Backlight module

Abstract

A backlight module includes a light guide structure formed of a first light medium material and having an incident surface and a light diffusion structure. The light diffusion structure is located inside the light guide structure and includes at least one hollow structure. The hollow structure forms a space for accommodating a second light medium. The first light medium is different from the second light medium. Another backlight module includes a light guide structure having a light guide portion extending along an extension direction and having a first bending portion, a second bending portion, an incident surface, a first reflecting surface, and a second reflecting surface in a direction perpendicular to the extension direction. The first reflecting surface is located at the first bending portion and faces the incident surface. The second reflecting surface is located at the first bending portion and faces the first reflecting surface. The hollow structure or the internal reflecting surface can reduce light and mix light, thereby improving the light intensity distribution of the backlight provided by the light guide structure.

Description

[0001] This invention is a divisional application of the invention patent with application number 202010729820.X, application date July 27, 2020, and invention title "Backlight Module". Technical Field

[0002] This invention relates to a backlight module, and more particularly to a backlight module with a light guide structure. Background Technology

[0003] Backlight modules are commonly used to provide backlighting for devices and typically use point light sources. When the light guide of a backlight module is small, for example, if the light guide extends in a long strip with its light-incident and light-exit surfaces located on opposite sides of the extension direction, light enters the light guide plate through the light-incident surface and exits through the light-exit surface. This light guide makes it difficult to effectively mix the light, resulting in noticeably uneven backlighting or even obvious light spots. To achieve uniform backlighting, the distance between the light-exit surface of the backlight module and the backlight projection target can usually be increased, or the size of the light guide plate of the backlight module can be increased, or multiple optical films, such as prism sheets, diffusers, and reflectors, can be stacked on it to enhance the light mixing effect. The former increases the space required to install the light-emitting module, while the latter increases the volume of the backlight module itself. Either way, it makes it difficult to reduce the size of the device equipped with the backlight module. Summary of the Invention

[0004] In view of the problems in the prior art, the object of the present invention is to provide a backlight module whose light guide structure utilizes a hollow structure to improve the light intensity distribution of the backlight provided by the backlight module.

[0005] To achieve the above objectives, the present invention proposes a backlight module comprising: a light guide structure formed of a material of a first light medium and having a first light incident surface and a light diffusion structure, the light diffusion structure being located inside the light guide structure and including at least one first hollow structure, the at least one first hollow structure forming a space for accommodating a second light medium, the first light medium being different from the second light medium.

[0006] As an optional technical solution, the at least one first hollow structure is adjacent to the first light-incident surface.

[0007] As an optional technical solution, the backlight module also includes a light source adjacent to the first light-incident surface, wherein the light emission direction of the light source is towards the first light-incident surface, and the light emitted by the light source enters the light guide structure through the first light-incident surface and is changed in direction by the light diffusion structure.

[0008] As an optional technical solution, the at least one first hollow structure includes a through hole, which is formed by a plurality of continuous walls of the light guide structure.

[0009] As an optional technical solution, the first light-incident surface is formed with a through groove, which is recessed toward the through hole.

[0010] As an optional technical solution, the at least one first hollow structure includes a plurality of triangular prism-shaped through holes, the plurality of triangular prism-shaped through holes being arranged along a reference arc segment, the reference arc segment having a notch facing the first light-incident surface.

[0011] As an optional technical solution, the at least one first hollow structure includes a slot formed by a plurality of continuous walls of the light guide structure.

[0012] As an optional technical solution, the slot has an extension path, which is arc-shaped or angular.

[0013] As an optional technical solution, the arc or the angle has a notch facing the first light-incident surface; or, the slot is crescent-shaped.

[0014] As an optional technical solution, the light guide structure has a surface that is adjacent to and extends substantially perpendicular to the first light incident surface, and the at least one first hollow structure includes a recess that is recessed from the surface toward the inside of the light guide structure, and the recess has a plurality of continuous walls of the light guide structure.

[0015] As an optional technical solution, the inner side of the light guide structure has a light source receiving groove, and the first light incident surface is the side of the light source receiving groove.

[0016] As an optional technical solution, the light source receiving groove has a second light-incident surface, which is opposite to the first light-incident surface.

[0017] As an optional technical solution, the backlight module further includes at least one first light source and at least one second light source, wherein the at least one first light source and the at least one second light source are alternately arranged in the light source receiving groove, the light emission direction of the at least one first light source is towards the first light incident surface, and the light emission direction of the at least one second light source is towards the second light incident surface.

[0018] As an optional technical solution, the backlight module further includes a first light source and a second light source. The inner side of the light guide structure has a first light source receiving groove and a second light source receiving groove. The first light source receiving groove and the second light source receiving groove are staggered on both sides of the reference axis. The first light-incident surface is the side of the first light source receiving groove adjacent to the reference axis, and the second light-incident surface is the side of the second light source receiving groove adjacent to the reference axis. The first light source is disposed in the first light source receiving groove, and the second light source is disposed in the second light source receiving groove. The light emission direction of the first light source is towards the first light-incident surface, and the light emission direction of the second light source is towards the second light-incident surface.

[0019] Therefore, in the aforementioned backlight module, the at least one hollow structure can change the direction and intensity of light travel, thereby improving the light intensity distribution of the backlight provided by the light guide structure.

[0020] Furthermore, the present invention also proposes another backlight module, comprising: a light guide structure formed of a first light medium material and including a first light guide portion and a second light guide portion, the first light guide portion and the second light guide portion being arranged along an arrangement direction and the first light guide portion extending along a first extension direction and the second light guide portion extending along a second extension direction, the first extension direction and the second extension direction being non-parallel to each other and both perpendicular to the arrangement direction, the light guide structure having a first light incident surface, a second light incident surface, a light emitting surface and a light diffusion structure, the first light incident surface being located in the first light guide portion, the second light incident surface being located in the second light guide portion, the light emitting surface extending along the arrangement direction, the light diffusion structure being located inside the first light guide portion and including at least one first hollow structure, each first hollow structure forming a space for accommodating a second light medium, the first light medium being different from the second light medium.

