TWI756111B - Backlight module - Google Patents

Abstract

A backlight module includes a light-guiding structure. The light-guiding structure includes a light-guiding portion. The light-guiding portion extends in an extension direction and has a first bending portion, a second bending portion, a light incidence surface, a first reflection surface, and a second reflection surface in a direction perpendicular to the extension direction. The first reflection surface is located at the first bending portion and toward the light incidence surface. The second reflection surface is located at the second bending portion and toward the first reflection surface.

Description

Backlight Module

The present invention relates to a backlight module, in particular to a backlight module with a light guide structure.

Backlight modules are commonly used to provide device backlighting, and typically use point light sources. When the size of the light guide member of the backlight module is small, for example, the light guide member extends in a long strip shape, and the light incident surface and the light exit surface are located on both sides of the extending direction, and the light enters the light guide plate through the light entrance surface and exits through the light exit surface. light guide plate. It is difficult for the light guide member to mix the light effectively, so that the backlight provided by the backlight module is obviously uneven and even produces obvious light spots. In order to make the backlight uniform, it is usually possible to increase the distance between the light-emitting surface of the backlight module and the projection target of the backlight, or to increase the size of the light guide plate of the backlight module or stack multiple optical films on it, such as a diaphanous film and a diffuser. , reflective sheet, etc. to increase the light mixing effect. The former will increase the space required for setting the light-emitting module, and the latter will increase the volume of the backlight module itself. In any case, the volume of the device equipped with the backlight module is not easily reduced.

In view of the problems in the prior art, one object of the present invention is to provide a backlight module, the light guide structure of which utilizes a plurality of internal reflection surfaces to increase the light travel path, so as to improve the light intensity distribution of the backlight provided by the backlight module.

The backlight module according to the present invention includes a light guide structure. The light guide structure includes a light guide portion, the light guide portion extending along an extending direction and having a first bending portion, a second bending portion, a light incident surface, a direction perpendicular to the extending direction A first reflecting surface and a second reflecting surface, the first reflecting surface is located at the first bending portion and faces the light incident surface, and the second reflecting surface is located at the second bending portion and faces the first reflecting surface. Thereby, the light entering the light guide portion through the light incident surface is sequentially transmitted to the first reflector The emitting surface and the second reflecting surface reflect, which can increase the path length of the light traveling in the light guide structure, so as to increase the light mixing effect, thereby improving the light intensity distribution of the backlight provided by the light guide structure.

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

1,3,3a,3b: Backlight module

12: Light guide structure

120: Plate Structure

120a: Surface

120b: Thickness

122: light incident surface

122a: Through groove

122b: Section radius

124, 125, 126: Light Diffusion Structures

1242, 1242', 1252, 1262: hollow structure

12420: Wall

1242a: Extended Path

1242b: Angle

1242c: side length

1252a: Triangular column through hole

1252b: Reference arc segment

1252c: center of circle

1252d: long edge

1252e:direction

1252f: Angle

1252g: Distance

1262a: Sag

1262b: depth

14,34: Light source device

142: circuit board

144, 344a, 344b: Light source

144a: Lighting direction

32,33: Light guide structure

322, 332a, 332b: Light source accommodating slot

322a, 333a: The first light incident surface

322b, 333b: The second light incident surface

322c, 333c: Reference axis

5,5a,5b: Backlight module

52, 53, 55: Light guide structure

522, 532, 533, 552: The first light guide part

522a: First subsection

522b: Second subsection

522c: Third subsection

5220a: First bend

5220b: Second bending part

5222, 5522: incident light surface

5522a, 5522b, 5522c: Light entrance area

5224: first reflecting surface

5226: Second reflective surface

5228: light-emitting surface

524: Second light guide part

54: Light source device

542: circuit board

544: Light Source

544a, 544b, 544c: Lighting direction

7: Lighting module

72: Light guide structure

722: The first light guide part

7222: The first light incident surface

7224: First hollow structure

7226: Reflective Surface

724: Second light guide part

7242: The second light incident surface

7244: Second hollow structure

726: light-emitting surface

74: The first light source device

742: circuit board

744: Light Source

76: Second light source device

762: Circuit Board

764: Light Source

8a: upper shell

8b: lower shell

D1, D2, D4, D5: extension direction

D3: Arrangement direction

d1: first direction

d2: the second direction

d3: third direction

FIG. 1 is a schematic diagram of a backlight module according to an embodiment.

FIG. 2 is a top view of the backlight module of FIG. 1 .

FIG. 3 is an enlarged view of the hollow structure of the light diffusing structure in FIG. 2 .

FIG. 4 is an enlarged view of a modified example of the hollow structure in FIG. 3 .

