Front light module and manufacturing method thereof

Abstract

The invention discloses a front light module and a manufacturing method thereof. The front light module comprises a light guide plate, a light source, a first waterproof layer, a second waterproof layer and a third waterproof layer, the edge of the light guide plate has an extension portion. The light source is located at the edge of the light guide plate. The two first waterproof layers are located on the bottom face and the top face of the light guide plate respectively. The second waterproof layer has a recess. The light source is located between the second waterproof layer and the edge of the light guide plate, and the extending part of the light guide plate extends into the concave part of the second waterproof layer. The third waterproof layer is in the recess of the second waterproof layer and surrounds the extension of the light guide plate. According to the design, the length of the glue injection channel can be increased, so that the third waterproof layer can be positioned in the concave part of the second waterproof layer and surrounds the extension part of the light guide plate, further, the glue injection area of the front light module can be easily controlled, and good waterproof performance is kept.

Description

Technical Field

[0001] The present disclosure relates to a front light module and a method for manufacturing the front light module. Background Art

[0002] Reflective display devices need to use a front light module to provide incident light in an environment with insufficient light. The front light module can use a light emitting diode (LED) as a light source, and the light emitting diode is a moisture-sensitive element. In order to achieve the purpose of waterproofing, it is necessary to use many different waterproof materials to enclose the LED light source area into a closed space to form a waterproof circle to prevent water vapor from entering and damaging the LED light source. However, there may be fine gaps between different waterproof materials. Although they can be further sealed with waterproof glue, the glue injection channel of the front light module is not designed, the channel is too short and it is difficult to control the glue injection area, which is prone to process risks and gaps, and thus cannot maintain good waterproof performance. In this way, when water vapor enters the LED light source area, if it stays at the electrode of the LED light source, it will cause a short circuit and damage the LED light source. Summary of the invention

[0003] A technical aspect of the present disclosure is a front light module.

[0004] According to some embodiments of the present disclosure, a front light module includes a light guide plate, a light source, a first waterproof layer, a second waterproof layer, and a third waterproof layer. The edge of the light guide plate has an extension portion. The light source is located at the edge of the light guide plate. The first waterproof layer is respectively located on the bottom surface and the top surface of the light guide plate. The second waterproof layer has a recessed portion. The light source is located between the second waterproof layer and the edge of the light guide plate, and the extension portion of the light guide plate extends into the recessed portion of the second waterproof layer. The third waterproof layer is located in the recessed portion of the second waterproof layer and surrounds the extension portion of the light guide plate.

[0005] In some embodiments, the third waterproof layer is located between the second waterproof layer and the extension portion of the light guide plate.

[0006] In some embodiments, the third waterproof layer contacts the side walls of the two first waterproof layers and the side walls of the light guide plate.

[0007] In some embodiments, the front light module further includes a fourth waterproof layer, which is located on the bottom surface of the first waterproof layer, the bottom surface of the third waterproof layer, and the bottom surface of the second waterproof layer on the bottom surface of the light guide plate.

[0008] In some embodiments, the fourth waterproof layer has a plurality of holes, and the holes are located in a region between the light guide plate and the second waterproof layer.

[0009] In some embodiments, the front light module further includes a fifth waterproof layer. The fifth waterproof layer is located on the bottom surface of the fourth waterproof layer and is configured to close the hole.

[0010] In some embodiments, the fourth waterproof layer and the fifth waterproof layer are polyethylene terephthalate (PET) film or Mylar film.

[0011] In some embodiments, the first waterproof layer and the second waterproof layer are foam glue, double-sided tape, moisture-curing glue, heat-curing glue, AB glue or UV-curing glue, and the third waterproof layer is moisture-curing glue, heat-curing glue, AB glue or UV-curing glue.

[0012] In some embodiments, the front light module further comprises a flexible circuit board, which is located on the top surface of the first waterproof layer, the top surface of the third waterproof layer and the top surface of the second waterproof layer on the top surface of the light guide plate.

[0013] A technical aspect of the present disclosure is a method for manufacturing a front light module.

[0014] According to some embodiments of the present disclosure, a method for manufacturing a front light module includes forming an extension of a light guide plate on an edge of the light guide plate; forming a first waterproof layer on the bottom and top surfaces of the light guide plate, respectively, wherein a light source is located at the edge of the light guide plate; forming a second waterproof layer having a recess so that the light source is located between the second waterproof layer and the edge of the light guide plate, wherein the extension of the light guide plate extends into the recess of the second waterproof layer; and injecting a third waterproof layer into the recess of the second waterproof layer so that the third waterproof layer surrounds the extension of the light guide plate.

