Backlight structure and manufacturing method therefor, backlight unit and display device

Abstract

A backlight structure, a backlight unit and a display device. The backlight structure comprises a first base layer (10), a first reflective layer (11), a second reflective layer (13), a light-emitting unit (15), and a color conversion structure (14), wherein a first surface (S1) of the first base layer (10) is provided with a plurality of first grooves (G1); the first reflective layer (11) is located at the bottoms of the first grooves (G1); and the second reflective layer (13) is located on the side of a transparent filling portion (12) facing away from the first base layer (10). The light-emitting unit (15) is located on the side of the second reflective layer (13) facing away from the first base layer (10), and the color conversion structure (14) is located between the light-emitting unit (15) and the first reflective layer (11). In the backlight structure, the color conversion structure is arranged between the light-emitting unit and the first reflective layer, thereby helping reduce the thickness of the backlight structure and improve a display effect.

Description

Backlight structure and its manufacturing method, backlight unit and display device Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a backlight structure and its manufacturing method, a backlight unit, and a display device. Background Technology

[0002] Passive light emission display devices mainly consist of a display panel and a backlight module. The display panel is located on the light-emitting side of the backlight module and is used to modulate the light emitted from the backlight module to achieve image display. Due to the trend of display devices becoming thinner, the thinning of the backlight module is a research hotspot in the industry.

[0003] Summary of the Invention

[0004] This disclosure provides a backlight structure and its manufacturing method, a backlight unit, and a display device, which can reduce the thickness of the display device and improve the display effect.

[0005] A first aspect of this disclosure provides a backlight structure, comprising:

[0006] First basal layer;

[0007] The first groove is located on the first surface of the first base layer;

[0008] The first reflective layer is located at the bottom of the first groove;

[0009] The second reflective layer is located on the side of the first groove away from the first base layer and at least covers a portion of the first surface; the second reflective layer has a first opening; the orthographic projection of the first opening on the first surface at least partially coincides with the orthographic projection of the first groove on the first surface.

[0010] The light-emitting unit is located on the side of the second reflective layer that faces away from the first substrate layer;

[0011] A color conversion structure is located between the light-emitting unit and the first reflective layer, and the orthographic projection of the color conversion structure on the first surface covers the orthographic projection of the first opening on the first surface.

[0012] Some of the backlight structures disclosed herein also include:

[0013] A second substrate layer is located between the first substrate layer and the second reflective layer; the second substrate layer includes a plurality of second grooves formed around the first groove; the depth of the second grooves is less than the thickness of the second substrate layer;

[0014] The blue light transmittance of the second basal layer is greater than or equal to 90%.

[0015] In some backlight structures provided in this disclosure, a second opening is provided in the second substrate layer;

[0016] The orthographic projection of the first opening on the first surface falls within the orthographic projection of the second opening on the first surface.

[0017] In some backlight structures disclosed herein, the surface of the second groove is an arc surface with a continuously varying tangent slope at various locations.

[0018] In some backlight structures provided in this disclosure, the surface of the second groove has at least one abrupt change in tangent slope, and / or the surface of the second groove is at least partially planar;

[0019] The second groove is also filled with scattering particles.

[0020] In some backlight structures provided in this disclosure, a plurality of third grooves are formed on the first surface of the first substrate layer; the plurality of third grooves are arranged around the first groove.

[0021] In some backlight structures disclosed herein, the surface of the third groove is an arc surface with a continuously varying tangent slope at various locations.

[0022] In some backlight structures provided in this disclosure, the inner surface of the third groove has at least one abrupt change in tangent slope, and / or the surface of the third groove is at least partially planar;

[0023] The third groove is also filled with scattering particles.

[0024] Among the backlight structures provided in this disclosure, the backlight structure also includes:

[0025] Multiple scattering protrusions are located between the first substrate layer and the second reflective layer; the multiple scattering protrusions are arranged around the first groove;

[0026] The scattering protrusions include a transparent substrate and scattering particles doped in the transparent substrate; the blue light transmittance of the transparent substrate is greater than or equal to 90%.

[0027] In some backlight structures provided in this disclosure, the orthographic projection of the first opening on the first surface falls within the orthographic projection of the first groove on the first surface.

[0028] Among the backlight structures provided in this disclosure, the backlight structure also includes:

[0029] An isolation dam is located between the second reflective layer and the light-emitting unit; the isolation dam surrounds the first opening to form an accommodating space, and the color conversion structure is set within the accommodating space.

[0030] In some backlight structures provided in this disclosure, the blue light transmittance of the transparent filling portion is greater than or equal to 90%; and / or, the blue light reflectance of the first reflective layer is greater than or equal to 90%; and / or, the blue light reflectance of the second reflective layer is greater than or equal to 90%.

[0031] In some backlight structures provided in this disclosure, the bottom of the first groove has a raised structure; a first reflective layer covers the surface of the raised structure.

[0032] A second aspect of this disclosure provides a backlight unit comprising a plurality of backlight structures according to any one of the above.

[0033] In some backlight units provided in this disclosure, the first base layer of multiple backlight structures is a continuous integral structure;

[0034] A fourth groove is formed on the second surface of the first substrate layer; the second surface is the surface opposite to the first surface of the first substrate layer.

[0035] The orthographic projection of the fourth groove on the first surface is located between the orthographic projections of the adjacent first groove on the first surface;

[0036] The depth of the fourth groove is 70% to 90% of the maximum thickness of the first base layer.

[0037] In some backlight units provided in this disclosure, the orthographic projection of the fourth groove on the first surface is a grid, and the orthographic projection of the first groove of the backlight structure on the first surface falls within the grid.

[0038] In some backlight units provided in this disclosure, the surface of the fourth groove is covered with a reflective medium;

[0039] The blue light reflectivity of the reflective medium is greater than or equal to 90%.

[0040] In some backlight units provided in this disclosure, the first substrate layers of multiple backlight structures are spliced ​​together;

[0041] The side of the first substrate layer is covered with a reflective medium; the side is the splicing surface of two adjacent first substrate layers.

[0042] The blue light reflectivity of the reflective medium is greater than or equal to 90%.

[0043] In some of the backlight units disclosed herein, adjacent backlight structures are directly bonded to each other through a reflective medium.

[0044] A third aspect of this disclosure provides a display device including a backlight unit of any of the above.

[0045] A fourth aspect of this disclosure provides a method for manufacturing a backlight structure, comprising:

[0046] Multiple first grooves are formed on the first surface of the first base layer;

[0047] A first reflective layer is covered at the bottom of the first groove;

[0048] A transparent filler portion is filled in the first groove and on the side of the first reflective layer opposite to the first substrate layer;

[0049] A second reflective layer is formed on the side of the transparent filling portion away from the first substrate layer, such that the second reflective layer at least partially covers the first surface of the first substrate layer; the second reflective layer has a first opening at the position corresponding to the first groove.

[0050] A color conversion structure is formed on the side of the transparent filling portion away from the first substrate layer; the orthogonal projection of the color conversion structure on the first surface covers the orthogonal projection of the first opening on the first surface layer.

[0051] Light-emitting units are fabricated on the side of the second reflective layer that is away from the first substrate layer.

[0052] The beneficial effects of this disclosure are as follows:

[0053] This disclosure provides a backlight structure, its manufacturing method, a display unit, and a display device. The backlight structure includes a first substrate layer, a first reflective layer, a second reflective layer, a light-emitting unit, and a color conversion structure. A first groove is formed on the first surface of the first substrate layer; the first reflective layer is located at the bottom of the first groove; the second reflective layer is located on the side of the transparent filling portion facing away from the first substrate layer and at least covers a portion of the first surface of the first substrate layer; the second reflective layer has a first opening, the orthographic projection of the first opening on the first surface at least partially coinciding with the orthographic projection of the first groove on the first surface; the light-emitting unit is located on the side of the second reflective layer facing away from the first substrate layer. The color conversion structure is located between the light-emitting unit and the first reflective layer, and the orthographic projection of the color conversion structure on the first surface overlaps the orthographic projection of the first opening on the first surface. The color conversion structure, positioned between the light-emitting unit and the first reflective layer, reduces the additional space occupied and lowers the thickness of the backlight structure, which is beneficial for meeting the requirements of thinner display devices. Furthermore, the path length difference of light incident on the color conversion structure at different angles is small, which can greatly reduce the color difference between light emitted from different areas of the backlight structure and improve the display effect. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments of this disclosure will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 is a schematic diagram of the cross-sectional structure of the backlight module in the related technology;

[0056] Figure 2A is a cross-sectional schematic diagram of a backlight structure provided in an embodiment of this disclosure;

[0057] Figure 2B is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0058] Figure 3A is a schematic diagram of the optical path of a backlight structure used for comparison;

[0059] Figure 3B is a schematic diagram of the optical path of a backlight structure provided in an embodiment of this disclosure;

[0060] Figure 4A is a cross-sectional micrograph of the first groove of the backlight structure provided in the embodiment of this disclosure;

[0061] Figure 4B is a diagram showing the relationship between the light coupling efficiency of the first groove and the surface shape of the first groove in the backlight structure provided in the embodiment of this disclosure.

[0062] Figure 4C is a diagram showing the relationship between the light coupling efficiency of the first groove and the reflectivity of the bottom surface of the second reflective layer in the backlight structure provided in the embodiment of this disclosure.

[0063] Figure 4D is a diagram showing the relationship between the light coupling efficiency of the first groove and the groove depth of the backlight structure provided in the embodiment of this disclosure.

[0064] Figure 5 shows the brightness uniformity test results of the backlight structure provided in the embodiment of this disclosure;

[0065] Figure 6 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0066] Figure 7 is a schematic diagram of another optical path for the backlight structure provided in an embodiment of this disclosure;

[0067] Figure 8A shows the emission spectrum of a color conversion structure provided in an embodiment of this disclosure;

[0068] Figure 8B shows the transmission spectrum of a second substrate layer provided in an embodiment of this disclosure;

[0069] Figure 8C shows the reflection spectrum of a first reflective layer provided in an embodiment of this disclosure;

[0070] Figure 8D shows the reflection spectrum of a second reflective layer provided in an embodiment of this disclosure;

[0071] Figure 9A shows the emission spectra at different positions obtained from simulation in one embodiment of this disclosure;

[0072] Figure 9B shows the chromaticity at different positions obtained from simulation and actual measurement in one embodiment of this disclosure;

[0073] Figure 9C shows the color shift at different positions obtained from simulation and actual measurement in one embodiment of this disclosure;

[0074] Figure 10A is a comparison diagram of the transmission spectra of several materials provided in the embodiments of this disclosure;

[0075] Figure 10B is a comparison diagram of the reflectance spectra of several materials provided in the embodiments of this disclosure;

[0076] Figure 10C shows the chromaticity at different locations as measured in another embodiment of this disclosure;

[0077] Figure 10D shows the color shift at different locations as measured in another embodiment of this disclosure;

[0078] Figure 11 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0079] Figure 12 is an enlarged cross-sectional schematic diagram of a second substrate layer provided in an embodiment of this disclosure;

[0080] Figure 13 is an enlarged cross-sectional schematic diagram of another second substrate layer provided in an embodiment of this disclosure;

[0081] Figure 14A is a top view of a second base layer provided in an embodiment of this disclosure;

[0082] Figure 14B is a top view of another second base layer provided in an embodiment of this disclosure;

[0083] Figure 14C is a top view of another second base layer provided in an embodiment of this disclosure;

[0084] Figure 15 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0085] Figure 16A is an enlarged cross-sectional view of another backlight structure provided in an embodiment of this disclosure;

[0086] Figure 16B shows the measured colorimetric performance at different locations according to another embodiment of this disclosure;

[0087] Figure 16C shows the color shift at different locations as measured in another embodiment of this disclosure;

[0088] Figure 17 is an enlarged cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0089] Figure 18A is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0090] Figure 18B shows the measured colorimetric performance at different locations according to another embodiment of this disclosure;

[0091] Figure 18C shows the color shift at different locations as measured in another embodiment of this disclosure;

[0092] Figure 19 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0093] Figure 20 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0094] Figure 21 is a schematic cross-sectional view of a backlight unit provided in an embodiment of this disclosure;

[0095] Figure 22 is a schematic cross-sectional view of another backlight unit provided in an embodiment of this disclosure;

[0096] Figure 23A is a schematic diagram of the optical path of a backlight unit provided in an embodiment of this disclosure for comparison;

[0097] Figure 23B is one of the brightness distribution diagrams of a backlight unit provided in an embodiment of this disclosure;

[0098] Figure 23C shows one of the brightness distribution curves of a backlight unit provided in an embodiment of this disclosure;

[0099] Figure 23D is a second brightness distribution diagram of a backlight unit provided in an embodiment of this disclosure;

[0100] Figure 23E is a second brightness distribution curve of a backlight unit provided in an embodiment of this disclosure;

