Light guide structure

Abstract

The present invention relates to the field of touch technology, and provides a light guide structure comprising a flexible circuit board, a light guide plate, a gasket, a light emitting diode, a waterproof glue, and a reflective layer. The flexible circuit board comprises a first side, a second side relative to the first side, a third side, and a fourth side relative to the third side. The light guide plate is arranged on the flexible circuit board and extends beyond the first side of the flexible circuit board. The gasket is arranged on the flexible circuit board on the same side as the light guide plate and extends along the second side. The light emitting diode is arranged on the flexible circuit board and is located between the light guide plate and the gasket. The waterproof glue is arranged on the third and fourth sides of the flexible circuit board, and the waterproof glue extends from the light guide plate to the gasket. The reflective layer is arranged on the light guide plate, the light emitting diode, and the gasket, and the reflective layer comprises at least two openings, each of which exposes the waterproof glue.

Description

Technical Field

[0001] The invention relates to a light guide structure. Background Art

[0002] With the advancement of technology, display panels have become the medium for transmitting information between devices and users. However, some display panels do not emit light on their own and often require an external light source to clearly display images. Therefore, a light-emitting component is typically placed on one side of a light guide plate (LGP). The light emitted by the light-emitting component is guided by the LGP and evenly distributed across the display surface of the display device.

[0003] However, light-emitting components are easily damaged by moisture, necessitating waterproofing. Current waterproofing methods use waterproof glue to seal gaps and prevent moisture from entering the components. However, due to the angle at which glue is dispensed and the difficulty of processing, it's difficult to observe the glue dispensing process, resulting in reduced process yield and less than ideal waterproofing results. Therefore, a novel display panel is needed to address these issues. Summary of the Invention

[0004] In order to solve the above-mentioned problem of visibility of the metal conductor and overcome the shortcomings of the prior art, the purpose of the present invention is to provide a light guide structure, comprising a flexible circuit board, a light guide plate, a gasket, a light emitting diode, a waterproof adhesive and a reflective layer. The flexible circuit board comprises a first side, a second side relative to the first side, a third side and a fourth side relative to the third side. The light guide plate is arranged on the flexible circuit board and extends beyond the first side of the flexible circuit board. The gasket is arranged on the flexible circuit board on the same side as the light guide plate and extends along the second side. The light emitting diode is arranged on the flexible circuit board and is located between the light guide plate and the gasket. The waterproof adhesive is arranged on the third and fourth sides of the flexible circuit board, and the waterproof adhesive extends from the light guide plate to the gasket. The reflective layer is arranged on the light guide plate, the light emitting diode and the gasket, and the reflective layer comprises at least two openings, each of which exposes the waterproof adhesive.

[0005] According to one or more embodiments of the present invention, the light emitted by the light emitting diode is configured to directly illuminate the light guide plate.

[0006] According to one or more embodiments of the present invention, the thickness of the spacer is the same as the thickness of the light emitting diode.

[0007] According to one or more embodiments of the present invention, the flexible printed circuit board, the light guide plate, the gasket, the reflective layer, and the waterproof adhesive form a closed space.

[0008] According to one or more embodiments of the present invention, the light guide structure further includes an adhesive layer, and the flexible printed circuit board is attached to the light guide plate via the adhesive layer.

[0009] According to another aspect of the present disclosure, a light guide structure is provided, comprising a flexible printed circuit board (FPC), a light guide plate (LGP), a light-emitting diode (LED), and waterproof adhesive. The light guide plate is disposed on the FPC and extends beyond the FPC. The LED is disposed on the FPC on the same side as the light guide plate. The waterproof adhesive completely covers the LED.

[0010] According to one or more embodiments of the present invention, the waterproof glue is configured to convert a first color temperature of light emitted by a light emitting diode into a second color temperature, where the second color temperature is different from the first color temperature.

[0011] According to one or more embodiments of the present invention, the second color temperature is 5700K.

[0012] According to one or more embodiments of the present invention, the light guide structure further includes an adhesive layer, and the flexible printed circuit board is bonded to the substrate via the adhesive layer.

[0013] According to one or more embodiments of the present invention, the waterproof adhesive is in direct contact with the light guide plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A top view of a light guide structure 100 according to some embodiments of the present invention is shown.

