A light uniforming keyboard backlight module with double light guide layers

Abstract

The utility model discloses a kind of light uniformity type keyboard backlight module with double light guide layer, including bottom plate, light source and light guide structure, the light guide structure includes sequentially laminated lower light guide layer, light uniformity layer and upper light guide layer, the light source is set at the side light entrance surface of lower light guide layer, the light uniformity layer is closely attached to the upper surface of lower light guide layer, the material of the light uniformity layer is translucent material with light scattering characteristic, the upper surface of the upper light guide layer is closely covered in light uniformity layer, the upper surface of the upper light guide layer is equipped with the light transmission area corresponding to keyboard keycap position, light is sequentially conducted horizontally in lower light guide layer, scattered vertically homogenized in light uniformity layer, after secondary conduction in upper light guide layer, it is evenly emitted from light transmission area. Overall scheme structure is simple, processing is convenient, while reducing production and use cost in improving light uniformity, and practicality is extremely strong.

Description

Technical Field

[0001] This utility model relates to the technical field of keyboard backlight modules, specifically a uniform light keyboard backlight module with dual light guide layers. Background Technology

[0002] Keyboard backlight modules are core components for improving the typing experience in low-light environments. Existing technologies mostly use a basic structure of a base plate, a single-sided light source, and a single light guide layer. Light is conducted through the light guide layer and emitted from the corresponding area of ​​the keycap. However, existing solutions have many drawbacks: First, the light uniformity is insufficient. A single light guide layer cannot compensate for the attenuation during the lateral transmission of light, resulting in excessively high brightness in the near-light source area and dimness in the far-light source area, easily forming obvious bright spots and dark areas. Second, the light utilization rate is low. Some light leaks to the base plate and is directly absorbed, lacking an effective light recovery structure. Third, the assembly and lighting range are limited. The light guide layer has poor adhesion to other components, and the gaps between layers cause disordered light refraction. Moreover, it can only illuminate the front of the keycap, and the side walls are prone to blackening due to insufficient light. Utility Model Content

[0003] In order to overcome the shortcomings of existing technical solutions, this utility model provides a uniform light keyboard backlight module with dual light guide layers, which can effectively solve the problems mentioned in the background technology.

[0004] The technical solution adopted by this utility model to solve its technical problem is:

[0005] A uniform light-guiding keyboard backlight module with dual light guide layers includes a base plate, a light source, and a light guide structure. The light guide structure includes a lower light guide layer, a uniform light layer, and an upper light guide layer stacked sequentially.

[0006] The light source is located at the light-incident surface on the side of the lower light guide layer;

[0007] The light-diffusing layer is tightly attached to the upper surface of the lower light guide layer, and the material of the light-diffusing layer is a semi-transparent material with light scattering properties.

[0008] The upper light guide layer tightly covers the upper surface of the light uniform layer, and the upper surface of the upper light guide layer is provided with a light-transmitting area corresponding to the position of the keyboard keycap;

[0009] The light rays are transmitted laterally through the lower light guide layer, vertically scattered and homogenized by the light homogenizing layer, and then transmitted twice through the upper light guide layer before being emitted uniformly from the light-transmitting area.

[0010] As a further description of the above technical solution, the material of the light-diffusing layer is silicone doped with scattering particles, an optical diffusion film, or a microstructured frosted surface layer, and the thickness of the light-diffusing layer is 0.1mm-0.5mm.

[0011] As a further description of the above technical solution, the lower surface of the lower light guide layer is provided with a first microstructure array, which is a hemispherical protrusion or a rhomboid dot, and the distribution density of the first microstructure array increases from the area near the light source to the area away from the light source.

[0012] As a further description of the above technical solution, the lower surface of the upper light guide layer is provided with a second microstructure array, which is a circular pit or a pyramidal protrusion uniformly distributed on the entire lower surface.

[0013] As a further description of the above technical solution, it also includes a reflective layer disposed below the lower light guide layer, wherein the reflective layer is a white PET film or a silver-plated reflective sheet.