[0021] As an optional technical solution, the light diffusion structure also includes at least one second hollow structure, which is located inside the second light guiding portion.

[0022] As an optional technical solution, the at least one first hollow structure extends perpendicular to the first extending direction, and the at least one second hollow structure extends obliquely to the second extending direction.

[0023] Therefore, in the aforementioned backlight module, the light guide structure can use the first light guide portion and the second light guide portion to guide the light emitted by light sources that are not located on the same plane, and make them exit the light guide structure with the same light emitting surface. This can increase the ability of the light guide structure to adapt to the surrounding structure. In addition, the at least one hollow structure can change the direction and intensity of light travel, thereby improving the light intensity distribution of the backlight provided by the light guide structure.

[0024] Another object of the present invention is to provide a backlight module whose light guide structure utilizes multiple internal reflective surfaces to increase the light travel path, thereby improving the light intensity distribution of the backlight provided by the backlight module.

[0025] To this end, the present invention also proposes a backlight module, comprising: a light guide structure, including a first light guide portion, the first light guide portion extending along an extension direction and having a first bend, a second bend, a light incident surface, a first reflective surface and a second reflective surface in a direction perpendicular to the extension direction, the first reflective surface being located at the first bend and facing the light incident surface, and the second reflective surface being located at the second bend and facing the first reflective surface.

[0026] As an optional technical solution, both the first reflective surface and the second reflective surface are planar, and the first reflective surface and the second reflective surface are parallel or perpendicular to each other.

[0027] As an optional technical solution, the light entering the first light guide portion through the light incident surface travels in a first direction, the light is reflected by the first reflective surface and then travels in a second direction, and the light is reflected by the second reflective surface and then travels in a third direction. The first direction and the third direction are opposite or the same.

[0028] As an optional technical solution, the light guide structure includes a second light guide portion, which is plate-shaped and extends along the extension direction. Light entering the first light guide portion through the light incident surface is reflected sequentially by the first reflective surface and the second reflective surface to enter the second light guide portion.

[0029] As an optional technical solution, the backlight module also includes a light source device, which is disposed adjacent to the light incident surface. The light emitted by the light source device enters the first light guide portion through the light incident surface and is reflected sequentially by the first reflective surface and the second reflective surface.

[0030] As an optional technical solution, the first light guide portion includes a first sub-part, a second sub-part, and a third sub-part. The second sub-part connects the first sub-part and the third sub-part. The first sub-part includes the light incident surface. The light source device includes a circuit board and multiple light sources. The first sub-part and the third sub-part are located on both sides of the circuit board. The multiple light sources are fixed on the circuit board, and the light emission direction of the multiple light sources is towards the light incident surface.

[0031] As an optional technical solution, the light source device includes multiple light sources, which are arranged adjacent to the light incident surface. The multiple light sources emit light in different directions and are directed toward the light incident surface. The multiple light sources emit different colors of light.

[0032] In this way, in the aforementioned backlight module, the light entering the light guide portion through the light incident surface is reflected by the first reflective surface and the second reflective surface in sequence. This can increase the path length of the light traveling in the light guide structure, thereby increasing the light mixing effect and improving the light intensity distribution of the backlight provided by the light guide structure.

[0033] Compared to the prior art, the backlight module of the present invention can generate light reduction and light mixing effects by using a hollow structure or an internal reflective surface, thereby improving the light intensity distribution of the backlight provided by the light guide structure. Therefore, the backlight module does not need to increase the structural size to solve the problem in the prior art that it is difficult to reduce the size of the backlight module or the device equipped with the backlight module in order to maintain the uniformity of the backlight.

[0034] The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a backlight module according to one embodiment.

[0037] Figure 2 for Figure 1 A top view of the backlight module.

[0038] Figure 3 for Figure 2 An enlarged view of the hollow structure of the light diffusion structure in the image.

[0039] Figure 4 for Figure 3 An enlarged view of a variation of the hollow structure in the image.

[0040] Figure 5 This is a top view of the hollow structure of a light diffusion structure according to an embodiment.

[0041] Figure 6 This is a top view of the hollow structure of a light diffusion structure according to an embodiment.

[0042] Figure 7 for Figure 6 A cross-sectional view of XX along the line.

[0043] Figure 8 This is a top view of a backlight module according to an embodiment.

[0044] Figure 9 This is a top view of a backlight module according to another embodiment.

[0045] Figure 10 This is a top view of a backlight module according to another embodiment.

[0046] Figure 11 This is a schematic diagram of a backlight module according to one embodiment.

[0047] Figure 12 for Figure 11 A cross-sectional view of the backlight module along line YY.

[0048] Figure 13 This is a cross-sectional view of a backlight module according to an embodiment.

[0049] Figure 14 This is a schematic diagram of the structural logic of the first light guide portion according to an embodiment.

[0050] Figure 15 This is an exploded view of a backlight module according to one embodiment.

[0051] Figure 16 for Figure 15 A bottom view of the backlight module.

[0052] Figure 17 This is a schematic diagram of a backlight module according to another embodiment.

[0053] Figure 18 for Figure 17 A cross-sectional view of the backlight module along line ZZ.

[0054] Figure 19 for Figure 17 A cross-sectional view of the backlight module along line WW. Detailed Implementation

[0055] To provide a further understanding of the purpose, structure, features, and functions of the present invention, detailed descriptions are provided below with reference to specific embodiments.

