Backlight module and display screen

Abstract

The utility model relates to a backlight module, which comprises a circuit board, a light guide plate and a light guide plate, the plurality of light-emitting elements are arranged on the circuit board; the light guide part is connected with the circuit board, a groove is formed in the light guide part, a containing space is formed between the groove and the circuit board, and the light-emitting element is located in the containing space; the light control layer is arranged on the inner side face of the groove, and the light control layer comprises a reflecting area with high reflectivity and a light-transmitting hollow-out area. The beneficial effects of the utility model lie in that the light mixing uniformity can be improved, the light loss can be reduced, and the light and thin structure can be realized.

Description

Technical Field

[0001] This utility model relates to the field of backlight module technology, specifically to a backlight module and a display screen. Background Technology

[0002] Direct-lit backlight modules allow for precise control of backlight in different areas, resulting in greater energy savings and improved contrast, effectively enhancing display performance. However, direct-lit backlight technology also faces several challenges. For example, due to the high-brightness area in the center of LEDs, adding a reflector can create a grid-like pattern. To achieve uniform light emission, solutions include increasing the mixing height, thickening the diffuser plate, or using multi-layer films. However, these methods not only reduce light energy utilization efficiency but also require more structural space, making it difficult to achieve a thinner backlight module and hindering the development of thinner and lighter display devices.

[0003] In addition, similar problems exist in the backlighting of key characters. The high brightness of the center of the LED affects the uniformity of the character display. As product space is continuously reduced, the character backlighting area is compressed, and conventional solutions can hardly meet the uniformity requirements. A universal uniform surface light source solution is needed to solve the problems of light energy waste, difficulty in thinning, and poor uniformity in the existing technology. Utility Model Content

[0004] The purpose of this invention is to provide a backlight module and display screen that can improve light mixing uniformity, reduce light loss, and achieve a thin and light structure.

[0005] A backlight module includes: a circuit board with a reflective layer on its surface; light-emitting elements, a plurality of light-emitting elements disposed on the circuit board; a light guide connected to the circuit board, the light guide having a groove, the groove forming an accommodating space with the circuit board, the light-emitting elements being located within the accommodating space; and a light-controlling layer disposed on the inner side of the groove, the light-controlling layer including a highly reflective reflective area and a light-transmitting hollow area.

[0006] In the above solution, the light guide is connected to the circuit board by means of gluing, etc. The groove on the light guide forms an accommodating space with the circuit board. The inner side of the groove is connected to the light control layer by means of gluing, etc. The light-emitting element is a point light source that emits light in all directions. The high reflectivity of the reflective area can reflect and redirect the light emitted by the light-emitting element. The reflectivity of the reflective area on the side of the light control layer away from the light guide can disperse part of the emitted light from the light-emitting element. The reflective layer on the surface of the circuit board can reflect the light upward, thereby reducing light loss. The hollow area plays a role in controlling the light transmittance, ensuring that enough light can reach the display area. While ensuring the light output effect, energy consumption is reduced. Part of the emitted light from the light-emitting element can pass through the hollow area of ​​the light control layer. The reflectivity of the side of the light control layer that contacts the light guide also plays a role in reflecting the light, realizing the effect of double-layer light mixing. This ensures that the focused light emitted by the light-emitting element can be more evenly dispersed in the light guide, transforming the point light source into a surface light source, while making the overall structure simple and thin.

[0007] Furthermore, the light-controlling layer is a reflective paper with Lambertian high reflectivity.

[0008] In the above scheme, reflective paper with Lambertian high reflectivity is used as a light control layer, which can efficiently reflect the light emitted by the light-emitting element in all directions, improving the light mixing efficiency. The characteristic of Lambertian reflection is that the light can be evenly scattered in all directions after reflection, so that the light that might have escaped or been absorbed can be reused. Part of the light emitted by the light-emitting element is directed to the light control layer, which disperses and reflects this part of the light. In conjunction with the reflective layer on the surface of the circuit board, the light is reflected upward, reducing the loss of light during the propagation process and improving the utilization rate of light energy.

[0009] Furthermore, the hollow area includes a plurality of first light-transmitting holes and second light-transmitting holes. The first light-transmitting holes are radially distributed with the center of the light-controlling layer as a reference, and the second light-transmitting holes are distributed on the outside of the first light-transmitting holes.

