of the present invention is shown below. Figure 1 and Figure 2 It includes: a substrate 110, a microlens array layer 120, and a grating layer 130.

[0018] The substrate 110 includes a plurality of light-emitting units, each of which includes at least a first color light-emitting subunit 111, a second color light-emitting subunit 112, and a third color light-emitting subunit 113.

[0019] The microlens array layer 120 is located on the light-emitting side of the substrate 110 and includes multiple microlens units, each corresponding to a light-emitting unit. Each microlens unit includes a first microlens subunit 121, a second microlens subunit 122, and a third microlens subunit 123. The first microlens subunit 121, the second microlens subunit 122, and the third microlens subunit 123 respectively cover the first color light-emitting subunit 111, the second color light-emitting subunit 112, and the third color light-emitting subunit 113. The optical parameters of the first microlens subunit 121, the second microlens subunit 122, and the third microlens subunit 123 are different from each other.

[0020] The grating layer 130 is located on the side of the microlens array layer 120 away from the substrate 110 and includes multiple grating regions. Each grating region corresponds to one light-emitting unit. The grating regions include a first grating sub-region 131, a second grating sub-region 132, and a third grating sub-region 133. The first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 are respectively disposed corresponding to a first color light-emitting sub-unit 111, a second color light-emitting sub-unit 112, and a third color light-emitting sub-unit 113. The grating lines of the first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 have different orientations.

[0021] Specifically, the substrate 110 can support the microlens array layer 120 and the grating layer 130. The substrate 110 may include a substrate, an anode layer, a light-emitting layer, a cathode layer, and a thin-film encapsulation layer. The light-emitting layer has multiple light-emitting units, each including at least a first-color light-emitting sub-unit 111, a second-color light-emitting sub-unit 112, and a third-color light-emitting sub-unit 113. For example, the first, second, and third colors can be red, green, and blue, respectively. The light-emitting units can be patterned using vapor deposition or inkjet printing. The outermost surface of the thin-film encapsulation layer serves as a reference surface for the fabrication of the optical functional layer, ensuring the fabrication and alignment of the microlens array layer 120. The microlens array layer 120 has multiple microlens sub-units, each aligned with one light-emitting unit.

[0022] The microlens subunit includes an independent first microlens subunit 121, a second microlens subunit 122, and a third microlens subunit 123, which respectively cover the first color light-emitting subunit 111, the second color light-emitting subunit 112, and the third color light-emitting subunit 113. The grating layer 130 includes multiple grating regions. Each grating region corresponds to one light-emitting unit. The grating regions include a first grating subregion 131, a second grating subregion 132, and a third grating subregion 133, which also correspond to the first color light-emitting subunit 111, the second color light-emitting subunit 112, and the third color light-emitting subunit 113, respectively.

[0023] The light emitted by each color emitting subunit enters the corresponding first microlens subunit 121, second microlens subunit 122, and third microlens subunit 123. Due to the inherent differences in band structure, emitting layer thickness, and emission spectrum between the emitting materials of different colors, the divergence angle distribution, equivalent light source position, and wavefront curvature of the emitted beams vary. If a traditional microlens with uniform parameters is used, the brightness attenuation curves of each color light will inevitably separate at large viewing angles, resulting in severe apparent angular dispersion and color coordinate shift.

[0024] Therefore, the lens curvature and optical parameters of the corresponding lens subunits can be designed differently for the different wavelength emission characteristics of each color emitting subunit, thereby reducing apparent angular aberration and chromatic coordinate shift. For example, for the red emitting subunit, due to the low refractive index, large divergence angle, and thick emitting layer of red light, the corresponding first microlens subunit 121 can be designed with a larger radius of curvature and a negative aspherical coefficient to provide stronger edge light convergence capability, correct spherical aberration caused by the volume light source, and match the red light emission wavefront with the target radiation mode. For the blue emitting subunit, due to the high refractive index, sensitivity to aberrations, and strong convergence required of blue light, the corresponding third microlens subunit 123 can adopt a higher-order aspherical term and a smaller effective focal length, ensuring efficient extraction of large-angle light while avoiding wavefront distortion caused by excessive convergence. For the green light-emitting subunit, which can serve as the reference channel with the highest visual sensitivity, the parameters of the second microlens subunit 122 achieve an optimal balance between aberration correction and process tolerance, and serve as a reference benchmark for the design of red and blue lenses. Thus, through the shaping of their respective microlenses, large-angle color shift is suppressed at the source.