[0015] In some embodiments, the manufacturing method of the front light module further includes attaching a fourth waterproof layer to the bottom surface of the first waterproof layer and the bottom surface of the second waterproof layer on the bottom surface of the light guide plate before injecting the third waterproof layer into the recess of the second waterproof layer, wherein the fourth waterproof layer has a plurality of holes.

[0016] In some embodiments, the manufacturing method of the front light module further includes attaching a fifth waterproof layer to the bottom surface of the fourth waterproof layer.

[0017] In some embodiments, the manufacturing method of the above-mentioned front light module also includes setting a flexible circuit board on the top surface of the first waterproof layer and the top surface of the second waterproof layer on the top surface of the light guide plate before injecting the third waterproof layer into the recessed portion of the second waterproof layer, so that the flexible circuit board, the second waterproof layer, the fourth waterproof layer, the two first waterproof layers and the light guide plate define a glue injection channel.

[0018] In some embodiments, the step of injecting the third waterproof layer into the recessed portion of the second waterproof layer further comprises injecting the third waterproof layer into a glue injection channel.

[0019] In some embodiments, the third waterproof layer is injected into the glue injection channel so that the air in the glue injection channel is discharged from the holes of the fourth waterproof layer.

[0020] In the above-mentioned embodiment of the present disclosure, since the edge of the light guide plate of the front light module has an extension, the second waterproof layer has a recess, and the extension of the light guide plate extends into the recess of the second waterproof layer, the length of the glue injection channel can be increased, so that the third waterproof layer can be located in the recess of the second waterproof layer and surround the extension of the light guide plate. In this way, the glue injection area of ​​the front light module can be easily controlled, maintaining good waterproof performance, and preventing water vapor from entering the light source area to cause a short circuit and damage the light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] When read together with the accompanying drawings, the aspects of the present disclosure can be best understood from the following embodiments. Note that according to standard practice in this industry, various features are not drawn to scale. In fact, the size of various features may be arbitrarily increased or reduced for clarity of discussion.

[0022] Figure 1 A top view of a front light module according to an embodiment of the present disclosure is shown;

[0023] Figure 2 Draw Figure 1 A partial enlarged view of the front light module;

[0024] Figure 3 Draw Figure 2 A cross-sectional view of the front light module along line segment 3-3;

[0025] Figure 4 A top view of a front light module according to another embodiment of the present disclosure is shown;

[0026] Figure 5 A flow chart of a method for manufacturing a front light module according to an embodiment of the present disclosure is shown.

[0027]

Explanation of symbols

[0028] 100,100a: front light module

[0029] 110: Light guide plate

[0030] 111: Edge

[0031] 112: Extension

[0032] 120: Light source

[0033] 130a, 130b: first waterproof layer

[0034] 140: Second waterproof layer

[0035] 142: concave part

[0036] 150: The third waterproof layer

[0037] 160: The fourth waterproof layer

[0038] 162: Holes

[0039] 170: Flexible printed circuit board

[0040] 180: The fifth waterproof layer

[0041] 3-3: Line segment

[0042] S1, S2, S3, S4: Steps DETAILED DESCRIPTION

[0043] The following disclosed embodiments provide many different embodiments, or examples, for implementing the different features of the subject matter provided. Specific examples of components and arrangements are described below to simplify the present invention. Of course, these examples are only examples and are not intended to be limiting. In addition, the present invention may repeat element symbols and / or letters in each example. This repetition is for the purpose of simplicity and clarity, and does not itself specify the relationship between the various embodiments and / or configurations discussed.

[0044] Spatially relative terms such as "below," "beneath," "lower," "above," "upper," and the like may be used herein for descriptive purposes to describe the relationship of one element or feature to another element or feature as illustrated in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation illustrated in the accompanying drawings. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should likewise be interpreted accordingly.

[0045] Figure 1 A top view of a front light module 100 according to an embodiment of the present disclosure is shown. The front light module 100 includes a light guide plate 110, a light source 120, and a flexible circuit board 170. The light source 120 is adjacent to the light guide plate 110 (the distance between the two is, for example, 0 to 1 mm), and the light from the light source 120 can enter from the side of the light guide plate 110, thereby lighting up the entire light guide plate 110. The flexible circuit board 170 can be electrically connected to the light source 120 to supply power to the light source 120. The flexible circuit board 170 extends outward from one side of the light guide plate 110 to cover the edge area of ​​the light guide plate 110, the light source 120, and other material layers. For the sake of clarity of the drawings, Figure 1 , Figure 2 and Figure 4 The uppermost flexible circuit board 170 is represented by a range surrounded by a thick line, and the light source 120 and other material layers covered by the flexible circuit board 170 are represented by solid lines, which are described first.