FIG. 5 is a top view of the hollow structure of the light diffusing structure according to an embodiment.

FIG. 6 is a top view of the hollow structure of the light diffusing structure according to an embodiment.

FIG. 7 is a cross-sectional view taken along line X-X of FIG. 6 .

8 is a top view of a backlight module according to an embodiment.

FIG. 9 is a top view of a backlight module according to another embodiment.

FIG. 10 is a top view of a backlight module according to another embodiment.

FIG. 11 is a schematic diagram of a backlight module according to an embodiment.

FIG. 12 is a cross-sectional view of the backlight module of FIG. 11 along the line Y-Y.

13 is a cross-sectional view of a backlight module according to an embodiment.

FIG. 14 is a schematic diagram of the structural logic of the first light guide portion according to an embodiment.

15 is an exploded view of a backlight module according to an embodiment.

FIG. 16 is a bottom view of the backlight module of FIG. 15 .

FIG. 17 is a schematic diagram of a backlight module according to another embodiment.

FIG. 18 is a cross-sectional view of the backlight module in FIG. 17 along the line Z-Z.

FIG. 19 is a cross-sectional view of the backlight module of FIG. 17 along the line W-W.

Please refer to Figure 1 and Figure 2. A backlight module 1 according to an embodiment includes a light guide structure 12 and a light source device 14 . The light guide structure 12 is formed of a material of a first optical medium (such as but not limited to a light-transmitting polymer material, such as integral molding through injection) and has a light incident surface 122 and a light diffusing structure 124 (the range of which is indicated by a dotted line). The frame is shown in the figure), the light diffusing structure 124 is located inside the light guiding structure 12 and includes a plurality of hollow structures 1242 . When the backlight module 1 is applied to the keyboard, the extending direction of the light incident surface 122 generally corresponds to the long side or the short side of the entire rectangular keyboard (not shown). The hollow structure 1242 forms a space for a second optical medium (eg, but not limited to accommodating air), and the first optical medium is different from the second optical medium. The light source device 14 includes a circuit board 142 (such as but not limited to a printed circuit board, a flexible printed circuit board, etc.) and a plurality of light sources 144 (such as but not limited to light emitting diodes) disposed thereon. The plurality of light sources 144 respectively correspond to the plurality of hollow structures 1242 and are disposed toward the light incident surface 122 , so that the light emitted by the plurality of light sources 144 (represented by thin arrows in the figure) enters the light guide structure 12 through the light incident surface 122 . The light entering the light guide structure 12 changes its traveling direction through the light diffusing structure 124 , so that the light guide structure 12 has a light mixing effect. In addition, in principle, the intensity of light passing through the hollow structure 1242 is weakened, so that the hollow structure 1242 also has the effect of adjusting the light intensity distribution.

In this embodiment, the light guide structure 12 is a plate-like structure 120 , and the light incident surface 122 is located at a side edge of the plate-like structure 120 and extends along an extension direction D1 (indicated by a double arrow in the figure). 142 also extends along the extending direction D1, the plurality of light sources 144 are also arranged along the extending direction D1 and the light-emitting direction 144a (shown in the figure by an arrow) faces the light incident surface 122; wherein, the light-emitting direction 144a is perpendicular to the extending direction D1, But in practice it is not limited to this. The plurality of hollow structures 1242 are disposed adjacent to the light incident surface 122 and the corresponding light sources 144 to increase the effect of the hollow structures 1242 to diffuse light and reduce light intensity, which is helpful for the backlight module 1 to provide a more uniform backlight. For the strip-shaped light guide structure (for example, extending along the extending direction D1 ), the aforementioned structure configuration can also provide a good effect of improving the light intensity distribution, which is helpful for reducing the volume of the backlight module.

See also Figure 3. In this embodiment, the hollow structure 1242 is a slot, which is substantially perpendicular to the The extending direction D1 and the light emitting direction 144 a penetrate through the light guide structure 12 . The slot is formed by a plurality of continuous wall surfaces 12420 of the light guide structure 12 (eg, connected in a ring shape) and has an extension path 1242a (represented by a dotted line in FIG. 3 ). The extension path 1242a is in the shape of an angle, and the angle has a notch, the notch is facing the light incident surface 122, and the corresponding light source 144 is disposed toward the recess. The slot can in principle provide refraction and reflection of the light entering the light guide structure 12 , thereby providing the effect of diffusing the light and reducing the intensity of the light after passing through. In addition, in this embodiment, the angular shape forms an included angle 1242b, and the included angle 1242b is between, for example, but not limited to, 90 degrees to 140 degrees. Also, the angle has a side length 1242c, and the side length 1242c is about, for example, but not limited to, 3.9 mm. In addition, in practice, the extending path 1242a of the slot can also have other geometric structures, such as an arc shape; in this case, the arc shape has a notch, and the notch faces the light incident surface 122, which also has diffusion and reduction functions. light effect. In addition, in practice, the light incident surface 122 may have a wavy structure (shown in dotted lines in FIG. 3 , for example, it may be formed at the same time when the light guide structure 12 is injection-molded), which can increase the diffusion effect. In addition, in this embodiment, the width of the slot of the hollow structure 1242 (along the extending path 1242a ) is a fixed value, but it can be changed in practice, for example, the hollow structure 1242 is modified to be wide in the middle and narrow on both sides, as shown in the figure 4 shows one of the hollow structures 1242', in the shape of a crescent moon. The hollow structure 1242' also has the effect of diffusing and reducing light.

