Backlight module and electronic device

Abstract

The application discloses a backlight module and an electronic device, which are used for improving the structural stability and optical performance of the backlight module. The application comprises a glue iron frame, a light guide plate and a backlight FPC; the light guide plate is arranged in the glue iron frame; a gap is arranged between the light guide plate and the side of the glue iron frame; the backlight FPC comprises an extension FPC, a main body FPC and a wire-out FPC; the main body FPC is arranged at the bottom of the glue iron frame and is located between the light guide plate and the glue iron frame; the two ends of the main body FPC are respectively connected with the extension FPC, and the extension FPC is arranged in the gap, and the extension FPC is used for reducing the activity space of the light guide plate in the glue iron frame; one end of the wire-out FPC is cross-connected with the main body FPC, a cross area is formed, and the wire-out FPC is arranged outside the glue iron frame.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a backlight module and electronic equipment. Background Technology

[0002] As the core optical component of LCD display devices, the backlight module is widely used in consumer electronics such as smartphones, tablets, automotive displays, and laptops, as well as industrial equipment. Its main function is to provide a uniform and stable light source for the LCD panel, which directly determines the brightness uniformity and visual effect of the displayed image. In the design and production of traditional backlight modules, the light guide plate is installed inside a plastic frame. During equipment transportation and use, the light guide plate and the sides of the plastic frame will continuously rub and collide, which can easily damage the optical structure of the light guide plate. To reduce the collision between the light guide plate and the plastic frame, a gap is usually reserved between them.

[0003] However, the gap between the light guide plate and the plastic frame can lead to insufficient constraint of the light guide plate within the plastic frame. In scenarios where the equipment shakes, falls, or the temperature changes cause the components to expand and contract, the light guide plate will wobble laterally or longitudinally along the inside of the plastic frame, causing the edges of the light guide plate to be bumped and damaged, thus reducing the service life of the light guide plate. Utility Model Content

[0004] To address the aforementioned technical problems, this application provides a backlight module and electronic device for improving the structural stability and optical performance of the backlight module.

[0005] The technical solution provided in this application is described below: The first aspect of this application provides a backlight module, including: a plastic frame, a light guide plate, and a backlight FPC; The light guide plate is disposed within the plastic frame; A gap is provided between the light guide plate and the side of the glued iron frame; The backlight FPC includes an extension FPC, a main body FPC, and an outgoing FPC; The main FPC is disposed at the bottom of the plastic frame and is located between the light guide plate and the plastic frame; The main body FPC is connected to the extension FPC at both ends, and the extension FPC is placed in the gap. The extension FPC is used to reduce the movement space of the light guide plate within the plastic frame. One end of the outgoing FPC is cross-connected to the main body FPC to form a cross area, and the outgoing FPC is placed outside the plastic frame.

[0006] Optionally, the side of the backlight FPC facing the light guide plate is covered with a double PI layer, which is used to improve the surface flatness of the FPC and enhance the support stability of the light guide plate.

[0007] Optionally, a PI reinforcing layer is provided on the side of the intersection area facing the plastic frame, and the PI reinforcing layer is used to enhance the bending strength of the intersection area.

[0008] Optionally, the outgoing FPC has a window area on the side facing the light guide plate, and the window area is located below the intersection area.

[0009] Optionally, the window area is a cut-out window structure.

[0010] Optionally, a PI reinforcement layer is provided on the inner side of the window area, the PI reinforcement layer being used to increase the strength of the window area.

[0011] Optionally, a first screen-printed black ink layer is provided on the side of the intersection area facing the light guide plate to block reflected light from entering the light guide plate.

[0012] Optionally, a second silkscreened black ink layer is provided at the other end of the outgoing FPC to block external ambient light from being reflected into the plastic frame through the outgoing FPC.

[0013] Optionally, the extended FPC and the main FPC are integrally formed.

[0014] A second aspect of this application provides an electronic device including the aforementioned backlight module; the backlight module is mounted on the electronic device.

[0015] As can be seen from the above technical solutions, this application has the following beneficial effects: The backlight module uses a combination structure of main FPC, extended FPC and outgoing FPC. The extended FPC fills the gap between the light guide plate and the side of the plastic frame, which effectively reduces the movement space of the light guide plate in the plastic frame. This avoids the wear problem caused by direct contact between the light guide plate and the plastic frame, and solves the problems of light guide plate shaking, uneven backlight and edge damage caused by excessive gap. This improves the structural stability and optical performance of the backlight module. Attached Figure Description

[0016] Figure 1 A schematic diagram of the backlight module provided in this application; Figure 2 A schematic diagram of one side of the backlight FPC provided in this application; Figure 3 A schematic diagram of the other side of the backlight FPC provided in this application. Detailed Implementation

