Backlight module and display device

Abstract

This invention provides a backlight module and a display device, relating to the display field, for improving the display brightness of a display panel in privacy mode. The backlight module includes: a first backlight structure, comprising a first light-emitting structure and a dimming layer located on the side of the first light-emitting structure facing the light-emitting surface of the backlight module; wherein the dimming layer includes multiple microstructures and a reflective barrier, the microstructures including reflective sidewalls, and adjacent microstructures being spaced apart; the reflective barrier being located between the microstructures and the first light-emitting structure, and the orthographic projections of the reflective barrier and the reflective sidewalls overlapping in a direction perpendicular to the plane of the backlight module; and a second backlight structure located on the side of the first backlight structure facing the light-emitting surface of the backlight module.

Description

[Technical Field]

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

[0002] Currently, the display device can switch between privacy mode and sharing mode. For example, while driving, the in-vehicle display screen on the passenger side can be switched to privacy mode to prevent the displayed image from being seen from the driver's perspective, ensuring driving safety.

[0003] However, existing display devices have low brightness in privacy mode. For example, in one related design of the backlight module of a display device, a light control film is used to absorb the large-angle light emitted through the light guide plate, allowing only the small-angle light to be emitted. While this can achieve the purpose of narrowing the viewing angle, it also results in very low light output brightness in privacy mode, making it difficult to match the brightness specifications. [Summary of the Invention]

[0004] In view of this, embodiments of the present invention provide a backlight module and a display device to improve the display brightness of the display panel in privacy mode.

[0005] On one hand, embodiments of the present invention provide a backlight module, including:

[0006] A first backlight structure includes a first light-emitting structure and a dimming layer located on the side of the first light-emitting structure facing the light-emitting surface of the backlight module. The dimming layer includes a plurality of microstructures and a reflective barrier. The microstructures include reflective sidewalls and are spaced apart from each other. The reflective barrier is located between the microstructures and the first light-emitting structure. In a direction perpendicular to the plane of the backlight module, the orthographic projections of the reflective barrier and the reflective sidewalls overlap.

[0007] The second backlight structure is located on the side of the first backlight structure facing the light-emitting surface of the backlight module. On the other hand, embodiments of the present invention provide a method for manufacturing a backlight module, comprising forming a first backlight structure and a second backlight structure, wherein the second backlight structure is located on the side of the first backlight structure facing the light-emitting surface of the backlight module;

[0008] The process of forming the first backlight structure includes: setting a dimming layer on one side of the first light-emitting structure, the dimming layer including multiple microstructures and multiple reflective barriers, the microstructures including reflective sidewalls and having a gap between adjacent microstructures, the reflective barriers being located between the microstructures and the first light-emitting structure, and the orthographic projections of the reflective barriers and the reflective sidewalls overlapping in a direction perpendicular to the plane where the backlight module is located.

[0009] In another aspect, embodiments of the present invention provide a display device, comprising:

[0010] The aforementioned backlight module;

[0011] The display panel is located on the side of the backlight module facing the light-emitting surface of the display device.

[0012] One of the above technical solutions has the following beneficial effects:

[0013] When the display device needs to be controlled in privacy mode, this embodiment of the invention does not directly absorb large-angle light. Instead, it uses the microstructure in the dimming layer to regulate the large-angle light, converting it into small-angle light that is emitted from the backlight module. Furthermore, after setting a reflective sidewall on the microstructure, this embodiment further sets a reflective barrier at the bottom of the microstructure, overlapping the orthographic projection of the reflective sidewall. Without the reflective barrier, when some light enters the interior of the microstructure towards the bottom, it may be blocked by the reflective sidewall and unable to pass through the microstructure, resulting in light loss. However, with the reflective barrier, this light entering towards the bottom of the microstructure is reflected back, allowing the light that was originally unable to escape to be reused and re-enter the dimming layer, thereby reducing light loss and further increasing the amount of small-angle light emitted through the first backlight structure. In other words, this embodiment of the invention utilizes the dual reflection of the reflective sidewall and the reflective barrier to regulate more light, enabling more small-angle light to be emitted in privacy mode.

[0014] Therefore, based on the technical solution provided by the embodiments of the present invention, in privacy mode, not only can the viewing angle be narrowed, but the amount of small-angle light ultimately emitted through the backlight module can also be greatly increased, thereby effectively improving the light output brightness of the display device in privacy mode and enabling it to better meet the brightness specifications of the display device. In other words, under the condition that the display device achieves the same brightness in privacy mode, the embodiments of the present invention can reduce the backlight brightness of the first backlight structure, thereby effectively reducing the power consumption of the backlight module. [Attached Image Description]

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a backlight module provided in an embodiment of the present invention;

[0017] Figure 2This is a schematic diagram of light transmission provided in an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram illustrating the comparison of light transmission provided in an embodiment of the present invention;

[0019] Figure 4 This is another schematic diagram of light transmission provided in an embodiment of the present invention;