In addition, in practice, the aforementioned through-slots can also be replaced by other through-structures. As shown in FIG. 5 , according to an embodiment, at least one light diffusing structure 125 includes a plurality of hollow structures 1252 , and the hollow structures 1252 include a plurality of triangular through holes 1252 a. The triangular column through hole 1252a is formed by connecting three continuous wall surfaces. The plurality of triangular column through holes 1252a are arranged along a reference arc segment 1252b (represented by a chain line in the figure). The reference arc segment 1252b has a notch, and the notch faces the light incident surface 122 . In this embodiment, the reference arc segment 1252b has a center 1252c (represented by a cross in FIG. 5 ). The triangular-shaped through-hole 1252a has a long edge 1252d (projected as a point in FIG. 5) that is perpendicular to the reference arc segment 1252b. The triangular-shaped through-hole 1252a defines a direction 1252e (represented by an arrow in FIG. 5 ), and the direction 1252e passes through the long edge 1252d and points to the center 1252c. The directions 1252e of the adjacent two triangular column through holes 1252a among the plurality of triangular column through holes 1252a form an included angle 1252f, and the included angle 1252f is approximately, for example Such as but not limited to 21 degrees. The corresponding light source 144 (represented by a dotted frame in FIG. 5 ) is disposed toward the light incident surface 122 and the plurality of triangular column through holes 1252 a (or the light diffusing structure 125 ).

In addition, in this embodiment, a through groove 122 a is formed on the light incident surface 122 , which is concave toward the light diffusing structure 125 . The light source 144 is disposed toward the through groove 122a. The cross-section of the penetration groove 122a is substantially semicircular and has a cross-sectional radius 122b. The cross-sectional radius 122b is three times the distance 1252g between the light diffusing structure 125 and the penetration groove 122a. For example, the distance 1252g is 1 mm, and the cross-sectional radius 122b is 3mm, but not limited to this in practice. In addition, in this embodiment, the center of 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. In addition, in practice, the number of the triangular column through holes 1252a is not limited to three. For example, the hollow structure 1252 includes one or more triangular column through holes 1252a. In addition, the hollow structure 1252 can also be implemented with one or more through-holes having the same or different polygonal cross-sections, which also has the effect of diffusion and light reduction.

In the foregoing embodiments, the hollow structures 1242 , 1242 ′, and 1252 are all implemented as through structures, but the implementation is not limited thereto. For example, the hollow structures 1242 , 1242 ′, 1252 are changed to blind hole structures having a certain depth (eg, greater than 1/3, 1/2, 2/3, 4/3, etc. of the thickness of the plate-shaped light guide structure 12 ). , it still has a certain degree of diffusion and light reduction effect. For another example, as shown in FIGS. 6 and 7 , at least one light diffusing structure 126 according to an embodiment includes a plurality of hollow structures 1262 . The plate-like structure 120 has a surface 120 a, and the surface 120 a is adjacent to a light incident surface 122 and extends substantially perpendicular to the light incident surface 122 . The hollow structure 1262 includes a recess 1262 a , which is concavely formed from the surface 120 a toward the inner side of the plate-like structure 120 , which is formed by a plurality of continuous walls of the light guide structure 12 . The corresponding light source 144 (represented by a dotted box in the figure) is disposed toward the light incident surface 122 and the recess 1262a. Similar to the aforementioned hollow structures 1242 and 1252 , the recesses 1262 a can in principle provide refraction and reflection for the light entering the light guide structure 12 , thereby providing the effect of light diffusion and reducing the intensity of light passing through the hollow structure 1262 . In practice, the depth 1262b of the recess 1262a is greater than one third of the thickness 120b of the plate-like structure 120, which can provide a good light diffusion effect. In addition, in this embodiment, the projected cross-section of the recess 1262a in the direction perpendicular to the extending direction D1 and the light-emitting direction 144a is rectangular, but In practice, it is not limited to this, for example, it can be a circle, a polygon, etc., and it can also be the same as the projected cross-section of the hollow structures 1242 and 1252 in the direction perpendicular to the extending direction D1 and the light-emitting direction 144a, and will not be described in detail. Among the several continuous wall surfaces constituting the hollow structure 1262, the wall surfaces of the front and rear low beams and the wall surfaces of the high beam along the light-emitting direction 144a may not be parallel to the light incident surface 122, but have an acute angle or an obtuse angle; in other words, the low beam The angles included between the wall surface and the high beam wall surface and the light incident surface 122 are selected from the combination of acute angle, obtuse angle or 0 degrees (parallel to each other).