[0017] In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and other terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0018] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0019] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0020] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0021] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] See Figures 1 to 3 The first aspect of this application provides an embodiment of a backlight module, which includes: 1. Glue frame, 2. Light guide plate, and 3. Backlight FPC; The light guide plate 2 is set inside the plastic frame 1; A gap is provided between the light guide plate 2 and the side of the glued iron frame 1; The backlight FPC3 includes an extension FPC31, a main body FPC32, and a cable exit FPC33; The main body FPC32 is set at the bottom inside the plastic frame 1 and is located between the light guide plate 2 and the plastic frame 1; The main body FPC32 is connected to two ends of an extension FPC31, and the extension FPC31 is placed in the gap. The extension FPC31 is used to reduce the movement space of the light guide plate 2 in the plastic frame 1. One end of the outgoing FPC33 is cross-connected to the main body FPC32 to form a cross area 4, and the outgoing FPC33 is placed outside the plastic iron frame 1.

[0023] The plastic-metal frame 1 is the basic load-bearing structure of the backlight module. Using a plastic and metal composite frame, it possesses certain structural strength and lightweight characteristics. The plastic-metal frame 1 has internal storage space, with a flat bottom surface to support the light guide plate 2 and the main body FPC 32. A specific width gap is reserved between the plastic-metal frame 1 and the light guide plate 2 on the sides. In this embodiment, the single-sided gap between the plastic-metal frame 1 and the light guide plate 2 is set to 0.3 mm. Simultaneously, the frame as a whole protects the internal components, preventing external impacts from directly affecting the light guide plate 2 and the backlight FPC.

[0024] Light guide plate 2: Light guide plate 2 is typically a thin plate structure made of transparent polymer material (such as PMMA). There is a gap between the bottom surface of light guide plate 2 and the bottom of the plastic frame 1, and a preset gap is maintained between the side surface of light guide plate 2 and the side edge of plastic frame 1. Light guide plate 2 can conduct, refract, and diffuse the light emitted by the light source on the main body FPC32, converting the line light source or point light source into a uniform surface light source, providing a stable backlight foundation for the LCD panel.

[0025] Backlight FPC3: The backlight FPC3, or flexible circuit board, is a component integrating power supply, signal transmission, and structural positioning functions. It is made entirely of a flexible substrate and consists of an extension FPC31, a main body FPC32, and an output FPC33. The main body FPC32 is located between the light guide plate 2 and the bottom of the plastic frame 1, serving as the carrier for the light source (such as LED beads) and directly providing incident light to the light guide plate 2. The extension FPC31 connects to both ends of the main body FPC32, extending the main body FPC32 a certain length into the gap. In this embodiment, the extension FPC31 is 0.2 mm long and is laid within the gap between the light guide plate 2 and the side of the plastic frame 1. By limiting the lateral displacement of the light guide plate 2, it balances the wobbling problem caused by an excessively large gap with the wear risk caused by direct contact. One end of the output FPC33 cross-connects with the main body FPC32 to form a cross area 4, while the other end extends to the outside of the plastic frame 1. It is responsible for transmitting power and signals from external circuits to the main body FPC32, enabling light source driving and control.

[0026] Working principle: When the light source on the main body FPC32 is powered on, it emits light that is directly incident on the side or bottom surface of the light guide plate 2. The light guide plate 2 uses its internal optical structure (such as dots and microstructures) to evenly diffuse the light across the entire surface, forming a surface light source. Simultaneously, the extended FPC31 fills the gap between the light guide plate 2 and the plastic frame 1, limiting the movement of the light guide plate 2 during equipment vibration or temperature changes, ensuring the relative position of the light source and the light guide plate 2 is stable, and avoiding uneven backlighting caused by a shift in the incident angle of the light. The outgoing FPC33 is connected to the main body FPC32 through the cross area 4, transmitting the drive signals and power from the external circuit to the light source, ensuring consistent luminous intensity, and ultimately providing uniform and stable backlight support for the LCD panel.

[0027] In this embodiment, the backlight module uses a combination structure of main body FPC32, extension FPC31 and outgoing FPC33. The extension FPC31 fills the gap between the light guide plate 2 and the side of the plastic frame 1, effectively reducing the movement space of the light guide plate 2 in the plastic frame 1. This avoids the wear problem caused by direct contact between the light guide plate 2 and the plastic frame 1, and solves the problems of light guide plate 2 shaking, uneven backlight and edge damage caused by excessive gap. This improves the structural stability and optical performance of the backlight module.

[0028] In an optional embodiment, a double PI layer 5 is laid on the side of the backlight FPC3 facing the light guide plate 2. The double PI layer 5 is used to improve the surface flatness of the backlight FPC and enhance the support stability of the light guide plate 2.