[0101] Figure 24A is a third brightness distribution diagram of a backlight unit provided in an embodiment of this disclosure;

[0102] Figure 24B is a third brightness distribution curve of a backlight unit provided in an embodiment of this disclosure;

[0103] Figure 25A is a schematic cross-sectional view of another backlight unit provided in an embodiment of this disclosure;

[0104] Figure 25B is a fourth brightness distribution diagram of a backlight unit provided in an embodiment of this disclosure;

[0105] Figure 25C is a fourth brightness distribution curve of a backlight unit provided in an embodiment of this disclosure;

[0106] Figure 25D is the fifth brightness distribution diagram of a backlight unit provided in an embodiment of this disclosure;

[0107] Figure 25E is the fifth brightness distribution curve of a backlight unit provided in an embodiment of this disclosure;

[0108] Figure 26 is a top view of a first base layer provided in an embodiment of this disclosure;

[0109] Figure 27A is a schematic cross-sectional view of another backlight unit provided in an embodiment of this disclosure;

[0110] Figure 27B is a top view of another backlight unit provided in an embodiment of this disclosure;

[0111] Figure 28 is a schematic cross-sectional structure of a display device provided in an embodiment of the present disclosure;

[0112] Figure 29 is a cross-sectional structural schematic diagram of another display device provided in an embodiment of this disclosure;

[0113] Figure 30 is a flowchart of the manufacturing method of the backlight structure provided in the embodiment of this disclosure;

[0114] Figure 31A is one of the schematic diagrams illustrating the manufacturing process of a backlight structure according to an embodiment of this disclosure;

[0115] Figure 31B is a second schematic diagram of the manufacturing process of a backlight structure provided in an embodiment of this disclosure;

[0116] Figure 32 is a schematic diagram of the manufacturing process of another backlight structure provided in an embodiment of this disclosure;

[0117] Figure 33 is a schematic diagram of the manufacturing process of another backlight structure provided in an embodiment of this disclosure;

[0118] Figure 34 is a schematic diagram of the manufacturing process of another backlight structure provided in the embodiments of this disclosure. Detailed Implementation

[0119] To make the above-described objects, features, and advantages of this disclosure more apparent and understandable, the disclosure will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction as described in this disclosure are illustrative of the accompanying drawings, but changes may be made as needed, and all such changes are included within the scope of protection of this disclosure. The accompanying drawings of this disclosure are for illustrative purposes only and do not represent actual scale.

[0120] Transmissive display devices mainly consist of a transmissive display panel and a backlight module. The transmissive display panel is located on the light-emitting side of the backlight module and is used to modulate the light emitted from the backlight module to achieve image display. The backlight module typically includes a light source and films such as quantum dot films and diffusion films stacked on the light-emitting side of the light source, resulting in a generally thick backlight module.

[0121] Figure 1 is a schematic diagram of the cross-sectional structure of the backlight module in the related technology.

[0122] For example, Figure 1 shows a typical cross-sectional structure of a backlight module in the related technology. As shown in Figure 1, the backlight module in the related technology usually includes a lamp plate 1, a quantum dot film 2 and a diffusion film 3 located on the light-emitting side of the lamp plate 1. Since the lamp plate 1, the quantum dot film 2 and the diffusion film 3 are independent film structures, they need to be assembled in a certain way, such as by bonding with an adhesive layer. Therefore, it is difficult to further reduce the thickness of the backlight module based on this structure, which makes it difficult to meet the development trend of thinner display devices.

[0123] In view of this, the first aspect of this disclosure provides a backlight structure that helps to overcome the above-mentioned problems.

[0124] Figure 2A is a cross-sectional schematic diagram of a backlight structure provided in an embodiment of the present disclosure; Figure 2B is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of the present disclosure.

[0125] In this embodiment of the present disclosure, as shown in Figures 2A and 2B, the backlight structure includes a first substrate layer 10, a first reflective layer 11, a transparent filling portion 12, a second reflective layer 13, a color conversion structure 14, and a light-emitting unit 15.

[0126] The first substrate layer 10 is used to support other structures disposed thereon. The shape and size of the first substrate layer 10 are adapted to the shape and size of the display device to which it is applied. Generally, the shape of the first substrate layer 10 can be square, rectangular, etc. When applied to irregularly shaped display devices, the shape of the first substrate layer 10 can also be circular or other irregular shapes, and there is no limitation here. The first substrate layer 10 can be made of transparent substrate materials commonly used in the display technology field, such as optical glass and optical plastics, and there is no limitation here.

[0127] A first groove G1 is formed on the first surface S1 of the first base layer 10. A first reflective layer 11 is located at the bottom of the first groove G1. The first reflective layer 11 is used to reflect light to the surrounding area of ​​the first groove G1 to achieve a uniform light effect.

[0128] In some embodiments, as shown in Figures 2A and 2B, the bottom of the first groove G1 has a raised structure 101. Specifically, the bottom of the first groove G1 protrudes upward to form the raised structure 101, and the first reflective layer 11 covers the surface of the raised structure 101 to improve the light uniformity effect. In specific implementations, the raised structure 101 can be formed in various ways. For example, in some embodiments, when etching the first base layer 10 to form the first groove G1, a portion of the first base layer 10 located in the central region of the first groove G1 can be retained to form the raised structure 101. The bottom of the first groove G1 can also be a flat structure, a recessed structure, an uneven structure, or other structures, which are not limited here.

[0129] The transparent filling portion 12 is located on the side of the first reflective layer 11 opposite to the first substrate layer 10 and fills the first groove G1. In specific implementations, the transparent filling portion 12 may completely fill the first groove G1, or the transparent filling portion 12 may include a portion that fills the first groove G1 and another portion that extends into the first opening of the second reflective layer 13, which is not limited here.

[0130] The second reflective layer 13 is located on the side of the transparent filling portion 12 facing away from the first base layer 10, and at least covers a portion of the first surface S1 of the first base layer 10. The second reflective layer 13 has a first opening H1. Specifically, the position of the first opening H1 corresponds to the position of the first groove G1, and it is used to transmit light emitted from the light-emitting unit 15. The orthographic projection of the first opening H1 on the first surface at least partially overlaps with the orthographic projection of the first groove G1 on the first surface S1. For example, the orthographic projection of the first opening H1 on the first surface S1 falls within the orthographic projection of the first groove G1 on the first surface S1, or the orthographic projection of the first groove G1 on the first surface S1 falls within the orthographic projection of the first opening H1 on the first surface S1, or the orthographic projection of the first opening H1 on the first surface S1 partially overlaps with the orthographic projection of the first groove G1 on the first surface S1, with the remaining portions not overlapping; this is not limited here. The second reflective layer 13 can be used to reflect light, improving light utilization and uniformity.

[0131] In some embodiments, as shown in Figures 2A and 2B, an opening H1 can be provided corresponding to a first groove G1. The orthographic projection of the first opening H1 on the first surface S1 falls within the orthographic projection of the corresponding first groove G1 on the first surface S1. The second reflective layer 13, located between the edge of the first opening H1 and the edge of the first groove G1, protrudes inward from the edge of the first groove G1. The portion of the second reflective layer 13 protruding inward from the edge of the first groove G1 does not contact the inner wall of the first groove G1, thereby forming an eaves structure 131 relative to the first groove G1. This eaves structure 131 can be used to reflect light and improve the utilization rate of light. No further limitations are imposed here.

[0132] In some embodiments, the orthographic projection of the top of the protruding structure 101 onto the first surface S1 falls within the orthographic projection of the first opening H1 onto the first surface S1. This allows full utilization of the first reflective layer 11 covering the surface of the protruding structure 101, reflecting light incident from the first opening H1 to the surrounding area of ​​the protruding structure 101 and improving the uniformity of the reflected light. Specifically, the top of the protruding structure 101 refers to the portion of the protruding structure 101 away from the second surface S2 of the first substrate 10, where the second surface S2 is the surface of the first substrate layer 10 opposite to the first surface S1. In specific implementations, along the direction from the second surface S2 to the first surface S1, the area of ​​the cross-section of the protruding structure 101 parallel to the direction of the first surface S1 gradually decreases. For example, the protruding structure 101 can be formed into a cone-like structure, causing the first reflective layer 11 attached to the sidewall of the protruding structure 101 to form an inclined slope or inclined curved surface relative to the first surface S1. This facilitates the first reflective layer 11 reflecting light to the surrounding area of ​​the protruding structure 101, thereby improving light utilization. No further limitations are specified here.

[0133] The light-emitting unit 15 is located on the side of the second reflective layer 13 facing away from the first substrate layer 10. The light-emitting unit 15 is used to provide a backlight source. In a specific implementation, the orthographic projection of the light-emitting unit 15 on the first surface S1 covers the orthographic projection of the first opening H1 on the first surface S1, which helps to improve the incident efficiency of the light emitted from the light-emitting unit 15 entering the first substrate layer 10 through the first opening H1, thereby improving the utilization rate of the light.

[0134] In specific implementations, the light-emitting unit 15 can be a light-emitting diode (LED), a mini light-emitting diode (Mini LED), or a micro light-emitting diode (Micro LED). The main difference between LEDs, Mini LEDs, and Micro LEDs lies in their size. LEDs typically have a planar dimension greater than 200 μm, Mini LEDs typically have a planar dimension between 50 μm and 200 μm, and Micro LEDs typically have a planar dimension less than 50 μm. The light-emitting unit 15 can also be an organic light-emitting diode (OLED) or other light-emitting devices; this is not a limitation.

[0135] The color conversion structure 14 is located between the light-emitting unit 15 and the transparent filling portion 12. The color conversion structure 14 is used to convert the color of the light emitted from the light-emitting unit 15, changing the color of the light emitted from the light-emitting unit 15 to the desired color. The color conversion structure 14 can be made of fluorescent material or quantum dot material, and is not limited thereto. For example, the light-emitting unit 15 can be a blue LED, and the color conversion structure 14 can be made of quantum dot material, converting the blue light emitted by the light-emitting unit 15 into white light for backlighting. The light-emitting unit 15 can also be a white LED, which can directly emit white light, and the color conversion structure 14 can be made of transparent material, allowing white light to pass through directly. Alternatively, the color conversion structure 14 can be air, and is not limited thereto. The orthographic projection of the color conversion structure 14 on the first surface S1 covers the orthographic projection of the first opening H1 on the first surface S1, thereby allowing the color conversion structure 14 to fully convert the color of the light incident from the first opening H1 into the first substrate layer 10, ensuring color accuracy.

[0136] In some embodiments, as shown in FIG2A, the transparent filling portion 12 is completely filled in the first groove G1, and the surface of the transparent filling portion 12 is flush with the first surface S1. The color conversion structure 14 can be completely or at least partially filled in the first opening H1.

[0137] In some embodiments, as shown in FIG2B, the transparent filling portion 12 completely fills the first groove G1 and the first opening H1, and the surface of the transparent filling portion 12 is flush with the surface of the second reflective layer 13 on the side opposite to the first substrate layer 10. The color conversion structure 14 may be entirely disposed on the surface of the transparent filling portion 12; or the color conversion structure 14 may be partially disposed on the surface of the transparent filling portion 12 and partially overlap the surface of the second reflective layer 13; or the color conversion structure 14 may be completely filled in the first groove G1; no limitation is made here.

[0138] In specific implementation, the setting method of the color conversion structure 14 can be adjusted according to the different filling conditions of the transparent filling part 12 in the first groove G1 and the first opening H1, and is not limited here.

[0139] In some embodiments of this disclosure, as shown in Figures 2A and 2B, the light L emitted from the light-emitting unit 15 undergoes color conversion via the color conversion structure 14 before entering the transparent filling portion 12. It then passes through the transparent filling portion 12 and enters the first reflective layer 11, where it is reflected in all directions. Part of the light is reflected by the first reflective layer 11 to the second reflective layer 13, and after reflection by the second reflective layer 13, it exits directly through the second surface S2 of the first substrate layer 10 to the outside of the first substrate layer 10. The remaining light undergoes multiple reflections between the second reflective layer 13 and the second surface S2 before exiting through the second surface S2 to the outside of the first substrate layer 10. In the backlight structure provided in this disclosure, the color conversion structure 14 is disposed between the light-emitting unit 15 and the first substrate layer 10. Compared to the related technology shown in Figure 1, where the quantum dot film 2 is disposed above the lamp panel, this reduces the additional thickness required for the quantum dot film 2. Furthermore, the light emitted from the light-emitting unit 15 has a certain diffusion and uniform light effect after being reflected multiple times by the first reflective layer 11 and the second reflective layer 13. This can reduce the use of the diffusion film, thereby further reducing the thickness of the backlight structure and helping to meet the requirements of thinner display devices.