In the foregoing embodiments, the light source 144 is disposed outside the plate-like structure 120 of the light guide structure 12 , but the implementation is not limited to this. As shown in FIG. 8 , a backlight module 3 according to an embodiment has substantially the same structure as the aforementioned backlight module 1 , and the backlight module 3 uses the component symbols of the backlight module 1 in principle, so other descriptions about the backlight module 3 , please refer to the relevant description of the backlight module 1 and its changes above, and will not go into details. The difference between the backlight module 3 and the backlight module 1 mainly lies in the arrangement position of the light source device 14 of the backlight module 3 relative to the light guide structure 12 . In the backlight module 3, the light guide structure 32 has a light source accommodating groove 322, one side of the light source accommodating groove 322 serves as a first light incident surface 322a, and the circuit board 142 (the hidden outline of which is shown in dotted lines in In the figure) corresponding to the light source accommodating groove 322 is provided, so that the plurality of light sources 144 are accommodated in the light source accommodating groove 322 and face the first light incident surface 322a. The shape of the light guide structure 32 corresponds to the four sides of the rectangular keyboard (not shown). In FIG. 8, the extension direction of the first light incident surface 322a is parallel to the short side of the keyboard, and the light source accommodating groove 322 is adjacent to the light guide structure 32 and the keyboard. The short side of the rectangular keyboard.

In this embodiment, the light source accommodating groove 322 is disposed adjacent to one side of the light guide structure 32 , and the light source 144 emits light toward the middle of the light guide structure 32 , but the practice is not limited to this. As shown in FIG. 9 , a backlight module 3 a according to an embodiment has substantially the same structure as the aforementioned backlight module 3 , and the backlight module 3 a uses the component symbols of the backlight module 3 in principle, so other descriptions about the backlight module 3 a , please refer to the relevant description of the backlight module 3 above, and will not go into details. The difference between the backlight module 3 a and the backlight module 3 mainly lies in the arrangement position of the light source device 34 of the backlight module 3 a relative to the light guide structure 12 . In the backlight module 3a, the other side surface of the light source accommodating groove 322 serves as a second light incident surface 322b, which is opposite to the first light incident surface 322a. Light source receiving slot 322 is located in the middle of the light guide structure 32 and extends substantially 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, which are alternately arranged in the light source accommodating grooves 322 along the reference axis 322c. With a light incident surface 322a, the light-emitting direction of the second light source 344b (indicated by an arrow in the figure) faces the second light incident surface 322b. In this way, the light source device 34 can respectively provide light to the portions of the light guide structure 32 on both sides of the light source accommodating groove 322 (or the reference axis 322c).

In this embodiment, a single light source accommodating groove 322 is used to accommodate the plurality of first light sources 344a and the plurality of second light sources 344b, but the implementation is not limited to this. As shown in FIG. 10 , according to an embodiment, a backlight module 3b has substantially the same structure as the aforementioned backlight module 3a, and the backlight module 3b uses the component symbols of the backlight module 3a in principle, so other explanations about the backlight module 3b , please refer to the relevant description of the backlight module 3a above, and no further description is required. The main difference between the backlight module 3b and the backlight module 3a is that the backlight module 3b does not have a single light source accommodating groove for accommodating the light sources 344a and 344b. In the backlight module 3b, the inside of the light guide structure 33 includes a plurality of first light source accommodating grooves 332a and a plurality of second light source accommodating grooves 332b, corresponding to the plurality of first light sources 344a and the plurality of second light sources respectively. 344b. The plurality of first light source accommodating grooves 332a and the plurality of second light source accommodating grooves 332b are staggered on both sides of the reference axis 333c along a reference axis 333c (represented by a chain line in the figure), such as shown in FIG. 10 . From the perspective, the plurality of first light source accommodating grooves 332a are located on the right side of the reference axis 333c, and the plurality of second light source accommodating grooves 332b are located on the left side of the reference axis 333c. The right side of the first light source accommodating groove 332a serves as a first light incident surface 333a, and the left side of the second light source accommodating groove 332b serves as a second light incident surface 333b. The first light source 344a is accommodated in the corresponding first light source accommodating groove 332a, and the light-emitting 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 incident light The surface 333a is located on the side of the first light source accommodating groove 332a adjacent to the reference axis 333c. The second light source 344b is accommodated in the corresponding second light source accommodating groove 332b, and the light-emitting direction of the second light source 344b (indicated by an arrow in the figure) faces the corresponding second light incident surface 333b, that is, the second incident light The surface 333b is located on the side of the second light source accommodating groove 332b adjacent to the reference axis 333c. Thereby, the light source device 34 can also provide light to the light guide structure 32 on both sides of the reference axis 322c, and the arrangement of the light source accommodating grooves 332a, 332b (and the light sources 344a, 334b) also helps to reduce the light guide to the light guide structure 33. distraction effect. In addition, in this embodiment, the light emitting directions of the first light source 344a and the second light source 344b are parallel and opposite, but the implementation is not limited to this. In addition, in this embodiment, the light source accommodating grooves 332a and 332b are implemented as through holes, but the implementation is not limited to this; for example, the light source accommodating grooves 332a and 332b are implemented as blind holes, which can further reduce the light source capacity. The grooves 332a and 332b interfere with the light guiding effect of the light guiding structure 33 .