[0025] The beam, shaped by the microlens subunit, enters the grating layer 130. Each color emitting subunit corresponds to a grating sub-region. The grating lines of the first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 are differentiated, with adjacent grating sub-regions having different grating line orientations, distributed according to the arrangement of the corresponding color subunits. When lateral leakage light from an adjacent emitting subunit enters a mismatched grating sub-region, the polarization state rotates due to the change in propagation path, resulting in a significant mismatch angle with the grating line orientation. Thus, efficient suppression of lateral optical crosstalk is achieved without sacrificing the aperture ratio.

[0026] The display panel provided in this embodiment of the invention compensates for the refractive index differences of different wavelengths of light by setting independent microlens subunits on each color light-emitting subunit and setting differentiated optical parameters according to the emitted light color. This makes the brightness attenuation curves of different emitted light colors tend to be consistent at large viewing angles, thereby suppressing large-angle color shift phenomena. Furthermore, by setting grating sub-regions with different grating line orientations on each color light-emitting subunit, polarization-selective suppression of lateral stray light is achieved. It should be noted that in other embodiments, the light-emitting unit may also include a fourth color light-emitting subunit, suitable for multi-primary-color displays. For example, the fourth color light-emitting subunit is a white light-emitting subunit. Each color light-emitting subunit can be arranged in a pentile, delta, or RGBW four-color arrangement. When the number of color light-emitting subunits in the light-emitting unit is greater than 3, the microlens unit is set with a corresponding number of microlens subunits with different parameters, and the grating region is set with a corresponding number of grating sub-regions with different grating line orientations.

[0027] Optionally, the emission wavelength of the first color light-emitting unit is greater than the emission wavelength of the second color light-emitting unit. The emission wavelength of the second color light-emitting unit is greater than the emission wavelength of the third color light-emitting unit.

[0028] The focal length of the first microlens subunit 121 is greater than the focal length of the second microlens subunit 122, and the aperture of the first microlens subunit 121 is greater than or equal to the aperture of the second microlens subunit 122. The focal length of the third microlens subunit 123 is less than the focal length of the second microlens subunit 122.

[0029] Specifically, in this embodiment of the invention, the first color is red, the second color is green, and the third color is blue. Since red light has the longest wavelength, the lowest refractive index, and a relatively large critical angle for total internal reflection, the lateral extension range of the red waveguide mode is greater than that of green and blue light, and the energy distribution is more dispersed. Therefore, the first microlens subunit 121 adopts a design with a longer focal length and a larger aperture. The longer focal length allows red light to reach the grating layer 130 with a smoother wavefront, adapting to its larger mode field distribution. The larger aperture fully collects the larger inherent divergence angle of the red light, avoiding edge light leakage and loss.

[0030] Green light falls within the middle range of the visible spectrum, with its refractive index, waveguide mode ratio, and divergence characteristics all falling between those of red and blue light. The parameters of the second microlens subunit 122 are determined through joint optimization of the overall optical path. The second microlens subunit 122 serves as the reference origin for the design of the first microlens subunit 121 and the third microlens subunit 123, ensuring that the three colors of light, after modulation, have satisfactory parameters on the incident surface of the grating layer 130.

[0031] Blue light has the shortest wavelength and the highest refractive index, resulting in the highest proportion of confined waveguide modes and surface plasmon modes. Therefore, the third microlens subunit 123 employs a shorter focal length and a stronger convergence angle. The shorter focal length allows blue light to converge into the grating layer 130 at a steeper angle, increasing the transverse wave vector component of the incident light. This makes it easier to satisfy the phase matching condition of the high-refractive-index waveguide mode, thereby improving the blue light extraction efficiency. Furthermore, the strong convergence design tightly confines the blue light energy to the central region of the light-emitting subunit, reducing lateral leakage to adjacent sub-light-emitting units.

[0032] After the three colors of light are modulated by their respective microlens subunits, the beams, which originally had different divergence characteristics due to wavelength differences, are shaped into beams with matched spot sizes and incident angle distributions on the incident surface of the grating layer 130. This microlens subunit processing allows for phase modulation of each color of light under uniform incident conditions in the grating layer 130, avoiding grating efficiency dispersion caused by inconsistent incident conditions. It should be noted that in other embodiments, the first, second, and third colors can also be other multi-primary color combinations, as long as the wavelength relationship is satisfied. The design of the lens subunits can also be optimized to suit the aforementioned focal length and aperture conditions.

[0033] Optionally, the first microlens subunit 121, the second microlens subunit 122, and the third microlens subunit 123 are all aspherical lenses.