[0020] Figure 5 This is another schematic diagram of light transmission provided in an embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram of a dimming layer provided in an embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of another structure of the dimming layer provided in an embodiment of the present invention;

[0023] Figure 8 This is another schematic diagram of light transmission provided in an embodiment of the present invention;

[0024] Figure 9 This is a schematic diagram of another structure of the dimming layer provided in an embodiment of the present invention;

[0025] Figure 10 This is a schematic diagram of a first backlight structure provided in an embodiment of the present invention;

[0026] Figure 11 This is a brightness comparison diagram of the present invention and related technologies provided in an embodiment of the present invention;

[0027] Figure 12 This is another schematic diagram of the first backlight structure provided in the embodiment of the present invention;

[0028] Figure 13 This is a top view of the second light guide plate provided in an embodiment of the present invention;

[0029] Figure 14 A process flow diagram of the manufacturing method provided in an embodiment of the present invention;

[0030] Figure 15 This is another process flow diagram of the manufacturing method provided in the embodiment of the present invention;

[0031] Figure 16 This is a schematic diagram of a display device provided in an embodiment of the present invention.

Detailed Implementation Methods

[0032] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0036] This invention provides a backlight module, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of a backlight module provided in an embodiment of the present invention. The backlight module includes a first backlight structure 1 and a second backlight structure 2, with the second backlight structure 2 located on the side of the first backlight structure 1 facing the light-emitting surface of the backlight module.

[0037] The first backlight structure 1 includes a first light-emitting structure 3 and a dimming layer 4 located on the side of the first light-emitting structure 3 facing the light-emitting surface of the backlight module. The dimming layer 4 includes multiple microstructures 5 and a reflective barrier 6. The microstructures 5 include reflective sidewalls 7, and there is a gap between adjacent microstructures 5. The reflective barrier 6 is located between the microstructures 5 and the first light-emitting structure 3. In a direction perpendicular to the plane where the backlight module is located, the orthographic projections of the reflective barrier 6 and the reflective sidewalls 7 overlap.

[0038] Based on the above structure, when it is necessary to control the display device to be in privacy mode, the first light-emitting structure 3 is controlled to emit light. For example... Figure 2 As shown, Figure 2This is a schematic diagram of light transmission provided in an embodiment of the present invention. The light emitted from the first light-emitting structure 3 is further incident on the upper dimming layer 4. Among them, a portion of the small-angle light A1 is directly emitted through the gap between adjacent microstructures 5. This portion of light is not controlled by the microstructures 5, and its transmission direction does not change. A portion of the small-angle light A2 is transmitted to the reflective sidewall 7 of the microstructure 5. After being reflected by the reflective sidewall 7, it is emitted at an even smaller angle. A portion of the large-angle light A3 is transmitted to the reflective sidewall 7 of a certain microstructure 5. After being reflected, it can be further transmitted to the reflective sidewall 7 of another microstructure 5. After being reflected again, it is emitted at a smaller angle. A portion of the light A4 is transmitted towards the bottom of the microstructure 5 and is reflected back by the reflective barrier 6 for reuse. This reused light is emitted towards the dimming layer 4 again. It can be emitted directly at a smaller angle or converted into small-angle light after being controlled by the microstructure 5.

[0039] When it is necessary to control the display device to be in shared mode, the second backlight structure 2 causes light to be emitted from the backlight module at a larger angle range.

[0040] It should be noted that, in combination Figure 2 The light with a small angle mentioned above refers to light with a small angle between its propagation direction and the normal direction F. This part of the light tends to propagate along the normal angle. On the other hand, the light with a large angle refers to light with a large angle between its propagation direction and the normal direction F. This part of the light tends to propagate along the oblique angle.

[0041] Based on the above analysis, when it is necessary to control the display device to be in privacy mode, the embodiments of the present invention do not directly absorb large-angle light, but use the microstructure 5 in the dimming layer 4 to regulate the large-angle light, so that it is converted into small-angle light and emitted from the backlight module. Moreover, after setting the reflective sidewall 7 on the microstructure 5, the embodiments of the present invention further set a reflective barrier 6 at the bottom of the microstructure 5 that overlaps with the orthographic projection of the reflective sidewall 7. If the reflective barrier 6 is not set, when a part of the light shines into the interior of the microstructure 5 towards the bottom of the microstructure 5, it may not be able to pass through the microstructure 5 due to the blocking of the reflective sidewall 7, resulting in loss. However, after setting the reflective barrier 6, when this part of the light shines into the bottom of the microstructure 5, it will be reflected back by the reflective barrier 6, so that the light that could not be emitted originally can be reused and re-emitted into the dimming layer 4, thereby reducing light loss and further increasing the amount of small-angle light emitted through the first backlight structure 1. That is, in this embodiment of the invention, more light is modulated by the dual reflection of the reflective sidewall 7 and the reflective barrier 6, so that more light at small angles can be emitted in privacy mode.