In the foregoing embodiments, the backlight modules 1, 3a, 3b use the hollow structures 1242, 1252, 1262 to change the traveling direction and intensity of the light in the light guide structures 12, 32, 33, so that the backlight modules 1, 3a, 3b Can provide a more uniform backlight. However, it is not limited in practice. For example, by increasing the path length of the light traveling in the light guide structure, the light mixing effect can also be increased. Please refer to Figure 11 and Figure 12. A backlight module 5 according to an embodiment includes a light guide structure 52 and a light source device 54 . The light guide structure 52 includes a first light guide portion 522. The first light guide portion 522 has a light incident surface 5222, a first reflection surface 5224, a second reflection surface 5226 and a light exit surface 5228. The first reflection surface 5224 Facing the light incident surface 5222 , the second reflecting surface 5226 is facing the first reflecting surface 5224 and the light exiting surface 5228 . The light source device 54 includes a circuit board 542 (such as but not limited to a printed circuit board, a flexible printed circuit board, etc.) and a plurality of light sources 544 (such as but not limited to light emitting diodes) disposed thereon. The plurality of light sources 544 are disposed adjacent to the light incident surface 5222 . The light emitted by the light source 144 (indicated by the thin arrow in the figure) enters the first light guide portion 522 through the light incident surface 5222 , and the light entering the light guide structure 12 changes its traveling direction through the light diffusion structure 124 , so as to improve the pairing of the light guide structure 12 . Light mixing effect. The first reflecting surface 5224 and the second reflecting surface 5226 are reflected in sequence.

In this embodiment, the first light guide portion 522 has a strip-like structure and extends along an extension direction D2 (represented by a double arrow in FIG. 11 ), the light incident surface 122 extends substantially along the extension direction D2, and the circuit board 542 also Extending along the extending direction D2, the plurality of light sources 544 are also arranged along the extending direction D2 and the light emitting direction 544a (represented by an arrow in the figure) faces the light incident surface 5222; wherein, the light emitting direction 544a is perpendicular to the extending direction D2, but It is not limited to this.

In this embodiment, the projected cross section of the first light guide portion 522 in the extending direction D2 is zigzag, that is, the first light guide portion 522 has a first bending portion 5220a and a In the second bending portion 5220b, the first reflecting surface 5224 is located at the first bending portion 5220a, and the second reflecting surface 5226 is located at the second bending portion 5220b. The light entering the first light guide portion 522 through the light incident surface 5222 travels in a first direction d1 (represented by an arrow in FIG. 12 ). The light is reflected by the first reflecting surface 5224 and travels in a second direction d2 (indicated by an arrow in FIG. 12 ). The light is reflected by the second reflective surface 5226 and travels in a third direction d3 (indicated by an arrow in FIG. 12 ). The first direction d1 is the same as the third direction d3. In this embodiment, the first reflecting surface 5224 and the second reflecting surface 5226 are both planes, and the two planes are parallel to each other, but the practice is not limited to this. For example, the first reflective surface 5224 and the second reflective surface 5226 may be slightly non-parallel to form an included angle therebetween. For another example, the first reflection surface 5224 and/or the second reflection surface 5226 may be curved surfaces.

In addition, in this embodiment, the light guide structure 52 further includes a second light guide portion 524, and the second light guide portion 524 is a plate-like structure. The light entering the first light guide portion 522 through the light incident surface 5222 is reflected by the first reflection surface 5224 and the second reflection surface 5226 in sequence, and exits the first light guide portion 522 from the light exit surface 5228 and enters the second light guide portion 524 . In practice, the first light guide portion 522 and the second light guide portion 524 can be integrally formed; at this time, the aforementioned light emitting surface 5228 physically disappears.