[0056] Please see Figure 1 and Figure 2 A backlight module 1 according to one embodiment includes a light guide structure 12 and a light source device 14. The light guide structure 12 is formed of a first light medium material (e.g., but not limited to, a light-transmitting polymer material, for example, integrally formed by injection molding) and has a light incident surface 122 and a light diffusion structure 124 (the extent of which is shown in the figure with a dashed box). The light diffusion structure 124 is located inside the light guide structure 12 and includes a plurality of hollow structures 1242. When the backlight module 1 is applied to a keyboard, the extension direction of the light incident surface 122 generally corresponds to the long or short side of the entire rectangular keyboard (not shown). The hollow structures 1242 form a space for accommodating a second light medium (e.g., but not limited to accommodating air), the first light medium being different from the second light medium. The light source device 14 includes a circuit board 142 (e.g., but not limited to, a printed circuit board, a flexible printed circuit board, etc.) and a plurality of light sources 144 (e.g., but not limited to, light-emitting diodes) disposed thereon. The plurality of light sources 144 are respectively positioned corresponding to the plurality of hollow structures 1242 and facing the light-incident surface 122, such that the light emitted by the plurality of light sources 144 (indicated by thin arrows) Figure 2 The light enters the light guide structure 12 via the light incident surface 122. The light entering the light guide structure 12 changes its direction of travel via the light diffusion structure 124, giving the light guide structure 12 a light mixing effect. Furthermore, the intensity of the light passing through the hollow structure 1242 will be reduced in principle, giving the hollow structure 1242 the effect of adjusting the light intensity distribution.

[0057] In this embodiment, the light guide structure 12 is plate-shaped, with the light incident surface 122 located at the side edge of the light guide structure 12 and extending along an extension direction D1 (indicated by a double arrow in the figure). The circuit board 142 also extends along the extension direction D1, and the plurality of light sources 144 are also arranged along the extension direction D1 with their emission direction 144a (indicated by an arrow in the figure) facing the light incident surface 122. The emission direction 144a is perpendicular to the extension direction D1, but this is not a limitation in actual operation. The plurality of hollow structures 1242 are arranged adjacent to the light incident surface 122 and the corresponding light sources 144, which increases the effect of the hollow structures 1242 in diffusing light and reducing light intensity, thus helping the backlight module 1 to provide a more uniform backlight. For strip-shaped light guide structures (e.g., extending along the extension direction D1), the aforementioned structural configuration can also provide a good improvement in light intensity distribution, which helps to reduce the size of the backlight module.

[0058] Please also refer to Figure 3 In this embodiment, the hollow structure 1242 is a slot, the extension direction of which is approximately perpendicular to the extension direction D1 and the light emission direction 144a, and the hollow structure 1242 penetrates the light guide structure 12. This slot is formed by multiple continuous walls 12420 of the light guide structure 12 (e.g., connected in a ring) and has an extension path 1242a (indicated by dashed lines). Figure 3 (In the middle). The extension path 1242a is angled, with a notch facing the light-incident surface 122, and the corresponding light source 144 is positioned facing the notch. This slot can, in principle, refract and reflect light entering the light guide structure 12, thereby providing light diffusion and reducing the intensity of light after it passes through. Furthermore, in this embodiment, the angle forms an included angle 1242b, which is between, for example, but not limited to, 90 degrees and 140 degrees. Also, the angle has a side length 1242c, which is approximately, for example, but not limited to, 3.9 mm. In practice, the extension path 1242a of the slot can also be other geometric structures, such as an arc; in this case, the arc has a notch facing the light-incident surface 122, similarly providing diffusion and light reduction effects. Furthermore, in practice, the light-incident surface 122 can have a wavy structure (indicated by dashed lines). Figure 3 In this embodiment, for example, it can be formed simultaneously during the injection molding of the light guide structure 12, which can increase the diffusion effect. Furthermore, in this embodiment, the slot width of the hollow structure 1242 (along the extension path 1242a) is a fixed value, but it can be varied in actual operation. For example, the hollow structure 1242 can be modified to be wider in the middle and narrower on both sides. Figure 4 The hollow structure 1242' shown is crescent-shaped. The hollow structure 1242' also has the effect of diffusing and reducing light.

[0059] Furthermore, in practice, the aforementioned slot penetrating the light guide structure 12 can also be replaced by other penetrating structures. For example... Figure 5 As shown, a light diffusion structure 125 according to one embodiment includes a plurality of hollow structures 1252, at least one hollow structure 1252 including a plurality of triangular prism-shaped through holes 1252a. Each triangular prism-shaped through hole 1252a is formed by three consecutive wall surfaces connected together. The plurality of triangular prism-shaped through holes 1252a are along a reference arc segment 1252b (indicated by a chain line). Figure 5 Arranged in a central (middle) pattern. The reference arc segment 1252b has a notch facing the light-incident surface 122. In this embodiment, the reference arc segment 1252b has a center 1252c (indicated by a cross). Figure 5 (in the middle). Each triangular prism through hole 1252a has a long edge 1252d perpendicular to the reference arc segment 1252b (in the middle). Figure 5 The projection is a point. Each triangular prism through hole 1252a defines a direction 1252e (indicated by an arrow). Figure 5 (In the middle), the direction 1252e passes through the long edge 1252d of the corresponding triangular prism through-hole 1252a and points towards the center 1252c. The directions 1252e of two adjacent triangular prism through-holes 1252a form an included angle 1252f, which is approximately, for example, but not limited to, 21 degrees. The corresponding light source 144 (indicated by a dashed box) Figure 5 The light-incident surface 122 and the plurality of triangular prism-shaped through holes 1252a (or light diffusion structure 125) are arranged in the middle.