[0042] Therefore, based on the structure provided by the embodiments of the present invention, in privacy mode, not only can the viewing angle be narrowed, but the amount of small-angle light ultimately emitted through the backlight module can also be greatly increased, thereby effectively improving the light output brightness of the display device in privacy mode and enabling it to better meet the brightness specifications of the display device. In other words, under the condition that the display device achieves the same brightness in privacy mode, the embodiments of the present invention can reduce the backlight brightness of the first backlight structure 1, thereby effectively reducing the power consumption of the backlight module.

[0043] It should be noted that the microstructure 5 in this embodiment of the invention can be a prism or other structure capable of converting large-angle light rays into small-angle light rays, or it can be a combination of multiple structures. However, the dimming layer 4 in this embodiment of the invention is not a traditional prism film. In a traditional prism film, the prisms are continuously arranged and are transparent. After light enters the prism film, it undergoes refraction and transmission inside the prism, and the prism film also allows large-angle light to escape. In contrast, the dimming layer 4 in this embodiment of the invention uses the reflective sidewall 7 of the microstructure 5 to change the direction of light transmission, rather than using the optical effects of light inside the microstructure 5 to control the light. This dimming layer 4 almost does not allow large-angle light to escape. Moreover, the microstructures 5 in this dimming layer 4 are not continuously arranged; there are gaps between adjacent microstructures 5, thus providing sufficient space for light to transmit between adjacent microstructures 5 or undergo multiple reflections between adjacent microstructures 5.

[0044] Furthermore, it should be noted that, unlike the light control film mentioned in the background art for absorbing large-angle light, the microstructure 5 in this embodiment of the invention is not a light-absorbing structure. This microstructure 5 does not absorb large-angle light, preventing its emission, but rather uses its reflective sidewall 7 to convert the transmission direction of large-angle light, transforming it into small-angle light for emission. That is, the microstructure 5 in this embodiment of the invention reuses large-angle light, which not only avoids brightness loss but also increases the emitted light brightness. Moreover, by further setting a reflective barrier 6 in this embodiment of the invention, dual reflection of light by the microstructure 5 and the reflective barrier 6 can be achieved, allowing more light to be converted into small-angle light, thus significantly improving the emitted light brightness in privacy mode.

[0045] In one feasible implementation, see again Figure 2 The microstructure 5 also includes a bottom surface 8, which is close to the first light-emitting structure 3 and intersects with the reflective sidewall 7. The angle between the reflective sidewall 7 and the bottom surface is less than 90°.

[0046] like Figure 3 As shown, Figure 3This is a schematic diagram of light transmission comparison provided by an embodiment of the present invention. Compared with a structure in which the angle between the reflective sidewall 7 and the bottom surface 8 is greater than or equal to 90°, by setting the angle between the reflective sidewall 7 and the bottom surface 8 to less than 90°, light of the same angle will be more likely to be converted into light of a smaller angle after being transmitted to the reflective sidewall 7.

[0047] Furthermore, combined Figure 4 and Figure 5 The angle between the tilt direction of the reflective sidewall 7 and the first direction is λ, where 5°≤λ≤10°, and the first direction is perpendicular to the plane where the backlight module is located. The first direction is the aforementioned normal direction F. In this embodiment of the invention, λ can be set to 10°. For example, when the microstructure 5 is a cone structure, the apex angle of the microstructure 5 is 20°.

[0048] When the angle λ between the tilt direction of the reflective sidewall 7 and the first direction is set between 5° and 10°, the microstructure 5 can better convert the light emitted from the first light-emitting structure 3 into light with a smaller angle, resulting in better collimation control of the light.

[0049] The following explanation uses λ = 10° as an example:

[0050] For light emitted at a small angle through the first light-emitting structure 3, such as Figure 4 As shown, Figure 4 This is another schematic diagram of light transmission provided in an embodiment of the present invention. The small-angle light B1 emitted by the first light-emitting structure 3 at an angle of 20° with the normal direction F is transmitted to the microstructure 5 and reflected by the reflective sidewall 7, and is then converted into light emitted along the normal direction F. The small-angle light B2 emitted by the first light-emitting structure 3 at an angle of 30° with the normal direction F is transmitted to the microstructure 5 and reflected by the reflective sidewall 7, and is then converted into light at an angle of 10° with the normal direction F. The small-angle light B3 emitted by the first light-emitting structure 3 at an angle of 40° with the normal direction F is transmitted to the microstructure 5 and reflected by the reflective sidewall 7, and is then converted into light at an angle of 20° with the normal direction F.

