Backlight module and display device

Abstract

The utility model provides a backlight module and a display device, and the backlight module comprises a reflector plate which is provided with a body part and reflecting parts arranged on one side of the body part in an array manner; the light sources are arranged between the adjacent reflecting parts; the reflection type polarized light brightness enhancement film is arranged on one side, far away from the body part, of the reflection part and is provided with a light-transmitting shaft; the included angle between the light transmitting shaft and the extending direction of the reflecting part is a first angle, and the first angle is configured to enable light rays emitted by the light source to be transmitted by the reflecting type polarized light brightness enhancement film when the light rays are reflected by the reflecting type polarized light brightness enhancement film and then reflected to the reflecting type polarized light brightness enhancement film through the reflecting part. By controlling the included angle between the light transmitting axis of the reflection type polarized light brightness enhancement film and the extension direction of the reflection part, the light reflected by the reflection type polarized light brightness enhancement film can be transmitted by the reflection type polarized light brightness enhancement film when being reflected to the reflection type polarized light brightness enhancement film through the reflection part, so that more light can be transmitted by the reflection type polarized light brightness enhancement film; and the light utilization rate is improved.

Description

Technical Field

[0001] This application relates to the field of display technologies, and particularly to a backlight module and a display device. Background Art

[0002] In related technologies, a backlight module mainly consists of a light source, a light guide plate, a reflective film, a diffusion film, a brightness enhancement film, etc. Among them, after the light emitted by the light source reaches the brightness enhancement film through the light guide plate and the diffusion film, a part of the light is transmitted by the brightness enhancement film, but a part of the light is also reflected by the brightness enhancement film. The reflected light will continue to propagate between the diffusion film, the light guide plate and the reflective sheet. These optical films will cause a certain loss of the light reflected by the brightness enhancement film, resulting in a low light utilization rate. Summary of the Utility Model

[0003] Embodiments of this application provide a backlight module and a display device, which can reduce the loss of light in the backlight module and improve the technical problem of low light utilization rate.

[0004] In a first aspect, embodiments of this application provide a backlight module, including:

[0005] A reflective sheet having a body portion and reflective portions arranged in an array on one side of the body portion;

[0006] A light source disposed between adjacent reflective portions;

[0007] A reflective-type polarizing brightness enhancement film disposed on the side of the reflective portion away from the body portion and having a transmission axis;

[0008] The included angle between the transmission axis and the extending direction of the reflective portion is a first angle, and the first angle is configured such that the light emitted by the light source is transmitted by the reflective-type polarizing brightness enhancement film when being reflected by the reflective-type polarizing brightness enhancement film and then reflected by the reflective portion to the reflective-type polarizing brightness enhancement film.

[0009] This application controls the included angle between the transmission axis of the reflective-type polarizing brightness enhancement film and the extending direction of the reflective portion, so that the light reflected by the reflective-type polarizing brightness enhancement film is transmitted by the reflective-type polarizing brightness enhancement film when being reflected by the reflective portion to the reflective-type polarizing brightness enhancement film, enabling more light to be transmitted by the reflective-type polarizing brightness enhancement film, thereby improving the light utilization rate.

[0010] In an embodiment, the first angle is α, satisfying:

[0011]

[0012] wherein, R is the reflectivity of the reflective sheet.

[0013] By making the first angle satisfy the above equation, the present application enables as much light reflected by the reflective polarizing brightness enhancement film to be transmitted by the reflective polarizing brightness enhancement film when reflected by the reflection part, thereby improving the light utilization rate.

[0014] In one embodiment, the reflection part has a first edge away from the body part;

[0015] The reflection part has a connected first reflection surface and a second reflection surface, and the connection between the first reflection surface and the second reflection surface is the first edge.