[0140] Figure 3A is a schematic diagram of the optical path of a backlight structure for comparison; Figure 3B is a schematic diagram of the optical path of a backlight structure provided in an embodiment of this disclosure.

[0141] Furthermore, the backlight structure provided in this disclosure can also improve the color uniformity of backlight rays emitted from different areas of the backlight structure.

[0142] For example, in another backlight structure designed by the researchers in this disclosure, as shown in Figure 3A, the color conversion structure 14 is completely set inside the first groove G1. Since the light incident on the color conversion structure 14 from different angles has a large difference in the path of propagation in the color conversion structure 14, the color of the light emitted from different areas has a large difference. Specifically, as shown in Figure 3A, the first ray L1 is incident on the color conversion structure 14 at a relatively large angle, and passes directly through the color conversion structure 14 from the edge of the first reflective layer 11. The path of the first ray L1 in the color conversion structure 14 is relatively short, and the color conversion component of the first ray L1 is relatively small, while the original color component is relatively large. For example, the original color of the first ray L1 is blue, and after passing through the color conversion structure 14, part of it is converted into red and green light, while the unconverted part remains blue light, that is, the blue light component is relatively large. The third ray L3 is incident on the color conversion structure 14 at a relatively large angle, and after being reflected by the first reflective layer 11, the third ray L3 is reflected by the second reflective layer 13. The path of the third ray L3 in the color conversion structure 14 is relatively long, and the color conversion component of the third ray L3 is relatively large, while the original color is relatively large. The first ray L1 has a smaller component, meaning it has a smaller component of blue light. The second ray L2 is incident into the color conversion structure 14 at an angle between the first ray L1 and the third ray L3. After being reflected by the first reflective layer 11, the second ray L2 is reflected by the second reflective layer 13. The second ray L2 has the longest propagation path in the color conversion structure 14, and the second ray L2 has the most components that undergo color conversion and the least components that retain the original color, meaning it has the least component of blue light. Therefore, it can be seen that the first ray L1, the second ray L2, and the third ray L3, which are incident into the color conversion structure 14 from different angles, have significantly different proportions of red, green, and blue color components after color conversion by the color conversion structure 14. This results in different colors of the first ray L1, the second ray L2, and the third ray L3 emitted from different areas of the backlight structure, leading to significant chromaticity differences and affecting the backlight effect.

[0143] In contrast, in some embodiments of this disclosure, as shown in FIG3B, a transparent filling portion 12 is filled in the first groove G1, and a color conversion structure 14 is disposed on the side of the transparent filling portion 12 facing away from the first substrate layer 10. Thus, the path length differences of the first light ray L1, the second light ray L2, and the third light ray L3 incident on the color conversion structure 14 from different angles are small. After color conversion by the color conversion structure 14, the proportions of red, green, and blue color components of the first light ray L1, the second light ray L2, and the third light ray L3 are similar, which can greatly reduce the color differences of the first light ray L1, the second light ray L2, and the third light ray L3 emitted from different areas of the backlight structure, thereby improving the display effect. In specific implementations, the backlight structure provided in the embodiments of this disclosure can also further reduce the color differences of the first light ray L1, the second light ray L2, and the third light ray L3 by adjusting the thickness of the color conversion structure 14 according to actual conditions; this is not limited here.

[0144] Generally, a backlight structure can exhibit good color performance when the ratio of red to green to blue components in the backlight is 0.25–0.35: 0.60–0.70: 0.03–0.07. For example, the ratio of red to green to blue components can be 0.3:0.65:0.05, and no specific limitation is made here.

[0145] In some embodiments of this disclosure, the coupled light efficiency can be improved by optimizing the morphology of the first groove G1, such as adjusting the depth, aspect ratio, and height of the protrusion structure of the first groove. Specifically, the coupled light efficiency refers to the ratio of light incident from the transparent filling portion 12 in the first groove G1 to the light incident from the first opening H1 to the transparent filling portion 12 in the first groove G1, which reflects the light utilization rate.

[0146] Figure 4A is a cross-sectional micrograph of the first groove of the backlight structure provided in the embodiment of the present disclosure; Figure 4B is a diagram showing the relationship between the light coupling effect of the first groove and the surface shape of the first groove of the backlight structure provided in the embodiment of the present disclosure; Figure 4C is a diagram showing the relationship between the light coupling effect of the first groove of the backlight structure provided in the embodiment of the present disclosure and the bottom surface reflectivity of the second reflective layer; Figure 4D is a diagram showing the relationship between the light coupling effect of the first groove of the backlight structure provided in the embodiment of the present disclosure and the groove depth of the first groove.

[0147] For example, Figures 4A and 4B illustrate the relationship between the coupling light effect of the first groove G1 in the backlight structure and the surface shape of the first groove G1. Since the first groove G1 is typically fabricated using wet or dry etching of the first substrate layer 10, as shown in Figure 4A, the surface shape of the first groove G1 mainly depends on the opening width w (which can be considered as the width of the orthographic projection of the first groove G1 onto the first surface of the first substrate 10; it can be either the maximum or minimum width, and the same standard measurement can be used for different first grooves G1, without limitation here) and the depth h of the first groove G1. Two backlight structures were designed with molybdenum (Mo) and silver (Ag) as the materials for the second reflective layer 13, respectively. Under the conditions of using the same size light-emitting unit 15 as the light source and the same opening width w, the coupling light efficiency of the first groove G1 was tested under different aspect ratios (the ratio of depth h to width w), as shown in Figure 4B. As the aspect ratio h / w of the first groove G1 increases, the coupling light efficiency of the first groove G1 gradually improves. When the aspect ratio h / w of the first groove G1 is less than 0.25, the increase rate of coupling light efficiency is faster. When the aspect ratio h / w of the first groove G1 is greater than or equal to 0.25, the coupling light efficiency can reach more than 90%, and the light utilization rate is high. The main reason for the influence of the aspect ratio h / w of the first groove G1 on the coupling efficiency is that when the aspect ratio h / w of the first groove G1 is small, for example, when the aspect ratio h / w of the first groove G1 is <0.25, the first groove G1 has a flat structure, and more light will be reflected through the first reflective layer 11 to the bottom surface of the eaves structure 131 formed inside the first groove G1 by the second reflective layer 13. Since the reflectivity of the second reflective layer 13 is low (for example, the reflectivity of Mo is usually only 57%), a large amount of light energy is lost. When the aspect ratio increases, the first groove G1 gradually takes on a vertically elongated structure, and less light is reflected to the bottom surface of the eaves structure 131. Instead, it directly enters the first substrate layer 10 with higher transmittance, thereby reducing light energy loss and improving coupling efficiency. As can be seen from Figure 4B, after replacing the material of the second reflective layer 13 with the low reflectivity Mo and the high reflectivity Ag, the coupling efficiency of the first groove G1 with an aspect ratio h / w <0.25 is also significantly improved. Figure 4C illustrates the relationship between the coupled light effect of the first groove G1 and the reflectivity of the second reflective layer 13. As can be seen from the figure, with the increase of the reflectivity of the second reflective layer 13, the reflectivity of the underside of the eaves formed by the second reflective layer 13 inside the first groove G1 is enhanced, and the coupled light effect of the first groove G1 gradually improves. Figure 4D illustrates the relationship between the depth of the first groove GI and the coupled light effect of the first groove G1. Under the condition that the first groove GI has a fixed aspect ratio (e.g., both aspect ratios are 0.5) and uses light-emitting units 15 of the same size as the light source, it can be seen from the figure that with the increase of the depth h of the first groove GI, the coupled light effect of the first groove G1 also gradually improves.

[0148] Figure 5 shows the brightness uniformity test results of the backlight structure provided in the embodiments of this disclosure.

[0149] Taking the center of the orthographic projection of the first groove G1 on the second surface S2 (or the center of the orthographic projection of the protrusion structure 101 on the second surface S2) as the origin, the brightness uniformity of the backlight structure is tested, as shown in Figure 5. It can be seen from the figure that the backlight structure provided in this embodiment can achieve a backlight brightness uniformity of more than 90% by adjusting the shape of the first groove G1, thus meeting the backlight brightness uniformity requirements of the display device.

[0150] Figure 6 is a third schematic diagram of the cross-sectional structure of the backlight structure provided in the embodiments of this disclosure.

[0151] In some embodiments, as shown in FIG6, the backlight structure further includes a light diffusion structure P. The light diffusion structure P is located between the first substrate layer 10 and the second reflective layer 13. The light diffusion structure P (the part within the dashed box in FIG6) is disposed around the first groove G1. The light diffusion structure P can receive light reflected by the first reflective layer 11 and incident on the light diffusion structure P after passing through the first substrate layer 10, and scatter the light to further improve the uniformity of the backlight brightness of the backlight structure.

[0152] In some embodiments, as shown in FIG6, the minimum distance R between the edge of the orthographic projection of the light diffusion structure P on the first substrate 10 and the edge of the orthographic projection of the first opening H1 on the first substrate 10 is greater than or equal to 7 μm, so as to reserve sufficient process margin and ensure the alignment accuracy during the fabrication of the light diffusion structure P.

[0153] In some embodiments, by specifically selecting the materials for the transparent filling portion 12, the first reflective layer 11, the second reflective layer 13, and the light diffusion structure P, and / or by employing a special manufacturing process for the light diffusion structure P, the color shift problem of the backlight light of the backlight structure provided in the embodiments of this disclosure can be reduced.

[0154] Figure 7 is another optical path diagram of the backlight structure provided in the embodiments of this disclosure.

[0155] For example, in some embodiments, as shown in FIG7, the backlight structure further includes a second substrate layer 16. The second substrate layer 16 is located between the first substrate layer 10 and the second reflective layer 13. The second substrate layer 16 includes a plurality of second grooves G2 formed around the first groove G1. And the depth of the second grooves G2 is less than the thickness of the second substrate layer 16. Specifically, when the second grooves G2 are formed on the second substrate layer 16 by etching or other processes, the second substrate layer 16 is not completely etched through along the thickness direction of the second substrate layer 16 (i.e., the direction perpendicular to the first surface S1), but the second substrate layer 16 at the bottom of the second groove G2 is retained. After the second reflective layer 13 is formed on the side of the second substrate layer 16 away from the first substrate layer 10, the second reflective layer 13 partially fills the second groove G2. The interface between the second reflective layer 13 and the second substrate layer 16 in the second groove G2 forms a scattering interface, so that the light diffuses at the interface through refraction, reflection and other forms. The second base layer 16 (i.e., the second base layer 16 within the dashed box in the figure) within the setting area of ​​the second groove G2 forms a light diffusion structure P.

[0156] In a specific implementation, as shown in Figure 7, the second base layer 16 can be a single layer, for example, the second base layer 16 can simultaneously cover the first surface S1 of the first base layer 10 and the surface covering the transparent filling portion 12. The light emitted from the light-emitting unit 15 undergoes color conversion by the color conversion unit 14, and after multiple transmissions through the second base layer 16 and multiple reflections through the first reflective layer 11 and the second reflective layer 13, it exits from the second surface S2 of the first base layer 10 at the first position A, second position B, third position C, and fourth position D, respectively, to the outside of the first base layer 10. Taking the center of the orthographic projection of the first groove G1 onto the second surface S2 (or the center of the orthographic projection of the protrusion structure 101 onto the second surface S2) as the origin O, the distances from the origin O at the first position A, second position B, third position C, and fourth position D gradually increase. Furthermore, before the light exits from the first position A, second position B, third position C, and fourth position D, the number of times it is transmitted through the second base layer 16 and the number of times it is reflected by the second reflective layer 13 gradually increase.

[0157] For some commonly used materials in the first reflective layer 11, the second reflective layer 13, and the first substrate layer 10, the first reflective layer 11 and the second reflective layer 13 have poor reflectivity for blue wavelength light, and the first substrate layer 10 has poor transmittance for blue wavelength light. Therefore, after the white light is converted by the color conversion unit 14, the blue component in the white light is greatly reduced after being reflected by the first reflective layer 11 and the second reflective layer 13 and transmitted through the second substrate layer 16. This results in a significant color shift in the backlight emitted from the backlight structure, especially for light emitted from positions farther from the origin O. The color shift becomes more severe due to the increased number of reflections by the second reflective layer 13 and the increased number of transmissions through the second substrate layer 16. Specifically, the color shift of the backlight emitted from the first position A to the fourth position D shows a significant increasing trend. From the first position A to the fourth position D, the color of the emitted light gradually becomes more yellow, and the color deviation value Δu′v′ is greater than 0.1, which seriously affects the backlight performance.

[0158] Figure 8A shows the emission spectrum of a color conversion structure provided in an embodiment of this disclosure; Figure 8B shows the transmission spectrum of a second substrate layer provided in an embodiment of this disclosure; Figure 8C shows the reflection spectrum of a first reflective layer provided in an embodiment of this disclosure; Figure 8D shows the reflection spectrum of a second reflective layer provided in an embodiment of this disclosure.