[0051] For light emitted at a slightly larger angle through the first light-emitting structure 3, such as Figure 5 As shown, Figure 5This is another schematic diagram of light transmission provided by an embodiment of the present invention. The small-angle light B4 emitted from the first light-emitting structure 3, with an angle of 50° to the normal direction F, is transmitted to a microstructure 5 and reflected by the reflective sidewall 7 of that microstructure 5. It then propagates along a transmission direction with an angle of 30° to the normal direction F towards an adjacent microstructure 5, and after being reflected again by the reflective sidewall 7 of the adjacent microstructure 5, it is finally converted into light with an angle of 10° to the normal direction F. Similarly, the small-angle light B4 emitted from the first light-emitting structure 3, with an angle of 60° to the normal direction F, is transmitted to a microstructure 5 and reflected by the reflective sidewall 7 of that microstructure 5. It then propagates along a transmission direction with an angle of 40° to the normal direction F towards an adjacent microstructure 5, and after being reflected again by the reflective sidewall 7 of the adjacent microstructure 5, it is finally converted into light with an angle of 20° to the normal direction F. Light with larger angles can undergo multiple reflections between the reflective sidewalls 7 of adjacent microstructures 5, and thus be converted into small-angle light before being emitted.

[0052] Furthermore, if λ is set to less than 5°, the tilt angle of the reflective sidewall 7 will be too small, which would place excessively high demands on the manufacturing process and make it difficult to control the process precision. Conversely, if λ is set to greater than 10°, the tilt angle of the reflective sidewall 7 will be too large. For example, combined with... Figure 6 When the microstructure 5 is a cone structure, an excessively large apex angle will result in a large diameter L of the microstructure 5, which in turn leads to a smaller number of microstructures 5 that can be set in the dimming layer 4, affecting the dimming effect. Therefore, setting λ between 5° and 10° not only allows the microstructure 5 to have a good dimming effect, but also reduces the manufacturing difficulty and increases the number of microstructures 5 that can be set in the dimming layer 4.

[0053] In one feasible implementation, such as Figure 6 As shown, Figure 6 This is a schematic diagram of a dimming layer 4 provided in an embodiment of the present invention. The reflective sidewalls 7 of the microstructure 5 intersect on the side away from the first light-emitting structure 3. The microstructure 5 includes a reflective material.

[0054] In the above configuration, the microstructure 5 can be a cone structure. When the angle between the tilt direction of the reflective sidewall 7 and the normal direction F is constant, the diameter L of the microstructure 5 can be reduced while ensuring that the microstructure 5 has a sufficient height h, so that more microstructures 5 can be set in a unit area to control more light. Alternatively, the height h of the microstructure 5 can be increased while ensuring that the microstructure 5 has a sufficient diameter L, thereby better controlling the light emitted from the first light guide plate at a slightly larger angle. For example, combined with Figure 5By increasing the height h of the microstructure 5, after the light at 50° and 60° is reflected by the reflective sidewall 7 of a certain microstructure 5, more reflected light can be further transmitted to the adjacent microstructure 5 and reflected by the reflective sidewall 7 of the adjacent microstructure 5, thereby achieving emission at a smaller angle and improving the output brightness in the narrow viewing angle display mode.

[0055] In addition, microstructure 5 is entirely formed of reflective material, which has better reflective performance and can also reduce the manufacturing difficulty of microstructure 5.

[0056] It should be noted that in the above structure, in the direction perpendicular to the plane where the backlight module is located, the orthogonal projection of the reflective barrier 6 can cover the orthogonal projection of the entire microstructure 5.

[0057] In one feasible implementation, such as Figure 7 As shown, Figure 7 This is another schematic diagram of the dimming layer 4 provided in an embodiment of the present invention. The microstructure 5 includes a light-transmitting body 9, which includes a bottom surface 10 close to the first light-emitting structure 3, a top surface 11 away from the first light-emitting structure 3, and sidewalls 12 intersecting the bottom surface 10 and the top surface 11 respectively. In a direction perpendicular to the plane of the backlight module, the top surface 11 overlaps with the bottom surface 10, and the area of ​​the top surface 11 is smaller than the area of ​​the bottom surface 10. The microstructure 5 also includes a reflective layer 13, which covers the light-transmitting sidewalls 12.

[0058] In the above configuration, the microstructure 5 can be a trapezoidal structure. When it is necessary to control the display device to be in privacy mode, such as... Figure 8 As shown, Figure 8 This is another light transmission schematic diagram provided by an embodiment of the present invention. For the portion of light incident toward the bottom of the microstructure 5, a portion of it can be directly emitted through the light-transmitting body 9 and its top surface 11. This structure allows more light at small angles to be emitted from the backlight module, further improving the light output brightness of the display device in privacy mode.

[0059] It should be noted that in this structure, the reflective sidewall 7 of the microstructure 5 is the sidewall of the reflective layer 13. Furthermore, in the direction perpendicular to the plane where the backlight module is located, the orthographic projection of the reflective barrier 6 can only cover the orthographic projection of the reflective sidewall 7 of the microstructure 5, while exposing the main body top surface 11 of the light-transmitting body 9, so that light incident at a small angle from the bottom of the microstructure 5 can pass through the top surface and be emitted.