[0016] The present application reflects the light reflected by the reflective polarizing brightness enhancement film by using the first reflection surface and the second reflection surface that define the first edge, and adjusts the polarization state of the light reaching the reflective polarizing brightness enhancement film again through the cooperation between adjacent reflection parts, so that as much light as possible is transmitted from the reflective polarizing brightness enhancement film, thereby improving the light utilization rate. At the same time, it helps to make the light reflected by the reflective polarizing brightness enhancement film reach the reflective polarizing brightness enhancement film again as much as possible, further improving the light utilization rate.

[0017] In one embodiment, the first reflection surface has a second edge parallel to the first edge, and the second edge is the intersection line of the first reflection surface and the body part;

[0018] The second reflection surface has a third edge parallel to the first edge, and the third edge is the intersection line of the second reflection surface and the reflective sheet body part.

[0019] By setting the positional relationship between the first reflection surface, the second reflection surface and the body part in this way, the present application helps to reduce the number of reflections experienced by the light during the period from being reflected by the reflective polarizing brightness enhancement film to returning to the reflective polarizing brightness enhancement film again, thereby reducing the absorption of light by the reflective sheet and improving the light utilization rate.

[0020] In one embodiment, the angles between the first reflection surface, the second reflection surface and the reflective sheet are the same.

[0021] By making the angles between the first reflection surface, the second reflection surface and the reflective sheet the same, the present application makes the distances between adjacent reflection parts the same, which is convenient for setting the light source to improve the light output uniformity. At the same time, it enables the light reflected by the reflective polarizing brightness enhancement film to reach the reflective polarizing brightness enhancement film again along a shorter propagation path, thereby improving the brightness of the backlight module.

[0022] In one embodiment, the angle between the first reflection surface and the second reflection surface is 90°.

[0023] By setting the angle between the first reflecting surface and the second reflecting surface to 90°, the light reflected by the reflective polarizing brightness enhancement film can be propagated to the reflective polarizing brightness enhancement film again along a shorter propagation path, thereby improving the brightness of the backlight module.

[0024] In one embodiment, the first reflecting surface is an arc surface recessed inward relative to the reflecting portion; and / or, the second reflecting surface is an arc surface recessed inward relative to the reflecting portion.

[0025] By setting the first reflecting surface and / or the second reflecting surface as an arc surface recessed inward relative to the reflecting portion, the light propagating to the first reflecting surface and / or the second reflecting surface can be focused, so that more light can be propagated to the reflective polarizing brightness enhancement film and transmitted, thereby improving the utilization rate of light.

[0026] In one embodiment, the backlight module further includes:

[0027] A bracket, which is arranged at one end of the reflecting portion away from the body portion, and the bracket is used to support the reflective polarizing brightness enhancement film.

[0028] By controlling the distance between the reflecting portion and the reflective polarizing brightness enhancement film through the bracket, it helps to ensure the utilization rate of the light of the backlight module.

[0029] In one embodiment, a first groove is formed at one end of the reflecting portion away from the body portion;

[0030] One end of the bracket is fixed in the first groove, and the other end extends out of the first groove.

[0031] By arranging the bracket in the first groove, the distance between the reflecting portion and the reflective polarizing brightness enhancement film can be ensured, thereby helping to ensure the utilization rate of the light of the backlight module.

[0032] In a second aspect, an embodiment of the present application provides a display device, including the above-mentioned backlight module. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0034] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, in which the same reference numerals represent the same parts in the following description.

[0035] Figure 1 It is a partial structural cross-sectional view of the backlight module provided by some embodiments of the present application;

[0036] Figure 2 It is a three-dimensional schematic diagram of a backlight module provided by some embodiments of the present application;

[0037] Figure 3 It is a cross-sectional view of a backlight module provided by some embodiments of the present application;

[0038] Figure 4 It is a three-dimensional schematic diagram of a reflection part provided by some embodiments of the present application;

[0039] Figure 5 It is a schematic diagram of the light propagation path in the backlight module provided by some embodiments of the present application;

[0040] Figure 6 It is a structural schematic diagram of another reflection part provided by some embodiments of the present application;

[0041] Figure 7 It is a cross-sectional view of a partial structure of another backlight module provided by some embodiments of the present application;

[0042] Figure 8 It is a structural schematic diagram of yet another reflection part provided by some embodiments of the present application;

[0043] Figure 9 It is a cross-sectional view of another backlight module provided by some embodiments of the present application.

