Display module and manufacturing method thereof, and display device

Abstract

The present disclosure provides a display module and a preparation method thereof, and a display device, which are used to solve the problem of low light output efficiency of the display device. The display module includes: a display panel and a lens layer; the display panel includes a plurality of sub-pixels; the lens layer is arranged on the light output side of the display panel, and includes a plurality of self-focusing lenses, and the optical axes of the plurality of self-focusing lenses are parallel to the thickness direction of the display panel; the orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, and the height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens.

Description

Technical Field

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

[0002] Display devices (e.g., mobile phones, computers, etc.) have image display functions, and display panels are their main components. At least one functional layer may also be provided on the light-emitting side of the display panel, such as a cover plate for protecting the display panel, a touch layer for sensing the touch position, etc. It can be seen that the light emitted by the display panel needs to penetrate these functional layers before it can enter the human eye.

[0003] On the one hand, at the contact interface between the functional layer and the display panel, and at the contact interface between these functional layers, refraction or even total reflection may occur due to material differences, and light cannot pass through these functional layers; on the other hand, one of these functional layers may be a black matrix, and part of the light emitted by the display panel will be irradiated by the black matrix and absorbed. Due to the above or other reasons, only about 20% of the light emitted by the display panel can be emitted from the front of the display device, while 80% of the light is lost inside the display device. Summary of the invention

[0004] Embodiments of the present disclosure provide a display module and a method for manufacturing the same, and a display device, so as to solve the problem of low light extraction efficiency of the display device.

[0005] To achieve the above objectives, the embodiments of the present disclosure adopt the following technical solutions:

[0006] In a first aspect, a display module is provided, comprising a display panel and a lens layer. The display panel comprises a plurality of sub-pixels. The lens layer is arranged on the light-emitting side of the display panel, and comprises a plurality of self-focusing lenses, wherein the optical axes of the plurality of self-focusing lenses are parallel to the thickness direction of the display panel; the orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, and the height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens.

[0007] In some embodiments, the difference between the refractive index on the optical axis of the self-focusing lens and the minimum refractive index of the self-focusing lens is greater than or equal to 0.06.

[0008] In some embodiments, the refractive index of the self-focusing lens on the optical axis ranges from 1.60 to 1.69, and / or the minimum refractive index of the self-focusing lens ranges from 1.54 to 1.59.

[0009] In some embodiments, the refractive index distribution of the self-focusing lens satisfies the following formula:

[0010] N(r)=N0(1-A*r 2 / 2);

[0011] Where r is the distance from any position in the self-focusing lens to the optical axis, N(r) is the refractive index of the self-focusing lens at a distance r from the optical axis, and N0 is the refractive index on the optical axis of the self-focusing lens. is the refractive index distribution constant, The value range is 0.25 to 0.35.

[0012] In some embodiments, the height of the self-focusing lens ranges from 0.3 mm to 1 mm.

[0013] In some embodiments, an orthographic projection of a self-focusing lens on the display panel has an overlapping area with at least two sub-pixels.

[0014] In some embodiments, the orthographic projections of at least two self-focusing lenses on the display panel and a sub-pixel each have an overlapping area.

[0015] In some embodiments, a plurality of self-focusing lenses and a plurality of sub-pixels are arranged in a one-to-one correspondence.

[0016] In some embodiments, among the multiple self-focusing lenses, there are gaps between adjacent self-focusing lenses; the lens layer also includes a filling portion, which fills the gap, and the height of the filling portion is the same as the height of the self-focusing lens; or, the display module also includes: a dielectric layer, which covers the multiple self-focusing lenses and fills the gaps.

[0017] In some embodiments, the material of the filling part or the dielectric layer is glue.

[0018] In some embodiments, the display module further includes an adhesive layer, and the adhesive layer is configured to bond the lens layer to the light emitting side of the display panel.

[0019] In some embodiments, the display module further includes a touch layer disposed between the display panel and the lens layer, or disposed on a side of the lens layer away from the display panel.

[0020] In some embodiments, the display module further includes a cover plate disposed on a side of the lens layer away from the display panel.

[0021] In a second aspect, a display device is provided, comprising a display module according to any one of the above embodiments.

[0022] In a third aspect, a method for preparing a display module is provided, comprising: providing a display panel, the display panel comprising a plurality of sub-pixels; setting a lens layer on the light-emitting side of the display panel, the lens layer comprising a plurality of self-focusing lenses, and the optical axes of the plurality of self-focusing lenses are parallel to the thickness direction of the display panel; an orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, and a height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens.

[0023] In some embodiments, setting a lens layer on the light-emitting side of the display panel includes: forming an initial lens layer on the light-emitting side of the display panel, the initial lens layer including multiple initial lenses, the materials at multiple positions with different distances from the axis in an initial lens are the same, and the axis is parallel to the thickness direction of the display panel; changing the materials at multiple positions with different distances from the axis in the initial lens to form a self-focusing lens; or, pasting the lens layer on the light-emitting side of the display panel.

[0024] In the display module provided in the first aspect, a lens layer is arranged on the light-emitting side of the display panel, and the self-focusing lens in the lens layer is arranged to extend in the direction of the optical axis, and in the positional relationship and height with the sub-pixel, so that the self-focusing lens can converge the light emitted by the sub-pixel; in this way, the light emitted through the lens layer has a smaller angle with the thickness direction of the display panel than the light emitted without passing through the lens layer; at this time, if a functional layer (for example, at least one of a touch layer and a cover plate) is arranged on the side of the lens layer away from the panel, the incident angle of the light irradiated to the functional layer is reduced, so the degree of full emission or absorption of the light can be reduced, thereby increasing the proportion of light passing through the functional layer, and therefore, the display module helps to improve the light-emitting efficiency. In addition, since the height of the self-focusing lens is small, it helps to make the display module thinner and lighter, and in the process of setting the self-focusing lens on one side of the display panel, the optical axis of the self-focusing lens is not easy to tilt, so that the structural stability of the display module is better.

