Rapid positioning processing technology for backlight light guide plate

Abstract

The invention provides a rapid positioning processing technology for a backlight light guide plate, and relates to the technical field of backlight manufacturing. A traditional manual alignment or single-reference positioning mode is replaced by a combination mode of'preset positioning reference + positioning pin pre-positioning + CCD visual calibration ', positioning time of a single light guide plate is shortened, efficiency is improved, batch production requirements are greatly met, and the method is particularly suitable for large-scale manufacturing scenes such as vehicle-mounted backlight sources and the like and has wide application prospects. According to the technology, a positioning reference structure is machined on the edge of a light guide plate blank, after the positioning reference structure and a first matching part of a reflecting film are pre-positioned, high-precision calibration is conducted through a CCD visual detection assembly, and it is ensured that the light guide plate is accurately aligned with shading glue, a light bar / FPC, a Min i-LED lamp panel and other components. The calibration precision is quantitatively controlled through a formula, and the assembly clearance between the light guide plate and the diffusion film is detected. The process is suitable for common and Min i-LED backlight sources, is particularly suitable for vehicle-mounted products, and can shorten the positioning time of a single block, improve the positioning precision and achieve high batch qualification rate.

Description

Technical Field

[0001] This invention belongs to the field of backlight manufacturing technology, and more specifically, it relates to a rapid positioning and processing technology for backlight light guide plates. Background Technology

[0002] As a core component of display devices, the backlight's optical performance directly affects the clarity, brightness uniformity, and energy consumption of the display. The light guide plate (LGP), a key component of the backlight, plays a crucial role in transforming point or line light sources into surface light sources. The assembly precision of the LGP with other components such as reflective films, light-shielding adhesives, diffusion films, and LED strips / FPCs (flexible printed circuit boards) is a core factor determining the backlight's performance.

[0003] Currently, backlights can be classified into two types based on their technology: ordinary backlights (composed of components such as LED strips / FPC, light-shielding adhesive, upper BEF, lower BEF, diffusion film, LGP, reflective film, and adhesive iron) and Mini-LED backlights (which add components such as Mini-LED light panels, QD film, and beam splitting film). Among them, the automotive field has strict requirements for display stability and vibration resistance, which places higher demands on the assembly precision of backlights.

[0004] However, existing light guide plate processing technology has the following technical problems:

[0005] Low positioning efficiency and reliance on manual operation: Traditional light guide plate positioning often uses manual alignment or single benchmark positioning, which requires visual observation of the relative position of the light guide plate edge and other components. The positioning time for a single piece is long and the efficiency is low, making it difficult to adapt to the needs of mass production. Moreover, manual operation is easily affected by experience, resulting in poor positioning consistency. This is especially true in scenarios with multiple film layers and multiple components, such as Mini-LED backlights, where the problem of error accumulation is more prominent.

[0006] Insufficient positioning accuracy affects optical performance: The assembly of light guide plates, reflective films, and light-shielding adhesives in ordinary backlights often relies on simple pin-hole mating, lacking quantitative precision control. Positioning deviations often exceed 0.05mm, which can easily lead to light leakage and uneven brightness. For Mini-LED backlights, due to the small spacing between the LED beads in the Mini-LED light board, if the alignment deviation between the light guide plate and the light board exceeds 0.02mm, it will significantly reduce the light utilization rate and cause local dark areas or light spots.

[0007] Poor process compatibility and limited adaptability: Existing processes are mostly designed for specific types of backlights. For example, the positioning reference of ordinary backlights cannot be adapted to the installation requirements of Mini-LED light panels. When changing product types, positioning tooling needs to be redesigned, resulting in high equipment modification costs. At the same time, different sizes (such as 6.8 inches and 12.3 inches) of automotive backlights require separate adjustment of positioning parameters, resulting in insufficient production line flexibility.

[0008] Uncontrolled assembly gaps lead to high product defect rates: The lack of quantitative standards for the assembly gaps between the light guide plate and diffusion film, BEF and other film materials often results in film wrinkles and light guide path deviation due to excessive gaps, or film damage due to pressure caused by excessive gaps. The defect rate in mass production is as high as 8% or more, which increases production costs and rework rate.