[0010] In the above scheme, the first light-transmitting hole is radially distributed with the center of the light-controlling layer as the reference. This layout can guide and disperse the central focused light emitted by the light-emitting element along different radial directions. The light emitted by the light-emitting element is relatively concentrated in the central area, and the radially distributed first light-transmitting hole can diffuse these concentrated light rays evenly in all directions. The second light-transmitting hole is distributed outside the first light-transmitting hole, which can enable the light to be distributed more widely and evenly in the light guide. The first and second light-transmitting holes, together with the reflective area, effectively avoid the excessive concentration of light in local areas and improve the uniformity of light distribution.

[0011] Furthermore, the first light-transmitting hole is circular, and the second light-transmitting hole is arc-shaped.

[0012] In the above scheme, the circular first light-transmitting hole can disperse the central concentrated light emitted by the light-emitting element in a uniform manner, and a portion of the light will be reflected back by the reflection area to achieve light mixing. The second light-transmitting hole is arc-shaped, which allows the dispersed light far from the center to pass through, thereby improving the uniformity and efficiency of light output.

[0013] Furthermore, the light guide is a PMMA block or a PC block.

[0014] In the above solution, PMMA and PC are both optical-grade transparent materials with excellent light transmittance, which minimizes energy loss when light propagates inside the light guide. This allows for efficient transmission of light emitted by the light-emitting element to the display area, thereby improving the brightness and light energy utilization of the backlight module. At the same time, PMMA and PC materials can effectively scatter and diffuse light. When light enters the light guide, it will be continuously scattered inside the material, evenly dispersing the concentrated light emitted by the point light source. The block-structured light guide has a simple structure, is easy to process, and can be mass-produced.

[0015] Furthermore, both the upper and lower surfaces of the light guide are smooth planes.

[0016] In the above solution, both the upper and lower surfaces of the light guide are smooth planes, which can reduce the scattering loss of light during transmission, make the light diffuse evenly within the light guide, and improve the light output uniformity of the backlight module.

[0017] Furthermore, the accommodating space is filled with transparent optical adhesive.

[0018] In the above solution, filling the accommodating space with transparent optical adhesive can improve the efficiency of light entering the light guide. The transparent optical adhesive can completely fill the accommodating space, eliminate air gaps, and provide a continuous and uniform propagation path for the light, enabling the light to propagate more orderly and improving the directionality and uniformity of the light entering the light guide.

[0019] Furthermore, the reflective layer is white paint or reflective paper.

[0020] In the above solution, white paint and reflective paper have high reflectivity, which can reflect a large amount of light shining on them back into the light guide. The white pigment particles in the white paint can scatter and reflect light, so that the light is reflected and propagated multiple times in the light guide, thereby improving the utilization rate of light. Moreover, the use of white paint and reflective paper can effectively control production costs.

[0021] Furthermore, the light-emitting element is an LED lamp bead, and the array of light-emitting elements is arranged on the circuit board.

[0022] In the above solution, the LED beads are arranged in an array to ensure uniform light distribution, reduce local differences in brightness and darkness, make the backlight module emit light more evenly, and improve the display effect.

[0023] A display screen comprising a backlight module as described in any of the above embodiments.

[0024] This utility model discloses a backlight module and display screen, which has the beneficial effects of improving light mixing uniformity, reducing light loss, and achieving a thinner and lighter structure. The light guide is connected to the circuit board by means of gluing or other methods. The groove on the light guide forms an accommodating space with the circuit board. The inner side of the groove is connected to a light control layer by means of gluing or other methods. The light-emitting element is a point light source that emits light in all directions. The reflective ability of the reflective area on the side of the light control layer away from the light guide can disperse part of the emitted light from the light-emitting element. The reflective layer on the surface of the circuit board can reflect the light upward, thereby reducing light loss. Part of the emitted light from the light-emitting element can pass through the hollow area of ​​the light control layer. The reflective ability of the side of the light control layer that contacts the light guide also plays a role in reflecting light, realizing a double-layer light mixing effect. This ensures that the focused light emitted by the light-emitting element can be more evenly dispersed in the light guide, transforming the point light source into a surface light source, while making the overall structure simple and thin. Attached Figure Description

[0025] Figure 1 This is a simplified schematic diagram of a backlight module according to one embodiment.