[0044] Explanation of reference numerals:

[0045] 1. Reflective sheet; 11. Reflection part; 111. First reflection surface; 112. Second reflection surface; 113. First groove; 114. First edge; 115. Second edge; 116. Third edge; 12. Body part;

[0046] 2. Light source;

[0047] 3. Reflective type polarizing brightness enhancement film; 31. Transmissive axis;

[0048] 4. Bracket. Detailed implementation manners

[0049] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; and "inner" and "outer" refer to the outline of the device.

[0050] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0051] In the present application, the term "exemplary" is used to mean "serving as an example, illustration, or description". Any embodiment described as "exemplary" in the present application is not necessarily to be construed as more preferred or more advantageous than other embodiments. In order for any person skilled in the art to implement and use the present application, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those skilled in the art can recognize that the present application can be implemented without these specific details. In other instances, well-known structures and processes are not described in detail to avoid unnecessary details from obscuring the description of the present application. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in the present application.

[0052] Please refer to Figures 1 to 3 , Figure 1 which is a partial structural cross-sectional view of a backlight module provided by some embodiments of the present application, Figure 2 and Figure 3It is a cross-sectional view of a backlight module provided by some embodiments of the present application. Some embodiments of the present application provide a backlight module, including: a reflector 1, having a main body portion 12 and a plurality of reflecting portions 11 arranged in an array on one side of the main body portion 12; a light source 2, disposed between adjacent reflecting portions 11; a reflective polarizing brightness enhancement film 3, disposed at one end of the reflecting portion 11 away from the main body portion 12, having a transmission axis 31; the included angle between the transmission axis 31 and the extending direction of the reflecting portion 11 is a first angle, and the first angle is configured such that the light emitted by the light source 2 is reflected by the reflective polarizing brightness enhancement film and then reflected by the reflecting portion 11 to the reflective polarizing brightness enhancement film 3 and transmitted by the reflective polarizing brightness enhancement film 3.

[0053] In the embodiments of the present application, by setting the polarization axis of the reflective polarizing brightness enhancement film 3 to form a first included angle with the extending direction of the reflecting portion 11, it helps to enhance the depolarization effect of the reflecting portion 11 on the light reflected by the reflective polarizing brightness enhancement film 3. Thus, when the light reflected by the reflective polarizing brightness enhancement film 3 is reflected by the reflecting portion 11 to the reflective polarizing brightness enhancement film 3 as much as possible, its polarization state can be transmitted by the reflective polarizing brightness enhancement film 3, so that more light can be transmitted by the reflective polarizing brightness enhancement film 3, thereby improving the light utilization rate.

[0054] In an embodiment of the present application, the first angle is α, satisfying:

[0055]

[0056] wherein, R is the reflectivity of the reflector 1.

[0057] It can be understood that a beam of natural light is incident on the interface formed by two homogeneous media with isotropic refractive indices N0 and N1 respectively. Among them, is the incident angle, is the refraction angle. Decompose the natural light, and define the linearly polarized light parallel to the reflection plane as s light, and the linearly polarized light perpendicular to the reflection plane as p light. According to the refraction law and Fresnel equations, the reflection coefficient r and transmission coefficient t of the two components satisfy the following formulas:

[0058]

[0059] It can be seen that the polarization state of light is related to the refractive index of the medium and the incident angle of light.

[0060] At the same time, the reflectivity R satisfies:

[0061]

[0062] In summary, the calculation formula of the first angle α of the present application can be obtained.