[0060] In one feasible implementation, such as Figure 9 As shown, Figure 9This is another schematic diagram of the dimming layer 4 provided in an embodiment of the present invention. The dimming layer 4 further includes a first substrate 14 and an adhesive portion 15. The microstructure 5 is embedded in the first substrate 14, and the adhesive portion 15 is located on the side of the first substrate 14 near the first light-emitting structure 3. The reflective barrier 6 is bonded to the adhesive portion 15. For example, two adjacent reflective barriers 6 are bonded together by the adhesive portion 15. To ensure light transmittance, the first substrate 14 can be formed of a transparent material such as polycarbonate, and the adhesive portion 15 can be formed of a transparent adhesive material.

[0061] In the above structure, on the one hand, the microstructure 5 is embedded in the first substrate 14, which can improve the stability of the position of the microstructure 5. On the other hand, the bonding between the reflective barrier 6 and the adhesive part can also improve the stability of the position of the reflective barrier 6, so that it can better correspond with the microstructure 5, thereby improving the reliability of light control of the two.

[0062] Furthermore, see again Figure 9 The dimming layer 4 also includes a second substrate 16, which is located on the side of the adhesive portion 15 and the reflective barrier 6 away from the first substrate 14. The second substrate 16 and the first substrate 14 can be formed of the same material.

[0063] In this structure, the first substrate 14 and the second substrate 16 can fully encapsulate the microstructure 5 and the reflective barrier 6, providing a certain degree of protection for the microstructure 5 and the reflective barrier 6, and further improving the overall reliability of the dimming layer 4.

[0064] Furthermore, since the second substrate 16 does not need to contain the microstructure 5, the second substrate 16 can be made thinner, that is, the thickness of the second substrate 16 is less than the thickness of the first substrate 14, so as to reduce the overall thickness of the backlight module.

[0065] In one feasible implementation, such as Figure 10 As shown, Figure 10 This is a schematic diagram of a first backlight structure 1 provided in an embodiment of the present invention. The first backlight structure 1 further includes at least one brightness enhancement film 17, which is located on one side of the dimming layer 4 to achieve a brightness enhancement effect.

[0066] Furthermore, see again Figure 10 The brightness enhancement film 17 is located between the dimming layer 4 and the first light-emitting structure 3.

[0067] When the brightness enhancement film 17 is located below the dimming layer 4, the light reflected back by the reflective barrier 6 can undergo optical effects such as refraction in the brightness enhancement film 17, thereby achieving reuse. The reused light then enters the dimming layer 4 again and is emitted directly at a smaller angle, or it is converted into light emitted at a smaller angle after being controlled by the microstructure 5, thereby increasing the center brightness of the display device in privacy mode to a greater extent.

[0068] In one configuration, to further improve the reuse of light and increase the output brightness, at least one brightness enhancement film 17 may include a dual brightness enhancement film (DBEF) 18 with reflective properties, and the dual brightness enhancement film 18 may be located on the side closer to the dimming layer 4.

[0069] Furthermore, this embodiment of the invention also performed optical modeling and simulation of the dimming layer 4. In this embodiment, the Lambertian distribution light source is controlled to emit light rays upwards by 180°. Under the first test condition, a conventional light control film as described in the background art is used to modulate the light, and an optical detector is used to detect surface illuminance and viewing angle brightness. Under the second test condition, the dimming layer 4 of this embodiment of the invention is used to modulate the light, and an optical detector is used to detect surface illuminance and viewing angle brightness. Based on the detection structure of the optical detector under the two test conditions, a diagram is drawn. Figure 11 The brightness contrast diagram shown is as follows. Figure 11 As shown, Figure 11 This is a brightness comparison diagram of the present invention and related technologies provided in an embodiment of the present invention. Figure 11 The solid line in the figure represents the curve relationship between the viewing angle and the normalized viewing angle brightness corresponding to the embodiments of the present invention. Figure 11 The dashed line in the figure represents the curve relationship between the viewing angle corresponding to the relevant technology and the normalized viewing angle brightness, combined with Figure 11 As can be seen, the dimming layer 4 in the embodiments of the present invention can achieve higher center viewing angle brightness and similar half-width angle. Therefore, compared with the prior art, the dimming layer 4 provided in the embodiments of the present invention can significantly improve the center viewing angle brightness of the display device in privacy mode.

[0070] In one feasible implementation, see again Figure 10 The first backlight structure 1 also includes a diffuser 19 located between the first light-emitting structure 3 and the dimming layer 4. The diffuser 19 can diffuse the light emitted from the first light-emitting structure 3 at a larger angle, so that the light enters the dimming layer 4 at more angles, avoiding the transmission angle of the light entering the dimming layer 4 being too singular.

[0071] In one feasible implementation, combined with Figure 6 and Figure 7 In the direction perpendicular to the plane of the backlight module, the distance between the orthographic projections of two adjacent microstructures 5 is d, where 0.085mm ≤ d ≤ 0.117mm. For example, when the diameter L of the microstructure 5 is 0.015mm, the distance k between the geometric centers of the orthographic projections of two adjacent microstructures 5 in the direction perpendicular to the plane of the backlight module can satisfy: 0.1mm ≤ k ≤ 0.132mm.