[0046] The front light module 100 can be applied to a reflective display device to provide front light to a display medium (such as electronic ink) when the ambient light is insufficient. In the following description, each layer structure of the front light module 100 will be described in detail.

[0047] Figure 2 Draw Figure 1 A partial enlarged view of the front light module 100. Figure 3 Draw Figure 2 A cross-sectional view of the front light module 100 along line segment 3-3. Figure 2 and Figure 3 , the light source 120 is located at the edge 111 of the light guide plate 110. The front light module 100 includes a first waterproof layer 130a, 130b, a second waterproof layer 140 and a third waterproof layer 150. The edge 111 of the light guide plate 110 has an extension portion 112. The extension portion 112 is a protruding structure, such as a long strip or a tooth shape. The first waterproof layer 130a is located on the top surface of the light guide plate 110, and the first waterproof layer 130b is located on the bottom surface of the light guide plate 110. In other words, the light guide plate 110 is located between the first waterproof layers 130a and 130b. The second waterproof layer 140 has a recess 142. The extension portion 112 of the light guide plate 110 extends into the recess 142 of the second waterproof layer 140, so that the extension portion 112 of the light guide plate 110 and the recess 142 of the second waterproof layer 140 can form two side walls of the channel to serve as a retaining wall for the third waterproof layer 150. The third waterproof layer 150 is located in the concave portion 142 of the second waterproof layer 140 and surrounds the extension portion 112 of the light guide plate 110. In addition, the light source 120 is located between the second waterproof layer 140 and the edge 111 of the light guide plate 110.

[0048] In some embodiments, the material of the light guide plate 110 can be glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other inorganic or organic materials suitable as light-conducting media. The appearance of the light guide plate 110 can be prepared by punching, CNC processing, laser cutting or integrated molding. The first waterproof layer 130a, 130b and the second waterproof layer 140 can be closed foam glue, waterproof double-sided tape, or moisture-cured, heat-cured, AB double-agent or UV-cured waterproof glue, and its material can be PMMA substrate, polyurethane (PU) substrate, silicone substrate or other adhesive system with waterproof performance. The third waterproof layer 150 is a moisture-cured, heat-cured, AB double-agent or UV-cured optical glue, and its material can be PMMA substrate, silicone substrate or other adhesive system with waterproof performance and good optical properties.

[0049] Specifically, since the edge 111 of the light guide plate 110 of the front light module 100 has an extension 112, the second waterproof layer 140 has a recess 142, and the extension 112 of the light guide plate 110 extends into the recess 142 of the second waterproof layer 140, the length of the glue injection channel (i.e., the area where the third waterproof layer 150 is located) can be increased, so that the third waterproof layer 150 can be located in the recess 142 of the second waterproof layer 140 and surround the extension 112 of the light guide plate 110. In this way, the glue injection area of ​​the front light module 100 can be easily controlled, maintaining good waterproof performance, preventing water vapor from entering the light source area to cause a short circuit and damage the light source 120, thereby increasing the service life of the front light module 100.

[0050] In this embodiment, the flexible circuit board 170 is located on the top surface of the first waterproof layer 130a, the top surface of the third waterproof layer 150, and the top surface of the second waterproof layer 140. The front light module 100 also includes a fourth waterproof layer 160. The fourth waterproof layer 160 is located on the bottom surface of the first waterproof layer 130b, the bottom surface of the third waterproof layer 150, and the bottom surface of the second waterproof layer 140. The flexible circuit board 170, the second waterproof layer 140, the fourth waterproof layer 160, the two first waterproof layers 130a, 130b, and the light guide plate 110 define a glue injection channel for the third waterproof layer 150 to fill, so that the third waterproof layer 150 is located between the second waterproof layer 140 and the extension portion 112 of the light guide plate 110, and the third waterproof layer 150 contacts the side walls of the two first waterproof layers 130a, 130b and the side walls of the light guide plate 110. Figure 2 The entrance of the glue injection channel is on the left side of the extension part 112 of the light guide plate 110, and the third waterproof layer 150 can be extended from the left side of the extension part 112 to the right side of the extension part 112 through injection. Through the above design, the reliability of the channel being filled with glue (i.e., the third waterproof layer 150) can be ensured, and the waterproof failure problem caused by insufficient glue filling can be avoided. In addition, the materials used in the front light module 100 are simple and the assembly stability is good.