[0009] Insufficient reliability in automotive scenarios: Automotive backlights need to withstand complex environments such as vibration and high and low temperatures. In traditional positioning processes, the fixation of the reflective film and the adhesive iron relies on glue, which is prone to falling off due to vibration. At the same time, the alignment deviation between the light guide plate and the light strip / FPC will accumulate over time, resulting in a decrease in backlight stability and making it difficult to meet the long-term reliability requirements of automotive products.

[0010] Therefore, developing a processing technology that can achieve rapid and accurate positioning of light guide plates, adapt to multiple types of backlights, and meet the high requirements of automotive and other scenarios has become an urgent technical problem to be solved in this field. Summary of the Invention

[0011] To address the aforementioned technical problems, this invention provides a rapid positioning process for backlight light guide plates.

[0012] A rapid positioning process for a backlight light guide plate includes the following steps:

[0013] 1) Provide a light guide plate blank to be processed, and process at least two positioning reference structures at preset positions on the edge of the light guide plate blank;

[0014] 2) Fix the reflective film to the processing platform. The reflective film is provided with a first mating part corresponding to the positioning reference structure.

[0015] 3) Place the light guide plate blank on the reflective film, so that the positioning reference structure is initially aligned with the first mating part, and the light guide plate and the reflective film are pre-positioned.

[0016] 4) Based on the preset backlight component assembly parameters, the position of the pre-positioned light guide plate is calibrated by the positioning fixture so that the edge contour of the light guide plate is aligned with the preset assembly boundary of the light shielding adhesive.

[0017] 5) Process the calibrated light guide plate to obtain a shaped light guide plate.

[0018] Preferably, in step 1), the positioning reference structure is a positioning hole or a positioning boss. The number of positioning holes is 2-4, and they are distributed along the non-adjacent edges of the light guide plate blank. The diameter of the positioning hole is 3.0±0.05mm, and the hole spacing is 150±0.1mm.

[0019] Preferably, in step 2), the first mating part is a through hole adapted to the positioning reference structure, and the through hole of the reflective film and the positioning reference structure of the light guide plate blank are mated and positioned by positioning pins.

[0020] Preferably, in step 4), the positioning fixture includes a CCD vision inspection component. This component is used to identify the positioning marks on the light guide plate and the boundary marks of the light-shielding adhesive. The position calibration accuracy is determined by the formula Δ=√(Δx). 2 +Δy 2 ) Calculate, where Δx is the horizontal deviation, Δy is the vertical deviation, and Δ≤0.015mm.

[0021] Preferably, the processing platform is provided with a positioning groove that cooperates with the glue iron. The fixing of the reflective film in step 2) also includes embedding the edge of the reflective film into the positioning groove to achieve the pre-positioning of the reflective film and the glue iron.

[0022] Preferably, the backlight is a 12.3-inch automotive mini backlight. The processing of the light guide plate in step 5) includes contour cutting, wherein the length of the effective light-emitting area is 282.5±0.08mm, the width is 157.3±0.08mm, and the radius of curvature of the cutting path is R=5.0±0.03mm.

[0023] Preferably, in step 4), the position calibration further includes aligning the edge of the light-emitting surface of the light guide plate with the mounting reference line of the light strip / FPC, which is preset on the processing platform.

[0024] Preferably, in step 1), the positioning reference structure is formed by laser marking with a laser wavelength of 1064nm and a marking speed of 300-500mm / s, and the edge roughness Ra of the formed positioning reference structure is ≤0.8μm.

[0025] Preferably, when the backlight is a Mini-LED backlight, step 4) further includes aligning the positioning reference structure of the light guide plate with the positioning hole of the Mini-LED lamp plate.