[0014] As a further description of the above technical solution, the thickness of the lower light guide layer is greater than the thickness of the upper light guide layer, the thickness of the lower light guide layer is 0.8mm-1.2mm, and the thickness of the upper light guide layer is 0.6mm-1.0mm.

[0015] As a further description of the above technical solution, the edge of the light-uniforming layer is provided with a positioning protrusion, the corresponding position of the base plate is provided with a positioning groove, and the lower light guide layer and the upper light guide layer are fixed together by the snap-fit ​​of the positioning protrusion and the positioning groove.

[0016] As a further description of the above technical solution, the side of the upper light guide layer extends with light guide teeth for providing auxiliary lighting to the sidewalls of the keycaps, and the light guide teeth are embedded in the gaps between the keyboard keycaps.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] The present invention provides a uniform light-guiding keyboard backlight module with dual light guide layers, which has at least one of the following beneficial effects during use:

[0019] By combining a dual light guide layer and a uniform light layer, the keyboard backlight uniformity is significantly improved. The gradient density microstructure of the lower light guide layer compensates for light transmission attenuation, the high-haze material of the uniform light layer achieves vertical scattering, and the microstructure of the upper light guide layer organizes the light direction. These three elements work together to completely eliminate bright spots and dark areas, ensuring uniform brightness across the keycap area. The reflective layer effectively recovers light leakage from the lower light guide layer, reducing light loss by 10%-15%, achieving energy saving while improving brightness. The snap-fit ​​structure of the positioning protrusions and positioning grooves ensures precise alignment and tight fit of the three light guide layers, avoiding light refraction disorder caused by interlayer gaps, and improving assembly stability and mass production consistency. The light guide teeth of the upper light guide layer provide full illumination of the front and side walls of the keycaps, solving the problem of blackening on the side walls of traditional backlights. The thickness of each layer is optimized to meet the needs of thinner and lighter keyboards, and multiple materials are available to balance cost and environmental tolerance. The overall solution has a simple structure and is easy to process, improving the user experience while reducing production and usage costs, making it highly practical. Attached Figure Description

[0020] Figure 1 This is an exploded structural diagram of a uniform light-guiding keyboard backlight module with dual light guide layers according to this utility model.

[0021] Figure 2 This is an exploded view of the light guide structure of a uniform light-guided keyboard backlight module with dual light guide layers according to this utility model.

[0022] Figure 3 This is a schematic diagram of the lower light guide layer of a uniform light-guiding keyboard backlight module with dual light guide layers according to this utility model.

[0023] Figure 4 This is a schematic diagram of the upper light guide layer of a uniform light-guiding keyboard backlight module with dual light guide layers according to this utility model.

[0024] Numbering on the map:

[0025] 1. Light guiding structure; 101. Lower light guiding layer; 102. Light uniform layer; 103. Upper light guiding layer; 104. First microstructure array; 105. Second microstructure array; 106. Light guiding teeth; 107. Reflective layer; 2. Base plate; 3. Light source. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] like Figure 1-4 As shown, this utility model provides a uniform light keyboard backlight module with dual light guide layers, including a base plate 2, a light source 3 and a light guide structure 1. The light guide structure 1 includes a lower light guide layer 101, a uniform light layer 102 and an upper light guide layer 103 stacked in sequence.

[0028] Light source 3 is located on the side of the light-incident surface of the lower light guide layer 101. After entering, the light diffuses laterally along the lower light guide layer 101. The first microstructure array 104 (hemispherical bumps / diamond dots) on the lower surface of the lower light guide layer 101, through the distribution design of "low density near light source 3 and high density far light source 3", compensates for the attenuation during light propagation and ensures that areas far from light source 3 can still obtain sufficient light.

[0029] The light source 3 is disposed on the side light-incident surface of the lower light guide layer 101;

[0030] The light-diffusing layer 102 is closely attached to the upper surface of the lower light guide layer 101, and the material of the light-diffusing layer 102 is a semi-transparent material with light scattering properties.