[0029] In this embodiment, the side of the backlight FPC3 facing the light guide plate 2 adopts a double-layer PI layer 5, namely a double-layer polyimide layer. The overlapping of two PI layers forms a surface structure that combines high strength and flatness. The double-layer PI layer 5 effectively fills the tiny depressions or circuit protrusions on the surface of the FPC substrate, ensuring that the side of the FPC in contact with the light guide plate 2 remains highly flat. This ensures a tight fit between the light guide plate 2 and the FPC, avoiding light reflection loss or localized dark areas caused by gaps. Simultaneously, the PI material possesses a certain mechanical strength, and the double-layer structure further enhances the support capacity of the backlight FPC for the light guide plate 2. It can resist the slight deformation pressure caused by temperature changes in the light guide plate 2, preventing wrinkles or bending of the backlight FPC during long-term use. This maintains the relative positional accuracy between the light guide plate 2 and the light source, ensuring the uniformity of light output and structural stability of the backlight module.

[0030] In an optional embodiment, a PI reinforcing layer 6 is provided on the side of the cross section 4 facing the plastic frame 1, the PI reinforcing layer 6 being used to enhance the bending strength of the cross section 4.

[0031] In this embodiment, since the crossover area 4 is a transitional part where the backlight FPC structure changes, it is prone to repeated bending stress due to uneven stress during backlight module assembly, equipment use, or temperature changes, becoming a weak point in the structure. By adding a PI reinforcement layer 6, a black flexible PI layer with a thickness of not less than 0.03 mm is used in this embodiment. Utilizing the high temperature resistance, tear resistance, and high mechanical strength of PI material, the bending resistance and structural rigidity of the crossover area 4 can be specifically improved, and the concentrated stress during bending can be dispersed, avoiding problems such as circuit breakage, substrate delamination, or solder joint detachment in the crossover area 4 due to long-term stress. At the same time, the black flexible PI not only has light-shielding performance comparable to screen-printed black ink, which can block external ambient light from being reflected into the plastic frame through the exit point, but also has flexible characteristics and a certain thickness of structural strength. This satisfies the structural requirement of the exit FPC 33 extending to the outside of the plastic frame 1, and ensures the structural reliability of the crossover area 4 during long-term use, thereby maintaining the stability of the backlight module circuit connection.

[0032] In an optional embodiment, the side of the outgoing FPC33 facing the light guide plate 2 has a window area 7, which is located below the intersection area 4. The window area 7 is a cut-out window structure.

[0033] In this embodiment, the cross area 4 is the connection and transition part between the main body FPC32 and the outgoing line FPC33. The area below the cross area 4 is adjacent to the bottom of the glue frame 1. The window area 7 removes the insulating layer of the outgoing line FPC33 facing the light guide plate 2 through the glue removal process, exposing the conductive pads or lines below, which facilitates circuit testing after module assembly or subsequent component installation.

[0034] In an optional embodiment, a PI reinforcement layer 8 is provided on the inner side of the window area 7, the PI reinforcement layer 8 being used to increase the strength of the window area 7.

[0035] In this embodiment, because the window area 7 adopts a cut-out design, the FPC substrate in its edge area is prone to cracking or delamination under stress (such as bending of the outgoing FPC33 or squeezing during module assembly) due to the removal of the adhesive layer and some materials. By setting or retaining a certain length of PI layer inside the window area 7, in this embodiment, the PI reinforcement layer 8 on both sides of the window area 7 is not less than 1 mm. Utilizing the high strength and bending resistance of PI material, the stress of the exposed circuit part can be dispersed, preventing the edge of the window area 7 from being damaged due to repeated deformation.

[0036] In an optional embodiment, a first silkscreened black ink layer 9 is provided on the side of the intersection area 4 facing the light guide plate 2 to block reflected light from entering the light guide plate 2.

[0037] In this embodiment, the surface of the intersection area 4 may have exposed metal lines or substrates. During the light transmission process of the light guide plate 2, these areas are prone to reflecting light and forming stray light. The first screen-printed black oil layer 9 is covered on the side of the intersection area 4 facing the light guide plate 2 by screen printing. Utilizing the high light-blocking properties of the black oil material, it can absorb or block the reflected light generated on the surface of the intersection area 4, preventing stray light from entering the interior of the light guide plate 2 and improving the overall reliability of the backlight FPC.

[0038] In an optional embodiment, a second silkscreen black ink layer 10 is provided at the other end of the outgoing FPC33 to block external ambient light from being reflected into the interior of the plastic frame 1 through the outgoing FPC33.

[0039] In this embodiment, the outgoing FPC33 needs to extend through the plastic frame 1 to the outside to achieve electrical connection. If the surface of the exposed end of the outgoing FPC33 is directly exposed, it is easy to reflect ambient light generated by other components inside the device. This reflected light may be conducted along the surface of the outgoing FPC33 and seep back into the plastic frame 1 through the gap between the outgoing FPC33 and the plastic frame 1. The second screen-printed black ink layer 10 covers the surface of the exposed end of the outgoing FPC33. Utilizing the high light-shielding properties of the black ink material, it can absorb external ambient light, block its reflection path, and prevent ambient light from entering the plastic frame 1 through the outgoing FPC33 and interfering with the light transmission of the light guide plate 2.