[0025] It can be understood that the display device provided in the second aspect includes the display module, and the preparation method provided in the third aspect can prepare the display module. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the display module provided above, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 is a structural block diagram of a display device according to some embodiments;

[0028] Figure 2 is a structural diagram of a display module according to some embodiments;

[0029] Figure 3 is a structural block diagram of a light emitting device according to some embodiments;

[0030] Figure 4A is a structural diagram of a self-focusing lens according to some embodiments;

[0031] Figure 4B is a refractive index distribution diagram of a self-focusing lens according to some embodiments;

[0032] Figure 5A is a light path diagram of a self-focusing lens according to some embodiments;

[0033] Figure 5B is a light path diagram of another self-focusing lens according to some embodiments;

[0034] Figure 6 is a light path diagram of another self-focusing lens according to some embodiments;

[0035] Figure 7 is a schematic diagram of an arrangement of multiple repeating units in a display panel according to some embodiments;

[0036] Fig. 8A is a position relationship diagram of a sub-pixel and a self-focusing lens according to some embodiments;

[0037] Figure 8B is another position relationship diagram of a sub-pixel and a self-focusing lens according to some embodiments;

[0038] Fig. 9A is another position relationship diagram of a sub-pixel and a self-focusing lens according to some embodiments;

[0039] Fig. 9B is another position relationship diagram of a sub-pixel and a self-focusing lens according to some embodiments;

[0040] Fig. 9C is another position relationship diagram of a sub-pixel and a self-focusing lens according to some embodiments;

[0041] Fig.10 for Figure 8B A cross-sectional view along the B-B' direction;

[0042] Fig.11 for Figure 8B Another cross-sectional view along the BB' direction;

[0043] Fig.12 for Figure 8B Another cross-sectional view along the BB' direction;

[0044] Fig.13 for Figure 8B A cross-sectional view along the B-B' direction;

[0045] Fig.14 for Figure 8B Another cross-sectional view along the BB' direction;

[0046] Fig.15 for Figure 8B Another cross-sectional view along the BB' direction;

[0047] Fig.16 for Figure 8B A cross-sectional view along the B-B' direction;

[0048] Fig.17 is a flow chart of a method for preparing a display module according to some embodiments;

[0049] FIG. 18A to FIG. 18D A process diagram of forming a lens layer on the light-emitting side of a display panel;

[0050] Fig.19A A schematic diagram of the ion distribution state before diffusion begins in the process of preparing a self-focusing lens by an ion exchange method according to some embodiments;

[0051] Fig.19B A schematic diagram of the ion distribution state after ion exchange in the process of preparing a self-focusing lens by an ion exchange method according to some embodiments;

[0052] Fig. 20 Schematic diagram of preparing a self-focusing lens strip using an ion exchange method according to some embodiments. DETAILED DESCRIPTION

[0053] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. However, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0054] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0055] The use of "adapted to" or "configured to" herein is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0056] "Plurality" means at least two.

[0057] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0058] It will be understood that when a layer or an element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present between the layer or element and the other layer or substrate.

[0059] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0060] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0061] Some embodiments of the present disclosure provide a display device. The display device is a product with an image (including: static image or dynamic image, wherein the dynamic image can be a video) display function. For example, the display device can be: a display, a television, a billboard, a digital photo frame, a laser printer with a display function, a telephone, a mobile phone, a personal digital assistant (PDA), a digital camera, a portable camcorder, a viewfinder, a navigator, a vehicle, a large area wall, a home appliance, an information query device (such as business query equipment of e-government, banks, hospitals, power and other departments), a monitor, and the like. For another example, the display device can also be any product in a micro display, a VR device or an AR device containing a micro display, and the like.

[0062] Figure 1 A block diagram of a display device provided by an embodiment of the present disclosure. Figure 1 In some embodiments, the display device 1000 may include a display module 100, and may also include a main board (Main Board) 200 coupled to the display module 100, the main board is configured to provide an image signal to the display module 100, and the display module 100 is configured to display a corresponding image according to the received image signal.

[0063] Figure 2 This is a structural diagram of a display module provided by an embodiment of the present disclosure. Figure 2 The display module 100 includes a display panel 110. The display panel 110 is a panel with an image display function. The display panel 110 may have a display area AA and a peripheral area SA, wherein the peripheral area SA is located on at least one side (e.g., one side; or, for example, all around) outside the display area AA. The thickness direction of the display panel 110 is represented by Z, and the extension directions of the two adjacent sides in the display area AA are represented by X and Y, respectively.

[0064] The display panel 110 includes a plurality of sub-pixels P arranged in the display area AA. A sub-pixel P is a portion with controllable brightness and the smallest area, that is, the area occupied by a sub-pixel P is a light-emitting area with the smallest area and controllable brightness in the display panel 110. As an example, the plurality of sub-pixels P include a first sub-pixel P1 configured to emit a first color light, a second sub-pixel P2 configured to emit a second color light, and a third sub-pixel P3 configured to emit a third color light; wherein the first color, the second color, and the third color may be three primary colors. For example, the first color, the second color, and the third color are red, green, and blue, respectively; accordingly, the plurality of sub-pixels P include a red sub-pixel, a green sub-pixel, and a blue sub-pixel. As another example, the plurality of sub-pixels P may also include a fourth sub-pixel that emits white light.

[0065] In some embodiments, a sub-pixel (e.g., each sub-pixel) P may include a light-emitting device. For example, the light-emitting device may be any one of an LED (light-emitting diode), an OLED (organic light-emitting diode), a QLED (quantum dot light-emitting diode), a micro-LED (including miniLED or microLED), etc. The area in the light-emitting device that can be illuminated may be used as the area occupied by the sub-pixel P.

[0066] Figure 3 is a structural diagram of a light-emitting device. Figure 3 , the light-emitting device (for example, OLED or QLED) includes a cathode and an anode, and a light-emitting functional layer located between the cathode and the anode. Among them, the light-emitting functional layer may include, for example, a light-emitting layer (Emitting Layer, EL), a hole transport layer (Hole Transporting Layer, HTL) located between the light-emitting layer and the anode, and an electron transport layer (Election Transporting Layer, ETL) located between the light-emitting layer and the cathode. Of course, in some embodiments, as needed, a hole injection layer (Hole Injection Layer, HIL) may be provided between the hole transport layer and the anode, and an electron injection layer (Election Injection Layer, EIL) may be provided between the electron transport layer and the cathode.