[0034] Specifically, aspherical lenses can achieve large-angle light correction by optimizing the curvature gradient of the edge region, maintaining a high degree of consistency in the wavefront morphology within the viewing angle range. This eliminates the inherent spherical aberration of spherical lenses, improves the wavefront matching degree of different colors of light reaching the grating layer 130, and enhances light extraction efficiency. Besides differences in the optical parameters of focal length, aperture, and convergence angle, the first microlens subunit 121, the second microlens subunit 122, and the third microlens subunit 123 can also be designed with optical parameters such as aspherical higher-order coefficients, lens sagitta, and micro / nano textures on the lens surface. The optical parameters of each microlens subunit can be determined through joint optimization of multiple factors such as the wavelength, refractive index, and grating period of the corresponding light-emitting subunit; the specific numerical relationships can be derived from existing optical simulations.

[0035] See Figure 2 The grating lines of the first grating sub-region 131 extend along the first direction X. The grating lines of the second grating sub-region 132 extend along the second direction Y. The first direction X and the second direction Y intersect in the same plane and are perpendicular.

[0036] The grating lines of the third grating sub-region 133 extend along the third direction Z. The third direction Z forms a 45° angle with the first direction X.

[0037] Specifically, the extension direction of the grating lines is the projection direction of the long axis of the grating surface grooves or ridges onto the plane of the substrate 110. The grating line direction determines the selective response of the grating to the polarization component of the incident light and the anisotropic characteristics of phase modulation. In this embodiment of the invention, the first direction X and the second direction Y intersect and are perpendicular in the same plane, and the third direction Z is in the same plane as the first direction X and forms an angle of ±45°. That is, the first direction X, the second direction Y, and the third direction Z are not parallel to each other in the same plane, so as to achieve maximum polarization direction resolution.

[0038] In this embodiment of the invention, the grating lines of the first grating sub-region 131 extend along a first direction X, for example, the first direction X is horizontal. Red light has the longest wavelength and mainly propagates in TM waveguide mode, with its electric field vector tending to be perpendicular to the interface. The horizontal grating lines in the first direction X make the electric field of the red light TM mode perpendicular to the grating lines, placing it in a high-phase modulation state of the grating, thus achieving efficient extraction. However, stray light leaking laterally from adjacent green and blue light-emitting sub-units into the red light region undergoes a rotation in polarization state due to the change in propagation path, no longer matching the horizontal grating lines, resulting in a significant decrease in coupling efficiency.

[0039] The grating lines of the second grating sub-region 132 extend along the second direction Y. For example, if the second direction Y is vertical, the second direction Y grating line corresponding to the green light emitting sub-unit is perpendicular to the first direction X grating line corresponding to the red light emitting sub-unit, so that the crosstalk suppression between the red and green colors reaches the theoretical maximum value.

[0040] The grating lines of the third grating sub-region 133 extend along the third direction Z, for example, at a 45° diagonal, forming a 45° angle with both the grating lines for red and green light. Blue light has a short wavelength and a high refractive index, resulting in a waveguide mode with stronger anisotropy. The 45° orientation allows the grating sub-region corresponding to blue light to simultaneously modulate the phase of both the horizontal and vertical polarization components, avoiding the color purity degradation caused by over-extraction of specific polarization modes of blue light from a single orientation. It also ensures that the leakage light from the second grating sub-region 132 corresponding to blue light maintains a 45° mismatch angle with both red and green light, achieving bidirectional symmetrical crosstalk suppression.

[0041] Each grating sub-region responds efficiently only to positive signal light matching its own orientation and originating from the corresponding emitting sub-unit, while exhibiting an inefficient or ineffective response to stray light from other sub-regions whose polarization state has been rotated. This orientation-selective spatial filtering mechanism achieves optical isolation between sub-pixels without introducing any light-absorbing materials or black matrices. It effectively eliminates color fringing and blurring at high-contrast edges, improving display contrast and color saturation.

[0042] Optionally, the grating periods of the first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 are less than the shortest wavelength of visible light. The grating depth is configured to produce a phase difference of π / 2 to π for the incident light.

[0043] Specifically, the shortest wavelength of visible light is typically taken as the lower limit of blue light, approximately 400 nm. The first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 constitute a subwavelength grating. In this embodiment of the invention, by controlling the grating depth, a stable phase difference of π / 2 to π is generated in the incident light, disrupting the total internal reflection constraint of the internal optical field of the device, and converting the waveguide mode and surface plasmon mode confined light into radiated outgoing light.