[0159] For example, in some embodiments, the emission spectrum of the color conversion structure 14 is shown in Figure 8A, where the horizontal axis represents the wavelength of the light emitted from the color conversion structure 14, and the vertical axis represents the intensity of the emitted light. This shows the intensity distribution of different wavelengths of light emitted from the light-emitting unit 15 after color conversion by the color conversion structure 14. The material of the second substrate layer 16 is a resin material, such as JEM-608, whose main components include 2-diazo-1,2-naphthoquinone-5-sulfonyl chloride and phenolic resin. Its transmission spectrum is shown in Figure 8B, where the horizontal axis represents the wavelength of light, and the vertical axis represents the transmittance of light. This shows the transmittance of light of different wavelengths passing through the second substrate layer 16. The first reflective layer 11 is a stacked structure of a silver material layer and an indium zinc oxide material layer (Ag / IZO). The reflection spectrum of the first reflective layer 11 is shown in Figure 8C, where the horizontal axis represents the wavelength of light, and the vertical axis represents the reflectance of light. This shows the reflectance of light of different wavelengths reflected by the first reflective layer 11. The material of the second reflective layer 13 is a triple-layer structure of indium tin oxide (ITO) / silver / indium tin oxide (ITO) material layer / silver material layer / indium tin oxide (ITO) material layer. The reflection spectrum of the second reflective layer 13 is shown in Figure 8D, where the horizontal axis is the wavelength of light and the vertical axis is the reflectivity of light. It shows the reflectivity of light of different wavelengths when reflected by the second reflective layer 13. As can be seen from Figures 8B to 8D, the reflectivity or transmittance of the first reflective layer 11, the second reflective layer 13, and the second base layer 16 for blue light (380nm-500nm) is much lower than that for red and green light, and both are less than 90%. Therefore, it can be understood that after the light emitted from the color conversion structure 14 is reflected or transmitted through the first reflective layer 11, the second reflective layer 13, and the second base layer 16, the blue light component is drastically reduced compared to the red and green light, resulting in a yellowish tint and a large color difference. Furthermore, the color difference becomes more severe for light emitted from the second surface S2 from a position further away from the origin O due to the increased number of reflections or refractions through the first reflective layer 11, the second reflective layer 13, and the second base layer 16.

[0160] Figure 9A shows the emission spectrum at different positions obtained from simulation in one embodiment of this disclosure; Figure 9B shows the chromaticity at different positions obtained from simulation and actual measurement in one embodiment of this disclosure; Figure 9C shows the color shift at different positions obtained from simulation and actual measurement in one embodiment of this disclosure.

[0161] The emitted spectrum of the backlight structure provided in embodiment 8A is simulated. The spectral data of the light emitted from different positions of the second surface S2 of the first substrate layer 10 can be approximated by the following formula: So=Ss*Rj*Tr 2i+1 *dm d1 *dm d2*…dm di *Ra i ;

[0162] Wherein, So represents the spectrum of light emitted from a certain position on the second surface S2 of the first base layer 10;

[0163] Ss represents the spectrum of light emitted from the color conversion structure to the transparent filling part 12;

[0164] Tr represents the transmission spectrum of the second substrate layer 16;

[0165] Rj represents the reflection spectrum of the first reflective layer 11;

[0166] Ra represents the reflection spectrum of the second reflective layer 13;

[0167] i represents the number of times the light is reflected by the second reflective layer 13 before exiting from the second surface S2; i can be calculated by the formula i = p / 2 / (h*tan(arcsin(1 / n)))+1, where p represents the distance between the exit position of the light and the origin O, h represents the thickness of the first base layer 10, and n represents the refractive index of the first base layer 10.

[0168] 2i+1 represents the number of times the light passes through the second base layer 16 before exiting the second surface S2; the light passes through the second base layer 16 once after exiting the color conversion structure 14, and passes through the second base layer 16 once before entering the second reflection layer 13 and once after being reflected by the second reflection layer 13 each time. Therefore, the number of times the light passes through the second base layer 16 before exiting the second surface S2 is 2i+1 times.

[0169] dm represents the maximum density of the second groove G2 provided in the second base layer 16. The density of the second groove G2 provided in the second base layer 16 increases with the distance from the origin O. The density of the second groove G2 can be represented by the proportion of the area occupied by the second groove G2 per unit area. Since there is a gap between two adjacent second grooves G2, the density of the second groove G2 is a value less than 1.

[0170] di represents the density of the second groove G2 at the reflection position when the light is reflected for the i-th time by the second reflective layer 13; dm di The correction coefficient represents the influence of the second groove G2 of the light diffusion structure P on the emitted spectrum So. Specifically, since light rays may only penetrate a portion of the thickness of the second substrate layer 16 before being reflected back, the lower the density of the second groove G2, the greater the probability of light rays completely penetrating the second substrate layer 16; conversely, the higher the density of the second groove G2, the lower the probability of light rays completely penetrating the second substrate layer 16. Therefore, through dmdi Corrections are made. For example, when the density of the second groove G2 is 0, that is, when the second substrate layer 16 does not have the second groove G2 at this position, the second groove G2 has no effect on light transmission, and the correction coefficient is 1, thus having no effect on the emitted spectrum So. When the density of the second groove G2 is large, that is, when the density of the second groove G2 at this position of the second substrate layer 16 is large, the second groove G2 has a greater effect on light transmission, and the correction coefficient is less than 1, thus affecting the emitted spectrum So.

[0171] For example, as shown in Figure 7, the light emitted from the first position A undergoes one reflection by the second reflective layer 13 before emission, i.e., the value of i is 1. It then passes through the second base layer 16 2i+1=3 times: once after passing through the color conversion structure 14, and once before and after reflection by the second reflective layer 13. Therefore, the formula for calculating the spectral data of the light emitted from the first position A is So. A =Ss*Rj*Tr 3 *dm d1 *Ra; The light emitted from position D at the fourth position undergoes four reflections by the second reflective layer 13 before emission, i.e., the value of i is 4. It then passes through the second base layer 16 nine times: first after passing through the color conversion structure 14, once before and once after the first reflection by the second reflective layer 13, once before and once after the second reflection by the second reflective layer 13, once before and once after the third reflection by the second reflective layer 13, once before and once after the third reflection by the second reflective layer 13, and once before and once after the fourth reflection by the second reflective layer 13. Therefore, the formula for calculating the spectral data of the light emitted from position D at the fourth position is So. A =Ss*Rj*Tr 9 *dm d1 *dm d2 *dm d3 *dm d4 *Ra 4 The spectral data of the light emitted from the second position B and the spectral data of the light emitted from the third position C are analogous and will not be elaborated here.

[0172] Substituting the spectral data shown in Figures 8B to 8D into the calculation formula for the emitted spectrum So, the emitted spectra at different emission positions A, B, C, and D were simulated and are shown in Figure 9A. It can be seen from the figure that, compared to the spectrum of light emitted from the color conversion structure to the transparent filling part 12, from position A to position D, as the distance between the emission position and the origin O increases, the intensity of the blue light band decreases sharply, while the intensity of the green and red light bands changes less compared to the blue light band. The simulated spectral data in Figure 9A were converted into color coordinates and color shift data, and the color coordinates and color shift data of the emitted light at different positions were actually measured, resulting in the color coordinate variation curve shown in Figure 9B and the color shift variation curve shown in Figure 9C. As shown in Figures 9B and 9C, both simulation and test results indicate that the color coordinates (x, y) increase with the distance between the emission position and the origin O, and the color shift Δu′v′ also increases with the distance between the emission position and the origin. Furthermore, the actual test results show a high degree of agreement with the simulation results. Therefore, it can be determined that the low reflectivity or low transmittance of the first reflective layer 11, the second reflective layer 13, and the second substrate layer 16 for blue light is a significant cause of the increased color shift in the backlight structure. Therefore, in practical implementation, the first reflective layer 11 and the second reflective layer 13 can be made of materials with high reflectivity for blue light, and the second substrate layer 16 can be made of materials with high transmittance for blue light to improve the color shift problem of the emitted light from the backlight structure.

[0173] Figure 10A is a comparison diagram of the transmission spectra of several materials provided in the embodiments of this disclosure; Figure 10B is a comparison diagram of the reflection spectra of several materials provided in the embodiments of this disclosure; Figure 10C is a colorimetric representation at different positions obtained by actual measurement in another embodiment of this disclosure; Figure 10D is a color shift representation at different positions obtained by actual measurement in another embodiment of this disclosure.

[0174] For example, the material of the second substrate layer 16 can be SOC-5004U photoresist, and the materials of the first reflective layer 11 and the second reflective layer 13 can both be Ag. Figure 10A shows the transmittance of SOC-5004U and two other commonly used resin materials for different wavelengths of light. As can be seen from the figure, the transmittance of SOC-5004U for blue light is greater than that of JEM-608 and LEM-608 Bleaching for blue light, and the transmittance of SOC-5004U for blue light is greater than 80%, and the transmittance for blue light above 430nm is greater than 90%. Figure 10B shows the reflectivity of Ag and two commonly used reflective materials for different wavelengths of light. As can be seen from the figure, Ag has a higher reflectivity for blue light than Ag+IZO and ITO / Ag / ITO for blue light. Furthermore, Ag has a reflectivity of more than 80% for blue light and more than 90% for blue light above 450nm.

[0175] The second substrate layer 16 is made of SOC-5004U, and both the first reflective layer 11 and the second reflective layer 13 are made of Ag in the backlight structure. The chromatic coordinates and color shift data of light emitted from different positions of the backlight structure were measured, resulting in the chromatic coordinate variation curves of light emitted from different positions as shown in Figure 10C, and the color shift variation curves of light emitted from different positions as shown in Figure 10D. Comparing Figures 10C and 9B, it can be seen that the deviation range of chromatic coordinate values ​​of light emitted from different positions in the embodiment corresponding to Figure 10C is significantly reduced compared to the embodiment corresponding to Figure 9B. Furthermore, comparing Figures 10D and 9C, it can be seen that the color shift of light emitted from different positions in the embodiment corresponding to Figure 10D is significantly reduced, and the difference between the maximum and minimum color shift is significantly reduced compared to the embodiment corresponding to Figure 9C. It can be seen that by using a high-transmittance material for the second substrate layer 16 and a high-reflectivity material for the first reflective layer 11 and the second reflective layer 13, the color shift of the backlight emitted from the backlight structure can be significantly reduced, and the color of the light emitted from different positions is more uniform.

[0176] In specific implementation, the material of the second substrate layer 16 can be a high-transmittance material, while the materials of the first reflective layer 11 and the second reflective layer 13 can be high-reflectance materials; or the material of the second substrate layer 16 can be a high-transmittance material, and the materials of the first reflective layer 11 and the second reflective layer 13 are not limited; or the first reflective layer 11 can be a high-reflectance material, and the materials of the second substrate layer 16 and the second reflective layer 13 are not limited; or the second reflective layer 13 can be a high-reflectance material, and the materials of the second substrate layer 16 and the first reflective layer 11 are not limited; no limitation is made here.

[0177] In some embodiments, the blue light transmittance of the second substrate layer 16 may be greater than or equal to 90%. It should be noted that the blue light transmittance of the second substrate layer 16 specifically refers to the transmittance of the second substrate layer 16 to the peak wavelength of the blue light emitted by the light-emitting unit; the transmittance to blue light other than the peak wavelength emitted by the light-emitting unit is not limited. It should also be noted that the blue light transmittance of the second substrate layer 16 in this disclosure is obtained by testing in air. The blue light transmittance of the second substrate layer 16 obtained by testing in different media may vary, and these variations are not specifically defined here.

[0178] Generally, the peak wavelength of the blue light emitted by the light-emitting unit 15 is between 450nm and 470nm. For example, if the peak wavelength of the blue light emitted by the light-emitting unit is 460nm, then the transmittance of the second substrate layer 16 for 460nm blue light is greater than or equal to 90%. In specific implementations, the peak wavelength of the blue light emitted by the light-emitting unit 15 can also be other values, such as between 380nm and 450nm, or between 470nm and 500nm, which is not limited here. In specific implementations, the blue light emitted by the light-emitting unit can have a smaller half-width at half-maximum (WHM) to improve color purity and increase the transmittance of the second substrate layer 16 for the blue light emitted by the light-emitting unit 15. For example, the WHM of the blue light emitted by the light-emitting unit 15 can be between 10nm and 30nm. For example, the WHM of the blue light emitted by the light-emitting unit 15 can be 20nm. The WHM of the blue light emitted by the light-emitting unit 15 can also be other values, which are not limited here.