[0060] Furthermore, in this embodiment, the light-incident surface 122 forms a through groove 122a, which is recessed toward the light-diffusing structure 125. The light source 144 is positioned toward the through groove 122a. The cross-section of the through groove 122a is approximately semi-circular and has a cross-sectional radius 122b. The cross-sectional radius 122b is three times the distance 1252g between the corresponding light-diffusing structure 125 and the through groove 122a. For example, if the distance 1252g is 1 mm, the cross-sectional radius 122b is 3 mm, but this is not a limitation in actual operation. Also, in this embodiment, the center of the circle corresponding to the cross-sectional radius 122b coincides with the center 1252c of the reference arc segment 1252b, and the light source 144 is approximately located on the center 1252c. Furthermore, in actual operation, the number of triangular prism-shaped through holes 1252a in the hollow structure 1252 is not limited to three. For example, the hollow structure 1252 may contain one or more triangular prism-shaped through holes 1252a. Also, the hollow structure 1252 may be implemented with one or more through holes having the same or different polygonal cross-sections, which also have the effect of diffusion and light reduction.

[0061] The hollow structures 1242, 1242', and 1252 in the aforementioned embodiments are all implemented as through structures, but this is not a limitation in actual operation. For example, the hollow structures 1242, 1242', and 1252 can be replaced with blind hole structures with a certain depth (e.g., greater than 1 / 3, 1 / 2, 2 / 3, 4 / 3, etc., the thickness of the plate-shaped light guide structure 12), which still have a certain degree of diffusion and light reduction effect. For another example, such as... Figure 6 and Figure 7 As shown, a light diffusion structure 126 according to one embodiment includes a plurality of hollow structures 1262. The light guide structure 12 has a surface 120a (shown as the bottom surface 120a in this embodiment), which extends adjacent to and substantially perpendicular to the incident light surface 122. The hollow structures 1262 include recesses 1262a formed by recessing from the surface 120a toward the inner side of the light guide structure 12, and are formed by a plurality of continuous wall surfaces of the light guide structure 12. A corresponding light source 144 (shown in dashed boxes in the figure) is disposed toward the incident light surface 122 and the recesses 1262a. Similar to the aforementioned hollow structures 1242 and 1252, the recesses 1262a can, in principle, provide refraction and reflection of light entering the light guide structure 12, thereby providing a light diffusion effect and reducing the intensity of light passing through the hollow structures 1262. In practical operation, the depth 1262b of the recess 1262a is greater than one-third of the thickness 120b of the light guide structure 12, which can provide a good light diffusion effect. Furthermore, in this embodiment, the projected cross-section of the recess 1262a in the direction perpendicular to the extension direction D1 and the light emission direction 144a is rectangular, but this is not a limitation in practice. For example, it can be circular, polygonal, etc., or it can be the same as the projected cross-section of the aforementioned hollow structures 1242 and 1252 in the direction perpendicular to the extension direction D1 and the light emission direction 144a, which will not be elaborated further. Among the several continuous walls constituting the hollow structure 1262, the two near-light walls and the far-light wall along the light emission direction 144a may not be parallel to the light-incident surface 122, but may form acute or obtuse angles; in other words, the angles formed between the near-light wall and the far-light wall and the light-incident surface 122 are selected from a combination of acute angles, obtuse angles, or 0 degrees (parallel to each other).

[0062] In the foregoing embodiments, the light source 144 is disposed on the outside of the light guide structure 12, but this is not a limitation in actual operation. Figure 8As shown, the backlight module 3 according to one embodiment has a structure that is largely the same as the aforementioned backlight module 1. The backlight module 3, in principle, uses the component symbols of the backlight module 1. Therefore, for further explanation of the backlight module 3, please refer directly to the previous description of the backlight module 1 and its variations; further details are not provided here. The main difference between the backlight module 3 and the backlight module 1 lies in the position of the light source device 14 relative to the light guide structure 12 in the backlight module 3. In the backlight module 3, its light guide structure 32 has a light source receiving groove 322. One side (which can also be considered a wall) of the light source receiving groove 322 serves as the first light-incident surface 322a. The circuit board 142 (whose hidden outline is shown in dashed lines in the figure) is positioned corresponding to the light source receiving groove 322, so that the plurality of light sources 144 are housed in the light source receiving groove 322 and face the first light-incident surface 322a. When the backlight module 3 is applied to a keyboard, the shape of the light guide structure 32 corresponds to the four sides of a rectangular keyboard (not shown). Figure 8 The extension direction of the first light-incident surface 322a is parallel to the short side of the keyboard, and the light source receiving groove 322 is adjacent to the light guide structure 32 and the short side of the rectangular keyboard.

[0063] In this embodiment, the light source receiving slot 322 is disposed adjacent to one side of the light guide structure 32, and the light source 144 emits light towards the middle part of the light guide structure 32, but this is not the limitation in actual operation. Figure 9 As shown, the backlight module 3a according to one embodiment is structurally similar to the aforementioned backlight module 3. The backlight module 3a generally uses the same component symbols as the backlight module 3. Therefore, for further explanation of the backlight module 3a, please refer directly to the previous explanation of the backlight module 3; further details will not be repeated here. The main difference between the backlight module 3a and the backlight module 3 lies in the position of the light source device 34 relative to the light guide structure 12 in the backlight module 3a. In the backlight module 3a, the other side (which can also be considered another wall surface) of the light source receiving groove 322 serves as the second light-incident surface 322b, which is opposite to the first light-incident surface 322a. The light source receiving groove 322 is located in the middle of the light guide structure 32 and extends approximately along a reference axis 322c (represented by a chain line in the figure). The light source device 34 includes a plurality of first light sources 344a and a plurality of second light sources 344b. The plurality of first light sources 344a and the plurality of second light sources 344b are staggered in the light source receiving groove 322 along the reference axis 322c. The light emission direction of the first light sources 344a (indicated by an arrow in the figure) is towards the first light incident surface 322a, and the light emission direction of the second light sources 344b (indicated by an arrow in the figure) is towards the second light incident surface 322b. In this way, the light source device 34 can provide light to the portions of the light guide structure 32 on both sides of the light source receiving groove 322 (or the reference axis 322c).