[0044] Optionally, in this embodiment of the invention, the grating region can be a rectangular relief grating. The grating periods of the first grating sub-region 131, the second grating sub-region 132, and the third grating sub-region 133 are 250 nm to 350 nm. The lower limit of 250 nm ensures that process deviations in actual manufacturing and the spectral tail of blue light-emitting materials may extend to around 380 nm. The lower limit of 250 nm provides sufficient safety margin, and the grating period still meets the subwavelength condition, avoiding visible light diffraction. Although a period that is too small is beneficial for suppressing diffraction, it will cause the feature size to approach the resolution limit of nanoimprinting or photolithography processes, resulting in a decrease in fill rate, difficulty in demolding, and deterioration in yield. At the same time, a period that is too small will cause the grating's equivalent refractive index to approach the air refractive index, weakening its ability to modulate the phase of incident light. The upper limit of 350 nm ensures that the feature size is large enough to maintain high-yield mass production, while also ensuring that the equivalent refractive index is within the effective control range. The 250nm to 350nm period can meet the subwavelength conditions, with no perceptible diffraction order in the full viewing angle range, and the purity of the displayed image reaches the optical limit, solving the rainbow pattern problem inherent in traditional microlens arrays or micron-scale gratings.

[0045] The grating depth determines the amount of phase delay accumulated when incident light passes through the grating layer 130. In this embodiment of the invention, the grating depth is 80 nm to 150 nm, resulting in a stable phase difference of π / 2 to π for the incident light. The grating material can be a nanoimprinted UV-curable resin with a refractive index of approximately 1.6. A phase difference of π / 2 provides sufficient phase perturbation strength to shift the effective wave vector of the waveguide mode, breaking the critical angle constraint of total internal reflection and coupling into a radiation mode. Below this value, the phase modulation is too weak, and the waveguide extraction gain is insufficient. π This can avoid the decrease in zero-order transmittance caused by excessive phase difference and the absorption loss caused by excessive energy of higher-order evanescent waves.

[0046] See Figure 1The display panel also includes a refractive index gradient matching layer 140. The refractive index gradient matching layer 140 is disposed between the microlens array layer 120 and the grating layer 130, and covers the microlens array layer 120. The refractive index of the refractive index gradient matching layer 140 increases continuously along the direction from the microlens array layer 120 to the grating layer 130.

[0047] Specifically, the refractive index of the graded-index matching layer 140 changes continuously and monotonically along the thickness direction. By eliminating discrete interfaces, the graded-index matching layer 140 disperses the originally concentrated Fresnel reflections into a destructive interference process of infinitely many infinitesimal reflections, thereby achieving broadband and wide-angle impedance matching. Compared with traditional multilayer discrete antireflection film stacking, the continuously graded-index matching layer 140 has no interlayer interface scattering and a smoother spectral response.

[0048] Optionally, the refractive index of the gradient matching layer 140 near the microlens array layer 120 is a first refractive index, and the refractive index of the gradient matching layer 140 near the grating layer 130 is a second refractive index. The first refractive index is the same as the material refractive index of the microlens array layer 120, and the second refractive index is the same as the material refractive index of the grating layer 130.

[0049] The refractive index of the graded matching layer 140 increases continuously from the first refractive index to the second refractive index along the direction from the microlens array layer 120 to the grating layer 130.

[0050] Specifically, the refractive index of the graded-index matching layer 140 changes continuously from a first refractive index to a second refractive index. The first refractive index is the same as or approximately the same as the refractive index of the microlens unit material. For example, when the microlens unit uses a UV-curable resin with a refractive index of approximately 1.48 to 1.52, the first refractive index can be selected from a value in the range of 1.40 to 1.55, such as 1.4.

[0051] The second refractive index is the same as or approximately the same as the refractive index of the grating material in grating layer 130. For example, if the refractive index of the grating material is 1.6, the second refractive index can be selected within the range of 1.55 to 1.75, such as 1.7. The increasing gradient transition ensures a smooth transition from a low-refractive-index lens to a high-refractive-index grating, avoiding residual reflections caused by end-point mismatch. It should be noted that the above values ​​are for illustrative purposes only and are not specific limitations. If the microlens unit uses a high-refractive-index material, such as n=1.8, the first refractive index should be adjusted upwards to 1.7 to 1.85. If the grating uses a low-refractive-index material, such as n=1.3, the second refractive index should be adjusted downwards to 1.25 to 1.35. It is sufficient that the refractive indices on both sides of the refractive index gradient matching layer 140 match the refractive indices of the adjacent layer materials.

