Backlight module and display device

Abstract

Embodiments of the present application provide a backlight module and a display device. The backlight module comprises a plurality of repeating units. Each repeating unit comprises at least a first light emitting element and a second light emitting element. The first light emitting element has a larger light emitting viewing angle than the second light emitting element. The first light emitting element and the second light emitting element have the same light emitting color. The backlight module is configured in a first light emitting mode, in which the first light emitting element emits light and the second light emitting element does not emit light. The backlight module is configured in a second light emitting mode, in which the first light emitting element does not emit light and the second light emitting element emits light. Thus, the display effect of the display device in a dark state is improved.

Description

Technical Field

[0001] This invention belongs to the field of display technology, specifically relating to backlight modules and display devices. Background Technology

[0002] In the rapidly developing information age, people are paying increasing attention to the protection of their personal information. As a result, a type of monitor with privacy features has emerged. This type of monitor allows only users at a direct viewing angle to read the displayed content, while onlookers at the side cannot see the content, effectively protecting the user's information privacy.

[0003] Currently, monitors that can switch between wide and narrow viewing angles typically use a dual LCD cell design, where one LCD cell is used for displaying the image and the other is used to switch between wide and narrow viewing angles. In privacy mode, the viewing angle of this structure is fixed and cannot be adjusted. Therefore, when the privacy viewing angle requires a black screen, there are problems such as light leakage in the dark because the transmittance of light of different wavelengths is not equal to zero. Summary of the Invention

[0004] This application provides a backlight module and display device to alleviate the shortcomings of related technologies.

[0005] To achieve the above functions, the technical solutions provided in this application are as follows:

[0006] This application provides a backlight module including multiple repeating units. Each repeating unit includes at least a first light-emitting element and a second light-emitting element. The light-emitting angle of the first light-emitting element is greater than that of the second light-emitting element, and the first light-emitting element and the second light-emitting element emit the same color.

[0007] The backlight module is configured in a first light-emitting mode, in which the first light-emitting element emits light and the second light-emitting element does not emit light; the backlight module is configured in a second light-emitting mode, in which the first light-emitting element does not emit light and the second light-emitting element emits light.

[0008] Optionally, in one embodiment, the backlight module includes:

[0009] A first dimming part is provided corresponding to the first light-emitting element. The first dimming part is located on the light-emitting side of the first light-emitting element. The first dimming part includes a first arc portion, which protrudes in a direction away from the first light-emitting element.

[0010] The second dimming part is disposed corresponding to the second light-emitting element. The second dimming part is disposed on the light-emitting side of the second light-emitting element. The second dimming part includes a second arc portion, which protrudes in a direction close to the second light-emitting element.

[0011] Optionally, in one embodiment, the second dimming unit includes a bottom wall and a reflective sidewall disposed around the bottom wall. The bottom wall is located on the side of the second dimming unit closer to the second light-emitting element. The bottom wall has a first opening, and the reflective sidewall has a second opening on the side away from the bottom wall. The width of the first opening is greater than or equal to the width of the second light-emitting element.

[0012] Optionally, in one embodiment, the backlight module further includes a plurality of lens portions disposed on the side of the second dimming portion away from the second light-emitting element, wherein the orthographic projection of the lens portions on the backlight module covers the orthographic projection of the second light-emitting element on the backlight module.

[0013] Optionally, in one embodiment, the repeating unit further includes a third light-emitting element and a fourth light-emitting element, wherein the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are arranged in an array within the repeating unit;

[0014] The first light-emitting element, the third light-emitting element, and the fourth light-emitting element all emit different colors.

[0015] Optionally, in one embodiment, the first light-emitting element emits blue light, the second light-emitting element emits blue light, the third light-emitting element emits red light, and the fourth light-emitting element emits green light.

[0016] The areas of the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are all equal.

[0017] Optionally, in one embodiment, the first dimming part is disposed on the light-emitting side of the third light-emitting element, and the first arc portion protrudes in a direction away from the third light-emitting element; the first dimming part is disposed on the light-emitting side of the fourth light-emitting element, and the first arc portion protrudes in a direction away from the fourth light-emitting element.