[0031] Light enters the tightly attached uniform light layer 102 upwards. The semi-transparent material (haze 60%-90%) containing scattering particles, such as silicone and optical diffusion film, scatters the horizontally transmitted concentrated light in a vertical direction, breaking the directional propagation characteristics of light and initially eliminating bright spots and dark areas.

[0032] The upper light guide layer 103 tightly covers the upper surface of the light uniform layer 102, and the upper surface of the upper light guide layer 103 is provided with a light-transmitting area corresponding to the position of the keyboard keycap.

[0033] The homogenized light enters the upper light guide layer 103, where a second microstructure array 105 (circular pits / pyramidal protrusions) evenly distributed on the lower surface further organizes the light direction, preventing the scattered light from becoming chaotic. The upper light guide layer 103 only sets light-transmitting areas at the corresponding positions of the keyboard keycaps to achieve directional constraint of the light.

[0034] The reflective layer 107 (white PET film / silver-plated reflective sheet) below the lower light guide layer 101 reflects the light leaking towards the base plate 2 back to the lower light guide layer 101, reducing light loss; the snap-fit ​​structure of the positioning protrusion and the positioning groove ensures that the lower light guide layer 101, the light uniform layer 102, and the upper light guide layer 103 are tightly fitted, avoiding light refraction disorder caused by the gap between layers; the light guide teeth 106 of the upper light guide layer 103 are embedded in the gap of the keycap, and conduct some light to the side wall of the keycap, realizing full-area illumination of the front and side of the keycap.

[0035] The light is transmitted laterally through the lower light guide layer 101, vertically scattered and homogenized by the light homogenizing layer 102, and then transmitted twice through the upper light guide layer 103 before being emitted uniformly from the light-transmitting area.

[0036] Furthermore, the light-diffusing layer 102 is made of silicone doped with scattering particles, an optical diffusion film, or a microstructured frosted surface layer, and its thickness is 0.1mm-0.5mm. (The haze value of the light-diffusing layer 102 is 60%-90%. In silicone doped with scattering particles, the particles (such as titanium dioxide or glass microspheres) diffuse and refract light, breaking the directional propagation of light; the optical diffusion film, through its surface or internal micro-uneven structure, causes light to scatter at multiple angles; the rough surface of the microstructured frosted surface layer disperses concentrated light through diffuse reflection. All three materials achieve the goal of "converting laterally transmitted concentrated light into vertically scattered light" through their physical structures.

[0037] The thickness range of 0.1mm-0.5mm is the key to balancing the scattering effect and light loss: if it is too thick (>0.5mm), the material will absorb more light and reduce the light utilization rate; if it is too thin (<0.1mm), the density of scattering particles or microstructures will be insufficient, and the bright spots transmitted from the lower light guide layer 101 cannot be completely eliminated.

[0038] The uniform light layer 102 effectively eliminates the uneven light distribution in the lower light guide layer 101 (solving the problem of localized overbrightness caused by the directionality of lateral light transmission) while retaining sufficient light intensity to provide uniform and ample incident light for the upper light guide layer 103. Multiple materials are available (silicone, diffusion film, frosted surface layer), allowing for flexible adaptation to different application scenarios based on production costs and environmental tolerance (such as high temperature resistance and aging resistance), thus enhancing the practicality of the technology.

[0039] Furthermore, the lower surface of the lower light guide layer 101 is provided with a first microstructure array 104, which is a hemispherical protrusion or a rhomboid dot, and the distribution density of the first microstructure array 104 increases from the area near the light source 3 to the area away from the light source 3.

[0040] The hemispherical bumps refract some of the laterally guided light upwards (into the uniform light layer 102) through curved surface reflection, while the rhomboid dots disperse the light through diffuse reflection at their edges. Both can break the total internal reflection constraint of light within the light guide layer and guide some of the light upwards for output.