[0052] The light beam exiting the microlens array layer 120 enters the low-refractive-index end of the graded-index matching layer 140. Since this side has a nearly identical refractive index to the microlens material, interface reflection is almost zero. The beam then propagates within the graded-index layer towards the grating layer 130, where the local refractive index increases as it propagates. When the beam reaches the side of the graded-index matching layer 140 near the grating layer 130, the equivalent optical impedance matches the incident end of the grating layer 130, allowing it to enter the grating layer 130 for subsequent phase modulation and waveguide extraction. The graded-index matching layer 140 significantly reduces interface reflection loss.

[0053] It should be noted that the continuous increase of refractive index in the refractive index gradient matching layer 140 is not limited to a specific functional form. For example, it can be a linear gradient, a parabolic gradient, an exponential gradient, a sinusoidal gradient, or a non-analytical gradient curve obtained based on an optimization algorithm. Different gradient profiles have different advantages and disadvantages in matching performance at different wavebands and angles, and the appropriate profile can be selected based on the target spectrum and process feasibility.

[0054] This invention also provides a display device, including a display panel according to any embodiment of the invention, thereby having the same beneficial effects, which will not be described again here. The display device can be applied to display scenarios such as smartphones, foldable tablets, automotive displays, and smart wearable devices.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display panel, characterized in that, include: Substrate, microlens array layer, and grating layer; The substrate includes a plurality of light-emitting units, and each light-emitting unit includes at least a first color light-emitting subunit, a second color light-emitting subunit, and a third color light-emitting subunit; The microlens array layer is located on the light-emitting side of the substrate and includes multiple microlens units, each of which corresponds to one light-emitting unit. Each microlens unit includes a first microlens subunit, a second microlens subunit, and a third microlens subunit. The first, second, and third microlens subunits respectively cover the first, second, and third color light-emitting subunits. The optical parameters of the first, second, and third microlens subunits are different from each other. The grating layer is located on the side of the microlens array layer away from the substrate and includes multiple grating regions; each grating region corresponds to one light-emitting unit; the grating region includes a first grating sub-region, a second grating sub-region, and a third grating sub-region; the first grating sub-region, the second grating sub-region, and the third grating sub-region are respectively configured to correspond to the first color light-emitting sub-unit, the second color light-emitting sub-unit, and the third color light-emitting sub-unit; wherein the grating lines of the first grating sub-region, the second grating sub-region, and the third grating sub-region are different from each other.

2. The display panel according to claim 1, characterized in that, The emission wavelength of the first color emitting unit is greater than that of the second color emitting unit; the emission wavelength of the second color emitting unit is greater than that of the third color emitting unit. The focal length of the first microlens subunit is greater than that of the second microlens subunit, and the aperture of the first microlens subunit is greater than or equal to that of the second microlens subunit; the focal length of the third microlens subunit is less than that of the second microlens subunit.

3. The display panel according to claim 2, characterized in that, The first microlens subunit, the second microlens subunit, and the third microlens subunit are all aspherical lenses.

4. The display panel according to claim 2, characterized in that, The grating lines of the first grating sub-region extend along a first direction; the grating lines of the second grating sub-region extend along a second direction; wherein the first direction and the second direction intersect in the same plane and are perpendicular; The grating lines of the third grating sub-region extend along a third direction; the third direction forms a 45° angle with the first direction.

5. The display panel according to claim 4, characterized in that, The grating periods of the first grating sub-region, the second grating sub-region, and the third grating sub-region are less than the shortest wavelength of visible light; the grating depth is configured to produce a phase difference of π / 2 to π for the incident light.

6. The display panel according to claim 5, characterized in that, The grating period of the first grating sub-region, the second grating sub-region, and the third grating sub-region is 250nm to 350nm, and the grating depth is 80nm to 150nm.

7. The display panel according to claim 1, characterized in that, It also includes a refractive index gradient matching layer; The refractive index gradient matching layer is disposed between the microlens array layer and the grating layer, and the refractive index gradient matching layer covers the microlens array layer; the refractive index of the refractive index gradient matching layer continuously increases along the direction from the microlens array layer to the grating layer.

8. The display panel according to claim 7, characterized in that, The refractive index of the graded-matching layer near the microlens array layer is a first refractive index, and the refractive index of the graded-matching layer near the grating layer is a second refractive index; wherein, the first refractive index is the same as the material refractive index of the microlens array layer, and the second refractive index is the same as the material refractive index of the grating layer. The refractive index of the graded-index matching layer continuously increases from the first refractive index to the second refractive index along the direction from the microlens array layer to the grating layer.

9. The display panel according to any one of claims 1-8, characterized in that, The first color light-emitting unit is a red light-emitting unit, the second color light-emitting unit is a green light-emitting unit, and the third color light-emitting unit is a blue light-emitting unit.

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

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