[0018] Optionally, in one embodiment, the backlight module further includes:

[0019] A microlens is disposed on the light-emitting side of the repeating unit;

[0020] A diffuser plate is disposed on the side of the microlens away from the repeating unit;

[0021] A prism is disposed on the side of the diffuser plate away from the microlens; and

[0022] A brightening layer is disposed on the side of the prism away from the diffuser plate.

[0023] Optionally, in one embodiment, the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are driven in a time-division manner using a field-sequence display method;

[0024] Wherein, a light-emitting frame of the backlight module includes at least a first time period, a second time period, and a third time period. The light-emitting time period of the third light-emitting element is one of the first time period, the second time period, and the third time period. The light-emitting time period of the fourth light-emitting element is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element. The light-emitting time period of the first light-emitting element or the second light-emitting element is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element and the fourth light-emitting element.

[0025] This application also provides a display device, including a display panel and any of the backlight modules described above; wherein the backlight module is located on the side of the backlight of the display panel.

[0026] The beneficial effects of the embodiments of this application are as follows: The embodiments of this application provide a backlight module and a display device. The backlight module includes multiple repeating units. By setting the repeating units to include at least a first light-emitting element and a second light-emitting element, the light-emitting viewing angle of the first light-emitting element is greater than that of the second light-emitting element, and the first light-emitting element and the second light-emitting element emit the same light color. The backlight module is configured in a first light-emitting mode in which the first light-emitting element emits light and the second light-emitting element does not emit light. The backlight module is also configured in a second light-emitting mode in which the first light-emitting element does not emit light and the second light-emitting element emits light. This helps to reduce the amount of light leakage of the display device under dark viewing angles, thereby improving the display effect of the display device under dark viewing angles. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the backlight emission path of the display device provided in the embodiments of this application configured in a first display mode;

[0029] Figure 2 A schematic diagram of the backlight emission path of the display device provided in the embodiments of this application configured in a second display mode;

[0030] Figure 3A top view of the backlight module provided in the embodiment of the application;

[0031] Figure 4 for Figure 3 Schematic diagram of the cross section at point A-Aˋ;

[0032] Figure 5 for Figure 3 Schematic diagram of the cross section at point B-Bˋ;

[0033] Figure 6 for Figure 3 Schematic diagram of the cross section at C-Cˋ;

[0034] Figure 7 This is a cross-sectional schematic diagram of the backlight module provided in the embodiments of this application;

[0035] Figure 8 The spectral curve of the backlight module provided in the embodiments of this application is shown. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working mode of the device, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only, and features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections or connections that allow communication; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] The following disclosure provides many different embodiments for implementing different structures of this application. To simplify the disclosure of this application, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0040] This application provides a backlight module and a display device. These will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0041] Please combine Figure 1 , Figure 2 and Figure 3 ;in, Figure 1 A schematic diagram of the backlight emission path of the display device provided in the embodiments of this application configured in a first display mode; Figure 2 A schematic diagram of the backlight emission path of the display device provided in the embodiments of this application configured in a second display mode; Figure 3 This is a top view of the backlight module provided in the embodiment of the application.

[0042] This embodiment provides a display device 1, which includes a display panel 20 and a backlight module 10; wherein, the backlight module 10 is located on the backlight side of the display panel 20, and the display panel 20 may be a light-emitting diode (LED) display panel, which is not specifically limited in this embodiment.

[0043] The display device 1 is configured in a first display mode and a second display mode. The light emission angle of the display device 1 in the second display mode is smaller than the light emission angle of the display device 1 in the first display mode. It should be noted that this embodiment takes the first display mode as the normal display mode and the second display mode as the privacy mode as an example to illustrate the technical solution of this application.