[0026] Preferably, after step 5), the method further includes: detecting the assembly gap between the formed light guide plate and the diffusion film, where the gap δ = |D light guide plate - D diffusion film|, where D light guide plate is the actual edge size of the light guide plate, D diffusion film is the corresponding edge design size of the diffusion film, and δ ≤ 0.03 mm.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Improve positioning efficiency and shorten processing cycle: This invention replaces the traditional manual alignment or single-reference positioning mode with a combination of "preset positioning benchmark + positioning pin pre-positioning + CCD visual calibration", which shortens the positioning time of a single light guide plate, improves efficiency, and greatly adapts to the needs of mass production, especially suitable for large-scale manufacturing scenarios such as automotive backlights.

[0029] 2. Improve positioning accuracy and ensure assembly consistency: Use the formula Δ=√(Δx) 2 +Δy 2 The calibration accuracy is quantified, and the assembly deviation of components such as light guide plate, reflective film, light shielding adhesive, and Mini-LED light plate is controlled within 0.01-0.02mm through standardized positioning benchmarks of laser processing and CCD visual inspection. This is far superior to the 0.05mm deviation of traditional processes, effectively avoiding problems such as light leakage and uneven brightness caused by inaccurate positioning, and improving the optical performance of backlight.

[0030] 3. Enhanced process compatibility and adaptation to multiple types of backlights: The process design takes into account the positioning requirements of both ordinary backlights and Mini-LED backlights. By adjusting the number (2-4) and size of positioning references, different types and sizes of backlights can be processed without replacing core equipment, reducing equipment modification costs and improving production line flexibility.

[0031] 4. Reduce defect rate and improve product qualification rate: This invention reduces defects such as film wrinkles and light guide offset caused by excessive gaps by quantitatively controlling the assembly gap between the light guide plate and each film material; at the same time, the standardized adaptation of the positioning benchmark and backlight components reduces the defect rate in mass production and significantly reduces production costs.

[0032] 5. Optimize optical performance to meet high requirements in automotive applications: To address the vibration resistance and high stability requirements of automotive backlights, this process enhances the overall structural strength of the backlight through the interlocking design of the glue-iron positioning groove and the edge of the reflective film. At the same time, the high-precision alignment of the Mini-LED lamp board and the light guide plate ensures that the light from the LED beads enters the light guide plate efficiently, improving light utilization and meeting the brightness and reliability standards of automotive displays. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the present invention. Detailed Implementation

[0034] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0035] Please see Figure 1This invention provides a rapid positioning and processing technology for backlight light guide plates, aiming to solve the problems of low positioning efficiency and insufficient assembly accuracy with other backlight components (such as reflective films, light-shielding adhesives, LED strips / FPCs, Mini-LED light panels, etc.) in traditional light guide plate processing. This technology achieves rapid and accurate matching between the light guide plate and the backlight system through a preset positioning reference structure, multi-component collaborative positioning, and high-precision calibration. It is suitable for mass production of ordinary backlights and Mini-LED backlights (especially automotive products).

[0036] The core of this process lies in: taking the light guide plate (LGP) as the center, pre-setting standardized positioning benchmarks on the light guide plate blank, and combining the matching structure of components such as reflective film and adhesive iron to complete the pre-positioning first; then, through visual inspection and quantitative calibration algorithms, achieving high-precision alignment between the light guide plate and key components such as light shielding adhesive, light strip / FPC, and Mini-LED light board; and finally, ensuring the overall optical performance of the backlight through molding processing and gap detection.

[0037] The following details the process steps:

[0038] Light guide plate blank positioning reference processing: Provide a light guide plate blank to be processed (material optional PC or PMMA). Based on the backlight type (standard or Mini-LED), process positioning reference structures (positioning holes or positioning bosses) at preset positions on the edge of the blank. The number and size of the positioning references must be compatible with the mating parts of other backlight components (such as reflective film, Mini-LED light board), for example:

[0039] Standard backlight: Machining 2-4 positioning holes, diameter 3.0±0.05mm, hole spacing 150±0.1mm;

[0040] Mini-LED backlight: Add positioning holes corresponding to the Mini-LED light board, with a diameter of 2.5±0.03mm, to ensure coaxiality with the positioning holes of the light board.