[0041] The light emitted by light source 3 gradually attenuates during lateral transmission due to material absorption and edge leakage (high light intensity near light source 3, low light intensity far from light source 3). Therefore, a low-density microstructure is used near light source 3 (to reduce premature upward light output and avoid local overbrightness), while a high-density microstructure is used far from light source 3 (to enhance the proportion of upward light output and compensate for light intensity attenuation). The uniform light intensity across the lower light guide layer 101 is achieved through "dynamic control of light output".

[0042] This design specifically addresses the issue of brightness difference caused by light attenuation over transmission distance, ensuring that the light output from the lower light guide layer 101 to the light homogenizing layer 102 is initially uniform, thus reducing the homogenization pressure on the light homogenizing layer 102. The microstructure design of hemispherical bumps / diamond dots eliminates the need for an additional light source 3, optimizing light distribution solely through physical structure, thereby reducing costs and avoiding increased energy consumption.

[0043] Furthermore, the lower surface of the upper light guide layer 103 is provided with a second microstructure array 105, which consists of circular pits or pyramidal protrusions uniformly distributed across the entire lower surface.

[0044] The light rays scattered by the light-monitoring layer 102 are randomly oriented (including light rays in multiple directions such as vertically upward and obliquely propagating). The circular pits "correct" the oblique light rays to an approximately vertical direction through reflection from the inner wall, and the pyramidal protrusions concentrate the scattered light to a vertically upward angle through multi-faceted refraction. Both of these can reduce the lateral diffusion of light within the light guide layer 103 (avoiding light leakage).

[0045] Since the light homogenizing layer 102 has achieved light homogenization, the second microstructure needs to be evenly distributed to match the uniformity of the incident light, ensuring that the light correction effect of each area of ​​the upper light guiding layer 103 is consistent, and avoiding light intensity fluctuations caused by local microstructure density differences.

[0046] The directionality of light is improved, and ineffective scattering (such as light leakage to the sides) within the upper light guide layer 103 is reduced, allowing more light to concentrate and emerge from the light-transmitting area, thus improving light utilization. The uniformly distributed microstructure matches the uniform incident light of the light-diffusing layer 102, further enhancing the overall uniformity of the backlight and ensuring consistent brightness in the corresponding areas of the keycaps.

[0047] Furthermore, it also includes a reflective layer 107 disposed below the lower light guide layer 101, wherein the reflective layer 107 is a white PET film or a silver-plated reflective sheet.

[0048] When light is transmitted within the lower light guide layer 101, some light will leak downwards (towards the base plate 2) due to microstructure reflection, material defects, etc. The reflective layer 107 reflects the leaked light back to the lower light guide layer 101 through its high reflectivity (white PET film has a reflectivity of about 85%-90%, and silver-plated reflective sheet has a reflectivity of about 95% or more), so that the light can re-participate in lateral transmission or be output upwards to the uniform light layer 102, thereby reducing light energy loss.

[0049] This directly improves light utilization (reducing light leakage loss by 10%-15%), allowing for increased backlight brightness under the same light source power, or reducing the power of light source power under the same brightness requirements, thus achieving energy savings. Simultaneously, it prevents light absorption by the base plate 2 (usually plastic or metal, which easily absorbs light), preventing a "dark area at the bottom" caused by light leakage absorption below the lower light guide layer 101, indirectly ensuring the uniformity of the overall light distribution of the lower light guide layer 101.

[0050] Furthermore, the thickness of the lower light guide layer 101 is greater than the thickness of the upper light guide layer 103. The thickness of the lower light guide layer 101 is 0.8mm-1.2mm, and the thickness of the upper light guide layer 103 is 0.6mm-1.0mm.

[0051] As the initial light transmission layer, it needs to undertake the task of long-distance lateral transmission. A thicker layer (0.8mm-1.2mm) can reduce the attenuation of light during transmission (insufficient thickness will cause light to leak more easily from the side), ensuring that there is still enough light in the far light source 3 region; at the same time, a thicker substrate also provides sufficient processing space for the first microstructure array 104 on the lower surface (avoiding the reduction of structural strength caused by excessively deep microstructures).