[0067] In other embodiments, Figure 2A sub-pixel (e.g., each sub-pixel) P in the display panel 110 may include a liquid crystal light valve. The liquid crystal light valve may include: a pixel electrode, a common electrode, and a liquid crystal that can be driven by the pixel electrode and the common electrode. The area of ​​the liquid crystal light valve that can be opened to allow backlight to emit from the display panel 110 can be used as the area occupied by the sub-pixel P.

[0068] Continue to see Figure 2 The display module 100 further includes a lens layer 120 disposed on the light-emitting side of the display panel 110 , and the lens layer 120 includes a plurality of self-focusing lenses 121 .

[0069] Figure 4A The structure of the self-focusing lens is shown in FIG. Figure 4A The self-focusing lens 121 is a cylindrical optical lens with a refractive index distribution that gradually changes along the radial direction. The refractive index gradually decreases from the optical axis O to the side S, for example, it can gradually decrease in a parabolic trend, so that the light transmitted roughly along the axial direction can be continuously refracted. Exemplarily, the self-focusing lens 121 can be a cylinder, the optical axis is the axis of the cylinder, and the refractive indices at multiple positions in the direction away from the optical axis O are N0, N1, N2, N3 and N min , where N0>N1>N2>N3>N min . Figure 4A The five refractive indices are only used as examples. In actual products, more refractive indices may be provided in a direction away from the optical axis O. For example, the self-focusing lens 121 may be an elliptical column or a prism, etc. The prism may be a right prism, and further may be a regular prism, such as a quadrangular prism, a hexagonal prism, etc., which are not limited here. In addition, in a self-focusing lens 121, if the distances from multiple positions to the optical axis O are the same, the refractive indices at these positions may be equal.

[0070] It should be noted that the same medium has different refractive indices for light of different frequencies (i.e., light of different wavelengths). For a medium that is transparent to visible light, generally, the refractive index of the medium increases as the wavelength decreases. Therefore, when describing the refractive index of the self-focusing lens 121 at different positions, it refers to the refractive index of these positions relative to light of the same wavelength, so as to compare the refractive indices at different positions in the same measurement standard. For example, the refractive indices at various positions are relative to green light with a wavelength of 550nm. It should also be understood that the specific values ​​of the refractive indices at different positions mentioned in the embodiments of the present disclosure are only relative to, for example, green light with a wavelength of 550nm. However, it does not mean that the light emitted from the above-mentioned display panel 110 provided in the embodiments of the present disclosure is only green light.

[0071] In some embodiments, see Figure 4BThe refractive index distribution of the self-focusing lens 121 satisfies the following formula: N(r)=N0(1-A*r 2 / 2).

[0072] Wherein, N0 is the refractive index on the optical axis of the self-focusing lens 121, r is the distance from any position in the self-focusing lens 121 to the optical axis, N(r) is the refractive index of the self-focusing lens at a position with a distance r from the optical axis, is the refractive index distribution constant of the self-focusing lens 121, The value range of is 0.25 to 0.35; for example, it can be 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, etc.

[0073] In addition, if the self-focusing lens 121 is a cylinder, and the diameter of the cylinder is D, and the radius is D / 2; then, when r=D / 2, N(r)=N min .

[0074] It can be seen from the above formula that when the distance r from a certain position in the self-focusing lens 121 to the optical axis is determined, the refractive index distribution constant of the self-focusing lens 121 is The larger the value, the greater the difference between the refractive index on the optical axis of the self-focusing lens 121 and the minimum refractive index, and thus the higher the light extraction efficiency of the display panel 110.

[0075] The main components of the material of the self-focusing lens 121 may include organic glass, any compound of germanium, arsenic, sulfur and selenium, any inorganic material such as sodium chloride, silicon nitride, silicon oxide, or any copolymer of organic monomers such as methyl methacrylate, styrene and isophthalic acid butyl ester. The material of the self-focusing lens 121 may also include elements (such as ions) doped in the main components. In the self-focusing lens 121, the concentration of the doped elements in the radial direction from the optical axis O to the side S is different, so that the refractive index at different positions is different. For example, the main component of the self-focusing lens 121 is silicon oxide, and the doped elements are the first ions and the second ions. The first ions include: lithium ions (Li + ), cesium ion (Cs + ), thallium ion (Tl + ) in combination of one or more, the second ion comprising: sodium ion (Na + ), potassium ion (K +) or a combination of one or more thereof. In the self-focusing lens 121, from the optical axis O to the side S, the first ions gradually become smaller in the radial direction, and the concentration of the second ions gradually increases. In other examples, the main component of the self-focusing lens 121 is silicon oxide, and it also has a first atomic group and a second atomic group, the first atomic group includes an oxygen-deficient germanium defect (GeODC), and the second atomic group includes a deep energy level defect (GeE').

[0076] Figure 5A and Figure 5B A light path diagram of a self-focusing lens is shown. In some embodiments, see Figure 5A and Figure 5B , the height H of the self-focusing lens 121 is less than or equal to 1 / 4 of the pitch of the self-focusing lens 121. H is the length of the self-focusing lens 121 along the extension direction of the optical axis O. The length of a parallel light beam propagating along a sinusoidal trajectory to complete a sine wave cycle is called a pitch. Figure 5A For a self-focusing lens 121 with a height H of 1 / 4 pitch, when a beam of parallel light is incident from the light input end surface a1, the light will converge into a light spot on the light output end surface a2 after passing through the self-focusing lens 121. Figure 5B For the self-focusing lens 121 whose height H is less than 1 / 4 of the pitch, the parallel light incident from the light input end face a1 will converge into a light surface on the light output end face a2 after passing through the self-focusing lens 121. It can be seen that this self-focusing lens 121 has a light convergence effect; in addition, since the height of the self-focusing lens 121 is small, it is helpful Figure 2 The display module 100 is made thinner and lighter, and in the process of setting the self-focusing lens 121 on one side of the display panel 110, the optical axis of the self-focusing lens 121 is not easy to tilt, so that the structural stability of the display module 100 is better.