[0044] The backlight module 10 includes a plurality of repeating units 120, each repeating unit 120 including at least a first light-emitting element 121 and a second light-emitting element 122. The light-emitting angle of the first light-emitting element 121 is greater than that of the second light-emitting element 122, and the first light-emitting element 121 and the second light-emitting element 122 emit the same color. The backlight module 10 is configured in a first light-emitting mode in which the first light-emitting element 121 emits light and the second light-emitting element 122 does not emit light. The backlight module 10 is also configured in a second light-emitting mode in which the first light-emitting element 121 does not emit light and the second light-emitting element 122 emits light.

[0045] Specifically, the display device 1 is configured in a first display mode, the backlight module 10 is configured in a first light-emitting mode, the first light-emitting element 121 emits light, and the second light-emitting element 122 does not emit light; the display device 1 is configured in a second display mode, the backlight module 10 is configured in a second light-emitting mode, the first light-emitting element 121 does not emit light, and the second light-emitting element 122 emits light.

[0046] It should be noted that currently, a dual-LCD cell design is commonly used to achieve viewing angle switching for the display. That is, the display device 1 includes a collimating backlight, a dimming LCD cell, and an LCD panel. The LCD panel is used for image display, and the dimming LCD cell is used to switch between wide and narrow viewing angles. Since the viewing angle range of this structure is fixed in privacy mode and cannot be adjusted, light leakage occurs in dark viewing angles. For example, there is a problem of light leakage in the blue light band in dark conditions with a large viewing angle, which causes abnormal display phenomena such as blue halo to appear on the display product in dark conditions with a large viewing angle, affecting the display effect.

[0047] It is understood that, in this embodiment, the repeating unit 120 is configured to include at least a first light-emitting element 121 and a second light-emitting element 122. The light-emitting angle of the first light-emitting element 121 is greater than that of the second light-emitting element 122, and the first light-emitting element 121 and the second light-emitting element 122 emit the same color. The backlight module 10 is configured in a first light-emitting mode where the first light-emitting element 121 emits light and the second light-emitting element 122 does not emit light. Alternatively, the backlight module 10 can be configured in a second light-emitting mode where the first light-emitting element 121 does not emit light and the second light-emitting element 122 emits light. Therefore, when the display device 1 is configured in the second display mode, the amount of light emitted from the backlight module 10 at a wide viewing angle can be reduced, thereby reducing light leakage in the display device 1 under dark viewing angles and improving the display effect of the display device 1 under dark viewing angles.

[0048] Please combine Figure 1 , Figure 2 and Figure 3 In one embodiment, the backlight module includes a substrate 11 and repeating units 120 disposed on the substrate 11. The substrate 11 includes a driving circuit, and the repeating units 120 include a plurality of light-emitting elements 12 arranged in an array. The driving circuit is used to provide driving electrical signals to the light-emitting elements 12. The light-emitting elements 12 include, but are not limited to, mini-light-emitting diodes (Mini-LEDs).

[0049] The repeating unit 120 includes a first light-emitting element 121, a second light-emitting element 122, a third light-emitting element 123, and a fourth light-emitting element 124. The first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are arranged in an array within the repeating unit 120. The first light-emitting element 121, the third light-emitting element 123, and the fourth light-emitting element 124 emit different colors, while the first light-emitting element 121 and the second light-emitting element 122 emit the same color.

[0050] Optionally, the first light-emitting element 121 emits blue light, the second light-emitting element 122 emits blue light, the third light-emitting element 123 emits red light, and the fourth light-emitting element 124 emits green light; wherein the areas of the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are all equal.

[0051] It should be noted that this embodiment does not impose specific limitations on the number, arrangement, light emission color of the first light emission element 121, the second light emission element 122, the third light emission element 123, and the fourth light emission element 124. This embodiment only illustrates the technical solution of this application by taking the light emission element 12 as including the first light emission element 121, the second light emission element 122, the third light emission element 123, and the fourth light emission element 124, with the first light emission element 121 emitting blue, the second light emission element 122 emitting blue, the third light emission element 123 emitting red, and the fourth light emission element 124 emitting green.