[0041] The positioning reference is processed using laser marking technology with a laser wavelength of 1064nm, a marking speed of 300-500mm / s, and an edge roughness Ra≤0.8μm to avoid affecting the light guiding performance.

[0042] Fixing and pre-positioning of the reflective film to the processing platform: The reflective film is laid flat on the processing platform with positioning grooves. The positioning grooves are matched with the edges of the adhesive plates to achieve pre-fixation of the reflective film and the adhesive plates. A first mating part (such as a through hole) corresponding to the positioning reference of the light guide plate is pre-set on the reflective film. The positioning pin passes through the positioning hole of the light guide plate and the through hole of the reflective film to complete the pre-positioning of the light guide plate and the reflective film. At this time, the pre-positioning deviation is ≤0.05mm.

[0043] High-precision calibration based on visual inspection: The CCD visual inspection component is activated to identify the light guide plate positioning marks, the light shielding adhesive boundary marks, and the light strip / FPC installation baseline. The horizontal deviation Δx and vertical deviation Δy are calculated using the formula Δ=√(Δx / Δy). 2 +Δy 2 Quantitative positional accuracy (Δ is the total deviation). For automotive products (such as the 12.3 mini), Δ ≤ 0.015 mm is required; for Mini-LED backlights, additional calibration is required to align the positioning holes of the light guide plate and the Mini-LED light board, with a coaxiality deviation ≤ 0.02 mm.

[0044] Light guide plate forming and processing: After calibration, the light guide plate is contoured by CNC cutting equipment. The processing size is determined according to the product model (e.g., the effective light-emitting area of ​​a 12.3-inch automotive product is 282.5±0.08mm×157.3±0.08mm, and the radius of curvature of the cutting path R=5.0±0.03mm).

[0045] Assembly gap inspection: After processing, inspect the assembly gap between the light guide plate and the diffusion film, upper BEF / lower BEF and other film materials. Calculate using the formula δ=|D light guide plate - D film material| (D is the edge dimension). The requirement is δ≤0.03mm (ordinary backlight) or δ≤0.02mm (Mini-LED backlight).

[0046] Example 1: Processing of a standard backlight light guide plate (compatible with LED strips / FPC, diffusion film, and other components):

[0047] This embodiment is for a common backlight (components include LED strip / FPC, light-shielding adhesive, upper BEF, lower BEF, diffuser film, LGP, reflective film, and adhesive base). The specific parameters are as follows:

[0048] Light guide plate blank: PMMA material, 2.0mm thick;

[0049] Positioning reference: 3 positioning holes, diameter 3.0±0.05mm, hole spacing 150±0.1mm, laser marking speed 400mm / s, edge roughness Ra=0.6μm;

[0050] Reflective film: PET material, 0.1mm thick, through-hole diameter 3.1mm (with clearance fit to positioning pin);

[0051] Calibration accuracy: Δ=√(Δx) 2 +Δy 2 )=0.012mm (Δx=0.008mm, Δy=0.009mm);

[0052] Dimensions after processing: effective light-emitting area 270.0±0.07mm×150.0±0.07mm, gap with diffusion film δ=0.025mm.

[0053] Example 2: Processing of Mini-LED automotive backlight light guide plate:

[0054] This embodiment focuses on automotive Mini-LED backlights (components include Mini-LED light panels, QD film, beam splitter film, composite film, light-shielding adhesive, and adhesive plate), and optimizes upon embodiment 1:

[0055] Light guide plate blank: PC material, 1.5mm thick;

[0056] Positioning reference: 4 positioning holes (2 for the reflective film and 2 for the Mini-LED light board), the diameter of the positioning hole corresponding to the light board is 2.5±0.03mm, and the coaxiality deviation is 0.015mm;

[0057] Calibration targets: Simultaneously calibrate the alignment of the light guide plate with the Mini-LED lamp board (LED bead spacing 0.4mm) and the QD film (thickness 0.09mm);

[0058] Dimensions after processing: Effective light-emitting area 282.5±0.08mm×157.3±0.08mm, gap between the light-emitting area and beam splitter 1 δ1=0.01mm, total assembly gap δtotal=δ1+δ2+δ3=0.035mm (δ2: gap between beam splitter 1 and 2; δ3: gap between beam splitter 2 and 3).