[0179] In specific implementations, the blue light transmittance of the second substrate layer 16 can be greater than or equal to any value between 90% and 100%, such as 95%, 96%, 97%, 98%, 99%, etc. The higher the blue light transmittance of the second substrate layer 16, the smaller the color shift of the backlight emitted by the backlight structure. Specifically, the material of the second substrate layer 16 can include polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or optical glass, for example, it can be SOC-5004U or 0002U type photoresist, wherein the main component of 002U type photoresist is polyvinyl cinnamate. Other materials that meet the requirements can also be used for the second substrate layer 16, which are not limited here.

[0180] In some embodiments, the blue light reflectivity of the first reflective layer 11 is greater than or equal to 90%. It should be noted that the blue light reflectivity of the first reflective layer 11 specifically refers to the reflectivity of the first reflective layer 11 for the peak wavelength of the blue light emitted by the light-emitting unit 15, and does not limit the transmittance of blue light in wavelengths other than the peak wavelength emitted by the light-emitting unit 15. It should also be noted that the blue light reflectivity of the first reflective layer 11 in this disclosure is obtained through testing in air. The blue light transmittance of the first reflective layer 11 obtained in different media may vary, and is not specifically limited here.

[0181] In specific implementation, the blue light reflectivity of the first reflective layer 11 can be greater than or equal to any value between 90% and 100%, such as 95%, 96%, 97%, 98%, 99%, etc. The higher the blue light reflectivity of the first reflective layer 11, the smaller the color shift of the backlight emitted by the backlight structure. Specifically, the material of the first reflective layer 11 can be a high-reflectivity metal material such as silver or aluminum, and is not limited here.

[0182] In some embodiments, the blue light reflectivity of the second reflective layer 13 is greater than or equal to 90%. It should be noted that the blue light reflectivity of the second reflective layer 13 specifically refers to the reflectivity of the second reflective layer 13 for the peak wavelength of the blue light emitted by the light-emitting unit 15, and is not limited to the reflectivity of blue light in bands other than the peak wavelength emitted by the light-emitting unit 15.

[0183] In specific implementation, the blue light reflectivity of the second reflective layer 13 can be greater than or equal to any value between 90% and 100%, such as 95%, 96%, 97%, 98%, 99%, etc. The higher the blue light reflectivity of the second reflective layer 13, the smaller the color shift of the backlight emitted by the backlight structure. Specifically, the material of the second reflective layer 13 can be a high-reflectivity metal material such as silver or aluminum, and is not limited here.

[0184] In some implementations, the blue light transmittance of the transparent filling portion 12 is greater than or equal to 90%. It should be noted that the blue light transmittance of the transparent filling portion 12 specifically refers to the transmittance of the transparent filling portion 12 to the peak wavelength of the blue light emitted by the light-emitting unit 15, and is not limited to the transmittance of blue light in wavelength bands other than the peak wavelength emitted by the light-emitting unit 15.

[0185] The blue light transmittance of the transparent filling portion 12 can be greater than or equal to any value between 90% and 100%, such as 95%, 96%, 97%, 98%, 99%, etc. The higher the blue light transmittance of the transparent filling portion 12, the smaller the color deviation of the backlight emitted by the backlight structure. Specifically, the material of the transparent filling portion 12 can be polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or optical glass, etc., specifically SOC-5004U or 0002U, etc., without limitation.

[0186] Figure 11 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure;

[0187] In some embodiments, as shown in FIG11, the second substrate layer 16 has a second opening H2 corresponding to the first opening H1. The orthographic projection of the second opening H2 on the first surface S1 at least partially overlaps with the orthographic projection of the corresponding first opening H1 on the first surface S1. By opening the second opening H2 in the second substrate layer 16 at the position corresponding to the first opening H1, and the area where the second opening H2 is opened is not provided with the second substrate layer 16, the light emitted from the color conversion structure 14 can directly enter the transparent filling portion through the second opening H1, thereby reducing the number of times the light emitted from the color conversion structure 14 propagates through the second substrate layer 16 after passing through the first opening H1, thereby further reducing the influence of the second substrate layer 16 on the blue light component in the backlight and reducing color shift.

[0188] In some embodiments, as shown in FIG11, the orthographic projection of the first opening H1 on the first surface S1 falls within the orthographic projection of the corresponding second opening H2 on the first surface S1. Specifically, the second opening H2 can be configured to have a larger opening size, thereby reducing the influence of the second substrate layer 16 on the blue light component in the backlight to a greater extent and reducing color shift.

[0189] Figure 12 is an enlarged cross-sectional schematic diagram of a second substrate layer provided in an embodiment of this disclosure.

[0190] In some embodiments, as shown in FIG12, the surface of the second groove G2 formed on the second base layer 16 is an arc surface with a continuously changing tangent slope at various points. That is to say, the surface of the second groove G2 is a smooth arc surface, characterized in that the tangent slope of two adjacent points on the arc surface changes continuously and smoothly. For example, the cross-sectional shape of the surface of the second groove G2 can be a circular arc curve, an elliptical curve, or a similar curve, which is not limited here. Since the inner surface of the second groove G2 is relatively smooth, it has a good scattering effect on light. The light diffusion structure P can be formed by forming the second groove G2 in the second base layer 16, thereby reducing the manufacturing difficulty. In addition, the thickness of the second base layer 16 in the area where the second groove G2 is set is relatively thin, the light transmittance is high, and the light efficiency is high.

[0191] In some embodiments, as shown in Figures 11 and 12, the second groove G2 may be formed on the surface of the second base layer 16 facing the second reflective layer 13, and the second reflective layer 13 is directly formed on the surface of the second base layer 16, with a corresponding groove formed on the second reflective layer 13 at the position corresponding to the second groove G2. In some embodiments, the second groove G2 may also be formed on the surface of the second base layer 16 away from the second reflective layer 13, which is not limited here.

[0192] Figure 13 is an enlarged cross-sectional schematic diagram of another second substrate layer provided in an embodiment of this disclosure.

[0193] In some embodiments, as shown in FIG13, the surface of the second groove G2 formed on the second base layer 16 has at least one abrupt change in slope, and / or, the surface of the second groove G2 is at least partially planar. The presence of at least one abrupt change in tangent slope on the surface of the second groove G2 on the second base layer 16 means that there is a corner T at the abrupt change in tangent slope, and the tangent slope changes abruptly between two adjacent points on either side of the corner T. For example, the cross-sectional shape of the inner surface of the second groove G2 forms a sharp angle at the corner T, and the cross-sectional lines on both sides of the corner T can be curved or straight. Light is prone to repeated reflection at the corner and cannot exit from the corner to the outside, resulting in reduced light diffusion efficiency. Furthermore, when the surface of the second groove G2 includes a partial planar surface, incident light at the same angle, after being reflected at different positions on the planar surface, will have the same angle of reflection, which may lead to poor light diffusion effect of the second groove G2. Therefore, in specific implementation, scattering particles 17 can be further filled into the second groove G2 to improve the light diffusion effect. The second base layer 16 in the setting area of ​​the second groove G2 and the scattering particles filled in the second groove G2 together form the light diffusion structure P. The material of the scattering particles 17 can be common scattering particle materials such as titanium dioxide and barium oxide, and is not limited here. By filling the second groove G2 with scattering particles to improve the light uniformity effect of the light diffusion structure P, the problem of poor light diffusion effect caused by corners or flat surfaces on the surface of the second groove G2 due to process fluctuations in the manufacturing process of the second groove G2 can be overcome, and the tolerance to process fluctuations can be improved.

[0194] Figure 14A is a top view of a second substrate layer provided in an embodiment of the present disclosure; Figure 14B is a top view of another second substrate layer provided in an embodiment of the present disclosure; Figure 14C is a top view of another second substrate layer provided in an embodiment of the present disclosure.

[0195] In some embodiments, as shown in FIG14A, the orthographic projection of the second groove G2 on the first surface can be a point shape. The point-shaped second groove G2 is characterized by a small difference in size along various directions of its orthographic projection on the first surface. For example, the shape of the orthographic projection of the second groove G2 on the first surface can be a circle or a nearly circular ellipse, a square or a nearly square polygon, etc., without limitation. Specifically, the depth of the second groove G2 can be set to 1μm to 15μm, without limitation. The maximum size of the orthographic projection of the second groove G2 on the first surface can be set to 2μm to 30μm, without limitation. The maximum size of the orthographic projection of the second groove G2 on the first surface specifically refers to the size of the orthographic projection of the second groove G2 on the first surface in the direction of maximum aperture. For example, when the orthographic projection of the second groove G2 on the first surface is a circle, the maximum size refers to the diameter of the circle; when the orthographic projection of the second groove G2 on the first surface is an ellipse, the maximum size refers to the length of the major axis of the ellipse; if the orthographic projection of the second groove G2 on the first surface is a square or other polygon, the maximum size refers to the length of the longest diagonal of the polygon; the same principle applies when the orthographic projection of the second groove G2 on the first surface is other shapes, which will not be elaborated here. In specific implementation, the distance between the orthographic projection of any second groove G2 on the first surface and the orthographic projection of the adjacent second groove G2 on the first surface can be set to 1μm to 10μm, which is not limited here.

[0196] In some embodiments, as shown in FIG14B, the shape of the orthographic projection of the second groove G2 on the first surface can be strip-shaped. The strip-shaped second groove G2 is characterized in that its orthographic projection on the first surface has a maximum size along a certain direction and a minimum size perpendicular to that direction. For example, the shape of the orthographic projection of the second groove G2 on the first surface can be a rectangle or a polygon with a large difference between its length and width, or an ellipse or a shape with a large difference between its major axis length and minor axis length, which is not limited here.

[0197] In some embodiments, as shown in FIG14C, the orthographic projection of the second groove G2 on the first surface can be annular, and the orthographic projection of the first opening H1 on the first surface is located within the annular pattern formed by the orthographic projection of the second groove G2 on the first surface, without limitation.

[0198] In some embodiments, the shape of the orthographic projection of the second groove G2 on the first surface can also be other shapes, which are not limited here.

[0199] Figure 15 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure.

[0200] In some embodiments, as shown in FIG15, a plurality of third grooves G3 are formed on the first surface S1 of the first substrate layer 10. The plurality of third grooves G3 are arranged around the first groove G1 to form a light diffusion structure P. The difference between the embodiment shown in FIG15 and the embodiment shown in FIG7 is that the embodiment shown in FIG15 does not have a second substrate layer 16, but instead directly forms the light diffusion structure P by forming the third grooves G3 on the surface of the first substrate layer 10. Since it is not necessary to fabricate an additional substrate layer on the surface of the first substrate layer 10, the thickness of the backlight structure can be further reduced, and since the number of film layers between the first substrate layer 10 and the second reflective layer 13 is reduced, the loss of blue light in the propagation process can be further reduced, and the color shift of the backlight light can be reduced.

[0201] Figure 16A is a cross-sectional enlarged schematic diagram of another backlight structure provided in an embodiment of the present disclosure; Figure 16B is a colorimetric representation at different positions obtained by actual measurement in another embodiment of the present disclosure; Figure 16C is a color shift representation at different positions obtained by actual measurement in another embodiment of the present disclosure.

[0202] In some embodiments, as shown in FIG16A, the surface of the third groove G3 formed on the first substrate layer 10 is an arc surface with a continuously changing tangent slope at various points. That is to say, the surface of the third groove G3 is a smooth arc surface, characterized in that the slope of the tangent at two adjacent points on the arc surface changes continuously and smoothly. For example, the cross-sectional shape of the surface of the third groove G3 can be a circular arc, an elliptical curve, or a similar curve, which is not limited here. Since the inner surface of the third groove G3 is relatively smooth, it has a good scattering effect on light. The light diffusion structure P can be formed using only the third groove G3 to reduce the manufacturing difficulty. Since the light diffusion structure P is composed only of the third groove G3, the absorption rate of the light diffusion structure P for blue light can be regarded as 0, which can maximize the blue light transmittance.

[0203] Both the first reflective layer 11 and the second reflective layer 13 are made of Ag. A third groove G3 is formed on the first substrate layer 10 to create a light diffusion structure P. The color coordinates and color shift data of the light emitted from different positions of the backlight structure are measured, resulting in the color coordinate variation curves of the light emitted from different positions as shown in Figure 16B and the color shift variation curves of the light emitted from different positions as shown in Figure 16C. Comparing Figures 16B and 9B, it can be seen that the deviation range of the color coordinate values ​​of the light emitted from different positions in the embodiment corresponding to Figure 16B is significantly reduced compared to the embodiment corresponding to Figure 9B. Furthermore, comparing Figures 16C and 9C, it can be seen that the color shift of the light emitted from different positions in the embodiment corresponding to Figure 16C is significantly reduced, and the difference between the maximum and minimum color shift is significantly reduced compared to the embodiment corresponding to Figure 9C. It can be seen that by using high reflectivity materials for the first reflective layer 11 and the second reflective layer 13, and by forming a light diffusion structure P by opening a third groove G3 on the surface of the first base layer 10, the color shift of the backlight emitted by the backlight structure can be significantly reduced, and the color of the light emitted from different positions is more uniform.