[0072] When d is between 0.085mm and 0.117mm, the spacing between two adjacent microstructures 5 is not too close, allowing some light at small angles to pass directly through the gap between them. Simultaneously, the spacing between two adjacent microstructures 5 is not too far either. Thus, combined with... Figure 6 When light at a large angle is reflected by the reflective sidewall 7 of a certain microstructure 5, the reflected light can be further transmitted to the adjacent microstructure 5 and reflected by the reflective sidewall 7 of the adjacent microstructure 5, thereby converting it into light at a smaller angle and sending it out.

[0073] In one feasible implementation, combined with Figure 6 and Figure 7 The microstructure 5 has a dimension h in the direction perpendicular to the plane where the backlight module is located, with a dimension of 0.2mm ≤ d ≤ 0.4mm.

[0074] When h is between 0.2 mm and 0.4 mm, the microstructure 5 has sufficient height, thus enabling the combination... Figure 5 When light at a large angle is reflected by the reflective sidewall 7 of a certain microstructure 5, the reflected light is more likely to be transmitted to the reflective sidewall 7 of the adjacent microstructure 5, and thus can be converted into light at a smaller angle and emitted.

[0075] In one feasible implementation, see again Figure 1 The first light-emitting structure 3 includes a first direct-downward backlight 20.

[0076] When the first light-emitting structure 3 adopts the first direct-downward backlight 20, on the one hand, the backlight emitted by the first direct-downward backlight 20 can be directly transmitted to the dimming layer 4, and there is no need to set a light guide plate in the first light-emitting structure 3. On the other hand, the display device can be dimmed in different areas by controlling the light emission brightness of the first direct-downward backlight 20. For example, when the display device is in privacy mode, the first direct-downward backlight 20 can be controlled to emit light only in the middle area, and not emit light in the edge area surrounding the middle area.

[0077] Or, in another setting, such as Figure 12 As shown, Figure 12 This is another schematic diagram of the first backlight structure 1 provided in the embodiment of the present invention. The first light-emitting structure 3 may also include a first light source 21 and a first light guide plate 22, wherein the first light source 21 is located on one side of the first light guide plate 22.

[0078] In one feasible implementation, combined with Figure 1 and Figure 13 , Figure 13This is a top view of the second light guide plate 24 provided in an embodiment of the present invention. The second backlight structure 2 includes a second light source 23 and a second light guide plate 24. The second light source 23 is located on one side of the second light guide plate 24. The second light guide plate 24 includes a plurality of dots 25, which can be located at the bottom of the second light guide plate 24, for example, as a polyhedral structure. The dots 25 are used to diffuse the light emitted by the second light source 23 that is transmitted within the second light guide plate 24, and not to diffuse the light incident on the second light guide plate 24 via the first backlight structure 1. In this way, the second backlight structure 2 can achieve large-angle light divergence without the need for a diffusion film or other structures, which can avoid the diffusion film affecting the collimated light incident via the first backlight structure 1 in privacy mode. Moreover, the absence of a diffusion film in the second backlight structure 2 also reduces the overall thickness of the second backlight structure 2, which helps to achieve a thinner and lighter design for the backlight module.

[0079] Based on the same inventive concept, this embodiment of the invention also provides a method for manufacturing a backlight module, which is used to manufacture the aforementioned backlight module.

[0080] Combination Figure 1 The manufacturing method includes forming a first backlight structure 1 and a second backlight structure 2, the second backlight structure 2 being located on the side of the first backlight structure 1 facing the light-emitting surface of the backlight module; wherein, the process of forming the first backlight structure 1 includes: setting a dimming layer 4 on one side of the first light-emitting structure 3, the dimming layer 4 including a plurality of microstructures 5 and a plurality of reflective barriers 6, the microstructures 5 including reflective sidewalls 7, and the adjacent microstructures 5 having a gap, the reflective barriers 6 being located between the microstructures 5 and the first light-emitting structure 3, and the orthographic projections of the reflective barriers 6 and the reflective sidewalls 7 overlapping in a direction perpendicular to the plane where the backlight module is located.

[0081] Based on the foregoing analysis, the backlight module formed by the above manufacturing method can not only narrow the viewing angle when the display device needs to be controlled in privacy mode, but also greatly increase the amount of small-angle light emitted by the backlight module, thereby effectively improving the light output brightness of the display device in privacy mode and enabling it to better meet the brightness specifications of the display device.

[0082] In one feasible implementation, combined with Figure 6 ,like Figure 14 As shown, Figure 14 This is a process flow diagram of the manufacturing method provided in an embodiment of the present invention. The process of forming the dimming layer 4 includes:

[0083] Step S1: A plurality of recesses 26 are formed by embossing in the first substrate 14, wherein the sidewalls of the recesses 26 intersect at the bottom of the recesses 26.