[0052] It is understood that in this embodiment, the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are arranged in an array within the repeating unit 120, and the areas of the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are all equal, that is, the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 each occupy one-quarter of the area of ​​the repeating unit 120, thereby improving the uniformity of the light emitted by the backlight module 10.

[0053] Furthermore, in this embodiment, the light-emitting angle of the first light-emitting element 121 is set to be greater than that of the second light-emitting element 122, and the first light-emitting element 121 and the second light-emitting element 122 emit the same color. The backlight module 10 is configured in a first light-emitting mode where the first light-emitting element 121 emits light and the second light-emitting element 122 does not emit light. Alternatively, the backlight module 10 can be configured in a second light-emitting mode where the first light-emitting element 121 does not emit light and the second light-emitting element 122 emits light. Therefore, when the display device 1 is configured in the second display mode, the amount of blue light emitted from the backlight module 10 over a wide viewing angle can be reduced, thereby reducing the amount of blue light leakage from the display device 1 in dark viewing angles and improving the display effect of the display device 1 in dark viewing angles.

[0054] Please combine Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 ;in, Figure 4 for Figure 3 Schematic diagram of the cross section at point A-Aˋ; Figure 5 for Figure 3 A schematic diagram of the cross-section at point B-Bˋ.

[0055] In one embodiment, the backlight module 10 includes a substrate 11 and a plurality of light-emitting elements 12 disposed on the substrate 11. The substrate 11 includes a driving circuit and a pad, the driving circuit and the pad being electrically connected. The pad is located on the surface of the substrate 11. The first light-emitting element 121 includes a first solder foot 1211 and a first light-emitting element 1212 connected to each other. The first solder foot 1211 is located on the side of the first light-emitting element 1212 near the pad and is electrically connected to the pad. The second light-emitting element 122 includes a second solder foot 1221 and a second light-emitting element 1222 connected to each other. The second solder foot 1221 is located on the side of the second light-emitting element 1222 near the pad and is electrically connected to the pad.

[0056] The backlight module 10 further includes a first dimming section 131 and a second dimming section 132. The first dimming section 131 is disposed corresponding to the first light-emitting element 121 and is located on the light-emitting side of the first light-emitting element 121. The first dimming section 131 includes a first arcuate portion 1311, which protrudes in a direction away from the first light-emitting element 121. The second dimming section 132 is disposed corresponding to the second light-emitting element 122 and is located on the light-emitting side of the second light-emitting element 122. The second dimming section 132 includes a second arcuate portion 1321, which protrudes in a direction close to the second light-emitting element 122.

[0057] Specifically, in one embodiment, the first dimming unit 131 can be a convex lens structure. The first dimming unit 131 covers the first light-emitting element 1212. The light-incident surface of the first dimming unit 131 faces the first light-emitting element 1212, and the light-emitting surface of the first dimming unit 131 is a protruding curved surface. When the light emitted from the first light-emitting element 1212 passes through the light-emitting surface of the first dimming unit 131 (taking the light emitted from the first dimming unit 131 into the air as an example), the light changes from a denser material to a less dense material. Therefore, the light emitted from the first light-emitting element 1212 will be deflected. Since the light emitted from the first light-emitting element 1212 is emitted into the air by the convex lens, the light will be deflected away from the normal direction of the first dimming unit 131. In other words, the first dimming unit 131 can appropriately adjust the angle of the light emitted from the first light-emitting element 121 to improve the light-emitting angle of the first light-emitting element 121, so that the light-emitting angle of the backlight unit in the first light-emitting mode is greater than the light-emitting angle of the backlight unit in the second light-emitting mode.