[0204] Figure 17 is a cross-sectional enlarged schematic diagram of another backlight structure provided in an embodiment of this disclosure.

[0205] In some embodiments, the third groove G3 has at least one abrupt change in slope, and / or, the surface of the third groove G3 is at least partially planar. The presence of at least one abrupt change in tangent slope on the surface of the third groove G3 means that there is a corner T at the abrupt change in tangent slope, and the tangent slope changes abruptly between two adjacent points on either side of the corner T. For example, the cross-sectional shape of the surface of the third groove G3 forms a sharp angle at the corner T, and the cross-sectional lines on both sides of the corner T can be curved or straight. Light is prone to repeated reflection at the corner and cannot exit from the corner, resulting in reduced light diffusion efficiency. Furthermore, when the surface of the second groove G2 includes a partial plane, incident light at the same angle, after being reflected at different positions on the plane, will have the same angle of reflection, which may lead to poor light diffusion effect of the second groove G2. Therefore, in specific implementations, scattering particles 17 can be filled into the third groove G3 to improve the light diffusion effect. The third groove G3 and the scattering particles filled in the third groove G3 together form a light diffusion structure P. The material of the scattering particles 17 can be common scattering particle materials such as titanium dioxide and barium oxide, and is not limited here. By filling the third groove G3 with scattering particles to improve the uniformity of the light diffusion structure P, the problem of poor light diffusion caused by corners or flat surfaces on the surface of the third groove G3 due to process fluctuations in the fabrication process can be overcome, thereby improving the tolerance to process fluctuations.

[0206] In some embodiments, the shape of the orthographic projection of the third groove G3 on the first surface can be a dot, a strip, or a ring. Specifically, in implementation, the shape and parameters of the third groove G3 can be set with reference to the shape and parameters of the second groove G2 in the foregoing embodiments, which will not be elaborated here.

[0207] Figure 18A is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of the present disclosure; Figure 18B is a colorimetric representation at different positions obtained by actual measurement in another embodiment of the present disclosure; Figure 18C is a color shift representation at different positions obtained by actual measurement in another embodiment of the present disclosure.

[0208] In some embodiments, as shown in FIG18A, the backlight structure further includes a plurality of scattering protrusions 18. The scattering protrusions 18 are located between the first substrate layer 10 and the second reflective layer 13. The plurality of scattering protrusions 18 are arranged around the first groove G1 to form a light diffusion structure P. The embodiment shown in FIG18A differs from the embodiment shown in FIG7 in that the embodiment shown in FIG18A does not have a second substrate layer 16, but instead has a plurality of spaced-apart scattering protrusions 18 directly arranged on the surface of the first substrate layer 10. Adjacent scattering protrusions 18 are spaced apart to form gaps, and the gaps are filled with the second reflective layer 13, thereby reducing the absorption of blue light and improving the color shift problem caused by blue light absorption.

[0209] In specific implementation, the scattering protrusion 18 includes a transparent substrate and scattering particles doped in the transparent substrate. The transparent substrate can be made of a high-transmittance material, and the scattering particles can be made of a high-reflectance material, thereby making the absorption rate of blue light by the scattering protrusion 18 less than a set value. For example, the blue light transmittance of the transparent substrate is greater than or equal to 90%, thereby increasing the transmittance of blue light by the transparent substrate. It should be noted that the blue light transmittance of the transparent substrate specifically refers to the transmittance of the transparent substrate to the peak wavelength of the blue light emitted by the light-emitting unit 15, and the transmittance of blue light in bands other than the peak wavelength emitted by the light-emitting unit 15 is not limited.

[0210] In practice, the blue light transmittance of the transparent substrate can be greater than or equal to any value between 90% and 100%, such as 95%, 96%, 97%, 98%, 99%, etc. The greater the blue light reflectance of the transparent substrate, the smaller the color deviation of the backlight emitted by the backlight structure.

[0211] In specific implementation, the scattering protrusion 18 can be manufactured by mixing scattering particles in an organic solvent, coating it onto the surface of the first substrate layer 10, and then performing a process of pre-baking, exposure, development, and post-baking. The organic solvent can have a low extinction coefficient, for example, less than 0.0001, thereby reducing the absorption of blue light by the transparent substrate formed after baking. For example, the organic solvent can be a mixture of water, n-propanol, resin, etc., without limitation. The scattering particles can be made of materials such as titanium dioxide or barium oxide, without limitation.

[0212] Both the first reflective layer 11 and the second reflective layer 13 are made of Ag. Multiple scattering protrusions 18 are set between the first base layer 10 and the second reflective layer 13 as a light diffusion structure. The color coordinates and color shift data of light emitted from different positions of the backlight structure are measured, resulting in the color coordinate variation curves of light emitted from different positions as shown in Figure 18B and the color shift variation curves of light emitted from different positions as shown in Figure 18C. Comparing Figures 18B and 9B, it can be seen that the deviation range of color coordinate values ​​of light emitted from different positions in the embodiment corresponding to Figure 18B is significantly reduced compared to the embodiment corresponding to Figure 9B. Furthermore, comparing Figures 18C and 9C, it can be seen that the color shift of light emitted from different positions in the embodiment corresponding to Figure 18C is significantly reduced, and the difference between the maximum and minimum color shift is significantly reduced compared to the embodiment corresponding to Figure 9C. It can be seen that by using high reflectivity materials for the first reflective layer 11 and the second reflective layer 13, and by setting multiple scattering protrusions 18 as light diffusion structures P between the first base layer 10 and the second reflective layer 13, the color shift of the backlight emitted by the backlight structure can be significantly reduced, and the color of the light emitted from different positions is more uniform.

[0213] Because the refractive index of the first substrate layer 10 is greater than that of air, some light rays at certain angles may undergo total internal reflection inside the first substrate layer 10 and cannot exit from the second surface S2 to the outside of the first substrate layer 10 for backlighting, resulting in poor light-gathering capability of the first substrate layer 10. In a specific implementation, the scattering angle of the scattering protrusion 18 can be adjusted to change the angular range of the light rays emitted from the scattering protrusion 18. This allows most light rays to enter the second surface S2 at an angle smaller than the total internal reflection angle and exit from the second surface S2 to the outside of the first substrate layer 10 for backlighting, thus improving the light-gathering capability. Specifically, the scattering angle of the scattering protrusion 18 represents the possible angular range of the reflected light rays after they are reflected by the scattering protrusion 18. For example, if the scattering angle of the scattering protrusion 18 is 20°, and the incident angle of the light rays entering the scattering protrusion 18 is 40°, then the possible angular range of the reflected light rays after reflection by the scattering protrusion is -20° to -60°. Specifically, when the scattering angle of the scattering protrusion 18 is greater than or equal to 80°, the first substrate layer 10 has a strong light-harvesting ability, and the light-harvesting ability of the first substrate layer 10 at this time is greater than 60%.

[0214] In this embodiment, the light diffusion structure P can also employ other structures besides those described in the foregoing embodiments. To avoid the absorption of blue light by the light diffusion structure P affecting color shift, the blue light absorption rate of the light diffusion structure P can be set to be less than a predetermined value, such as 15%, 10%, 5%, etc., which is not limited here. Blue light not absorbed by the light diffusion structure P can be diffused through transmission or reflection, thereby being effectively utilized.

[0215] Figure 19 is the seventh cross-sectional structural schematic diagram of the backlight structure provided in the embodiments of this disclosure.

[0216] In some embodiments, as shown in FIG19, the backlight structure further includes an isolation dam 19. The isolation dam 19 is located between the second reflective layer 13 and the light-emitting unit 15. The isolation dam 19 forms an accommodating space around the first opening H1, and the color conversion structure 14 is disposed within the accommodating space. The isolation dam 19 can be used to define the position of the color conversion structure 14. In some embodiments, the isolation dam 19 can be made of a material with high reflectivity, thereby reflecting the light emitted from the color conversion structure 14 in all directions and improving the light utilization rate.

[0217] Figure 20 is a cross-sectional schematic diagram of another backlight structure provided in an embodiment of this disclosure.

[0218] In some embodiments, as shown in FIG20, the backlight structure further includes a first encapsulation layer 20. The first encapsulation layer 20 is located between the second reflective layer 13 and the light-emitting unit 15, and the first encapsulation layer 20 covers the entire surface of the second reflective layer 13 and the color conversion structure 14. The first encapsulation layer 20 can protect the film layers such as the color conversion structure 14, thereby reducing the risk of water and oxygen erosion causing the color conversion structure 14 to fail. The first encapsulation layer 20 can be a single-layer structure or a multi-layer structure, which is not limited here.

[0219] In some embodiments, as shown in FIG20, the backlight structure further includes a driving circuit layer 21. The driving circuit layer 21 is formed between the first packaging layer 20 and the light-emitting unit 15. A driving circuit is formed in the driving circuit layer 21 for driving the light-emitting unit 15 to emit light. The driving circuit layer 21 includes pads, and the light-emitting unit 15 is electrically connected to the circuit in the driving circuit layer through the pads.

[0220] In some embodiments, as shown in FIG20, the backlight structure further includes a second encapsulation layer 22. The second encapsulation layer 22 is located on the side of the light-emitting unit 15 facing away from the first substrate layer 10. The second encapsulation layer 22 is disposed over its entire surface, thereby protecting the light-emitting unit 15 and other film layers. In specific implementations, the second encapsulation layer 22 can be made of materials with high reflectivity, such as white oil or white glue, so as to reflect light into the first opening and improve the utilization rate of light. No limitation is made here.

[0221] The backlight structure provided in this disclosure may also include other structures necessary to achieve specific functions. These can be manufactured according to actual conditions during implementation and are not limited herein. The structures of the above embodiments of this disclosure can be combined arbitrarily without conflict, and the resulting structures will not be described in detail here.

[0222] Figure 21 is a schematic cross-sectional view of a backlight unit provided in an embodiment of this disclosure.

[0223] A second aspect of this disclosure provides a backlight unit. The backlight unit includes a plurality of backlight structures 1 provided in any of the above embodiments. As shown in FIG21, the plurality of backlight structures 1 are arranged on the same plane according to a predetermined arrangement to provide backlighting. In specific implementations, the plurality of backlight structures can be arranged in an array along two mutually perpendicular directions, which is not limited here.

[0224] Figure 22 is a schematic cross-sectional view of another backlight unit provided in an embodiment of this disclosure.

[0225] In some embodiments, as shown in FIG22, in the backlight unit, the first base layer 10 of the plurality of backlight structures 1 is a continuous integral structure. That is, the first grooves of the plurality of backlight structures 1 are formed on the same first base layer 10. In specific manufacturing, multiple first grooves can be formed simultaneously on the first surface S1 of the same first base layer through the same etching process, thereby being used to manufacture multiple backlight structures 1.

[0226] In some embodiments, as shown in FIG22, a fourth groove G4 can be formed on the second surface S2 of the first substrate layer 10. The second surface S2 is the surface opposite to the first surface S1 of the first substrate layer 10. The orthographic projection of the fourth groove G4 on the first surface S1 lies between the orthographic projections of adjacent first grooves G1 on the first surface S1. By etching the fourth groove G4 on the second surface S2 between adjacent first grooves G1, since the refractive index of the first substrate layer 10 is generally greater than the refractive index of air in the fourth groove G4, light rays at certain angles can undergo total internal reflection when incident on the surface of the fourth groove G4 during propagation in the first substrate layer 10. This improves brightness uniformity and prevents crosstalk between adjacent backlight structures.

[0227] In specific manufacturing, the depth of the fourth groove G4 can be set to 70% to 90% of the maximum thickness of the first base layer 10, for example, it can be set to 80%. Specifically, the depth of the fourth groove G4 refers to its dimension along the direction perpendicular to the first surface S1. The thickness of the first base layer 10 specifically refers to its dimension along the direction perpendicular to the first surface S1. Since the first base layer 10 is thinner at the location of the fourth groove G4 and thicker in the area outside the location of the fourth groove G4, the maximum thickness of the first base layer 10 can be expressed as the thickness of the area outside the location of the fourth groove G4. The deeper the fourth groove G4, the higher the efficiency of total internal reflection of light propagating inside the first base layer 10 at the surface of the fourth groove G4, which can further improve brightness uniformity and reduce light crosstalk. Considering the strength of the first base layer 10, an excessively deep fourth groove G4 may cause the strength of the first base layer 10 to deteriorate at the location where the fourth groove G4 is located, making it prone to breakage. Therefore, the depth of the fourth groove G4 can be specifically set by taking into account both the light reflection effect and the strength of the first base layer 10, and is not limited here.