[0051] In addition, the front light module 100 may further include a fifth waterproof layer 180. The fifth waterproof layer 180 is located on the bottom surface of the fourth waterproof layer 160. The fourth waterproof layer 160 and the fifth waterproof layer 180 may be polyethylene terephthalate (PET) film or Mylar film.

[0052] It should be understood that the connection relationship, materials and functions of the components described above will not be repeated, and will be described first. In the following description, other types of front light modules will be described.

[0053] Figure 4 FIG. 1 is a top view of a front light module 100a according to another embodiment of the present disclosure. Figure 3 Same. See also Figure 3 and Figure 4The front light module 100a includes a light guide plate 110, a light source 120, first waterproof layers 130a, 130b, a second waterproof layer 140, a third waterproof layer 150, a fourth waterproof layer 160, a fifth waterproof layer 180 and a flexible circuit board 170. Figure 2 The difference between the embodiments is that the fourth waterproof layer 160 has a plurality of holes 162, which are located in the area between the light guide plate 110 and the second waterproof layer 140 and are staggered and non-overlapping with the light source 120. Figure 4 As shown. In this embodiment, the fifth waterproof layer 180 located on the bottom surface of the fourth waterproof layer 160 is configured to close the hole 162 of the fourth waterproof layer 160. The fourth waterproof layer 160 can be attached before the third waterproof layer 150 is injected, and then the third waterproof layer 150 is injected. The hole 162 of the fourth waterproof layer 160 can be used as a vent when injecting the third waterproof layer 150, making it easier to inject the third waterproof layer 150. After the third waterproof layer 150 is injected and cured, the fifth waterproof layer 180 can be attached so that water vapor will not invade from the hole 162 of the fourth waterproof layer 160.

[0054] In the following description, a method for manufacturing the front light module 100a will be described.

[0055] Figure 5 A flow chart of a method for manufacturing a front light module according to an embodiment of the present disclosure is depicted. The method for manufacturing a front light module includes the following steps. In step S1, an extension of a light guide plate is formed at the edge of the light guide plate. For example, the shape of the light guide plate can be prepared by punching, CNC processing, laser cutting or one-piece molding. Then in step S2, a first waterproof layer is formed on the bottom and top surfaces of the light guide plate, wherein the light source is located at the edge of the light guide plate. Then in step S3, a second waterproof layer having a recess is formed so that the light source is located between the second waterproof layer and the edge of the light guide plate, wherein the extension of the light guide plate extends into the recess of the second waterproof layer. Thereafter, in step S4, a third waterproof layer is injected into the recess of the second waterproof layer so that the third waterproof layer surrounds the extension of the light guide plate. In addition, steps S1 to S4 may each include multiple detailed steps, other steps may be included between step S1 and step S4, and other steps may also be included before step S1 and after step S4.

[0056] See also Figure 3 and Figure 4When manufacturing the front light module 100a, the edge 111 of the light guide plate 110 can be punched, CNC machined or laser cut to form a long strip extension 112. Then, the first waterproof layers 130a and 130b can be formed on the top and bottom surfaces of the light guide plate 110 by coating or attaching. Then, the second waterproof layer 140 with the concave portion 142 can be formed, so that the light source 120 is located between the second waterproof layer 140 and the edge 111 of the light guide plate 110, and the extension 112 of the light guide plate 110 extends into the concave portion 142 of the second waterproof layer 140. The second waterproof layer 140 may be formed by coating or attaching the flexible circuit board 170 on the bottom surface or the top surface of the fourth waterproof layer 160, and then the flexible circuit board 170 is disposed on the top surface of the first waterproof layer 130a and the top surface of the second waterproof layer 140, and the fourth waterproof layer 160 is attached to the bottom surface of the first waterproof layer 130b and the bottom surface of the second waterproof layer 140. The order of disposing the flexible circuit board 170 and the fourth waterproof layer 160 is not intended to limit the present disclosure, and they may also be disposed simultaneously so that the second waterproof layer 140 is sandwiched between the two. In this embodiment, the fourth waterproof layer 160 has a hole 162.

[0057] Before injecting the third waterproof layer 150 into the recess 142 of the second waterproof layer 140, the flexible circuit board 170, the second waterproof layer 140, the fourth waterproof layer 160, the first waterproof layer 130a, 130b and the light guide plate 110 define a glue injection channel. After the glue injection channel is formed, the third waterproof layer 150 can be injected into the recess 142 of the second waterproof layer 140, that is, the third waterproof layer 150 is injected into the aforementioned glue injection channel. When injecting the third waterproof layer 150 into the glue injection channel, the air in the glue injection channel can be discharged from the holes 162 of the fourth waterproof layer 160. After the third waterproof layer 150 is formed, the fifth waterproof layer 180 can be attached to the bottom surface of the fourth waterproof layer 160 to close the holes 162 to prevent water vapor from intruding. Through the above steps, it can be obtained Figure 4 The front light module 100a.