[0084] Step S2: The reflective material is poured into the recess 26 to form a microstructure 5 embedded in the first substrate 14.

[0085] Step S3: An adhesive portion 15 and a reflective barrier 6 are formed on one side of the first substrate 14, and the reflective barrier 6 is bonded to the adhesive portion 15.

[0086] The microstructure 5 formed by the above method has its reflective sidewalls 7 intersecting on the side away from the first light-emitting structure 3. Thus, when the angle between the tilt direction of the reflective sidewalls 7 and the normal direction F is constant, the diameter L of the microstructure 5 can be reduced while ensuring sufficient height h, allowing for a larger number of microstructures 5 to be set within a unit area and more light to be controlled. Alternatively, the height h of the microstructure 5 can be increased while ensuring sufficient diameter L, thereby achieving better control over light emitted at slightly larger angles through the first light guide plate.

[0087] Furthermore, see again Figure 14 After forming the adhesive portion 15 and the reflective barrier 6 on one side of the first substrate 14, the process of forming the dimming layer 4 further includes:

[0088] Step S4: A second substrate 16 is formed on the side of the adhesive portion 15 and the reflective barrier 6 away from the first substrate 14.

[0089] At this time, the first substrate 14 and the second substrate 16 can fully encapsulate the microstructure 5 and the reflective barrier 6, providing a certain degree of protection for the microstructure 5 and the reflective barrier 6 and improving the overall reliability of the dimming layer 4.

[0090] In one feasible implementation, combined with Figure 7 ,like Figure 15 As shown, Figure 15 This is another process flow diagram of the manufacturing method provided in the embodiment of the present invention. The process of forming the dimming layer 4 includes:

[0091] Step K1: A plurality of recesses 26 are formed by embossing in the first substrate 14. Each recess 26 includes a recess bottom surface 27 and a recess sidewall 28. The recess bottom surface 27 overlaps with the recess opening 29, and the area of ​​the recess bottom surface 27 is smaller than the area of ​​the opening 29.

[0092] Step K2: A reflective layer 13 is formed on the recessed sidewall 28, and a light-transmitting material is poured into the recess 26 to form a light-transmitting body 9, thereby forming a microstructure 5 embedded in the first substrate 14.

[0093] Step K3: An adhesive portion 15 and a reflective barrier 6 are formed on one side of the first substrate 14, and the reflective barrier 6 is bonded to the adhesive portion 15.

[0094] Combination Figure 7 and Figure 8The microstructure 5 formed by the above process includes a light-transmitting body 9 and a reflective layer 13. When it is necessary to control the display device to be in privacy mode, a portion of the light incident toward the bottom of the microstructure 5 can be directly emitted through the light-transmitting body 9 and its top surface 11. This structure allows more light at small angles to be emitted from the backlight module, further improving the light output brightness of the display device in privacy mode.

[0095] Furthermore, see again Figure 15 After forming the adhesive portion 15 and the reflective barrier 6 on one side of the first substrate 14, the process of forming the dimming layer 4 further includes:

[0096] Step K4: A second substrate 16 is formed on the side of the adhesive portion 15 and the reflective barrier 6 away from the first substrate 14.

[0097] At this time, the first substrate 14 and the second substrate 16 can fully encapsulate the microstructure 5 and the reflective barrier 6, providing a certain degree of protection for the microstructure 5 and the reflective barrier 6 and improving the overall reliability of the dimming layer 4.

[0098] Based on the same inventive concept, embodiments of the present invention also provide a display device, such as... Figure 16 As shown, Figure 16 This is a schematic diagram of a display device provided in an embodiment of the present invention. The display device includes the backlight module 100 and a display panel 200, with the display panel 200 located on the side of the backlight module 100 facing the light-emitting surface of the display device. The specific structure of the backlight module 100 has been described in detail in the above embodiments and will not be repeated here. In this embodiment of the present invention, Figure 16 The display device shown can be an in-vehicle display screen, such as a central control screen, or any electronic device with display function, such as a mobile phone, tablet computer, laptop computer, e-reader, or television.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A backlight module, characterized in that, include: A first backlight structure includes a first light-emitting structure and a dimming layer located on the side of the first light-emitting structure facing the light-emitting surface of the backlight module. The dimming layer includes multiple microstructures and a reflective barrier. Each microstructure includes a reflective sidewall, and adjacent microstructures are spaced apart. Each microstructure and the reflective barrier correspond one-to-one. Each microstructure also includes a bottom surface, which is close to the first light-emitting structure and intersects with the reflective sidewall. The reflective barrier is located between the bottom surface of its corresponding microstructure and the first light-emitting structure. In a direction perpendicular to the plane of the backlight module, the orthographic projections of the reflective barrier and the reflective sidewall overlap. The second backlight structure is located on the side of the first backlight structure facing the light-emitting surface of the backlight module.

2. The backlight module according to claim 1, characterized in that, The angle between the reflective sidewall and the bottom surface is less than 90°.