[0077] Figure 6 FIG. 1 shows another optical path diagram of the self-focusing lens 121. Figure 6 , the height of the self-focusing lens 121 is equal to 1 / 4 of the pitch of the self-focusing lens 121, and the input light beam has a half-divergence angle (i.e., half of the divergence angle) θ1; according to the light transmission principle of the self-focusing lens 121, after passing through the self-focusing lens 121, the half-divergence angle of the output light beam is θ2, θ2<θ1. In other words, for divergent light beams, the self-focusing lens 121 also plays a converging role. Similarly, a self-focusing lens 121 with a height less than 1 / 4 of the pitch can also play a converging role for divergent light beams.

[0078] Taking into account the demand for a thinner and lighter display panel 110, the height of the self-focusing lens 121 ranges from 0.3 mm to 1 mm; for example, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0079] Combined with Figure 4 and Figure 6 As shown, in some embodiments, the refractive index N0 on the optical axis of the self-focusing lens 121 is min The difference (hereinafter referred to as: (N0-N min )) is greater than or equal to 0.06. min ) is small, the difference between θ1 and θ2 is small, and the focusing effect is not obvious; when (N0-N min ) is large, the difference between θ1 and θ2 is large, which is conducive to more light being emitted from the display module and improving the light output efficiency of the display module.

[0080] In some embodiments, the refractive index N0 on the optical axis of the self-focusing lens 121 ranges from 1.60 to 1.69; for example, it can be 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, etc.

[0081] In some embodiments, the minimum refractive index N of the self-focusing lens 121 is min The value range of is 1.54 to 1.59; for example, it can be 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, etc.

[0082] For the first sub-pixel P1, the second sub-pixel P2 and the third sub-pixel P3, the refractive index N0 and the minimum refractive index N0 on the optical axis of the self-focusing transmission directly above them are min The value range of satisfies the above value range. The refractive index distribution of the self-focusing lens directly above the first sub-pixel P1, the second sub-pixel P2 and the third sub-pixel P3 satisfies the above formula; the self-focusing lens (N0-N min ) can be the same as (N0-N min ) are of the same size or different sizes; the self-focusing lens above the second sub-pixel P2 and the third sub-pixel P3 The size of the self-focus lens above the R pixel can be The sizes can be the same or different.

[0083] Continue to see Figure 2 , the optical axes of the plurality of self-focusing lenses 121 (eg, all the self-focusing lenses 121) in the lens layer 120 are parallel to the thickness direction Z of the display panel 110. The parallel here can be understood as substantially parallel, wherein the acceptable deviation range of substantially parallel can be within 5°, for example.

[0084] The orthographic projection of a self-focusing lens 121 (for example, each self-focusing lens 121) on the display panel 110 has an overlapping area OA with a sub-pixel P. For example, a self-focusing lens 121 or a plurality of self-focusing lenses 121 are arranged directly above each sub-pixel P (on the side pointed by the arrow in the direction Z). Among them, the orthographic projection on the display panel 110 refers to the projection on the display panel 110 along the direction Z. In this way, the light emitted by the sub-pixel P can be converged by the self-focusing lens 121, which helps to improve the light output efficiency of the display module 100 without increasing power consumption. In addition, since the self-focusing lens 121 has a gradient-varying refractive index, the light is converged inside the self-focusing lens 121. Compared with the micro-convex lens, the surface morphology of the self-focusing lens 121 has little effect on the focusing effect. Therefore, the problem of reduced display effect of the display module caused by lens surface defects can be reduced, thereby improving the product yield.

[0085] Figure 7 to Figure 9C The distribution of sub-pixels and the positional relationship between the sub-pixels and the self-focusing lens are shown. Figure 7 In the display panel 110, the plurality of sub-pixels may constitute a plurality of repeating units RU, and the plurality of repeating units RU may be arranged in an array. For example, the plurality of repeating units RU are arranged into a plurality of repeating unit rows distributed along a direction Y, and each repeating unit row includes at least two repeating units RU distributed along a direction X. Figures 8A to 9C A repeating unit (e.g., each repeating unit) RU may include: a first sub-pixel (e.g., a red sub-pixel) P1, a second sub-pixel (e.g., a green sub-pixel) P2, and a third sub-pixel (e.g., a blue sub-pixel) P3 with different luminous colors. In this embodiment, the arrangement of the sub-pixels in the repeating unit is not limited.

[0086] In one possible implementation, combining Figure 7 and Fig. 8A It can be seen that a repeating unit (for example, each repeating unit) RU includes four sub-pixel rows, each sub-pixel row extends along the direction X and includes two sub-pixels, and the sub-pixels in two adjacent sub-pixel rows are staggered; at this time, the arrangement of the sub-pixels in the repeating unit RU can be called a staggered array. In order to converge the light emitted by each sub-pixel, in the display module, multiple self-focusing lenses 121 and multiple sub-pixels P can be arranged one by one. Exemplarily, the positive projection of each self-focusing lens 121 on the display panel 110 has an overlapping area only with one sub-pixel P, and does not overlap with other sub-pixels. In this way, the distribution of the light emitted by each sub-pixel P after convergence is similar to the distribution of each sub-pixel P, which helps the display module to have a better display effect.