In addition, as shown in FIG. 12, on the other hand, the first light guide portion 522 includes a first sub-section 522a, a second sub-section 522b and a third sub-section 522c, and the second sub-section 522b is connected to the first sub-section 522b. A subsection 522a and a third subsection 522c. The first sub-section 522a includes a light incident surface 5222, the first reflecting surface 5224 (and the first bending portion 5220a) is located at the connection between the first sub-section 522a and the second sub-section 522b, and the second reflecting surface 5226 (and the second bending portion 522b) A fold 5220b) is located where the second sub-section 522b and the third sub-section 522c join. The light enters the first sub-section 522a through the light incident surface 5222 and travels in the first direction d1. Then, the light is reflected by the first reflecting surface 5224 and enters the second sub-portion 522b and travels in the second direction d2. Next, it is reflected by the second reflecting surface 5226 and enters the third sub-section 522c and travels in the third direction d3. also, The first sub-section 522a and the third sub-section 522c are located on both sides of the second direction d2, so that the first light guide section 522 has a zigzag structure, and the first direction d1 is the same as the third direction d3. The first sub-section 522a and the third sub-section 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.

In addition, 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 shown in FIG. 13, the backlight module 5a according to another embodiment is similar in structure to the backlight module 5, and the backlight module 5a uses the component symbols of the backlight module 5 in principle, so other descriptions about the backlight module 5a , please refer to the related descriptions about the backlight module 5 and its changes above, and will not go into details. The difference between the backlight module 5a and the backlight module 5 is mainly that in the first light guide portion 532 of the light guide structure 53 of the backlight module 5a, the first sub-portion 522a and the third sub-portion 522c are located in the second direction d2 (or The first light guide portion 532 has a reverse C-shaped structure, and the first reflecting surface 5224 and the second reflecting surface 5226 are located at the turning points of the reverse C-shaped (ie, the first and second bending parts 5220a, 5220b), the first direction d1 is opposite to the third direction d3. Likewise, the first sub-section 522a and the third sub-section 522c are also located on both 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. In addition, the first sub-section 522a and the third sub-section 522c are located on the same side of the second direction d2 (or the second sub-section 522b), which helps to reduce the exposure of the backlight module 5a in the direction perpendicular to the second direction d2. width. In addition, in this embodiment, the first reflecting surface 5224 and the second reflecting surface 5226 are both planes, and the two planes are perpendicular to each other, but the practice is not limited to this. For example, the first reflecting surface 5224 and the second reflecting surface 5226 may be slightly non-perpendicular and form an acute angle or an obtuse angle that is close to a right angle therebetween. For another example, the first reflection surface 5224 and/or the second reflection surface 5226 may be curved surfaces.

In addition, in the foregoing embodiments, the directions d1 , d2 , and d3 of the light traveling in the light guide structures 52 and 53 are on the same plane, but the implementation is not limited to this. For example, as shown in FIG. 14 , the first sub-portion 522a, the second sub-portion 522b and the third sub-portion 522c of the first light guide portion 533 according to an embodiment are in a three-dimensional configuration logically. To simplify the description, the first light guide portion 533 uses the same element as the first light guide portion 522 Piece symbol. 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 .

In the foregoing embodiments, the light incident surface 5222 is generally a flat surface, but is not limited to this in practice. For example, as shown in FIG. 15 and FIG. 16 , the backlight module 5b according to another embodiment is similar in structure to the backlight module 5, and the backlight module 5b uses the component symbols of the backlight module 5 in principle. For other descriptions, please refer to the relevant descriptions about the backlight module 5 and its changes above, and will not be repeated. The difference between the backlight module 5b and the backlight module 5 is mainly that the plurality of light sources 544 of the backlight module 5b face the first light source of the light guide structure 55 in different light-emitting directions 544a, 544b, and 544c (shown by arrows in FIG. 16 ). The light incident surface 5522 of the light guide portion 552 is disposed; wherein, the plurality of light emitting directions 544a, 544b, 544c are radially distributed, which also contributes to light diffusion. In this embodiment, each of the three light sources 544 is a group, respectively emitting light of different colors, such as but not limited to red light, green light and blue light; in practice, the plurality of light sources 544 can also be grouped by other numbers of light sources. , without further elaboration. In addition, in this embodiment, the light incident surface 5522 also forms a through groove corresponding to the installation direction of the light source 544 (or the light emission directions 544a, 544b, 544c), which is concave toward the first reflecting surface 5224 and includes different directions Light incident areas 5522a, 5522b, 5522c, the light-emitting directions of the plurality of light sources 54 are respectively directed toward the corresponding light incident areas 5522a, 5522b, 5522c, so that the light emitted by each light source 544 is still substantially perpendicular to the incident light surface 5522 (or corresponding to the light incident surface 5522). light incident areas 5522a, 5522b, 5522c).