[0063] In this embodiment, the first angle α is related to the refractive index of the reflective sheet 1. When designing the backlight module, after determining the reflective sheet 1, the first angle α can be calculated according to the reflectivity of the reflective sheet 1. Then, according to the specific position of the transmission axis 31 of the reflective polarizing brightness enhancement film 3, the extending direction of the reflection portion 11 on the reflective sheet 1 can be determined. In this embodiment, by making the first angle α satisfy the above equation, so that as much light reflected by the reflective polarizing brightness enhancement film 3 as possible can be reflected by the reflection portion 11 and then reach the reflective polarizing brightness enhancement film 3, and its polarization state can be transmitted by the reflective polarizing brightness enhancement film 3, thereby improving the light utilization rate.

[0064] Please refer to Figure 4 , Figure 4 which is a three-dimensional schematic diagram of the reflection portion provided in some embodiments of the present application. In an embodiment of the present application, the reflection portions 11 all have a first edge 114 away from the body portion 12; the reflection portion 11 has a connected first reflection surface 111 and a second reflection surface 112, and the connection portion of the first reflection surface 111 and the second reflection surface 112 is the first edge 114.

[0065] On the light-emitting surface of the reflective polarizing brightness enhancement film 3, the areas where no transmitted light exits will appear dark, and these dark areas will affect the final image display effect. Therefore, in this embodiment, the side of the reflection portion 11 away from the body portion 12 is the first edge 114, so as to reduce the contact area between the reflection portion 11 and the reflective polarizing brightness enhancement film 3, thereby reducing the area of the region where the reflective polarizing brightness enhancement film 3 cannot be irradiated by light and improving the final image display effect. At the same time, the first reflection surface 111 and the second reflection surface 112 that define the first edge 114 are used to reflect the light reflected by the reflective polarizing brightness enhancement film 3, so that these reflected lights finally reach the reflective polarizing brightness enhancement film 3 and can be transmitted by the reflective polarizing brightness enhancement film 3 to improve the light utilization rate.

[0066] In an embodiment of the present application, the first reflection surface 111 has a second edge 115 parallel to the first edge 114, and the second edge 115 is the intersection line of the second reflection surface 112 and the body portion 12; the second reflection surface 112 has a third edge 116 parallel to the first edge 114, and the third edge 116 is the intersection line of the second reflection surface 112 and the body portion 12.

[0067] It should be noted that light will be lost due to absorption by the film material during propagation. Please refer to Figure 4 and Figure 5 , Figure 5It is a schematic diagram of the light propagation path in the backlight module provided by some embodiments of the present application. In this embodiment, by making the cross-section of the reflection part 11 triangular, the light reflected by the reflective polarizing brightness enhancement film 3 reaches the reflective polarizing brightness enhancement film 3 after being reflected by the first reflection surface 111 and the second reflection surface 112 on both sides of the light source 2, and is transmitted through the reflective polarizing brightness enhancement film 3. In this embodiment, the first reflection surface 111 and the second reflection surface 112 are used to reflect the light reflected by the reflective polarizing brightness enhancement film 3 to the reflective polarizing brightness enhancement film 3. The light is only reflected between the first reflection surface 111 and the second reflection surface 112, with fewer reflection times, reducing the absorption of light by the reflection sheet 1 and lowering the light loss, thereby improving the light utilization rate.

[0068] In an embodiment of the present application, the angles between the first reflection surface 111, the second reflection surface 112 and the reflection sheet 1 are the same.

[0069] Please refer to Figure 1 and Figure 5 , in this embodiment, making the angles between the first reflection surface 111, the second reflection surface 112 and the reflection sheet 1 the same can ensure that the distances between adjacent reflection parts 11 are the same, facilitating the setting of the light source 2 to improve the light output uniformity. At the same time, it helps the light reflected by the reflective polarizing brightness enhancement film 3 to reach the reflective polarizing brightness enhancement film 3 again with a shorter propagation path, thereby increasing the brightness of the backlight module.

[0070] In an embodiment of the present application, the angle between the first reflection surface 111 and the second reflection surface 112 is 90°.