[0026] Figure 2 This is a schematic diagram of the structure of laser-processed reflective paper according to one embodiment.

[0027] Figure 3 This is a schematic diagram of a die-cutting technique for cutting reflective paper according to one embodiment.

[0028] Figure 4 This is a simplified schematic diagram of the optical path mainline in one embodiment.

[0029] Explanation of reference numerals in the attached diagram: 1. Circuit board; 2. Light-emitting element; 3. Light guide; 31. Groove; 4. Light control layer; 41. Reflective area; 42. Light control area; 421. First light-transmitting hole; 422. Second light-transmitting hole. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0031] like Figures 1 to 4As shown in a preferred embodiment, a backlight module of the present invention includes: a circuit board 1, light-emitting elements 2, a light guide 3, and a light control layer 4. The surface of the circuit board 1 is provided with a reflective layer; multiple light-emitting elements 2 are disposed on the circuit board 1; the light guide 3 is connected to the circuit board 1, and a groove 31 is provided on the light guide 3, forming an accommodating space between the groove 31 and the circuit board 1, and the light-emitting elements 2 are located in the accommodating space; the light control layer 4 is disposed on the inner side of the groove 31, and the light control layer 4 includes a highly reflective reflective area 41 and a light-transmitting hollow area 42, and the light control layer 4 is used to control the transmitted light and the reflected light.

[0032] The light guide 3 is connected to the circuit board 1 by means of gluing or other methods. The groove 31 on the light guide 3 forms an accommodating space with the circuit board 1. The inner side of the groove 31 is connected to the light control layer 4 by means of gluing or other methods. The light-emitting element 2 is a point light source that emits light in all directions. The reflective ability of the reflective area 41 on the side of the light control layer 4 away from the light guide 3 can disperse part of the emitted light from the light-emitting element 2. The reflective layer on the surface of the circuit board 1 can reflect the light upward, thereby reducing light loss. Part of the emitted light from the light-emitting element 2 can pass through the hollow area 42 of the light control layer 4. The reflective ability of the side of the light control layer 4 that contacts the light guide 3 also plays a role in reflecting the light, realizing the effect of double-layer light mixing. This ensures that the focused light emitted by the light-emitting element 2 can be more evenly dispersed in the light guide 3, transforming the point light source into a surface light source, while making the overall structure simple and thin.

[0033] The high reflectivity of the reflective area 41 can reflect and redirect the light emitted by the light-emitting element 2, while the cutout area 42 allows some light to pass through directly, thus controlling the light transmittance. The cutout area 42 ensures that enough light can reach the display area, reducing energy consumption while ensuring the light output effect.

[0034] In this embodiment, the light-emitting element 2 is an LED lamp bead, which is arranged in an array to ensure uniform light distribution, reduce local brightness differences, and make the light output of the backlight module more uniform, thus improving the display effect. The LED lamp beads are soldered onto the circuit board 1, and the light control layer 4 is located at the top of the groove 31. Since the accommodating space is cylindrical, the light control layer 4 is correspondingly circular. Through the structural combination of the light guide 3 and the light control layer 4, the focused light emitted by the LED lamp beads is evenly dispersed within the entire light guide 3 and emitted uniformly from the front, achieving the effect of converting direct-lit point light source light output into surface light source light output.

[0035] In the application of the backlight panel of the MINI LED display, the light emitted by each LED bead is no longer a concentrated point light after passing through the light guide 3 and the light control layer 4, but is evenly distributed in independent zones, thus achieving a uniform light effect. The light control layer 4 can precisely control the direction and angle of light propagation, preventing excessive light scattering and the formation of halos, and the structure is thinner and lighter.

[0036] In the application of backlighting for character keys, the combination of light guide 3 and light control layer 4 can be designed and adjusted according to the different areas and shapes of the character keys, thereby achieving uniform light in any area and improving backlight uniformity. Since light guide 3 and light control layer 4 can evenly disperse light, the utilization efficiency of light is improved. Under the same backlight uniformity requirements, compared with traditional backlight solutions, the number of LED beads used can be reduced, thus optimizing costs.