[0058] The foregoing summarizes the features of several embodiments so that those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art will appreciate that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present disclosure.

Claims

1. A front light module, characterized in that: include: A light guide plate, one edge of which has an extension portion; a light source, located at the edge of the light guide plate; A first waterproof layer is located on a bottom surface and a top surface of the light guide plate; a second waterproof layer having a concave portion, wherein the light source is located between the second waterproof layer and the edge of the light guide plate, and the extending portion of the light guide plate extends into the concave portion of the second waterproof layer; as well as A third waterproof layer is located in the concave portion of the second waterproof layer and surrounds the extending portion of the light guide plate.

2. The front light module according to claim 1, characterized in that: The third waterproof layer is located between the second waterproof layer and the extending portion of the light guide plate.

3. The front light module according to claim 1, characterized in that: The third waterproof layer contacts the side walls of the two first waterproof layers and the side wall of the light guide plate.

4. The front light module according to claim 1, characterized in that: Also includes: A fourth waterproof layer is located on the bottom surface of the first waterproof layer, the bottom surface of the third waterproof layer and the bottom surface of the second waterproof layer on the bottom surface of the light guide plate.

5. The front light module according to claim 4, characterized in that: The fourth waterproof layer has a plurality of holes, and the plurality of holes are located in a region between the light guide plate and the second waterproof layer.

6. The front light module according to claim 5, characterized in that: Also includes: A fifth waterproof layer is located on the bottom surface of the fourth waterproof layer and is configured to close the plurality of holes.

7. The front light module according to claim 6, characterized in that: The fourth waterproof layer and the fifth waterproof layer are polyethylene terephthalate (PET) films or Mylar films.

8. The front light module according to claim 1, characterized in that: The first waterproof layer and the second waterproof layer are foam glue, double-sided tape, or moisture-curing, heat-curing, AB double-agent or ultraviolet light-curing waterproof glue, and the third waterproof layer is optical glue that is moisture-curing, heat-curing, AB double-agent or ultraviolet light-curing glue.

9. The front light module according to claim 1, characterized in that: Also includes: A flexible circuit board is located on the top surface of the first waterproof layer, the top surface of the third waterproof layer and the top surface of the second waterproof layer on the top surface of the light guide plate.

10. A method for manufacturing a front light module, characterized in that: include: forming an extension portion of a light guide plate at an edge of the light guide plate; Forming a first waterproof layer on a bottom surface and a top surface of a light guide plate, wherein a light source is located at the edge of the light guide plate; forming a second waterproof layer having a concave portion so that the light source is located between the second waterproof layer and the edge of the light guide plate, wherein the extending portion of the light guide plate extends into the concave portion of the second waterproof layer; and A third waterproof layer is injected into the concave portion of the second waterproof layer, so that the third waterproof layer surrounds the extending portion of the light guide plate.

11. The method for manufacturing a front light module according to claim 10, wherein: Also includes: Before injecting the third waterproof layer into the concave portion of the second waterproof layer, a fourth waterproof layer is attached to the bottom surface of the first waterproof layer and the bottom surface of the second waterproof layer on the bottom surface of the light guide plate, wherein the fourth waterproof layer has a plurality of holes.

12. The method for manufacturing a front light module according to claim 11, wherein: Also includes: A fifth waterproof layer is attached to the bottom surface of the fourth waterproof layer.

13. The method for manufacturing a front light module according to claim 11, wherein: Also includes: Before injecting the third waterproof layer into the recessed portion of the second waterproof layer, a flexible circuit board is arranged on the top surface of the first waterproof layer and the top surface of the second waterproof layer on the top surface of the light guide plate, so that the flexible circuit board, the second waterproof layer, the fourth waterproof layer, the first waterproof layer and the light guide plate define a glue injection channel.

14. The method for manufacturing a front light module according to claim 13, wherein: Injecting the third waterproof layer into the concave portion of the second waterproof layer further comprises: Inject the third waterproof layer into the glue injection channel.

15. The method for manufacturing a front light module according to claim 14, wherein: The third waterproof layer is injected into the glue injection channel so that the air in the glue injection channel is discharged from the plurality of holes in the fourth waterproof layer.

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