[0064] In this embodiment, a single light source receiving slot 322 is used to accommodate multiple first light sources 344a and multiple second light sources 344b, but this is not the limitation in actual operation. Figure 10 As shown, the backlight module 3b according to one embodiment has a structure that is largely the same as the aforementioned backlight module 3a. The backlight module 3b generally uses the same component symbols as the backlight module 3a. Therefore, for further explanation of the backlight module 3b, please refer directly to the previous explanation of the backlight module 3a; further details will not be repeated here. The main difference between the backlight module 3b and the backlight module 3a is that the backlight module 3b does not use a single light source receiving slot to house the light sources 344a and 344b. In the backlight module 3b, the inner side of its light guide structure 33 includes multiple first light source receiving slots 332a and multiple second light source receiving slots 332b, respectively corresponding to the multiple first light sources 344a and the multiple second light sources 344b. That is, the multiple first light source receiving slots 332a correspond to the multiple first light sources 344a, and the multiple second light source receiving slots 332b correspond to the multiple second light sources 344b. The plurality of first light source receiving slots 332a and the plurality of second light source receiving slots 332b are staggered on both sides of the reference axis 333c (represented by a chain line in the figure), for example, as shown in the figure. Figure 10From a certain perspective, multiple first light source receiving slots 332a are located to the right of reference axis 333c, and multiple second light source receiving slots 332b are located to the left of reference axis 333c. The right-facing side (which can also be considered a wall) of the first light source receiving slot 332a serves as the first light-incident surface 333a, and the left-facing side (which can also be considered a wall) of the second light source receiving slot 332b serves as the second light-incident surface 333b. A first light source 344a is housed in its corresponding first light source receiving slot 332a, and the emission direction of the first light source 344a (indicated by an arrow in the figure) faces the corresponding first light-incident surface 333a; that is, the first light-incident surface 333a is located on the side of the first light source receiving slot 332a adjacent to reference axis 333c. The second light source 344b is housed in a corresponding second light source receiving slot 332b. The light emission direction of the second light source 344b (indicated by an arrow in the figure) is towards the corresponding second light-incident surface 333b, that is, the second light-incident surface 333b is located on the side of the second light source receiving slot 332b adjacent to the reference axis 333c. In this way, the light source device 34 can also provide light to the portions of the light guide structure 32 on both sides of the reference axis 322c, and the arrangement of the light source receiving slots 332a and 332b (and the light sources 344a and 334b) also helps to reduce their interference with the light guiding effect of the light guide structure 33. Furthermore, in this embodiment, the light emission directions of the first light source 344a and the second light source 344b are parallel and opposite, but this is not a limitation in actual operation. Furthermore, in this embodiment, the light source receiving slots 332a and 332b are implemented as through holes, but this is not a limitation in actual operation; for example, the light source receiving slots 332a and 332b are implemented as blind holes, which can further reduce the interference of the light receiving slots 332a and 332b on the light guiding effect of the light guiding structure 33.

[0065] In the foregoing embodiments, backlight modules 1, 3a, and 3b utilize hollow structures 1242, 1252, and 1262 to alter the direction and intensity of light travel within light guide structures 12, 32, and 33, thereby enabling backlight modules 1, 3a, and 3b to provide more uniform backlighting. However, in actual operation, this is not a limitation; for example, increasing the path length of light travel within the light guide structure can also enhance the light mixing effect. Please refer to [link to relevant documentation]. Figure 11 and Figure 12According to one embodiment, a backlight module 5 includes a light guide structure 52 and a light source device 54. The light guide structure 52 includes a first light guide portion 522, which has a light incident surface 5222, a first reflective surface 5224, a second reflective surface 5226, and a light emitting surface 5228. The first reflective surface 5224 faces the light incident surface 5222, and the second reflective surface 5226 faces the first reflective surface 5224 and the light emitting surface 5228. The light source device 54 includes a circuit board 542 (e.g., but not limited to, a printed circuit board, a flexible printed circuit board, etc.) and a plurality of light sources 544 (e.g., but not limited to, light-emitting diodes) disposed thereon. The plurality of light sources 544 are disposed adjacent to the light incident surface 5222. Light emitted by the light source 144 (indicated by thin arrows in the figure) enters the first light guide portion 522 via the light incident surface 5222. The light entering the light guide structure 12 changes its direction of travel via the light diffusion structure 124 to enhance the light mixing effect of the light guide structure 12. And reflect in sequence to the first reflecting surface 5224 and the second reflecting surface 5226.

[0066] In this embodiment, the first light guide portion 522 has a strip-shaped structure and extends along an extension direction D2 (indicated by a double arrow). Figure 11 (in the middle) extends, the light-incident surface 5222 extends approximately along the extension direction D2, the circuit board 542 also extends along the extension direction D2, and multiple light sources 544 are also arranged along the extension direction D2 with their light-emitting direction 544a (indicated by an arrow in the figure) facing the light-incident surface 5222; wherein, the light-emitting direction 544a is perpendicular to the extension direction D2, but this is not a limitation in actual operation.