[0058] In one embodiment, the second dimming unit 132 includes a bottom wall 1322 and a reflective sidewall 1323 surrounding the bottom wall 1322. The bottom wall 1322 is located on the side of the second dimming unit 132 closer to the second light-emitting element 122. The bottom wall 1322 has a first opening 1322A, and the reflective sidewall 1323 has a second opening 1323A on the side away from the bottom wall 1322. The width of the first opening 1322A is greater than or equal to the width of the second light-emitting element 122. The second opening 1323A is provided corresponding to the first opening 1322A, and the second light-emitting body 1222 is provided inside the first opening 1322A; of the light emitted by the second light-emitting body 1222, part of the light is emitted directly from the second opening 1323A, and the other part of the light is reflected to the second opening 1323A after reaching the reflective sidewall 1323; specifically, the reflective sidewall 1323 of the reflective cup includes, but is not limited to, any one of a sphere, quadratic surface, freeform surface, hyperbolic surface, parabola or ellipsoid.

[0059] Optionally, the center line of the second dimming part 132 and the center line of the second light-emitting element 1222 overlap. The second dimming part 132 can be a microlens and can be made of a high refractive index material so that the light emitted by the second light-emitting element 1222 undergoes total internal reflection at the reflective sidewall 1323, thereby achieving light focusing so that the light emission angle of the second light-emitting element 122 is smaller than that of the first light-emitting element 121.

[0060] It is understood that in this embodiment, by setting the second light-emitting body 1222 at the first opening 1322A of the bottom wall 1322 and the reflective sidewall 1323 surrounding the second light-emitting body 1222, the total amount of light emitted by the second light-emitting body 1222 remains unchanged. By changing the optical path design, the light scattered to the side of the display panel 20 is focused onto the entire surface of the display panel 20 as much as possible. This utilizes the light-gathering characteristics of microlenses to increase the brightness of the display panel 20 without increasing additional power consumption, thereby improving the display effect of the display panel 20.

[0061] Optionally, please combine Figure 1 , Figure 2 , Figure 3 and Figure 6 ;in, Figure 6 for Figure 3 A schematic diagram of the cross-section at point C-Cˋ.

[0062] In one embodiment, the first dimming unit 131 is disposed on the light-emitting side of the third light-emitting element 123, and the first arc portion 1311 protrudes in a direction away from the third light-emitting element 123; the first dimming unit 131 is disposed on the light-emitting side of the fourth light-emitting element 124, and the first arc portion 1311 protrudes in a direction away from the fourth light-emitting element 124. The first dimming unit 131 can appropriately adjust the angles of the light emitted by the first light-emitting element 121, the third light-emitting element 123, and the fourth light-emitting element 124, thereby improving the light-emitting viewing angles of the first light-emitting element 121, the third light-emitting element 123, and the fourth light-emitting element 124, so that the light-emitting viewing angle of the backlight module 10 in the first light-emitting mode is greater than the light-emitting viewing angle of the backlight unit in the second light-emitting mode, thereby improving the display effect of the display device 1 configured in the first display mode.

[0063] Please continue to combine Figure 1 , Figure 2 , Figure 3 and Figure 4 In one embodiment, the backlight module 10 further includes a plurality of lens portions 14, which are disposed on the side of the second dimming unit 132 away from the second light-emitting element 122. The center line of the lens portion 14 overlaps with the center line of the second light-emitting element 122, and the orthographic projection of the lens portion 14 on the backlight module 10 covers the orthographic projection of the second light-emitting element 122 on the backlight module 10. Thus, by utilizing the cooperation between the second dimming unit 132 and the lens portion 14 to exert a synergistic effect, the light directly emitted from the first opening 1322A of the second dimming unit 132 can be further focused, thereby increasing the light output brightness along the plane of the backlight module 10 and reducing the amount of light emitted from the second light-emitting element 122 at a wide viewing angle. This helps to reduce the amount of light leakage of the display device 1 in dark viewing angles and improve the display effect of the display device 1 in dark viewing angles.

[0064] It should be noted that the backlight module 10 further includes a first encapsulation layer and a second encapsulation layer stacked together. The first encapsulation layer is disposed on the side of the light-emitting element 12 away from the substrate 11; the second encapsulation layer is disposed on the side of the second dimming part 132 away from the second light-emitting element 122; the lens part 14 may be disposed on the side of the second encapsulation layer away from the second dimming part 132, or the lens part 14 may be disposed within the second encapsulation layer. This embodiment does not specifically limit this.