[0228] To more clearly illustrate the beneficial effects of creating a fourth groove in the first substrate layer in the backlight unit provided in the embodiments of this disclosure, the researchers of this disclosure compared the backlight effect of the backlight unit with the fourth groove in the first substrate layer with the backlight effect of the backlight unit without the fourth groove in the first substrate layer.

[0229] Figure 23A is a schematic diagram of the optical path of a backlight unit provided in an embodiment of the present disclosure for comparison; Figure 23B is one of the brightness distribution diagrams of a backlight unit provided in an embodiment of the present disclosure; Figure 23C is one of the brightness distribution curves of a backlight unit provided in an embodiment of the present disclosure; Figure 23D is another brightness distribution diagram of a backlight unit provided in an embodiment of the present disclosure; Figure 23E is another brightness distribution curve of a backlight unit provided in an embodiment of the present disclosure.

[0230] Specifically, as shown in Figure 23A, in the backlight unit where the fourth groove is not formed in the first base layer 10, when only a single light-emitting unit is lit, for example, when only the first light-emitting unit 151 is lit, the first light ray L1 emitted by the first light-emitting unit 151 will be reflected by the first reflective layer 11 and propagate to the periphery of the first groove G1. Due to the obstruction of the first reflective layer 11, only a very small number of the first light rays L1 will propagate to the coverage area SD covered by the orthographic projection of the first reflective layer 11 on the second surface S2, and then exit from the coverage area SD to the outside of the first base layer 10. The brightness distribution when the first light-emitting unit 151 is lit alone is tested, and the brightness distribution diagram shown in Figure 23B and the brightness distribution curve shown in Figure 23C are obtained. Combining Figures 23B and 23C, it can be seen that when the first light-emitting unit 151 is lit alone, the halo formed by the light emitted by the first light-emitting unit 151 on the second surface S2 is relatively large, and the size of the halo in the first direction Y is about 6mm. The distance SP between the centers of the orthographic projections of two adjacent light-emitting units on the second surface S2 is approximately 2 mm. The halo size formed by the light emitted from the first light-emitting unit 151 on the second surface S2 is much larger than the distance SP between the centers of the orthographic projections of two adjacent light-emitting units on the second surface S2. Furthermore, at the location corresponding to the coverage area SD, the brightness of the light emitted by the first light-emitting unit 151 is much lower than the brightness of other areas. In other words, when the first light-emitting unit 151 is lit alone, the halo formed by the light emitted by the first light-emitting unit 151 is large, and the uniformity of brightness distribution is very poor.

[0231] As shown in Figure 23A, in the backlight unit where the fourth groove is not formed in the first base layer 10, when the first light-emitting unit 151 and the adjacent second light-emitting unit 152 and third light-emitting unit 153 are lit simultaneously, the light from the first light-emitting unit 151 blocked by the first reflective layer 11 can be compensated by the second light-emitting unit 152 and the third light-emitting unit 153, thereby improving the brightness uniformity. For example, as shown in Figure 23A, the second light ray L2 emitted from the second light-emitting unit 152 propagates inside the first base layer 10 and is incident on the first reflective layer 11 after total internal reflection on the second surface S2. After being reflected by the first reflective layer 11, the second light ray L2 is emitted from the position corresponding to the coverage area SD, thereby improving the brightness of the light emitted from the position corresponding to the coverage area SD. As shown in Figure 23D, when the first light-emitting unit 151 and the adjacent second light-emitting unit 152 and third light-emitting unit 153 are lit simultaneously, the brightness distribution around the center of the orthographic projection of the first light-emitting unit 151 on the second surface S2 is relatively uniform. However, along the first direction Y, the size of the halo formed with the center of the orthographic projection of the first light-emitting unit 151 on the second surface S2 as the origin is about 6mm, which is still larger than the distance SP between the centers of the orthographic projections of two adjacent light-emitting units on the second surface S2. This means that the light crosstalk between two adjacent backlight structures is large, and it cannot meet the halo size requirements when applied to scenarios that require strict control of the emitted halo size, such as local dimming technology.

[0232] Figure 24A is a third brightness distribution diagram of a backlight unit provided in an embodiment of this disclosure; Figure 24B is a third brightness distribution curve of a backlight unit provided in an embodiment of this disclosure.

[0233] As shown in Figure 22, in the backlight unit with the fourth groove G4 in the first base layer 10, when only a single light-emitting unit is lit, for example, only the first light-emitting unit 151 is lit, part of the light L emitted from the first light-emitting unit 151 undergoes total internal reflection at the surface of the fourth groove G4 during its propagation inside the first base layer 10. After total internal reflection at the second surface S2 of the first base layer 10, it is incident on the surface of the first reflective layer 11. After reflection by the first reflective layer 11, the light emitted from the coverage area SD covered by the orthographic projection of the first reflective layer 11 onto the second surface S2 exits to the outside of the first base layer 10, thereby increasing the brightness of the light emitted from the corresponding position of the coverage area SD and improving the uniformity of the brightness distribution of the light emitted from the first light-emitting unit 151. Furthermore, because the light undergoes total internal reflection at the surface of the fourth groove G4, the probability of the light emitted from the first light-emitting unit 151 propagating into adjacent backlight structures is reduced, effectively avoiding crosstalk between the light emitted from adjacent backlight structures and helping to reduce the halo size. Specifically, as shown in Figures 24A and 24B, the halo formed on the second surface by the light emitted from the first light-emitting unit 151 has a size of approximately 2.8 mm in the first direction Y. This is significantly smaller than the halo size when the first base layer 10 does not have the fourth groove. It is also close to the distance SP between the centers of the orthographic projections of two adjacent light-emitting units on the second surface S2. Furthermore, the brightness of the halo is relatively uniformly distributed in the first direction Y, which can meet the needs of special application scenarios such as local dimming technology.

[0234] Figure 25A is a cross-sectional structural schematic diagram of another backlight unit provided in an embodiment of the present disclosure; Figure 25B is a fourth brightness distribution diagram of a backlight unit provided in an embodiment of the present disclosure; Figure 25C is a fourth brightness distribution curve of a backlight unit provided in an embodiment of the present disclosure; Figure 25D is a fifth brightness distribution diagram of a backlight unit provided in an embodiment of the present disclosure; Figure 25E is a fifth brightness distribution curve of a backlight unit provided in an embodiment of the present disclosure.

[0235] In some embodiments, as shown in FIG25A, the surface of the fourth groove G4 is further covered with a reflective medium RE. The reflective medium RE can be made of a material with high reflectivity, such as silver, aluminum, titanium dioxide, calcium oxide, etc. The reflective medium can be an element or a mixture, and is not limited herein. The reflective medium RE can be a thin layer structure covered on the surface of the fourth groove G4 by a coating process such as sputtering deposition, or it can be completely filled inside the fourth groove G4 by a coating process, thereby covering the surface of the fourth groove G4, and is not limited herein. The reflective medium RE has high reflectivity, so it can reflect incident light at any angle. Compared with total internal reflection, it can improve reflection efficiency, improve light utilization, and further reduce light crosstalk between adjacent backlight structures.

[0236] In practice, the reflective medium RE can be made of a material with a blue light reflectivity greater than or equal to 90%, thereby increasing the reflectivity of blue light, reducing color difference, and improving the display effect. It should be noted that the blue light reflectivity of the reflective medium RE specifically refers to the reflectivity of the reflective medium RE for the peak wavelength of the blue light emitted by the light-emitting unit 15, and the reflectivity for blue light in wavelengths other than the peak wavelength emitted by the light-emitting unit 15 is not limited.

[0237] The researchers in this publication tested the brightness distribution of the backlight unit shown in Figure 25A. When only a single light-emitting unit is lit, for example, only the first light-emitting unit 151 is lit, as shown in Figures 25B and 25C, the halo formed on the second surface S2 by the light emitted from the first light-emitting unit 151 has a size of approximately 2.1 mm in the first direction Y, which is closer to the distance SP between the centers of the orthographic projections of two adjacent light-emitting units on the second surface S2. Furthermore, the uniformity of the brightness distribution of the halo in the first direction Y is further improved, which can better meet the needs of special application scenarios such as local dimming technology. When the first light-emitting unit 151 is lit simultaneously with the adjacent second light-emitting unit 152 and third light-emitting unit 153, as shown in Figures 25D and 25E, it can be seen that the brightness of the light emitted by the backlight unit is uniformly distributed throughout the entire light-emitting area, exhibiting a good backlight effect.

[0238] Figure 26 is a top view of a first base layer provided in an embodiment of this disclosure.

[0239] Figure 26 can be considered as a top view taken from the side where the second surface of the first substrate 10 is located. In some embodiments, as shown in Figure 26, the orthographic projection of the fourth groove G4 on the first surface is a grid, and the orthographic projection of the first groove G1 of the backlight structure on the first surface falls within the grid. Thus, light can be reflected by the fourth groove G4 around a single grid, reducing the problem of light crosstalk between backlight structures set in different grids.

[0240] In some embodiments, as shown in FIG26, only one first groove G1 can be set in a grid, that is, only one backlight structure can be set in a single grid, which is conducive to achieving more precise local dimming.

[0241] In some embodiments, multiple first grooves G1 can be set in a grid, that is, multiple backlight structures can be set in a single grid at the same time, and a grid can be used as a dimming area. In specific implementation, multiple backlight structures in a grid can be dimmed at the same time, which is not limited here.

[0242] Figure 27A is a cross-sectional structural schematic diagram of another backlight unit provided in an embodiment of the present disclosure; Figure 27B is a top view structural schematic diagram of another backlight unit provided in an embodiment of the present disclosure.

[0243] In some embodiments, as shown in Figures 27A and 27B, multiple backlight structures 1 in the same backlight unit are independent components, and the first base layer 10 of each backlight structure 1 is spliced ​​together to form a backlight unit as a whole.

[0244] In some embodiments, as shown in Figures 27A and 27B, the side surface of the first substrate layer 10 is covered with a reflective structure RE. Specifically, the side surface of the first substrate layer 10 refers to the splicing surface where two adjacent first substrate layers 10 are joined. The reflective medium RE can be made of a material with high reflectivity, such as silver, aluminum, titanium dioxide, calcium oxide, etc. The reflective medium can be a single substance or a mixture, and is not limited here. The reflective medium RE can be deposited on the side surface of the first substrate layer 10 by a coating process such as sputtering deposition, or it can be covered on the side surface of the first substrate layer 10 by a coating method, and is not limited here. In specific implementations, the reflective medium RE can cover only the side surface of the first substrate layer 10, or it can cover the entire side surface of the backlight structure, including the side surface of the first substrate layer 10, and is not limited here. The reflective medium RE has high reflectivity, thus it can reflect incident light at any angle. Compared with total internal reflection, it can improve reflection efficiency, increase light utilization, and further reduce light crosstalk between adjacent backlight structures.

[0245] In practice, the reflective medium RE can be made of a material with a blue light reflectivity greater than or equal to 90%, thereby increasing the reflectivity of blue light, reducing color difference, and improving the display effect. It should be noted that the blue light reflectivity of the reflective medium RE specifically refers to the reflectivity of the reflective medium RE for the peak wavelength of the blue light emitted by the light-emitting unit 15, and the reflectivity for blue light in wavelengths other than the peak wavelength emitted by the light-emitting unit 15 is not limited.

[0246] In some embodiments, adjacent backlight structures 1 are directly bonded to each other via a reflective medium RE, thereby reducing the number of adhesive layers used to bond adjacent backlight structures 1, lowering costs, and reducing the space occupied by the adhesive layers. This facilitates increasing the number of backlight structures 1 included in a single backlight unit and improving backlight brightness. For example, the reflective medium RE may include reflective particles and an adhesive substrate. The reflective particles are doped in the adhesive substrate and can be used to reflect light. The adhesive substrate can firmly bond adjacent first substrate layers 10 together, which is not limited here.

[0247] The backlight unit provided in this disclosure may also include other structures necessary to achieve specific functions. These can be manufactured according to actual conditions during implementation and are not limited here. The structures of the backlight units provided in the above embodiments of this disclosure can be arbitrarily combined without conflict, and the resulting structures will not be described in detail here. The backlight unit provided in this disclosure also has the same or similar technical effects as the backlight structure provided in any of the foregoing embodiments of this disclosure during specific implementation, and these effects will not be described in detail here.

[0248] Figure 28 is a cross-sectional structural diagram of a display device provided in an embodiment of this disclosure.

[0249] A third aspect of this disclosure provides a display device. As shown in FIG28, the display device includes a display panel 200 and a backlight unit 100 provided in any of the foregoing embodiments. The display panel 200 is located on the side of the first substrate layer 10 of the backlight unit 10 that faces away from the light-emitting unit 15. The display device provided in the embodiments of this disclosure has the same or similar technical effects as the backlight unit 100 provided in any of the foregoing embodiments in specific implementation, and will not be described in detail here.