[0040] In an optional embodiment, the extension FPC31 and the main body FPC32 are integrally molded.

[0041] In this embodiment, the extended FPC31 and the main body FPC32 are integrally prepared using the same substrate and processing technology, rather than being formed separately and then connected by welding or gluing. This avoids the interface gaps or stress concentration points that may exist in separate connections, making the mechanical properties of the transition area between the extended FPC31 and the main body FPC32 more uniform. It can withstand the continuous squeezing or pulling force of the light guide plate 2 caused by vibration and temperature changes, reducing the risk of breakage and delamination at the connection point, and enhancing the stability and durability of the overall structure of the backlight module.

[0042] A second aspect of this application provides an electronic device, including a backlight module; the backlight module is mounted on the electronic device.

[0043] The electronic device can specifically be a smartphone, tablet computer, laptop computer, in-vehicle display, smart wearable device, or other product that relies on liquid crystal display, integrating the backlight module of any of the aforementioned embodiments. The backlight module specifically includes a plastic frame 1, a light guide plate 2, and a backlight FPC 3. The light guide plate 2 is disposed inside the plastic frame 1 and connected to the bottom, with a gap between its side and the plastic frame 1. The backlight FPC 3 includes a main body FPC 32, an extension FPC 31, and an outgoing line FPC 33. The main body FPC 32 is located between the light guide plate 2 and the bottom of the plastic frame 1. The extension FPC 31 is connected to both ends of the main body FPC 32 and fills the gap between the light guide plate 2 and the plastic frame 1. One end of the outgoing line FPC 33 intersects with the main body FPC 32 to form an intersection area 4 and extends to the outside of the plastic frame 1. Meanwhile, the backlight FPC3 has a double PI layer 5 on the side facing the light guide plate 2, the cross area 4 has a PI reinforcement layer 6 on the side facing the glue frame 1, the outgoing FPC33 has a cut-out window structure on the side facing the light guide plate 2 and below the cross area 4, the cross area 4 has a first silkscreen black oil layer 9 on the side facing the light guide plate 2, and the other end of the outgoing FPC33 has a second silkscreen black oil layer 10.

[0044] In this embodiment, the backlight module provides a uniform and pure surface light source for the display panel of electronic devices by extending the FPC31 filling gap, strengthening the PI layer structure, and blocking stray light with a silkscreen black oil layer. This avoids bright spots and shadows on the screen caused by uneven backlighting and improves the user's visual experience.

[0045] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A backlight module, characterized in that, include: Glue frame, light guide plate and backlight FPC; The light guide plate is disposed within the plastic frame; A gap is provided between the light guide plate and the side of the glued iron frame; The backlight FPC includes an extension FPC, a main body FPC, and an outgoing FPC; The main FPC is disposed at the bottom of the plastic frame and is located between the light guide plate and the plastic frame; The main body FPC is connected to the extension FPC at both ends, and the extension FPC is placed in the gap. The extension FPC is used to reduce the movement space of the light guide plate within the plastic frame. One end of the outgoing FPC is cross-connected to the main body FPC to form a cross area, and the outgoing FPC is placed outside the plastic frame.

2. The backlight module according to claim 1, characterized in that, The backlight FPC has a double PI layer on the side facing the light guide plate. The double PI layer is used to improve the surface flatness of the FPC and enhance the support stability of the light guide plate.

3. The backlight module according to claim 1, characterized in that, A PI reinforcing layer is provided on the side of the intersection area facing the plastic frame, and the PI reinforcing layer is used to enhance the bending strength of the intersection area.

4. The backlight module according to claim 1, characterized in that, The outgoing FPC has a window area on the side facing the light guide plate, and the window area is located below the intersection area.

5. The backlight module according to claim 4, characterized in that, The window area is a cut-out window structure.

6. The backlight module according to claim 4, characterized in that, A PI reinforcement layer is provided on the inner side of the window area, which is used to increase the strength of the window area.

7. The backlight module according to claim 1, characterized in that, The cross section facing the light guide plate has a first silkscreen black ink layer, which is used to block reflected light from entering the light guide plate.

8. The backlight module according to claim 1, characterized in that, The other end of the outgoing FPC is provided with a second silkscreen black ink layer to block external ambient light from being reflected into the plastic frame through the outgoing FPC.

9. The backlight module according to any one of claims 1 to 8, characterized in that, The extended FPC and the main FPC are integrally formed.

10. An electronic device, characterized in that, The electronic device includes a backlight module as described in any one of claims 1 to 9; the backlight module is mounted on the electronic device.

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