[0065] Please combine Figure 1 , Figure 2 and Figure 7 ;in, Figure 7This is a cross-sectional schematic diagram of the backlight module provided in the embodiments of this application.

[0066] In one embodiment, the backlight module 10 includes a substrate 11, a repeating unit 120, and a dimming layer 15. The repeating unit 120 includes at least a first light-emitting element 121 and a second light-emitting element 122. The light-emitting angle of the first light-emitting element 121 is greater than that of the second light-emitting element 122. The first light-emitting element 121 and the second light-emitting element 122 emit the same color. The dimming layer 15 is disposed on the light-emitting side of the light-emitting element 12. The orthographic projection of the dimming layer 15 on the substrate 11 covers the orthographic projection of the light-emitting element 12 on the substrate 11.

[0067] Specifically, the dimming layer 15 includes a microlens 151, a diffuser plate 152, a prism 153, and a brightness enhancement layer 154. The microlens 151 is disposed on the light-emitting side of the repeating unit 120, the diffuser plate 152 is disposed on the side of the microlens 151 away from the repeating unit 120, the prism 153 is disposed on the side of the diffuser plate 152 away from the microlens 151, and the brightness enhancement layer 154 is disposed on the side of the prism 153 away from the diffuser plate 152.

[0068] It is understood that in this embodiment, by setting the orthogonal projection of the dimming layer 15 on the substrate 11 to cover the orthogonal projection of the light-emitting element 12 on the substrate 11, and the dimming layer 15 includes stacked microlenses, diffusers, prisms and brightness enhancement layers, the light output brightness along the plane of the backlight module 10 is increased, and the brightness of the display panel 20 is improved without increasing additional power consumption, thereby improving the display effect of the display panel 20.

[0069] Please combine Figure 1 , Figure 2 , Figure 3 and Figure 8 ;in, Figure 8 The spectral curve of the backlight module provided in the embodiments of this application is shown.

[0070] In one embodiment, the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are driven in a time-division manner using a field-sequence display method; wherein, a light-emitting frame of the backlight module 10 includes at least a first time period, a second time period, and a third time period, the light-emitting time period of the third light-emitting element 123 is one of the first time period, the second time period, and the third time period, the light-emitting time period of the fourth light-emitting element 124 is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element 123, and the light-emitting time period of the first light-emitting element 121 or the second light-emitting element is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element 123 and the fourth light-emitting element 124.

[0071] Furthermore, the multiple repeating units on the backlight module can be controlled by the chip. It is understood that in this embodiment, the first light-emitting element 121, the second light-emitting element 122, the third light-emitting element 123, and the fourth light-emitting element 124 are driven in a time-division manner by using a field-sequence display method, dividing the original light-emitting frame into a first time period, a second time period, and a third time period. The backlight module 10 emits a backlight of a different color in each time period. Compared with the prior art, which uses a combination of monochromatic backlight and color filter to achieve a color light emission effect, this embodiment can achieve a color light emission effect through multiple light-emitting elements 12, thereby omitting the color filter, improving the backlight transmittance, reducing backlight requirements, and reducing power consumption and cost.

[0072] Please continue to combine Figure 1 and Figure 2 In one embodiment, the display device 1 further includes a dimming unit 30, a first polarizer 41, a second polarizer 42, and a third polarizer 43; the dimming unit 30 is disposed between the backlight module 10 and the display panel 20; the first polarizer 41 is disposed between the backlight module 10 and the dimming unit 30; the second polarizer 42 is disposed on the side of the dimming unit 30 away from the first polarizer 41, and the light transmission axis direction of the second polarizer 42 is the same as the light transmission axis direction of the first polarizer 41; the third polarizer 43 is disposed on the display panel 20 away from the second polarizer 42.

[0073] like Figure 1As shown, when the display device 1 is configured in a first display mode, polarized light emitted along the first direction z passes through the second polarizer 42 in at least a portion, and polarized light emitted along the second direction m passes through the second polarizer 42 in at least a portion, so that users viewing the display device 1 along both the first direction z and the second direction m can observe the display screen 20, that is, the display device 1 can display normally.