3. The backlight module according to claim 2, characterized in that, The angle between the tilt direction of the reflective sidewall and the first direction is λ, where 5°≤λ≤10°, and the first direction is perpendicular to the plane where the backlight module is located.

4. The backlight module according to claim 1, characterized in that, The reflective sidewalls of the microstructure intersect on the side away from the first light-emitting structure, and the microstructure includes a reflective material.

5. The backlight module according to claim 1, characterized in that, The microstructure includes a light-transmitting body, which includes a bottom surface close to the first light-emitting structure, a top surface away from the first light-emitting structure, and sidewalls that intersect the bottom surface and the top surface of the body respectively. In a direction perpendicular to the plane where the backlight module is located, the top surface of the body overlaps with the bottom surface of the body, and the area of ​​the top surface of the body is smaller than the area of ​​the bottom surface of the body. The microstructure also includes a reflective layer that covers the sidewall of the main body.

6. The backlight module according to claim 1, characterized in that, The dimming layer further includes a first substrate and an adhesive portion. The microstructure is embedded in the first substrate, the adhesive portion is located on the side of the first substrate near the first light-emitting structure, and the reflective barrier is bonded to the adhesive portion.

7. The backlight module according to claim 6, characterized in that, The dimming layer further includes a second substrate, which is located on the side of the adhesive portion and the reflective barrier away from the first substrate.

8. The backlight module according to claim 1, characterized in that, The first backlight structure further includes at least one brightness enhancement film, which is located on one side of the dimming layer.

9. The backlight module according to claim 8, characterized in that, The brightness enhancement film is located between the dimming layer and the first light-emitting structure.

10. The backlight module according to claim 1, characterized in that, The first backlight structure further includes a diffuser sheet located between the first light-emitting structure and the dimming layer.

11. The backlight module according to claim 1, characterized in that, In the direction perpendicular to the plane where the backlight module is located, the distance between the orthographic projections of two adjacent microstructures is d, 0.085 mm ≤ d ≤ 0.117 mm.

12. The backlight module according to claim 1, characterized in that, The microstructure has a dimension h in the direction perpendicular to the plane of the backlight module, where 0.2 mm ≤ h ≤ 0.4 mm.

13. The backlight module according to claim 1, characterized in that, The first light-emitting structure includes a first direct-downward backlight.

14. The backlight module according to claim 1, characterized in that, The second backlight structure includes a second light source and a second light guide plate. The second light source is located on one side of the second light guide plate. The second light guide plate includes a plurality of dots. The dots are used to diffuse the light emitted by the second light source that is transmitted within the second light guide plate, and to prevent the diffusion of light incident on the second light guide plate via the first backlight structure.

15. A method for manufacturing a backlight module, characterized in that, To manufacture the backlight module as described in claim 1, the method includes forming a first backlight structure and a second backlight structure, wherein the second backlight structure is located on the side of the first backlight structure facing the light-emitting surface of the backlight module. The process of forming the first backlight structure includes: setting a dimming layer on one side of the first light-emitting structure. The dimming layer includes multiple microstructures and multiple reflective barriers. Each microstructure includes a reflective sidewall. Each microstructure and each reflective barrier corresponds one-to-one and there is a gap between adjacent microstructures. Each microstructure also includes a bottom surface. The bottom surface is close to the first light-emitting structure and intersects with the reflective sidewall. The reflective barrier is located between the bottom surface of its corresponding microstructure and the first light-emitting structure. In a direction perpendicular to the plane where the backlight module is located, the orthographic projections of the reflective barrier and the reflective sidewall overlap.

16. The method of manufacturing according to claim 15, wherein, The process of forming the dimming layer includes: Multiple recesses are embossed in a first substrate, wherein the sidewalls of the recesses intersect at the bottom of the recesses; The reflective material is poured into the recess to form the microstructure embedded in the first substrate; An adhesive portion and the reflective barrier are formed on one side of the first substrate, and the reflective barrier is bonded to the adhesive portion.

17. The manufacturing method according to claim 15, characterized in that, The process of forming the dimming layer includes: Multiple recesses are embossed in a first substrate. Each recess includes a bottom surface and a sidewall. The bottom surface overlaps with the opening of the recess, and the area of ​​the bottom surface is smaller than the area of ​​the opening. A reflective layer is formed on the sidewall of the recess, and a light-transmitting material is poured into the recess to form a light-transmitting body, thereby forming the microstructure embedded in the first substrate; An adhesive portion and the reflective barrier are formed on one side of the first substrate, and the reflective barrier is bonded to the adhesive portion.

18. The manufacturing method according to claim 16 or 17, characterized in that, After forming the adhesive portion and the reflective barrier on one side of the first substrate, the process of forming the dimming layer further includes forming a second substrate on the side of the adhesive portion and the reflective barrier away from the first substrate.

19. A display device, characterized in that, include: The backlight module as described in any one of claims 1 to 14; The display panel is located on the side of the backlight module facing the light-emitting surface of the display device.

Images