As described above, the backlight modules 5, 5a, 5b use the reflective surfaces 5224, 5226 inside the light guide structures 52, 53, 55 to reflect light, so that the light can travel roughly along the extension paths of the light guide structures 52, 53, 55, In order to increase the path length of the light traveling in the light guide structures 52 , 53 , and 55 , the light mixing effect is increased, which also helps to improve the uniformity of the backlight provided by the backlight modules 5 , 5 a and 5 b .

In addition, in the aforementioned backlight modules 1, 3, 3a, 3b, 5, 5a, and 5b, the light sources 144, 344a, 344b, and 544 are generally arranged in the same plane and emit light parallel to the plane, for example, in the light guide structures 12, 522 in, its There is only a single light incident surface 122, 5222, but it is not limited in practice. For example, it may be necessary to allow light to enter from multiple light entry surfaces because of the avoidance of certain components such as cable exit structures, or because of design aesthetics. However, when the light comes from multiple light-incident surfaces, but eventually exits together on the same flat plane (for example, the light-exiting surface extends corresponding to the long side of the keyboard), it is necessary to solve the problems of brightness differences and uneven light mixing in various parts of the light-exiting surface.

As shown in FIGS. 17 to 19 , a 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, which are arranged along an arrangement direction D3 and respectively extend along a first extension direction D4 and a second extension direction D5; wherein the extension direction D3 , D4 and D5 are indicated by a double arrow in the figure. The first extending direction D4 and the second extending 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 disposed corresponding to the first light guide portion 722 and the second light guide portion 724, respectively, so that the light emitted by the first light source device 74 and the second light source device 76 respectively pass through the first light guide portion. 722 and the second light guide portion 724 enter the light guide structure 72 .

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 plurality of holes disposed thereon. The plurality of light sources 744 are respectively disposed in the plurality of holes to face the corresponding plurality of first light incident surfaces 7222, and the light-emitting direction of the light sources 744 is indicated by an arrow in FIG. 18 . Thereby, the light emitted by the light source 744 will enter the first light guide portion 722 through the first light incident surface 7222 . The plurality of light sources 744 and their corresponding plurality of first light incident surfaces 7222 are arranged along the arrangement direction D3, and the arrangement direction is perpendicular to the first extending 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 The 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 so as to face the corresponding second light incident surface 7242, and the light emitting direction of the light sources 764 is indicated by an arrow in FIG. 19 middle. The plurality of light sources 764 and their corresponding plurality of second light incident surfaces 7242 are also arranged along the arrangement direction D3, and their arrangement direction is the same as the second extension direction D5. Thereby, the light emitted by the light source 764 will enter the second light guide portion 724 through the second light incident surface 7242 . In addition, the light guide structure 72 has a light emitting surface 726, which extends straight along the arrangement direction D3, for example, extends straight along the long side or the short side of the keyboard. The light rays entering the light guide structure 72 through the first light guide portion 722 and the second light guide portion 724 respectively will exit the light guide structure 72 through different partial sections of the same light exit surface 726 .

In this embodiment, the inner side of the first light guide portion 722 includes a plurality of first hollow structures 7224 corresponding to the plurality of first light incident surfaces 7222 . The first hollow structure 7224 extends perpendicular to the first extending direction D4. The first hollow structure 7224 is a blind hole structure with a light reduction effect; in practice, the first hollow structure 7224 can also be implemented by other structures (including the structure extension direction, geometry, etc.), such as the hollow structure 1242 mentioned above. , 1252, 1262 and their variations. Similarly, the inner side of the second light guide portion 724 includes a plurality of second hollow structures 7244 corresponding to the plurality of second light incident surfaces 7242 . The second hollow structure 7244 extends obliquely to the second extending direction D5. The second hollow structure 7244 is a blind hole structure with diffusion and light reduction effects; in practice, the first hollow structure 7224 can also be implemented by other structures (eg, with different extension directions, geometric shapes, etc.), such as The foregoing is about hollow structures 1242, 1252, 1262 and variations thereof. In addition, in this embodiment, the surfaces of the first light incident surface 7222 and the second light incident surface 7242 are formed with diffusion structures (such as, but not limited to, wave structures, groove structures, etc., for example, which can be emitted from the light guide structure 72 ). When forming, forming at the same time), it helps to increase the degree of light mixing in the light guide structure 72 . In practice, 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 exit surface 726 and the light path from the second light incident surface 7242 to the light exit surface 726, so that the backlight The module 7 can provide a relatively uniform backlight through the light emitting surface 726 . As shown in FIG. 19 , the partial section of the light-emitting surface 726 corresponding to the second light-incident surface 7242 is located in the light-emitting direction of the light source 764 or directly in front of the second light-incident surface 7242 ; and in FIG. 18 , corresponding to the first light-incident surface 7222 The partial section of the light-emitting surface 726 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 guide portion 722 can be bent to form one or more reflecting surfaces 7226 to guide the light from the first light incident surface 7222 to a corresponding partial section of the light exit surface 726 .