[0037] The structural design of the light guide 3 and the light control layer 4 has high versatility and can be adapted to white LEDs and blue Chip LEDs with different packaging forms such as SMT (Surface Mount Technology), NCSP (Non-Content Chip Package), and CSP (Chip Package), making it widely applicable.

[0038] like Figure 2 and Figure 3 As shown, in some embodiments, the light-controlling layer 4 is a reflective paper with Lambertian high reflectivity. The reflective paper with Lambertian high reflectivity, as the light-controlling layer 4, can efficiently reflect the light emitted by the light-emitting element 2 in all directions, improving the light mixing efficiency. The characteristic of Lambertian reflection is that light is evenly scattered in all directions after reflection, allowing light that might otherwise escape or be absorbed to be reused. A portion of the light emitted by the light-emitting element 2 is directed towards the light-controlling layer 4, which disperses and reflects this portion of light. Combined with the reflective layer on the surface of the circuit board 1, the light is reflected upwards, reducing light loss during propagation and improving the utilization rate of light energy.

[0039] In this embodiment, the light control layer 4 can also be a highly reflective material that is achieved by means of printing or spraying. Any surface that can control the transmission and reflection of light can be used as the light control layer 4.

[0040] like Figure 2 and Figure 3As shown, in some embodiments, the hollow area 42 includes multiple first light-transmitting holes 421 and second light-transmitting holes 422. The first light-transmitting holes 421 are radially distributed with reference to the center of the light-controlling layer 4, and the second light-transmitting holes 422 are distributed outside the first light-transmitting holes 421. The radial distribution of the first light-transmitting holes 421 with reference to the center of the light-controlling layer 4 allows the centrally focused light emitted by the light-emitting element 2 to be guided and dispersed along different radial directions. The light emitted by the light-emitting element 2 is relatively concentrated in the central area, and the radially distributed first light-transmitting holes 421 can diffuse these concentrated light rays evenly in all directions. The second light-transmitting holes 422 are distributed outside the first light-transmitting holes 421, which allows the light to be distributed more widely and evenly within the light guide 3. The first light-transmitting holes 421 and the second light-transmitting holes 422, together with the reflective area 41, effectively avoid excessive concentration of light in local areas and improve the uniformity of light distribution.

[0041] Specifically, for the light-controlling layer 4, different processing methods will result in certain differences in the pattern, such as... Figure 2 To laser process patterns on reflective paper, such as... Figure 3 For die-cutting reflective paper, laser processing does not require consideration of shape limitations, but die-cutting reflective paper requires consideration of the integrity of the graphic during transfer and attachment, meaning the graphic must be a single, integrated structure.

[0042] like Figure 2 and Figure 3 As shown, in some embodiments, the first light-transmitting hole 421 is circular, and the second light-transmitting hole 422 is arc-shaped. The circular first light-transmitting hole 421 can disperse the central concentrated light emitted by the light-emitting element 2 in a uniform manner, and a portion of the light will be reflected back by the reflective area 41 to achieve light mixing. The arc-shaped second light-transmitting hole 422 can allow the dispersed light far from the center to pass through, thereby improving the uniformity and efficiency of light output.

[0043] like Figure 1 As shown, in some embodiments, the light guide 3 is a three-dimensional structure made of optical-grade transparent material. The light guide 3 is made of optical-grade transparent material, which has high light transmittance and can minimize light loss during transmission. The light guide 3 can be a three-dimensional structure of any shape, and has a wide range of applications.

[0044] like Figure 1As shown, in some embodiments, the light guide 3 is a PMMA cube or a PC cube. Both PMMA and PC are optical-grade transparent materials with excellent light transmittance, which minimizes energy loss when light propagates inside the light guide 3. This allows for efficient transmission of light emitted by the light-emitting element 2 to the display area, thereby improving the brightness and light energy utilization of the backlight module. At the same time, PMMA and PC materials can effectively scatter and diffuse light. When light enters the light guide 3, it will be continuously scattered inside the material, evenly dispersing the concentrated light emitted by the point light source. The cube-structured light guide 3 has a simple structure, is easy to process, and can be mass-produced.

[0045] like Figure 1 As shown, in some embodiments, the upper and lower surfaces of the light guide 3 are both smooth planes. The fact that both the upper and lower surfaces of the light guide 3 are smooth planes reduces scattering loss of light during transmission, allowing light to diffuse uniformly within the light guide 3 and improving the light output uniformity of the backlight module.