[0071] Please refer to Figure 1 and Figure 5 , in the present application, by setting the angle between the first reflection surface and the second reflection surface to 90°, the light reflected by the reflective polarizing brightness enhancement film can reach the reflective polarizing brightness enhancement film again with a shorter propagation path, thereby increasing the brightness of the backlight module. Further, the angles between the first reflection surface 111 and the reflection sheet 1 and between the second reflection surface 112 and the reflection sheet 1 are the same, that is, the triangle formed by the first reflection surface 111, the second reflection surface 112 and the body part 12 of the reflection sheet 1 is an isosceles right triangle, enabling the light reflected by the reflective polarizing brightness enhancement film 3 to reach the reflective polarizing brightness enhancement film 3 with a shorter propagation path, thereby increasing the brightness of the backlight module.

[0072] Please refer to Figure 6 , Figure 6 is a schematic structural diagram of another reflection part provided by some embodiments of the present application. In an embodiment of the present application, the first reflection surface 111 is an arc surface recessed inward relative to the reflection part 11; and / or, the second reflection surface 112 is an arc surface recessed inward relative to the reflection part 11.

[0073] The first reflecting surface 111 and the second reflecting surface 112 are used to reflect the light reflected by the reflective polarizing brightness enhancement film 3 to the reflective polarizing brightness enhancement film 3. In this embodiment, the first reflecting surface 111 and / or the second reflecting surface 112 are set as arc surfaces that are recessed inward relative to the reflecting portion 11, which can concentrate the light propagating to the first reflecting surface 111 and / or the second reflecting surface 112, so that more light can propagate to the reflective polarizing brightness enhancement film 3 and be transmitted, improving the utilization rate of light.

[0074] Exemplarily, in an embodiment of the present application, both the first reflecting surface 111 and the second reflecting surface 112 are set as arc surfaces.

[0075] Please refer to Figure 7 and Figure 9 , Figure 7 is a partial cross-sectional view of another backlight module provided by some embodiments of the present application, Figure 9 is another cross-sectional view of a backlight module provided by some embodiments of the present application. In an embodiment of the present application, the backlight module further includes: a bracket 4 disposed at one end of the reflecting portion 11 away from the body portion 12, and the bracket 4 is used to support the reflective polarizing brightness enhancement film 3.

[0076] In the related art, a diffusion plate is usually disposed between the reflective polarizing brightness enhancement film 3 and the reflector 1. However, after the light passes through the diffusion plate, the polarization state of the light will change. The purpose of controlling the angle between the transmission axis 31 of the reflective polarizing brightness enhancement film 3 and the extending direction of the reflecting portion 11 in the present application is to make the light reflected by the reflective polarizing brightness enhancement film 3 be transmitted by the reflective polarizing brightness enhancement film 3 when it is reflected by the reflecting portion 11 to the reflective polarizing brightness enhancement film 3, so that more light can be transmitted by the reflective polarizing brightness enhancement film 3, thereby improving the light utilization rate. Therefore, the diffusion plate is discarded in the backlight module provided by the embodiment of the present application. However, this also shortens the distance between the reflective polarizing brightness enhancement film 3 and the reflector 1, that is, the distance between the light source 2 and the reflective polarizing brightness enhancement film 3 is shortened, and the distance between the light source 2 and the reflective polarizing brightness enhancement film 3 will affect the light propagation path and the light utilization rate in the backlight module. If the distance is too close, light shadows will appear on the light-emitting surface of the reflective polarizing brightness enhancement film 3, affecting the final image display effect. If the distance is too far, it will increase the overall thickness and production cost of the backlight module. Therefore, in this embodiment, a bracket 4 is disposed between the reflecting portion 11 and the reflective polarizing brightness enhancement film 3 to supplement the increased distance between the reflective polarizing brightness enhancement film 3 and the reflector 1 after the diffusion plate is discarded, thereby ensuring the light utilization rate of the backlight module.