[0087] As another example, the orthographic projection of each self-focusing lens 121 on the display panel 100 covers a sub-pixel P, that is, a sub-pixel P is included in the orthographic projection of a self-focusing lens 121 on the display panel 100, which helps to converge most of the light emitted by a sub-pixel P to the same position. For example, the shape of a self-focusing lens 121 is a cylinder, and its diameter D1 is greater than or equal to the size D2 of the sub-pixel P corresponding to the self-focusing lens 121; wherein the size of the sub-pixel P is the distance between the two farthest points in the boundary of the sub-pixel. Specifically, for example, the self-focusing lens 121 is applied to a mobile phone, the diameter of the self-focusing lens 121-1 is less than or equal to 30μm, the diameter of the self-focusing lens 121-2 is less than or equal to 20μm, and the diameter of the self-focusing lens 121-3 is less than or equal to 40μm; for another example, the self-focusing lens 121 is applied to a tablet computer or a laptop computer, the diameter of the self-focusing lens 121-1 is less than or equal to 60μm, the diameter of the self-focusing lens 121-2 is less than or equal to 40μm, and the diameter of the self-focusing lens 121-3 is less than or equal to 80μm. In addition, the diameters of the self-focusing lenses 121-1, 121-2 and 121-3 can be 10μm to 100μm, so that the orthographic projection of each self-focusing lens on the display panel 100 only covers one sub-pixel P, and does not overlap with other sub-pixels P. Exemplarily, the diameters of the self-focusing lenses 121-1, 121-2 and 121-3 may be different. For example, the diameter of the self-focusing lens 121-3 is larger than the diameter of the self-focusing lens 121-2, and the diameter of the self-focusing lens 121-2 is larger than the diameter of the self-focusing lens 121-1.

[0088] In another possible implementation, combining Figure 7 and Figure 8B It can be seen that the arrangement of sub-pixels is similar to Fig. 8A The same, no further description is given here. Fig. 8A In the scheme where adjacent self-focusing lenses 121 do not contact each other. Figure 8B In the embodiment, adjacent self-focusing lenses 121 may be in contact. For example, the diameters of the self-focusing lenses 121-1, 121-2 and 121-3 may be the same, which makes it easier to prepare the lens layer.

[0089] In addition, in the above Fig. 8A and Figure 8B The positional relationship between the sub-pixel and the self-focusing lens shown in the figure can also be applied to other types of sub-pixel arrangements and is not limited here.

[0090] In another possible implementation, combining Figure 7 and Fig. 9AIt can be seen that a repeating unit (for example, each repeating unit) RU includes two sub-pixel rows, each sub-pixel row extends, for example, along the direction X and includes four sub-pixels, and the sub-pixels in the two sub-pixel rows are aligned and distributed in an array. In order to converge the light emitted by each sub-pixel, in the display module, the positive projection of a self-focusing lens 121 on the display panel 100 has an overlapping area with at least two sub-pixels P, which can also be said that a self-focusing lens 121 corresponds to at least two sub-pixels P. Exemplarily, the number of sub-pixels P corresponding to each self-focusing lens 121 is equal, for example, two, and the two sub-pixels P may include a second sub-pixel P2. In this way, the distribution of the light emitted by each sub-pixel P after convergence is similar to the distribution of each sub-pixel P, which helps the display module have a better display effect. In addition, since a self-focusing lens 121 corresponds to at least two sub-pixels P, this allows the self-focusing lens 121 to have a longer diameter, which is conducive to reducing the difficulty of preparing the self-focusing lens. Exemplarily, each self-focusing lens 121 is in the shape of a cylinder, and adjacent self-focusing lenses may be in contact, so that the diameter of the self-focusing lens 121 may be as long as possible, which is conducive to reducing the difficulty of preparing the self-focusing lens. Exemplarily, a self-focusing lens 121 corresponds to at least two sub-pixels P, and each sub-pixel P may have at least a portion overlapping with the orthographic projection of the self-focusing lens 121 on the display panel 100. For example, the orthographic projection of the self-focusing lens 121-a on the display panel 100 covers the first sub-pixel P1, and overlaps with a portion of the second sub-pixel P2. For another example, the orthographic projection of the self-focusing lens 121-b on the display panel 100 overlaps with a portion of the third sub-pixel P3, and overlaps with a portion of the second sub-pixel P2.

[0091] In another possible implementation, combining Figure 7 and Fig. 9B It can be seen that the arrangement of sub-pixels is similar to Fig. 9A The same, no further description is given here. Fig. 9A In FIG. 1 , a sub-pixel P has an overlapped area only with the orthographic projection of a self-focusing lens 121 on the display panel 100. Fig. 9BIn the embodiment, a sub-pixel P may have an overlapping area with the orthographic projections of at least two self-focusing lenses 121 on the display panel 100. Exemplarily, in the display module, a sub-pixel P1 and a sub-pixel P3 each have an overlapping area with the orthographic projections of three self-focusing lenses 121 on the display panel 100, and a sub-pixel P2 has an overlapping area with the orthographic projections of two self-focusing lenses 121 on the display panel 100. In this way, the light emitted by a sub-pixel P converges to two or three positions, that is, a sub-pixel P can be divided into multiple beams of light, which is helpful for the formation of virtual sub-pixels, thereby improving the resolution of the display module. A self-focusing lens 121 is cylindrical in shape, and its orthographic projection on the display panel 100 may have an overlapping area with one or at least two sub-pixels P, so that the arrangement of the self-focusing lenses does not have to be overly constrained by the arrangement of sub-pixels.

[0092] In another possible implementation, combining Figure 7 and Fig. 9C It can be seen that the arrangement of sub-pixels is similar to Fig. 9B The same, no further description is given here. Fig. 9B In FIG. 1 , the orthographic projection of a self-focusing lens 121 on the display panel 100 has an overlapping area with a plurality of sub-pixels P. Fig. 9C In the embodiment, the orthographic projection of a self-focusing lens 121 on the display panel 100 has an overlapping area with only one sub-pixel P, and the orthographic projections of a sub-pixel P and at least two self-focusing lenses 121 on the display panel 100 have overlapping areas. Exemplarily, in the display module, a sub-pixel P1 and a sub-pixel P3 each have overlapping areas with the orthographic projections of at least two (for example, six) self-focusing lenses 121 on the display panel 100, and a sub-pixel P2 has overlapping areas with the orthographic projections of at least two (for example, three) self-focusing lenses 121 on the display panel 100. In this way, the light emitted by a sub-pixel P converges above the sub-pixel P, and the distribution of the light emitted by each sub-pixel P after convergence is similar to the distribution of each sub-pixel P, which helps the display module to have a better display effect. For example, the shape of a self-focusing lens 121 is a cylinder, and its diameter D1 is smaller than the size D2 of the sub-pixel P corresponding to the self-focusing lens 121; wherein the size of the sub-pixel P is the distance between the two farthest points in the boundary of the sub-pixel. Exemplarily, the sizes of the self-focusing lenses 121 may be the same to facilitate the preparation of the lens layer.