[0067] In this embodiment, the projected cross-section of the first light-guiding portion 522 in the extending direction D2 is Z-shaped, that is, the first light-guiding portion 522 has a first bend 5220a and a second bend 5220b in the direction perpendicular to the extending direction D2. The first reflective surface 5224 is located in the first bend 5220a, and the second reflective surface 5226 is located in the second bend 5220b. Light entering the first light-guiding portion 522 via the light-incident surface 5222 travels in the first direction d1 (indicated by an arrow). Figure 12 The light ray travels in the middle. After being reflected by the first reflecting surface 5224, it travels in the second direction d2 (indicated by an arrow). Figure 12 The light ray travels in a third direction d3 (indicated by an arrow) after being reflected by the second reflecting surface 5226. Figure 12 (In the middle) travel. The first direction d1 is the same as the third direction d3. In this embodiment, both the first reflecting surface 5224 and the second reflecting surface 5226 are planes, and the two planes are parallel to each other, but this is not a limitation in actual operation. For example, the first reflecting surface 5224 and the second reflecting surface 5226 may be slightly non-parallel and form an angle between them. As another example, the first reflecting surface 5224 and / or the second reflecting surface 5226 may be curved surfaces.

[0068] Furthermore, in this embodiment, the light guide structure 52 also includes a second light guide portion 524, which has a plate-like structure. Light entering the first light guide portion 522 via the light incident surface 5222 is sequentially reflected by the first reflecting surface 5224 and the second reflecting surface 5226, exiting the first light guide portion 522 from the light emitting surface 5228 and entering the second light guide portion 524. In actual operation, the first light guide portion 522 and the second light guide portion 524 can be integrally formed; in this case, the aforementioned light emitting surface 5228 physically disappears.

[0069] In addition, such as Figure 12 As shown, in another aspect, the first light guide portion 522 includes a first sub-portion 522a, a second sub-portion 522b, and a third sub-portion 522c, with the second sub-portion 522b connecting the first sub-portion 522a and the third sub-portion 522c. The first sub-portion 522a includes a light-incident surface 5222, a first reflective surface 5224 (and a first bending portion 5220a) located at the junction of the first sub-portion 522a and the second sub-portion 522b, and a second reflective surface 5226 (and a second bending portion 5220b) located at the junction of the second sub-portion 522b and the third sub-portion 522c. Light enters the first sub-portion 522a via the light-incident surface 5222 and travels in a first direction d1. Then, the light is reflected by the first reflective surface 5224 and enters the second sub-portion 522b, traveling in a second direction d2. Next, it is reflected again by the second reflective surface 5226 and enters the third sub-portion 522c, traveling in a third direction d3. Furthermore, the first sub-part 522a and the third sub-part 522c are located on both sides of the second direction d2, making the first light guide portion 522 have a Z-shaped structure, with the first direction d1 being the same as the third direction d3. The first sub-part 522a and the third sub-part 522c are located on both sides of the circuit board 542 in the second direction d2, which helps to reduce the thickness of the backlight module 5 in the second direction d2.

[0070] Furthermore, in practice, the size of the backlight module 5 can be further reduced by modifying the structure of the first light guide portion 522. For example, as... Figure 13As shown, the backlight module 5a according to another embodiment is structurally similar to the backlight module 5. The backlight module 5a generally uses the component symbols of the backlight module 5. Therefore, for other descriptions of the backlight module 5a, please refer directly to the previous descriptions of the backlight module 5 and its variations; further details are not provided here. The main difference between the backlight module 5a and the backlight module 5 lies in the fact that in the first light-guiding portion 532 of the light-guiding structure 53 of the backlight module 5a, the first sub-part 522a and the third sub-part 522c are located on the same side of the second direction d2 (or the second sub-part 522b), making the first light-guiding portion 532 have an inverted C-shaped structure. The first reflective surface 5224 and the second reflective surface 5226 are located at the turning point of the inverted C-shape (i.e., the first and second bending portions 5220a and 5220b), and the first direction d1 is opposite to the third direction d3. Similarly, the first sub-part 522a and the third sub-part 522c are also located on opposite sides of the circuit board 542 in the second direction d2, which helps to reduce the thickness of the backlight module 5a in the second direction d2. Furthermore, the first sub-part 522a and the third sub-part 522c are located on the same side of the second direction d2 (or the second sub-part 522b), which helps to reduce the width of the backlight module 5a in the direction perpendicular to the second direction d2. In addition, in this embodiment, the first reflective surface 5224 and the second reflective surface 5226 are both planes, and these two planes are perpendicular to each other, but this is not a limitation in actual operation. For example, the first reflective surface 5224 and the second reflective surface 5226 may be slightly non-perpendicular, forming an acute or obtuse angle close to a right angle between them. As another example, the first reflective surface 5224 and / or the second reflective surface 5226 may be curved surfaces.

[0071] Furthermore, in the aforementioned embodiments, the directions d1, d2, and d3 of the light rays traveling within the light guide structures 52 and 53 share a common plane, but this is not a limitation in actual operation. For example, as... Figure 14 As shown, the first sub-parts 522a, 522b, and 522c of the first light guide portion 533 according to one embodiment are arranged in a three-dimensional configuration. For simplicity, the component notation of the first light guide portion 533 is adopted from that of the first light guide portion 522. In this embodiment, the first direction d1 and the third direction d3 are not parallel; for example, the first direction d1, the second direction d2, and the third direction d3 are perpendicular to each other. This helps to increase the design flexibility of the first light guide portion 533.