[0015] Figure 2 Schematic cross-sectional view of the light guide structure 100 along line AA′ according to some embodiments of the present invention is shown.

[0016] Figure 3 Schematic cross-sectional view of the light guide structure 100 along line BB′ according to some embodiments of the present invention is shown.

[0017] Figure 4 A top view of a light guide structure 200 according to some embodiments of the present invention is shown.

[0018] Figure 5 Schematic cross-sectional view of the light guide structure 200 along line CC′ according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0019] The following disclosure provides numerous different embodiments, or examples, for implementing various features of the provided objects. The specific examples of components and arrangements described below are intended to simplify the disclosure. These are, of course, merely illustrative and not intended to be limiting. For example, component dimensions are not limited by the disclosed ranges or values but may depend on the component's manufacturing process conditions and / or desired properties.

[0020] Unless the context clearly indicates otherwise, singular terms used herein include the plural. Reference to "one embodiment" as a specific reference refers to a specific feature, structure, or characteristic in at least one embodiment of the present disclosure. Therefore, the phrase "in one embodiment" when used throughout the disclosure does not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, these specific features, structures, or characteristics may be combined as appropriate.

[0021] FIG1 illustrates a top view of a light-guiding structure 100 according to some embodiments of the present invention. FIG2 illustrates a schematic cross-sectional view of the light-guiding structure 100 along line AA' according to some embodiments of the present invention. FIG3 illustrates a schematic cross-sectional view of the light-guiding structure 100 along line BB' according to some embodiments of the present invention. Referring first to FIG1 , the light-guiding structure 100 includes a flexible printed circuit board 110, a light guide plate 120, a light-emitting diode 130, a gasket 140, a reflective layer 150, and a waterproof adhesive 160. It should be noted that, for greater clarity, the reflective layer 150 is represented by a thicker dashed line. Furthermore, since a portion of the flexible printed circuit board 110 is located below the light guide plate 120, a dashed line is used to indicate its location.

[0022] The flexible printed circuit board 110 includes a first side 111, a second side 112, a third side 113, and a fourth side 114. The first side 111 is opposite the second side 112, while the third side 113 is opposite the fourth side 114. In some embodiments, the third side 113 and the fourth side 114 are perpendicular to the first side 111 and the second side 112, respectively.

[0023] Referring to FIG. 2 , the light guide plate 120 is disposed on the flexible printed circuit board 110 and extends beyond the first side 111 of the flexible printed circuit board 110. In some embodiments, the light guide plate 120 may be made of poly(methylmethacrylate) (PMMA), cycloolefin polymer (COP), or polycarbonate (PC).

[0024] In some embodiments, the light guide structure 100 further includes an adhesive layer 170 disposed between the light guide plate 120 and the flexible printed circuit board 110. The light guide plate 120 is bonded to the flexible printed circuit board 110 via the adhesive layer 170. In some embodiments, the adhesive layer 170 may be an optically clear adhesive (OCA).

[0025] The gasket 140 is disposed on the second side 112 of the flexible printed circuit board 110. In some embodiments, the gasket 140 is flush with the second side 112 of the flexible printed circuit board 110. In certain embodiments, the gasket 140 may be made of foam. The gasket 140 is used to isolate moisture from the outside, preventing moisture from infiltrating through the second side 112 of the flexible printed circuit board 110. In some embodiments, the gasket 140 has an adhesive layer (not shown) disposed between the gasket 140 and the flexible printed circuit board 110. The adhesive layer secures the gasket 140 to the flexible printed circuit board 110.

[0026] Referring to FIG. 3 , LED 130 is disposed on flexible printed circuit board 110 and between light guide plate 120 and spacer 140. Note that in some embodiments, LED 130 does not contact light guide plate 120 or spacer 140. In some embodiments, distance d1 between LED 130 and spacer 140 is approximately 50 μm to approximately 500 μm, such as 100 μm, 200 μm, 300 μm, or 400 μm. In some embodiments, as shown in FIG. 1 , light guide structure 100 includes a plurality of LEDs 130.