In addition, in this embodiment, the light guide structure 72 is also through the light diffusion structure composed of the first hollow structure 7224 and the second hollow structure 7244 to adjust the light entering the light guide structure 72 (including the travel path, light intensity, etc. ), so it also has the effect of adjusting the light intensity distribution. For other descriptions of the components of the backlight module 7, reference may be made to the foregoing descriptions of the components of the backlight module 1 and their modifications, and will not be repeated. In addition, in this embodiment, the light guide structure 72 further includes another first light guide portion 722 ′, which is arranged on the other side of the second light guide portion 724 relative to the first light guide portion 722 along the arrangement direction D3 . In practice, the backlight module 7 can be applied to the optical decoration of the keyboard, for example, to emit light along the long side of the keyboard. As shown in FIG. 18 , the light guide structure 72 is sandwiched between the upper shell 8a and the lower shell 8b of the keyboard (both shown in dotted lines in the figure), and the light emitting surface 726 is exposed on the keyboard. Various visual effects can be created by controlling the light sources 744 and 764 to emit light individually. The light guide structure 72 can adapt to the internal structure or component configuration of the keyboard through the arrangement of the first light guide portion 722 and the second light guide portion 724 . In practice, the light guide structure 72 may include more light guide parts with different structures to increase its adaptability to the internal structure of the keyboard or the configuration of components.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

5: Backlight module

52: Light guide structure

522: The first light guide part

5222: light incident surface

5224: first reflecting surface

5226: Second reflective surface

5228: light-emitting surface

524: Second light guide part

54: Light source device

542: circuit board

544: Light Source

D2: extension direction

Claims (8)

A backlight module, comprising: a light guide structure, including a first light guide portion, the first light guide portion extending along an extending direction and having a first bending portion, a A second bending portion, a light incident surface, a first reflecting surface, and a second reflecting surface, the first reflecting surface is located at the first bending portion and faces the light incident surface, and the second reflecting surface is located at the first reflecting surface. Two bent portions face the first reflection surface, the light incident surface forms a through groove, which is concave toward the first reflection surface; and a light source device, the light source device includes a plurality of light sources, adjacent to the light incident surface and Set towards the through groove, the light sources of the plurality of light sources have different light-emitting directions and face the light incident surface, and the light emitted by the plurality of light sources enters the first light guide portion through the light incident surface and is sequentially reflected by the first light surface and the second reflecting surface. The backlight module of claim 1, wherein the first reflecting surface and the second reflecting surface are both planes, and the two planes are parallel or perpendicular to each other. The backlight module of claim 1, wherein the light entering the first light guide portion through the light incident surface travels in a first direction, and the light travels in a second direction after being reflected by the first reflecting surface, The light travels in a third direction after being reflected by the second reflecting surface, and the first direction is opposite to or the same as the third direction. The backlight module of claim 1, wherein the light guide structure comprises a second light guide portion, the second light guide portion is a plate-like structure and extends along the extending direction, and enters the first light guide portion through the light incident surface. The light of a light guide portion is reflected by the first reflection surface and the second reflection surface in sequence, so as to enter the second light guide portion. The backlight module of claim 1, wherein the first light guide portion comprises a first sub-section, a second sub-section and a third sub-section in a direction perpendicular to the extending direction, the second sub-section Partly connecting the first subsection and the third subsection, the first subsection includes the light incident surface, the light The source device includes a circuit board and a plurality of light sources, the first sub-section and the third sub-section are located on both sides of the circuit board in a direction perpendicular to the extending direction, and the plurality of light sources are fixed on the circuit board, The light-emitting directions of the plurality of light sources face the light incident surface. The backlight module of claim 5, wherein the cross-section of the first sub-section, the second sub-section and the third sub-section as a whole perpendicular to the extending direction is C-shaped or Z-shaped. The backlight module of claim 1, wherein the plurality of light sources emit light of different colors. The backlight module of claim 1, wherein the through-groove has a plurality of light incident regions, and the light-emitting directions of the plurality of light sources are respectively directed toward the plurality of light incident regions.

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