[0072] In the foregoing embodiments, the light-incident surface 5222 is generally flat, but this is not a limitation in actual operation. For example, as Figure 15 and Figure 16As shown, the backlight module 5b according to another embodiment is structurally similar to backlight module 5. Backlight module 5b generally uses the component symbols of backlight module 5. Therefore, for further explanation of backlight module 5b, please refer directly to the previous description of backlight module 5 and its variations; further details will not be repeated here. The main difference between backlight module 5b and backlight module 5 lies in the fact that the multiple light sources 544 of backlight module 5b emit light in different directions 544a, 544b, and 544c (indicated by arrows). Figure 16 In this embodiment, the light-incident surface 5522 of the first light-guiding portion 552 of the light-guiding structure 55 is provided; wherein, the plurality of light-emitting directions 544a, 544b, and 544c are radially distributed, which also helps to diffuse the light. In this embodiment, every three light sources 544 are grouped together, emitting different colors of light, such as, but not limited to, red, green, and blue light; in actual operation, other numbers of light sources can also be used to group the plurality of light sources 544, which will not be elaborated further. In addition, in this embodiment, the light-incident surface 5522 also includes light-incident areas 5522a, 5522b, and 5522c in different directions corresponding to the setting direction of the light source 544 (or its light-emitting direction 544a, 544b, 544c), so that the light emitted by each light source 544 is still approximately perpendicular to the light-incident surface 5522 (or the corresponding light-incident areas 5522a, 5522b, and 5522c).

[0073] As explained above, backlight modules 5, 5a, and 5b utilize the reflective surfaces 5224 and 5226 inside the light guide structures 52, 53, and 55 to reflect light, allowing the light to travel approximately along the extension path of the light guide structures 52, 53, and 55. This increases the path length of the light within the light guide structures 52, 53, and 55, thereby enhancing the light mixing effect. This also helps improve the uniformity of the backlight provided by backlight modules 5, 5a, and 5b.

[0074] Furthermore, in the aforementioned backlight modules 1, 3, 3a, 3b, 5, 5a, and 5b, the light sources 144, 344a, 344b, and 544 are approximately positioned on the same plane and emit light parallel to that plane. For example, in the light guide structures 12 and 522, there is only a single light-incident surface 122 and 5222, but this is not a limitation in actual operation. For example, to avoid certain components such as cable exit structures, or for aesthetic reasons, light may need to enter from multiple light-incident surfaces. However, when light comes from multiple light-incident surfaces but ultimately needs to exit from the same flat plane (e.g., the light-exiting surface extends along the long side of the keyboard), it is necessary to solve the problems of brightness differences and uneven light mixing at various points on the light-exiting surface.

[0075] like Figures 17 to 19As shown, the backlight module 7 includes a light guide structure 72, a first light source device 74, and a second light source device 76. The light guide structure 72 has a first light guide portion 722 and a second light guide portion 724. The first light guide portion 722 and the second light guide portion 724 are arranged along the arrangement direction D3 and extend along the first extension direction D4 and the second extension direction D5, respectively. Specifically, the first light guide portion 722 extends along the first extension direction D4, and the second light guide portion 724 extends along the second extension direction D5. The arrangement direction D3, the first extension direction D4, and the second extension direction D5 are all indicated by double arrows in the figure. The first extension direction D4 and the second extension direction D5 are not parallel to each other and are both perpendicular to the arrangement direction D3. The first light source device 74 and the second light source device 76 are respectively positioned corresponding to the first light guide portion 722 and the second light guide portion 724, such that the light emitted by the first light source device 74 and the second light source device 76 enters the light guide structure 72 through the first light guide portion 722 and the second light guide portion 724, respectively.

[0076] In this embodiment, the first light guide portion 722 has a plurality of first light incident surfaces 7222, which are implemented by a plurality of holes; correspondingly, the first light source device 74 includes a circuit board 742 and a plurality of light sources 744 disposed thereon, the plurality of light sources 744 being respectively disposed in the plurality of holes to face the plurality of corresponding first light incident surfaces 7222, and the light emission direction of the light source 744 is indicated by an arrow. Figure 18 In this way, the light emitted by the light source 744 enters the first light guide portion 722 via the first light incident surface 7222. The plurality of light sources 744 and their respective first light incident surfaces 7222 are arranged along the arrangement direction D3, which is perpendicular to the first extension direction D4. Similarly, the second light guide portion 724 has a plurality of second light incident surfaces 7242, which are implemented by a plurality of notches formed on one side of the second light guide portion 724; correspondingly, the second light source device 76 includes a circuit board 762 and a plurality of light sources 764 disposed thereon. The plurality of light sources 764 are respectively disposed in the plurality of notches facing the corresponding second light incident surface 7242, and the light emission direction of the light source 764 is indicated by an arrow. Figure 19 The plurality of light sources 764 and their respective corresponding plurality of second light-incident surfaces 7242 are also arranged along the arrangement direction D3, which is perpendicular to the second extension direction D5. Thus, the light emitted by the light sources 764 enters the second light guide portion 724 via the second light-incident surface 7242. Furthermore, the light guide structure 72 has a light-emitting surface 726 that extends straight along the arrangement direction D3, for example, along the long or short side of the keyboard. The light entering the light guide structure 72 via the first light guide portion 722 and the second light guide portion 724 will collectively exit the light guide structure 72 via different local sections of the same light-emitting surface 726.