[0027] Referring to both Figures 1 and 2 , waterproof adhesive 160 is disposed on the third side 113 and the fourth side 114 of the flexible printed circuit board 110 , and extends from the light guide plate 120 to the gasket 140 . Therefore, waterproof adhesive 160 prevents moisture from penetrating the light guide structure 100 through the third side 113 or the fourth side 114 of the flexible printed circuit board 110 and damaging the LEDs 130 .

[0028] Referring to Figures 1, 2, and 3, the reflective layer 150 is disposed on the light guide plate 120, the LEDs 130, and the gasket 140. It is noteworthy that the reflective layer 150 includes at least two openings 155, each of which exposes the waterproof adhesive 160. In other words, the openings 155 of the reflective layer 150 are disposed above the waterproof adhesive 160. In some embodiments, the reflective layer 150 is a white tape. Therefore, the reflective layer 150 can be attached to the light guide plate 120, the LEDs 130, and the gasket 140 after the light guide plate 120, the LEDs 130, and the gasket 140 are disposed on the flexible printed circuit board 110. In some embodiments, the reflective layer 150 can block light emitted in a vertical direction from the LEDs 130, preventing light from leaking from the edges of the light guide plate 120. Furthermore, the reflective layer 150 can also reflect light, directing the light emitted by the LED 130 toward the light guide plate 120, thereby increasing the efficiency of light utilization. In some embodiments, the flexible printed circuit 110, light guide plate 120, gasket 140, reflective layer 150, and waterproof adhesive 160 form an enclosed space 180. Notably, the waterproof adhesive 160 is only disposed on the third side 113 and fourth side 114 of the flexible printed circuit 110 and does not flow between the light guide plate 120 and the LED 130, or between the LED 130 and gasket 140. Furthermore, in some embodiments, the thickness of the LED 130 is the same as that of the gasket 140. In some embodiments, the thickness of the LED 130, the thickness of the gasket 140, and the thickness of the light guide plate 120 are substantially the same. Therefore, the reflective layer 150 can be completely adhered to the LED 130 and gasket 140, ensuring a better seal between the reflective layer 150.

[0029] It should be noted that if the reflective layer 150 does not include the opening 155, waterproof adhesive 160 must be injected from the third side 113 and the fourth side 114 of the flexible printed circuit board 110 to prevent moisture from seeping in from the third side 113 and the fourth side 114. This not only requires flipping the light guide structure 100 to inject the waterproof adhesive 160, but also makes it difficult to observe the adhesive dispensing process, causing the waterproof adhesive 160 to easily flow onto the light-emitting surface of the LED 130, thereby affecting the light-emitting efficiency of the LED 130.

[0030] The reflective layer 150 of the present invention includes at least two openings 155. When injecting waterproof adhesive 160, adhesive can be dispensed directly through these openings 155. Therefore, during the manufacturing process, there is no need to flip the light guide structure 100; adhesive can be dispensed directly from above the reflective layer 150, significantly reducing manufacturing complexity. Furthermore, the technical solution of the present invention makes it easier to inspect adhesive dispensing and prevent waterproof adhesive 160 from flowing onto the light-emitting surface of the LED 130. Therefore, in some embodiments, light emitted by the LED 130 directly impinges on the light guide plate 120.

[0031] In some embodiments, the viscosity of the injected waterproof adhesive 160 is approximately 25 Pa·s to 35 Pa·s, for example, 28 Pa·s, 30 Pa·s, or 32 Pa·s. If the viscosity of the waterproof adhesive 160 is too low, the waterproof adhesive 160 may easily flow onto the light-emitting surface of the LED 130 or between the LED 130 and the gasket 140. If the viscosity of the waterproof adhesive 160 is too high, it may be difficult to seal the third side 113 and the fourth side 114 of the flexible printed circuit board 110, thereby making it difficult to form the enclosed space 180. In some embodiments, the waterproof adhesive 160 is a room-temperature curing adhesive. After dispensing, the waterproof adhesive 160 can be cured by allowing it to stand for a period of time.

[0032] The present invention also provides another light guide structure. Please refer to FIG. 4 , which illustrates a top view of a light guide structure 200 according to some embodiments of the present invention. In the drawings of the present invention, similar components or features may be assigned the same reference numerals. Light guide structure 200 includes a flexible printed circuit board 110, a light guide plate 120, an LED 130, and waterproof adhesive 260. Because waterproof adhesive 260 covers LED 130, the position of LED 130 is indicated by a dashed line in FIG. 4 .