[0052] As a secondary conduction and directional output layer, its main function is to guide the light after homogenization to the light-transmitting area without long-distance lateral conduction. The thinner thickness (0.6mm-1.0mm) can reduce the overall module thickness (to adapt to the trend of thinner keyboards) and at the same time reduce the scattering loss of light inside (excessive thickness will increase the ineffective scattering path).

[0053] Furthermore, the edge of the light-diffusing layer 102 is provided with a positioning protrusion, and the corresponding position of the base plate 2 is provided with a positioning groove. The lower light guide layer 101 and the upper light guide layer 103 are fixed together by the snap-fit ​​of the positioning protrusion and the positioning groove.

[0054] The snap-fitting of the positioning protrusion and the positioning groove can precisely limit the relative positions of the lower light guide layer 101, the light uniform layer 102, and the upper light guide layer 103, ensuring that the three-layer structure is completely aligned. At the same time, the pressure generated by the snap-fitting makes the three layers fit tightly together, avoiding unexpected refraction of light between layers caused by gaps (such as reflection loss at the air-material interface).

[0055] Furthermore, the upper light guide layer 103 has light guide teeth 106 extending along its side to provide auxiliary lighting for the sidewalls of the keycaps, and the light guide teeth 106 are embedded in the gaps between the keyboard keycaps.

[0056] As an extension of the upper light guide layer 103, the light guide teeth 106 can conduct some light to the gap between the keycaps. Through diffuse reflection or refraction of the tooth surface, the light is directed to the side wall of the keycap (usually a non-transparent material, which needs to rely on side lighting to improve visibility), thus supplementing the shortcomings of traditional backlighting that only illuminates the front of the keycap.

[0057] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A uniform light-guiding keyboard backlight module with dual light guide layers, comprising a base plate, a light source, and a light guide structure, characterized in that, The light guide structure includes a lower light guide layer, a light uniform layer, and an upper light guide layer stacked sequentially. The light source is located at the light-incident surface on the side of the lower light guide layer; The light-diffusing layer is tightly attached to the upper surface of the lower light guide layer, and the material of the light-diffusing layer is a semi-transparent material with light scattering properties. The upper light guide layer tightly covers the upper surface of the light uniform layer, and the upper surface of the upper light guide layer is provided with a light-transmitting area corresponding to the position of the keyboard keycap; The light rays are transmitted laterally through the lower light guide layer, vertically scattered and homogenized by the light homogenizing layer, and then transmitted twice through the upper light guide layer before being emitted uniformly from the light-transmitting area.

2. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The material of the light-diffusing layer is silicone doped with scattering particles, an optical diffusion film, or a microstructured frosted surface layer, and the thickness of the light-diffusing layer is 0.1mm-0.5mm.

3. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The lower surface of the lower light guide layer is provided with a first microstructure array, which is a hemispherical protrusion or a rhomboid dot, and the distribution density of the first microstructure array increases from the area near the light source to the area away from the light source.

4. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The lower surface of the upper light guide layer is provided with a second microstructure array, which consists of circular pits or pyramidal protrusions uniformly distributed across the entire lower surface.

5. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: It also includes a reflective layer located below the lower light guide layer, wherein the reflective layer is a white PET film or a silver-plated reflective sheet.

6. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The thickness of the lower light guide layer is greater than that of the upper light guide layer. The thickness of the lower light guide layer is 0.8mm-1.2mm, and the thickness of the upper light guide layer is 0.6mm-1.0mm.

7. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The edge of the light-diffusing layer is provided with a positioning protrusion, and the corresponding position of the base plate is provided with a positioning groove. The lower light guide layer and the upper light guide layer are fixed together by the positioning protrusion and the positioning groove.

8. A uniform light-guiding keyboard backlight module with dual light guide layers according to claim 1, characterized in that: The upper light guide layer has light guide teeth extending from its side to provide auxiliary lighting for the sidewalls of the keycaps, and the light guide teeth are embedded in the gaps between the keyboard keycaps.

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