[0077] In this embodiment, the inner side of the first light guide portion 722 includes a plurality of first hollow structures 7224, which correspond to a plurality of first light incident surfaces 7222. The first hollow structures 7224 extend perpendicularly to the first extending direction D4. The first hollow structures 7224 are blind aperture structures, which have a light reduction effect; in actual operation, the first hollow structures 7224 can also be implemented by other structures (including structural extending direction, geometry, etc.), such as the hollow structures 1242, 1252, 1262 and their variations mentioned above. Similarly, the inner side of the second light guide portion 724 includes a plurality of second hollow structures 7244, which correspond to a plurality of second light incident surfaces 7242. The second hollow structures 7244 extend obliquely to the second extending direction D5. The second hollow structure 7244 is a blind hole structure, which has diffusion and light reduction effects. In actual operation, the first hollow structure 7224 can also be implemented by other structures (e.g., structures with different extension directions, geometric shapes, etc.), such as the hollow structures 1242, 1252, 1262 and their variations mentioned above. Furthermore, in this embodiment, the surfaces of the first light-incident surface 7222 and the second light-incident surface 7242 are formed with diffusion structures (e.g., but not limited to wave structures, groove structures, etc., which can be formed simultaneously during the injection molding of the light guide structure 72), which helps to increase the light mixing degree within the light guide structure 72. In actual operation, the first hollow structure 7224 and the second hollow structure 7244 can be designed based on the light path from the first light-incident surface 7222 to the light-emitting surface 726 and the light path from the second light-incident surface 7242 to the light-emitting surface 726, so that the backlight module 7 can provide more uniform backlight through the light-emitting surface 726. Figure 19 As shown, the second hollow structure 7244 corresponds to a local section of the light-emitting surface 726 of the second light-incident surface 7242, and is located in the light-emitting direction of the light source 764 or directly in front of the second light-incident surface 7242; while Figure 18 In this configuration, the first hollow structure 7224 corresponds to a local section of the light-emitting surface 726 of the first light-incident surface 7222, and is not located directly in front of the light-emitting direction of the first light-incident surface 7222 or the light source 744. The first light-guiding portion 722 can be bent to form one or more reflective surfaces 7226, guiding the light from the first light-incident surface 7222 to the corresponding local section of the light-emitting surface 726.

[0078] Furthermore, in this embodiment, the light guide structure 72 is also a light diffusion structure composed of the first hollow structure 7224 and the second hollow structure 7244, which adjusts the light entering the light guide structure 72 (including the path of travel, light intensity, etc.), thus also having the effect of adjusting the light intensity distribution. For other descriptions of the components of the backlight module 7, please refer to the relevant descriptions of the components of the backlight module 1 and their variations above, which will not be repeated here. In addition, in this embodiment, as... Figure 17As shown, the light guide structure 72 further includes another first light guide portion 722', which is arranged along the arrangement direction D3 on the other side of the second light guide portion 724 relative to the first light guide portion 722. In practical operation, the backlight module 7 can be applied to optical decorative applications of keyboards, for example, emitting light along the long side of the keyboard. Figure 18 As shown, the light guide structure 72 is sandwiched between the upper shell 8a and the lower shell 8b of the keyboard (both shown as dashed lines in the figure), with the light-emitting surface 726 exposed on the keyboard. By controlling the light sources 744 and 764 to emit light independently, various visual effects can be created. The light guide structure 72, through the arrangement of the first light guide portion 722 and the second light guide portion 724, can adapt to the internal structure or component configuration of the keyboard. In actual operation, the light guide structure 72 can include more light guide portions with different structures to increase its adaptability to the internal structure or component configuration of the keyboard.

[0079] Compared to the prior art, the backlight module of the present invention can generate light reduction and light mixing effects by using a hollow structure or an internal reflective surface, thereby improving the light intensity distribution of the backlight provided by the light guide structure. Therefore, the backlight module does not need to increase the structural size to solve the problem in the prior art that it is difficult to reduce the size of the backlight module or the device equipped with the backlight module in order to maintain the uniformity of the backlight.

[0080] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A backlight module, characterized in that... Include: A light guide structure is formed of a material of a first light medium and has a first light incident surface and a light diffusion structure arranged parallel to the first light incident surface. The light diffusion structure is located inside the light guide structure and includes at least one first hollow structure. The at least one first hollow structure forms a space for accommodating a second light medium. The first light medium is different from the second light medium. The at least one first hollow structure includes a plurality of continuous wall surfaces of the light guide structure forming a slot, the slot having an extension path in the shape of a crescent, arc or angle, and the slot having a notch and a convex edge opposite to the notch, the notch facing the first light incident surface and the convex edge away from the first light incident surface. The light guide structure has a light source receiving groove on its inner side, and the first light incident surface is the side surface of the light source receiving groove; The light source receiving slot has a second light-incident surface, which is opposite to the first light-incident surface; The backlight module also includes at least one first light source and at least one second light source, wherein the at least one first light source and the at least one second light source are alternately arranged in the light source receiving groove, the light emission direction of the at least one first light source is towards the first light incident surface, and the light emission direction of the at least one second light source is towards the second light incident surface; The light diffusion structure further includes at least one second hollow structure, the first light-incident surface is located between the at least one first light source and the at least one first hollow structure, and the second light-incident surface is located between the at least one second light source and the at least one second hollow structure.

2. The backlight module according to claim 1, characterized in that: The at least one first hollow structure is adjacent to the first light-incident surface.

3. The backlight module according to claim 1, characterized in that: The notch of the at least one first hollow structure is located between the corresponding convex edge and the first light-incident surface.

4. The backlight module according to claim 1, characterized in that: The surface of the first light-receiving surface has a diffusion structure formed by a wave structure or a groove structure.

5. The backlight module according to claim 1, characterized in that: The slot has a crescent-shaped extension path and two tapering ends.

6. The backlight module according to claim 1, characterized in that: The plurality of continuous walls of the at least one first hollow structure include a near-light wall and a far-light wall opposite to the near-light wall, wherein the near-light wall and the far-light wall form an arc-shaped or angular extension path and are parallel to each other; or, the plurality of continuous walls of the at least one first hollow structure include a near-light wall and a far-light wall opposite to the near-light wall, wherein the near-light wall and the far-light wall form a crescent-shaped, arc-shaped or angular extension path and are not parallel to each other.

7. The backlight module according to claim 1, characterized in that: The light emission direction of the at least one first light source is away from the light emission direction of the at least one second light source.

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