[0074] like Figure 2 As shown, when the display device 1 is configured in the second display mode, polarized light emitted along the first direction z passes through the second polarizer 42 at least partially, and polarized light emitted along the second direction m is absorbed by the second polarizer 42. This allows a user viewing the display device 1 along the first direction z to observe the display screen 20, while a user viewing the display device 1 along the second direction m cannot observe the display screen 20. In other words, the privacy mode of the display device 1 is achieved.

[0075] It should be noted that the first direction z is the direction in which the user looks directly at the display device 1 or the normal direction of the second polarizer 42; the second direction m is the privacy protection direction. When the display device 1 is configured in the second display mode, the user viewing the display device 1 along the second direction m cannot observe the display screen of the display panel 20, and the display device 1 is in a dark state. Furthermore, this embodiment takes the first light emanating along the first direction z and the second light emanating along the second direction m as an example to illustrate the technical solution of this application.

[0076] like Figure 1 and Figure 2 As shown, the dimming unit 30 includes a first electrode 31 and a second electrode 32 disposed opposite to each other, and a dimming liquid crystal layer 33 located between the first electrode 31 and the second electrode 32. The dimming liquid crystal layer 33 includes a polymer network 331 and a plurality of liquid crystal molecules 332 distributed in the polymer network 331. The polymer network 331 is arranged along a third direction w, and the third direction w is inclined relative to the normal of the second polarizer 42. The dimming unit 30 is used to adjust the polarization state of light. By adjusting the voltage difference between the first electrode 31 and the second electrode 32, the liquid crystal molecules 332 are deflected, thereby controlling the display device 1 to be configured in a first display mode or a second display mode.

[0077] Furthermore, after the light emitted by the backlight module 10 passes through the first polarizer 41, it forms linearly polarized light with a polarization direction parallel to the transmission axis of the first polarizer 41. After the linearly polarized light reaches the dimming unit 30, the dimming unit 30 adjusts the polarization state of the linearly polarized light to form polarized light emission. That is, after the light emitted by the backlight module 10 passes through the first polarizer 41 and the dimming unit 30, it forms polarized light. After the polarized light reaches the second polarizer 42, the second polarizer 42 selectively transmits the polarized light according to the polarization state of the polarized light.

[0078] Specifically, such as Figure 1 As shown, in the first display mode, the long axis of the liquid crystal molecules 332 is arranged along a fourth direction, which is different from the third direction w, so that more light can pass through the second polarizer 42, thereby improving the viewing angle range of the display panel 20 in the first display mode; as Figure 2 As shown, in the display device 1 configured in the second display mode, the long axis of the liquid crystal molecules 332 is arranged along the third direction w, and the light emission angle of the display device 1 in the second display mode is smaller than the light emission angle in the first mode; wherein, the first electrode layer 31 and the second electrode layer 32 are used to apply voltage to control the long axis of the liquid crystal molecules 332 to switch between the third direction and the fourth direction.

[0079] It is understood that when the display device 1 is configured in the first display mode or the second display mode, since the polarization direction of the first light only passes through the long axis of the liquid crystal molecule 332, the first light does not experience a phase difference after passing through the liquid crystal molecule 332, that is, the polarization direction remains unchanged. However, when the display device 1 is configured in the second display mode, the polarization direction of the second light is at a certain angle to the liquid crystal molecule 332. Therefore, the second light experiences a phase difference after passing through the liquid crystal molecule 332, resulting in a change in the polarization direction. When the phase difference Re = nλ / 2, where n is an integer, and the polarization direction of the second light is at a 45-degree angle to the liquid crystal molecule 332, the polarization direction of the second light deflects by 90 degrees after passing through the liquid crystal molecule 332, and thus cannot directly pass through the second polarizer 42. That is, the second light with the changed polarization direction will be blocked by the second polarizer 42, thereby reducing or eliminating the brightness of the display device 1 in the first direction, thus serving as a privacy protection function.