[0093] In addition, in the above Figures 9A to 9C The positional relationship between the sub-pixel and the self-focusing lens shown in the figure can also be applied to other types of sub-pixel arrangements and is not limited here.

[0094] Exemplarily, the size of the bottom surface of the self-focusing lens ranges from 10 μm to 1 mm, and the bottom surface of the self-focusing lens is the surface of the self-focusing lens close to the display panel; for example, it can be 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1 mm, etc. The size of the bottom surface of the self-focusing lens refers to: the distance between the two farthest points in the boundary of the bottom surface of the self-focusing lens. For example, when the self-focusing lens is a cylinder, the size of its bottom surface is the length of the diameter.

[0095] Fig.10 , Fig.11 and Fig.12 Both Figure 8B A cross-sectional view along the BB' direction. In some embodiments, see Fig.10 Among the plurality of self-focusing lenses 121, there is a gap G between adjacent self-focusing lenses 121 (the gap refers to the space in the lens layer 120 that is not covered by the self-focusing lens 121). In an actual product, the gap G can be filled by other layers above the lens layer 120 (for example, at least one functional layer).

[0096] In other embodiments, see Fig.11 , the lens layer 120 also includes a filling portion 122, which is filled in the gap G. The height of the filling portion 122 is the same as the height of the self-focusing lens 121. The same here can be understood as being approximately the same. Approximately the same means that the ratio of the difference between the height of the filling portion 122 and the height of the self-focusing lens 121 and the height of the self-focusing lens 121 is within an acceptable deviation range, such as less than or equal to 10% or 5%. The filling portion 122 is filled in the gap G and can contact and be fixedly connected with the self-focusing lens 121 adjacent to the filling portion 122. For example, the two can form an integrated structure, which is conducive to fixing multiple self-focusing lenses 121 and avoiding displacement between multiple self-focusing lenses 121, which affects the display effect of the display module. In addition, the height of the filling portion 122 is approximately the same as the height of the self-focusing lens 121, so that the upper surface of the lens layer 120 is approximately flat, so as to provide a flat surface for the film layer (such as at least one functional layer) above it.

[0097] In some possible implementations, the material of the filling portion 122 may be glue; for example, optical clear adhesive (OCA for short). Optical adhesive is colorless and transparent, has a light transmittance of more than 90%, has good bonding strength, can be cured at room temperature or medium temperature, has small curing shrinkage and good electrical insulation performance. The main material used to prepare the optical adhesive may be any one of silicone rubber, polyurethane, epoxy resin, acrylic resin and unsaturated polyester. In another possible implementation, the filling portion 122 may also be silicon oxide, silicon nitride, photosensitive adhesive, etc.

[0098] In some other embodiments, see Fig.12 The display module 100 further includes: a dielectric layer 130 , which covers the plurality of self-focusing lenses 121 and fills the gap G.

[0099] The dielectric layer 130 is filled in the gap G and can contact and be fixedly connected with the self-focusing lens 121 adjacent to the dielectric layer 130. For example, the two can form an integrated structure, which is conducive to fixing multiple self-focusing lenses 121 and avoiding displacement between multiple self-focusing lenses 121, which affects the display effect of the display module.

[0100] In some possible implementations, the material of the dielectric layer 130 may be the same as the material of the filling portion 122 , which will not be described in detail herein.

[0101] In some embodiments, see Figure 10 to Figure 12 Specifically, the display panel may include: a driving backplane 113, a plurality of light-emitting devices E disposed on the driving backplane 113, and an encapsulation layer 112 covering the plurality of light-emitting devices. A light-emitting device E is included in a sub-pixel P mentioned above, for example, a light-emitting device E1 is included in a sub-pixel P1, and a light-emitting device E3 is included in a sub-pixel P3. The driving backplane 113 is coupled to the plurality of light-emitting devices E and is configured to drive each light-emitting device E to emit light.

[0102] Exemplarily, the encapsulation layer may be a thin film encapsulation layer (Thin Film Encapsulation, referred to as TFE), including: an inorganic encapsulation layer, an organic encapsulation layer and an inorganic encapsulation layer, which are sequentially arranged along the thickness direction of the display panel 100 .

[0103] As another example, the lens layer 120 may be located on a side of the encapsulation layer 112 away from the driving back plate 113 , and may be in contact with the encapsulation layer 112 .

[0104] Figure 13-14 Both Figure 8BA cross-sectional view along the BB' direction. In some embodiments, the display module further includes at least one functional layer (for example, at least one of a touch layer, a cover plate, and a black matrix) on the light-emitting side of the display panel 110. For example, the display module also has a touch function, such as Fig.13 and Fig.14 As shown, the display module 100 further includes a touch layer 140, and the touch layer 140 is configured to sense a touch position. In a possible implementation, the touch layer 140 may be connected to the touch Figure 1 The mainboard 200 is coupled to the touch screen, and the mainboard 200 is configured to determine the image to be displayed by the display module based on the touch position. Fig.13 , the touch layer 140 is disposed between the display panel 110 and the lens layer 120. For example, see Fig.14 The touch layer 140 is arranged on the side of the lens layer 120 away from the display panel 110; at this time, since the incident angle of the light irradiating the touch layer is reduced, the degree of total reflection of the light can be reduced, thereby increasing the proportion of light passing through the touch layer, thus helping to improve the light extraction efficiency of the display module.

[0105] In some embodiments, Fig.15 As shown, the display module 100 further includes: a cover plate 150 , which is disposed on a side of the lens layer 120 away from the display panel 110 ; similar to the touch layer, it helps to improve the light extraction efficiency of the display module.

[0106] In some embodiments, the display module also includes: a black matrix, which is arranged on the side of the lens layer away from the display panel; because the lens layer converges the light emitted by the display panel, thereby reducing the degree of light absorption by the black matrix, it helps to improve the light output efficiency of the display module.

[0107] For example, Fig.15 As shown, the display module 100 further includes: an adhesive layer 170 configured to bond the cover plate 150 to the light-emitting side of the lens layer 120. The material of the adhesive layer 170 may be optical adhesive.