[0033] FIG5 illustrates a cross-sectional view of a light guide structure 200 along line CC' according to some embodiments of the present invention. Referring to FIG5 , a light guide plate 120 is disposed on and extends beyond the flexible printed circuit board 110. In some embodiments, the material of the light guide plate 120 may be poly(methyl methacrylate) (PMMA), cycloolefin polymer (COP), or polycarbonate (PC).

[0034] In some embodiments, the light guide structure 200 further includes an adhesive layer 170 disposed between the light guide plate 120 and the flexible printed circuit board 110. The light guide plate 120 is bonded to the flexible printed circuit board 110 via the adhesive layer 170. In some embodiments, the adhesive layer 170 may be an optically clear adhesive (OCA).

[0035] The LED 130 is disposed on the flexible printed circuit board 110 on the same side as the light guide plate 120. In some embodiments, the light guide structure 200 includes a plurality of LEDs 130. In some embodiments, the LEDs 130 do not contact the light guide plate 120.

[0036] The waterproof glue 260 completely covers the light-emitting diode 130. It is worth noting that the waterproof glue 260 of the light-guiding structure 200 can be the same as or different from the waterproof glue 160 of the light-guiding structure 100. In some embodiments, the waterproof glue 260 is configured to convert the first color temperature of the light emitted by the light-emitting diode 130 into a second color temperature, wherein the second color temperature is different from the first color temperature. In other words, the waterproof glue 260 can change the color of the light emitted by the light-emitting diode 130 to a desired color. Therefore, the waterproof glue 260 can be made of a material that matches the color of the light emitted by the light-emitting diode 130. In some embodiments, the above-mentioned second color temperature is 5700K. Similar to the waterproof glue 160, the waterproof glue 260 is used to prevent external moisture from damaging the light-emitting diode 130.

[0037] The waterproof adhesive 260 completely covers the LED 130, eliminating the need for gaskets. This reduces the number of manufacturing steps and effectively prevents moisture from damaging the LED 130. Furthermore, by selecting waterproof adhesive 260 that matches the color of the light emitted by the LED 130, the choice of LED 130 is more flexible. For example, a blue LED can be paired with the matching waterproof adhesive to produce the desired white light (5700K).

[0038] The present invention illustratively provides various light guide structures, allowing users to select the appropriate embodiment based on their needs. Through the technical solutions of the present invention, waterproof light guide structures can be fabricated using a simpler manufacturing process. Furthermore, this simplified manufacturing process improves process yield and increases productivity per person hour.

[0039] Although the present invention has been disclosed above in terms of embodiments, this is not intended to limit the present invention. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the appended patent applications.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A light guide structure, characterized in that: Include: A flexible printed circuit board comprises a first side, a second side opposite to the first side, a third side, and a fourth side opposite to the third side; a light guide plate disposed on the flexible printed circuit board and extending beyond the first side of the flexible printed circuit board; a gasket, disposed along the second side and on the flexible printed circuit board on the same side as the light guide plate; a light emitting diode, disposed on the flexible printed circuit board and located between the light guide plate and the spacer; a waterproof adhesive disposed on the third side and the fourth side of the flexible printed circuit board, the waterproof adhesive extending from the light guide plate to the gasket; as well as A reflective layer is disposed on the light guide plate, the light emitting diode and the gasket. The reflective layer comprises at least two openings, and each opening exposes the waterproof glue. 2 . The light guide structure according to claim 1 , wherein the light emitted by the light emitting diode is configured to directly illuminate the light guide plate. 3 . The light guide structure as claimed in claim 1 , wherein a thickness of the spacer is the same as a thickness of the light emitting diode. 4 . The light guide structure as claimed in claim 1 , wherein the flexible printed circuit board, the light guide plate, the gasket, the reflective layer and the waterproof adhesive form a closed space. 5 . The light guide structure according to claim 1 , further comprising an adhesive layer, wherein the flexible printed circuit board is attached to the light guide plate via the adhesive layer.

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