[0250] Figure 29 is a cross-sectional structural schematic diagram of another display device provided in an embodiment of this disclosure.

[0251] In some embodiments, as shown in FIG29, the display panel 200 is a liquid crystal display panel. The display panel 200 includes an array substrate 201 and a counter substrate 202 disposed opposite to each other, and a liquid crystal layer 203 located between the array substrate 201 and the counter substrate 202. Specifically, as shown in FIG29, the first base layer 10 of the backlight unit 100 can be reused as the substrate of the array substrate 201, that is, the film structure of the array substrate 201 can be directly fabricated on the surface of the first base layer 10 of the backlight unit 100, thereby facilitating a further reduction in the thickness of the display device. In some embodiments, the first base layer 10 of the backlight unit 100 can also be reused as the substrate of the counter substrate 202, that is, the film structure of the counter substrate 202 can be directly fabricated on the surface of the first base layer 10 of the backlight unit 100, which is not limited here.

[0252] Figure 30 is a flowchart of the manufacturing method of the backlight structure provided in the embodiment of this disclosure.

[0253] A fourth aspect of this disclosure provides a method for manufacturing a backlight structure. As shown in FIG30, the method for manufacturing a backlight structure includes the following steps:

[0254] S301: A plurality of first grooves are formed on the first surface of the first base layer;

[0255] S302: Cover the bottom of the first groove with a first reflective layer;

[0256] S303: A transparent filler portion is filled in the first groove and on the side of the first reflective layer away from the first substrate layer;

[0257] S304: A second reflective layer is formed on the side of the transparent filling portion away from the first substrate layer, such that the second reflective layer at least covers a portion of the first surface of the first substrate layer; the second reflective layer has a first opening at the position corresponding to the first groove;

[0258] S305: A color conversion structure is formed on the side of the transparent filling portion away from the first substrate layer; the orthogonal projection of the color conversion structure on the first surface covers the orthogonal projection of the first opening on the first surface layer.

[0259] S306: A light-emitting unit is fabricated on the side of the second reflective layer that is away from the first substrate layer.

[0260] The backlight structure manufacturing method provided in this disclosure is beneficial for reducing the thickness of the backlight structure, and thus for reducing the thickness of the display device. Furthermore, according to the backlight structure manufacturing method provided in this disclosure, the first groove is filled with a transparent filler portion, and the color conversion structure is disposed on the side of the transparent filler portion facing away from the first substrate layer, which is beneficial for improving the color uniformity of the backlight light emitted from different areas of the backlight structure.

[0261] Figure 31A is one of the schematic diagrams of the manufacturing process of a backlight structure provided in an embodiment of the present disclosure; Figure 31B is another schematic diagram of the manufacturing process of a backlight structure provided in an embodiment of the present disclosure.

[0262] In a specific implementation, as shown in Figure 31A, multiple first grooves G1 can be formed on the first surface of the first substrate layer 10 by the following method: a first mask M1 is formed on the first surface of the first substrate layer 10, and the first mask M1 has an opening at the position corresponding to the first groove G1; the first substrate layer 10 exposed by the opening of the first mask M1 is etched by an etching solution to form the first groove G1. For example, the opening of the first mask M1 can be an annular opening, with part of the first mask M1 located in the outer region of the annular opening and part of the first mask M1 located in the region surrounded by the annular opening, so that when the first substrate layer 10 is etched, the first groove G1 and the protrusion structure 101 located at the bottom of the first groove G1 can be formed simultaneously.

[0263] After the first groove G1 is formed, the first mask M1 can be retained, and the first reflective layer 11 can be fabricated by sputtering deposition or other methods. During the sputtering deposition process, the reflective material partially covers the surface of the protruding structure 101 to form the first reflective layer 11, and the remaining part is deposited on the surface of the first mask M1. The first mask M1 and the reflective material on it can be removed together in subsequent processes.

[0264] After the first reflective layer 11 is fabricated, a transparent material is filled into the first groove G1 to form a transparent filling part 12.

[0265] As shown in Figure 31B, after removing the first mask M1 and the reflective material thereon, a second reflective layer 13 is formed on the side of the transparent filling portion 12 facing away from the first substrate layer 10. The second reflective layer 13 covers the first surface of the first substrate layer 13, and a first opening H1 is formed in the second reflective layer 13 at the position corresponding to the first groove G1 by etching or other processes. Then, a color conversion structure 14 is fabricated on the side of the transparent filling portion 12 facing away from the first substrate layer 10. After fabricating the color conversion structure 14, a light-emitting unit 15 is fabricated on the side of the second reflective layer 13 facing away from the first substrate layer 10, so that the color conversion structure 14 is located between the light-emitting unit 15 and the transparent filling portion 12.

[0266] Figure 32 is a schematic diagram of the manufacturing process of another backlight structure provided in the embodiments of this disclosure.

[0267] In some embodiments, as shown in FIG32, the method for fabricating a backlight structure provided in the embodiments of the present disclosure further includes, before forming a second reflective layer on the side of the transparent filling portion away from the first substrate layer: forming a second substrate layer 16 on the side of the first transparent filling portion 12 away from the transparent filling portion 10; then forming a second mask M2 on the side of the second substrate layer 16 away from the first substrate layer 10, the second mask M2 having a plurality of openings exposing the second substrate layer 16; etching the second substrate layer 16 through the plurality of openings of the second mask M2 to form a plurality of second grooves G2, the second substrate layer 16 in the area where the second grooves G2 are set forming a light diffusion structure P. After forming the light diffusion structure P, the second reflective layer 13 and other structures are then fabricated sequentially.

[0268] Figure 33 is a schematic diagram of the manufacturing process of another backlight structure provided in the embodiments of this disclosure.

[0269] In some embodiments, before forming the second reflective layer on the side of the transparent filler away from the first substrate layer, the method further includes: forming a plurality of third grooves on the first surface of the first substrate layer; the plurality of third grooves being arranged around the first groove.

[0270] In some embodiments, as shown in FIG33, the third groove G3 can be fabricated before the first groove G1 is formed. Specifically, as shown in FIG33, before the first groove G1 is formed, a third mask M3 is first formed on the first surface of the first substrate layer 10. The third mask M3 has multiple openings that expose the first substrate layer 10. Then, the first substrate layer 10 is etched through the third mask M3 to form multiple third grooves G3, which form a light diffusion structure P. Then, the third mask M3 is removed, and the first mask M1 is formed on the first surface of the first substrate layer 10. Subsequent processes are then performed according to the fabrication process shown in FIG31A and FIG31B.

[0271] In some embodiments, a first groove G1 may be made first, and then a third groove G3 may be made on the first surface of the first base layer 10, which is not limited here.

[0272] Figure 34 is a schematic diagram of the manufacturing process of another backlight structure provided in the embodiments of this disclosure.

[0273] In some embodiments, before forming the second reflective layer on the side of the transparent filler portion away from the first substrate layer, the method further includes: forming a plurality of scattering protrusions on one side of the first surface of the first substrate; the scattering protrusions include a transparent substrate and scattering particles doped in the transparent substrate; the plurality of scattering protrusions are arranged around the first groove. Specifically, as shown in FIG34, after the transparent filler portion 12 is filled in the first groove, and before forming the second reflective layer on the side of the transparent filler portion 12 away from the first substrate layer 10, a scattering material layer F is first formed on the first surface of the first substrate layer 10, the scattering material layer F including a transparent substrate and scattering particles doped in the transparent substrate; then a fourth mask M4 is formed on the side of the scattering material layer F away from the first substrate layer 10, the fourth mask M4 including a plurality of mask blocks corresponding to the scattering protrusions 18; the scattering material layer F outside the area covered by the mask blocks is etched through the fourth mask M4, retaining the scattering material layer F located directly below the mask blocks of the fourth mask M4, forming a plurality of scattering protrusions 18.

[0274] In specific implementation, the method for manufacturing the backlight structure provided in the embodiments of this disclosure can also be adjusted according to the specific structure of the backlight structure provided in the first aspect of this disclosure, which will not be elaborated here.

[0275] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0276] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A backlight structure, wherein, include: First basal layer; The first groove is located on the first surface of the first base layer; The first reflective layer is located at the bottom of the first groove; A second reflective layer is located on the side of the first groove opposite to the first base layer, and at least partially covers the first surface; the second reflective layer has a first opening; The orthographic projection of the first opening on the first surface at least partially coincides with the orthographic projection of the first groove on the first surface; The light-emitting unit is located on the side of the second reflective layer that is away from the first substrate layer; A color conversion structure is located between the light-emitting unit and the first reflective layer, and the orthographic projection of the color conversion structure on the first surface covers the orthographic projection of the first opening on the first surface.

2. The backlight structure as described in claim 1, wherein, The backlight structure also includes: A second base layer is located between the first base layer and the second reflective layer; the second base layer includes a plurality of second grooves formed around the first groove; the depth of the second grooves is less than the thickness of the second base layer; The blue light transmittance of the second substrate layer is greater than or equal to 90%.

3. The backlight structure as described in claim 2, wherein, The second base layer has a second opening; The orthographic projection of the first opening onto the first surface falls within the orthographic projection of the second opening onto the first surface.

4. The backlight structure as described in claim 2 or 3, wherein, The surface of the second groove is an arc surface in which the tangent slope changes continuously at various points.

5. The backlight structure as described in claim 2 or 3, wherein, The surface of the second groove has at least one abrupt change in tangent slope, and / or the surface of the second groove is at least partially planar; The second groove is also filled with scattering particles.

6. The backlight structure as described in claim 1, wherein, The first surface of the first base layer has a plurality of third grooves; the plurality of third grooves are arranged around the first groove.

7. The backlight structure as described in claim 6, wherein, The surface of the third groove is an arc surface with a continuously changing tangent slope at each location.

8. The backlight structure as described in claim 6, wherein, The inner surface of the third groove has at least one abrupt change in tangent slope, and / or the surface of the third groove is at least partially planar; The third groove is also filled with scattering particles.

9. The backlight structure as described in claim 1, wherein, The backlight structure also includes: Multiple scattering protrusions are located between the first substrate layer and the second reflective layer; the multiple scattering protrusions are arranged around the first groove; The scattering protrusion includes a transparent substrate and scattering particles doped in the transparent substrate; the blue light transmittance of the transparent substrate is greater than or equal to 90%.

10. The backlight structure according to any one of claims 1 to 9, wherein, The orthographic projection of the first opening on the first surface falls within the orthographic projection of the first groove on the first surface.

11. The backlight structure according to any one of claims 1 to 10, wherein, The backlight structure also includes: An isolation dam is located between the second reflective layer and the light-emitting unit; the isolation dam forms an accommodating space around the first opening, and the color conversion structure is disposed within the accommodating space.

12. The backlight structure according to any one of claims 1 to 11, further comprising a transparent filling portion located on the side of the first reflective layer opposite to the first substrate layer and filling the first groove; in, The blue light transmittance of the transparent filling portion is greater than or equal to 90%; and / or, the blue light reflectance of the first reflective layer is greater than or equal to 90%; and / or, the blue light reflectance of the second reflective layer is greater than or equal to 90%.

13. The backlight structure according to any one of claims 1 to 12, wherein, The bottom of the first groove has a raised structure; the first reflective layer covers the surface of the raised structure.

14. A backlight unit, wherein, It includes multiple backlight structures as described in any one of claims 1 to 13.

15. The backlight unit as claimed in claim 14, wherein, The first substrate layer of the multiple backlight structures is a continuous integral structure; A fourth groove is formed on the second surface of the first substrate layer; the second surface is the surface opposite to the first surface of the first substrate layer. The orthographic projection of the fourth groove on the first surface lies between the orthographic projections of the adjacent first grooves on the first surface. The depth of the fourth groove is 70% to 90% of the maximum thickness of the first base layer.

16. The backlight unit as claimed in claim 15, wherein, The orthographic projection of the fourth groove on the first surface is a grid, and the orthographic projection of the first groove of the backlight structure on the first surface falls within the grid.

17. The backlight unit as claimed in claim 15 or 16, wherein, The surface of the fourth groove is covered with a reflective medium; The blue light reflectivity of the reflective medium is greater than or equal to 90%.

18. The backlight unit as claimed in claim 14, wherein, The first substrate layers of multiple backlight structures are spliced ​​together; The side surface of the first substrate layer is covered with a reflective medium; the side surface is the splicing surface of two adjacent first substrate layers. The blue light reflectivity of the reflective medium is greater than or equal to 90%.

19. The backlight unit as claimed in claim 18, wherein, The adjacent backlight structures are directly bonded to each other through the reflective medium.

20. A display device, wherein, Includes a display panel and a backlight unit as described in any one of claims 14 to 19; The display panel is located on the side of the first substrate layer of the backlight structure that faces away from the light-emitting unit.

Images