[0077] Please refer to Figure 8 , Figure 8It is a schematic structural diagram of another reflection part provided by some embodiments of the present application. In an embodiment of the present application, first grooves 113 are respectively formed at one ends of the reflection part 11 away from the body part 12; one end of the bracket 4 is fixed in the first groove 113, and the other end extends out of the first groove 113.

[0078] In this embodiment, the bracket 4 is fixed by forming the first grooves 113 at one ends of the reflection part 11 away from the body part 12, and the bracket 4 is used to supplement the increased distance between the reflective polarizing brightness enhancement film 3 and the reflector 1 after the diffusion plate is discarded, so as to ensure the utilization rate of the light in the backlight module.

[0079] In an embodiment of the present application, the bracket 4 is colorless and transparent.

[0080] The bracket 4 in the backlight module provided by some embodiments of the present application is used to support the reflective polarizing brightness enhancement film 3. Therefore, when designing the bracket 4, the influence of the bracket 4 on the light propagation in the backlight module should be avoided or reduced. The factors affecting the light propagation of the bracket 4 are mainly the color and light transmittance of the bracket 4. For example, if the bracket 4 is made of a colored material, the bracket 4 will absorb the light of other colors (that is, the colors other than the color of the bracket 4 itself). If the bracket 4 is made of a non-transparent material, part of the light will not be able to pass through. Therefore, in this embodiment, making the bracket 4 made of a colorless and transparent material can reduce the influence of the bracket 4 on the light propagation in the backlight module and improve the utilization rate of the light.

[0081] On the other hand, an embodiment of the present application provides a display device, including the above-mentioned backlight module.

[0082] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0083] The embodiments, implementation manners and related technical features of the present application can be combined and replaced with each other without conflict.

[0084] The above embodiments of the present application have been introduced in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A backlight module, characterized in that, Comprising: A reflective sheet having a main body portion and reflective portions arrayed on one side of the main body portion; A light source disposed between adjacent reflective portions; A reflective polarizing brightness enhancement film disposed on the side of the reflective portion away from the main body portion and having a transmission axis; The angle between the transmission axis and the extending direction of the reflective portion is a first angle, and the first angle is configured such that light emitted by the light source is reflected by the reflective polarizing brightness enhancement film and then reflected by the reflective portion to the reflective polarizing brightness enhancement film and is transmitted by the reflective polarizing brightness enhancement film.

2. The backlight module according to claim 1, wherein The first angle is α and satisfies: wherein R is the reflectivity of the reflective sheet.

3. The backlight module according to claim 1, wherein The reflective portion has a first edge away from the main body portion; The reflective portion has a connected first reflective surface and a second reflective surface, and the connection between the first reflective surface and the second reflective surface is the first edge.

4. The backlight module according to claim 3, wherein The first reflective surface has a second edge parallel to the first edge, and the second edge is the intersection line of the first reflective surface and the main body portion; The second reflective surface has a third edge parallel to the first edge, and the third edge is the intersection line of the second reflective surface and the main body portion.

5. The backlight module according to claim 3, wherein, The angles between the first reflective surface and the second reflective surface and the main body portion are the same.

6. The backlight module according to claim 3 or 5, characterized in that, The angle between the first reflective surface and the second reflective surface is 90°; 7. The backlight module according to claim 3, characterized in that, The first reflective surface is an arc surface recessed inward with respect to the reflective portion; and / or, the second reflective surface is an arc surface recessed inward with respect to the reflective portion.

8. The backlight module according to claim 1, wherein The backlight module further comprises: A bracket disposed at one end of the reflective portion away from the main body portion, and the bracket is used to support the reflective polarizing brightness enhancement film.

9. The backlight module according to claim 8, wherein, A first groove is formed at one end of the reflective portion away from the main body portion; One end of the bracket is fixed in the first groove, and the other end extends out of the first groove.

10. A display device, characterized in that, Comprising the backlight module according to any one of claims 1 to 9.

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