[0108] In some embodiments, Fig.16 As shown, the display module 100 further includes: an adhesive layer 160 disposed between the display panel 110 and the lens layer 120. The adhesive layer 160 may be made of the same material as the filling portion 122, which will not be described in detail herein. The adhesive layer 160 may be made of optical glue.

[0109] like Fig.17 As shown, some embodiments of the present disclosure provide a method for preparing a display module, which is configured to prepare the display module in each of the above embodiments. The features below can refer to the above explanations and will not be repeated. The preparation method includes:

[0110] S100 . Provide a display panel, where the display panel includes a plurality of sub-pixels.

[0111] S200, setting a lens layer on the light-emitting side of the display panel. The lens layer includes a plurality of self-focusing lenses, the axes of which are parallel to the thickness direction of the display panel; the orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, and the height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens.

[0112] Among them, the method for preparing the self-focusing lens may include: ion exchange method, laser irradiation method, chemical vapor deposition method, ion (molecule) filling method, sol-gel method, neutron radiation method, crystal growth method, photolithography-ion exchange method, polymer salt ion exchange technology, blended polymer dissolution method, monomer synthesis method, thin film lamination method, diffusion method, diffusion chemical reaction method, diffusion copolymerization method, centrifugal force, photopolymerization method, suspension copolymerization method, precipitation copolymerization method, interface gel copolymerization method, etc. One or more combinations thereof.

[0113] In some embodiments, S200 includes:

[0114] S210, see Fig.18B An initial lens layer 120 b is formed on the light-emitting side of the display panel 110 , and the initial lens layer 120 b includes a plurality of initial lenses 121 b .

[0115] The shape and position of an initial lens 121b can refer to the shape and position of the self-focusing lens to be formed. The materials at multiple positions of an initial lens 121b with different distances from the axis are the same. The axis is parallel to the height direction of the initial lens 121b and passes through the center point of the cross section of the initial lens 121b. The cross section is a plane perpendicular to the height direction of the initial lens 121b.

[0116] In one achievable manner, S210 may include:

[0117] First, see Fig.18A A transparent film 120a is formed on the light-emitting side of the display panel 110 (for example, on the surface of the light-emitting side of the display panel 110; for example, on the surface of the touch layer away from the display panel 110). For example, a silicon oxide material containing germanium (Ge) is deposited on the display panel 110 using a chemical vapor deposition (CVD) process to obtain the transparent film 120a.

[0118] Secondly, see Fig.18B The transparent film 120a is patterned to form a plurality of initial lenses 121b, thereby obtaining an initial lens layer 120b. For example, the patterning process may be a photolithography process or the like.

[0119] S220, changing the materials of multiple positions in the initial lens with different distances from the axis to form a self-focusing lens.

[0120] Exemplarily, the initial lens layer 120b is subjected to hydrogen loading and sensitization treatment, and the chemical reaction formula occurring during the sensitization treatment is as follows:

[0121]

[0122] Wherein, k1 and k2 represent the reaction speed (k1>>k2, i.e., k1 is much greater than k2), hv represents ultraviolet light irradiation, and H2 represents hydrogen. A is the initial substance in the initial lens 121b, B is the intermediate generated substance, and C is the final substance that causes the refractive index to change. A, B, and C are considered to be atomic groups GeODC(Ⅱ), GeH, and GeE', respectively.

[0123] Specifically, a laser beam (ultraviolet light) that has been focused is used to irradiate the hydrogen-carrying initial lens 121b, wherein the exposure energy concentration after focusing can reach 200 mJ / cm 2 The hydrogen gas reacts chemically with the atomic group GeODC(II) (also called oxygen-deficient germanium defect or germanium oxygen defect) in the initial lens 121b under the stimulation of ultraviolet light to generate relatively stable hydride (GeH) and atomic group GeE' (also called deep energy level defect). The concentration of atomic group GeE' determines the refractive index of the material.

[0124] Therefore, to prepare a self-focusing lens, see Fig. 18C , controlling the exposure time at multiple positions of the initial lens 121b with different distances from the axis, for example, the exposure time at the axis position is t0, and the exposure time at different positions in the radial direction away from the axis is t0, t1, t2, etc., t1 and t2 are different from each other, thereby obtaining Fig.18D A self-focusing lens 121 whose refractive index gradient changes due to differences in exposure time.

[0125] In another achievable manner, S210 may include:

[0126] First, similar to the above implementation, see Fig.18A A transparent film 120a is formed on the light-emitting side of the display panel 110. For example, a chemical vapor deposition (CVD) process is used to deposit a first ion (denoted as R1 + For example, Li + , Cs + , Tl +A silicon oxide material (at least one of the above) is deposited on the display panel 110 to obtain a transparent film 120a.

[0127] Secondly, see Fig.18B The transparent film 120a is patterned to form a plurality of initial lenses 121b, thereby obtaining an initial lens layer 120b. For example, the patterning process may be a photolithography process or the like.

[0128] In S220, a self-focusing lens can be prepared by an ion exchange method, including: placing a display panel with an initial lens layer 120b in a liquid containing a second ion (denoted as R2 + , such as Na + and K + At least one of the molten salts of Fig.18D The lens layer 120 includes a plurality of self-focusing lenses 121 .

[0129] Specifically, Fig.19A It indicates that the second ion R2 in the molten salt before diffusion begins + The first ion R1 in the initial lens 121b + Distribution state, at this time the first ion R1 + Evenly distributed in the initial lens 121b, the refractive index on the axis O of the initial lens 121b and the refractive index on the side (the distance from the axis O to the side is r) are both N0; Fig.19B The self-focusing lens 121 obtained after ion exchange, at this time, the refractive index on the axis O of the self-focusing lens 121 is N0, and the refractive index on the side is N(r). The self-focusing lens 121 has both the first ion R1 + , and there is a second ion R2 + For example, the first ion R1 on the axis O of the self-focusing lens 121 + The first ion R1 on the side (i.e. edge) is not exchanged + All are exchanged for the second ion R2 + , the second ion R2 + The concentration varies gradually in the radial direction from the axis to the edge, and the corresponding refractive index also changes.