[0046] like Figure 1 As shown, in some embodiments, the accommodating space is filled with transparent optical adhesive. Filling the accommodating space with transparent optical adhesive can improve the efficiency of light entering the light guide 3. The transparent optical adhesive can completely fill the accommodating space, eliminate air gaps, and provide a continuous and uniform propagation path for light, enabling the light to propagate more orderly and improving the directionality and uniformity of light entering the light guide 3.

[0047] The transparent optical adhesive used to fill the accommodating space can be applied to the integrated light panel of the display backlight. When combined with the upper optical film, the light mixing effect is better. Since the integrated light panel itself has good light control, fewer optical films are required. This makes the backlight module more efficient and the structure thinner. The integrated light panel can also block moisture from affecting the LED phosphor, thus improving reliability.

[0048] For the backlighting of character keys, depending on the structural space, options include filling the interior of the light guide 3 with optical adhesive, nesting without filling, or adding positioning feet to fix the light guide 3.

[0049] like Figure 1 As shown, in some embodiments, the reflective layer is white paint or reflective paper. White paint and reflective paper have high reflectivity, which can reflect a large amount of light incident on them back into the light guide 3. The white pigment particles in the white paint can scatter and reflect light, so that the light undergoes multiple reflections and propagation within the light guide 3, thereby improving the utilization rate of light. Moreover, the use of white paint and reflective paper can effectively control production costs.

[0050] A display screen including a backlight module as described in any of the above embodiments.

[0051] This utility model discloses the working principle and process of a backlight module and display screen. The light emitted by the light-emitting element 2 enters the accommodating space. When the light reaches the position of the light control layer 4, part of the light is scattered in various directions, which makes the originally concentrated light begin to spread to a wider area. At the same time, part of the emitted light from the light-emitting element 2 can directly pass through the light control layer 4 and enter the interior of the light guide 3. The surface of the circuit board 1 is provided with a reflective layer. When the light propagates to the bottom of the accommodating space and comes into contact with the circuit board 1, the reflective layer will reflect the light upward back into the accommodating space and the light guide 3. Through the reflection and scattering effects of different surfaces of the light control layer 4 and the reflection effect of the reflective layer of the circuit board 1, the effect of double-layer light mixing is achieved. The light is continuously reflected, scattered and refracted in the accommodating space and the light guide 3, so that the originally focused point light source light is gradually and evenly dispersed throughout the entire light guide 3.

[0052] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0055] Although the description of this utility model has been given in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A backlight module, characterized in that, include: Circuit board, wherein a reflective layer is provided on the surface of the circuit board; Light-emitting elements, wherein multiple light-emitting elements are disposed on the circuit board; A light guide is provided, which is connected to the circuit board. The light guide has a groove, and an accommodating space is formed between the groove and the circuit board. The light-emitting element is located in the accommodating space. A light-controlling layer is disposed on the inner side of the groove, the light-controlling layer including a highly reflective reflective area and a light-transmitting hollow area.

2. The backlight module according to claim 1, characterized in that, The light-controlling layer is a reflective paper with Lambertian high reflectivity.

3. The backlight module according to claim 1, characterized in that, The hollow area includes multiple first light-transmitting holes and second light-transmitting holes. The first light-transmitting holes are radially distributed with the center of the light-controlling layer as the reference, and the second light-transmitting holes are distributed on the outside of the first light-transmitting holes.

4. The backlight module according to claim 3, characterized in that, The first light-transmitting hole is circular, and the second light-transmitting hole is arc-shaped.

5. The backlight module according to claim 1, characterized in that, The light guide is a PMMA block or a PC block.

6. The backlight module according to claim 1, characterized in that, The upper and lower surfaces of the light guide are both smooth planes.

7. The backlight module according to claim 1, characterized in that, The accommodating space is filled with transparent optical adhesive.

8. The backlight module according to claim 1, characterized in that, The reflective layer is white paint or reflective paper.

9. The backlight module according to claim 1, characterized in that, The light-emitting element is an LED lamp bead, and the array of light-emitting elements is arranged on the circuit board.

10. A display screen, characterized in that, It includes a display panel and a backlight module as described in any one of claims 1 to 9.

Images