[0080] Optionally, please refer to Figure 1 or Figure 2In one embodiment, the second polarizer 42 includes a polarizing sub-film 421 and a brightness enhancement film 422. The brightness enhancement film 422 is disposed between the polarizing sub-film 421 and the dimming unit 30. By utilizing the polarization characteristics of the brightness enhancement film 422, the utilization rate of the light emitted by the backlight module 10 can be improved, thereby increasing the brightness of the display panel 20.

[0081] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0082] The foregoing has provided a detailed description of a backlight module and display device provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A backlight module, characterized in that, It includes multiple repeating units, each of which is composed of a first light-emitting element, a second light-emitting element, a third light-emitting element, and a fourth light-emitting element. The first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are arranged in an array within the repeating unit. The light-emitting angle of the first light-emitting element is greater than that of the second light-emitting element. The first light-emitting element and the second light-emitting element emit the same color, while the first light-emitting element, the third light-emitting element, and the fourth light-emitting element emit different colors. The backlight module includes a first dimming unit and a second dimming unit. The first dimming unit is disposed corresponding to the first light-emitting element and is located on the light-emitting side of the first light-emitting element, the light-emitting side of the third light-emitting element, and the light-emitting side of the fourth light-emitting element. The second dimming unit is disposed corresponding to the second light-emitting element and is located on the light-emitting side of the second light-emitting element. The backlight module is configured in a first light-emitting mode, in which the first light-emitting element emits light and the second light-emitting element does not emit light; the backlight module is configured in a second light-emitting mode, in which the first light-emitting element does not emit light and the second light-emitting element emits light.

2. The backlight module according to claim 1, characterized in that, The first dimming part includes a first arc portion, which protrudes in a direction away from the first light-emitting element; The second dimming part includes a second arc portion, which protrudes toward the direction of the second light-emitting element.

3. The backlight module according to claim 2, characterized in that, The second dimming unit includes a bottom wall and a reflective sidewall surrounding the bottom wall. The bottom wall is located on the side of the second dimming unit closer to the second light-emitting element. The bottom wall has a first opening, and the reflective sidewall has a second opening on the side away from the bottom wall. The width of the first opening is greater than or equal to the width of the second light-emitting element.

4. The backlight module according to claim 3, characterized in that, The backlight module further includes multiple lens portions, which are disposed on the side of the second dimming portion away from the second light-emitting element, wherein the orthographic projection of the lens portions on the backlight module covers the orthographic projection of the second light-emitting element on the backlight module.

5. The backlight module according to claim 1, characterized in that, The first light-emitting element emits blue light, the second light-emitting element emits blue light, the third light-emitting element emits red light, and the fourth light-emitting element emits green light. The areas of the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are all equal.

6. The backlight module according to claim 2, characterized in that, The first arc portion protrudes in a direction away from the third light-emitting element; the first arc portion protrudes in a direction away from the fourth light-emitting element.

7. The backlight module according to claim 1, characterized in that, The backlight module also includes: A microlens is disposed on the light-emitting side of the repeating unit; A diffuser plate is disposed on the side of the microlens away from the repeating unit; A prism is disposed on the side of the diffuser plate away from the microlens; and A brightening layer is disposed on the side of the prism away from the diffuser plate.

8. The backlight module according to claim 1, characterized in that, The first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element are driven in a time-division manner using a field-sequence display method; Wherein, a light-emitting frame of the backlight module includes at least a first time period, a second time period, and a third time period. The light-emitting time period of the third light-emitting element is one of the first time period, the second time period, and the third time period. The light-emitting time period of the fourth light-emitting element is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element. The light-emitting time period of the first light-emitting element or the second light-emitting element is one of the first time period, the second time period, and the third time period that is different from that of the third light-emitting element and the fourth light-emitting element.

9. A display device, characterized in that, It includes a display panel and a backlight module as described in any one of claims 1 to 8; wherein the backlight module is located on the side of the backlight of the display panel.

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