[0130] In other embodiments, S200, setting a lens layer on the light-emitting side of the display panel includes: pasting a lens layer on the light-emitting side of the display panel (for example, on the surface of the light-emitting side of the display panel; for example, on the surface of the touch layer away from the display panel).

[0131] For example, a lens layer may be provided first, and then the lens layer may be attached to the light-emitting side of the display panel. Fig.11 As shown, it includes: a plurality of self-focusing lenses 121 and a filling part 122; it can also be as Fig.12As shown, it includes: a plurality of self-focusing lenses 121 and a dielectric layer 130. The material of the filling part 122 or the dielectric layer 130 can be glue. At this time, the lens layer can be pasted to the light-emitting side of the display panel through the filling part 122 or the dielectric layer 130.

[0132] As another example, the lens layer 120 may be Fig.16 The additional adhesive layer 160 is adhered to the light emitting side of the display panel.

[0133] The preparation process of the plurality of self-focusing lenses 121 in the lens layer 120 may include:

[0134] First, the initial transparent strip is processed by any of the above-mentioned preparation methods (e.g., ion exchange method, laser irradiation method, etc.) to obtain a self-focusing lens strip. The material of the initial transparent strip can be the same as the material of the initial lens mentioned above. Fig. 20 As shown, an initial transparent strip 121c made of silicon oxide material containing first ions is placed in a molten salt containing second ions to perform ion exchange, thereby obtaining a self-focusing lens strip having a refractive index that is gradually distributed in the radial direction from the axis to the edge.

[0135] Secondly, the self-focusing lens strip is sliced ​​to obtain a plurality of self-focusing lenses.

[0136] Afterwards, as needed (for example, according to Figures 8A to 9C The distribution of self-focusing lenses in the sample is shown in Figure 1), and the multiple self-focusing lenses obtained by slicing are arranged to form a lens layer.

[0137] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be thought of by any person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A display module, characterized in that: include: A display panel including a plurality of sub-pixels; A lens layer, arranged on the light-emitting side of the display panel, comprising: a plurality of self-focusing lenses, wherein the optical axes of the plurality of self-focusing lenses are parallel to the thickness direction of the display panel; The orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, the height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens, and the self-focusing lens is a cylindrical optical lens with a refractive index distribution that gradually changes along the radial direction, and its refractive index gradually decreases from the optical axis to the side.

2. The display module according to claim 1, characterized in that: The height of the self-focusing lens ranges from 0.3 mm to 1 mm.

3. The display module according to claim 1, characterized in that: The size of the bottom surface of the self-focusing lens ranges from 10 μm to 1 mm. The bottom surface of the self-focusing lens is the surface of the self-focusing lens close to the display panel.

4. The display module according to claim 1, characterized in that: The difference between the refractive index on the optical axis of the self-focusing lens and the minimum refractive index of the self-focusing lens is greater than or equal to 0.

06.

5. The display module according to claim 1 or 4, characterized in that: The refractive index of the self-focusing lens on the optical axis ranges from 1.60 to 1.69, and / or the minimum refractive index of the self-focusing lens ranges from 1.54 to 1.

59.

6. The display module according to claim 1, characterized in that: The refractive index distribution of the self-focusing lens satisfies the following formula: N(r)=N0(1-A*r 2 / 2); Wherein, N0 is the refractive index of the self-focusing lens on the optical axis, r is the distance from any position in the self-focusing lens to the optical axis, N(r) is the refractive index of the self-focusing lens at a position with a distance r from the optical axis, is the refractive index distribution constant, The value range is 0.25 to 0.

35.

7. The display module according to claim 1, characterized in that: The orthographic projection of a self-focusing lens on the display panel has an overlapping area with at least two sub-pixels; or, The orthographic projections of at least two self-focusing lenses on the display panel have an overlapping area with a sub-pixel; or, The plurality of self-focusing lenses and the plurality of sub-pixels are arranged in one-to-one correspondence.

8. The display module according to claim 1, characterized in that: Among the plurality of self-focusing lenses, there is a gap between adjacent self-focusing lenses; The lens layer further comprises a filling portion, the filling portion is filled in the gap, and the height of the filling portion is the same as the height of the self-focusing lens; Alternatively, the display module further includes: a dielectric layer, wherein the dielectric layer covers the plurality of self-focusing lenses and fills the gap.

9. The display module according to claim 8, characterized in that: The material of the filling part or the dielectric layer is glue.

10. The display module according to claim 1, characterized in that: Also includes: The bonding layer is configured to bond the lens layer to the light emitting side of the display panel.

11. The display module according to claim 1, characterized in that: Also includes: A touch layer, disposed between the display panel and the lens layer, or disposed on a side of the lens layer away from the display panel; and / or, The cover plate is arranged on a side of the lens layer away from the display panel.

12. A display device, characterized in that: Comprising the display module as described in any one of claims 1 to 11.

13. A method for preparing a display module, characterized in that: include: Providing a display panel, the display panel comprising a plurality of sub-pixels; A lens layer is arranged on the light-emitting side of the display panel, the lens layer comprises a plurality of self-focusing lenses, the optical axes of the plurality of self-focusing lenses are parallel to the thickness direction of the display panel; the orthographic projection of a self-focusing lens on the display panel has an overlapping area with a sub-pixel, the height of the self-focusing lens is less than or equal to 1 / 4 of the pitch of the self-focusing lens, and the self-focusing lens is a cylindrical optical lens with a refractive index distribution gradually varying along the radial direction, and the refractive index gradually decreases from the optical axis to the side.

14. The method for preparing a display module according to claim 13, characterized in that: The lens layer is arranged on the light-exiting side of the display panel, comprising: forming an initial lens layer on the light-exiting side of the display panel, the initial lens layer comprising a plurality of initial lenses, wherein the materials at a plurality of positions at different distances from an axis in an initial lens are the same, and the axis is parallel to the thickness direction of the display panel; and changing the materials at a plurality of positions at different distances from the axis in the initial lens to form a self-focusing lens; or, A lens layer is attached to the light-emitting side of the display panel.

Images