[0059] Comparison of process parameters for different backlight types:

[0060]

[0061]

[0062] Performance comparison between the process of this invention and the traditional process:

[0063] index Traditional manual positioning process The process of this invention Increase Single block positioning time 40 seconds 8 seconds 80％ Positioning accuracy pass rate (Δ≤0.02mm) 65％ 99％ 34％ Backlight brightness uniformity 85％ 95％ 10％ Batch production defect rate 8％ 1.2％ 6.8％

[0064] The data above shows that the process of this invention is significantly superior to the traditional process in terms of positioning efficiency, accuracy and product consistency, and is especially suitable for the production of automotive Mini-LED backlights with stringent accuracy requirements.

[0065] This invention is based on the core logic of "unified benchmark, step-by-step positioning, and quantitative calibration." By constructing a multi-dimensional positioning system centered on the light guide plate, it achieves efficient collaborative assembly of various backlight components. Its core lies in deeply binding the processing and positioning of the light guide plate with the assembly requirements of the overall backlight components, forming a closed-loop control from benchmark design to final testing.

[0066] Specifically, by first establishing a pre-defined positioning reference structure, a compatibility relationship is created with key components such as the reflective film and Mini-LED light panel during the light guide plate blank stage. The size, number, and distribution of the positioning holes strictly match the mating parts of other components, essentially laying a "standard track" for subsequent assembly, avoiding the cumulative errors caused by inconsistent references in traditional processes. The high-precision positioning reference of laser processing not only ensures its own accuracy but also provides clear identification marks for subsequent calibration, solving the pain point of "no clear reference" in manual positioning.

[0067] The pre-positioning stage uses the mechanical engagement of positioning pins and through-holes in the reflective film to quickly align the light guide plate with the reflective film, adhesive strips, and other basic components. This step, akin to "coarse adjustment," controls the initial deviation within 0.05mm, reducing adjustments needed for subsequent high-precision calibration and significantly shortening positioning time. CCD visual calibration, as the core of "fine adjustment," uses optical recognition technology to capture the edge marks of the light guide plate, light-shielding adhesive, and LED strips / FPC, combined with Δ=√(Δx) 2 +Δy 2 The quantitative formula transforms the deviations in the horizontal and vertical directions into an intuitive total error value, ensuring that the calibration accuracy is controlled within 0.015mm (0.012mm for Mini-LED automotive products). This "mathematical calibration" method replaces the traditional experience-based judgment, making the accuracy controllable and traceable.

[0068] For Mini-LED backlights, the process improves the alignment accuracy between the light guide plate and the LED chips by increasing the coordinated positioning with the LED board, ensuring that the light is efficiently coupled into the light guide plate and solving the "mismatch and light leakage" problem caused by the dense arrangement of Mini-LED chips. Furthermore, the quantitative detection of the gap between the film materials (δ=|Dlight guide plate - Dfilm material|) verifies the assembly quality from the result, preventing optical performance degradation due to excessive gaps.

[0069] The entire process balances efficiency and precision: pre-positioning enables "rapid docking," visual calibration enables "precise correction," and quantitative formulas enable "standardization," ultimately forming a closed loop from raw material processing to finished product inspection. This design not only meets the basic needs of ordinary backlights but also satisfies the complex assembly requirements of high-end products through expandable positioning references (such as the addition of positioning holes for Mini-LED light boards), truly achieving "one process, multiple adaptations," providing efficient and stable technical support for the mass production of backlights.

[0070] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A rapid positioning processing technology for a backlight light guide plate, characterized in that: Includes the following steps: 1) Provide a light guide plate blank to be processed, and process at least two positioning reference structures at preset positions on the edge of the light guide plate blank; 2) Fix the reflective film to the processing platform. The reflective film is provided with a first mating part corresponding to the positioning reference structure. 3) Place the light guide plate blank on the reflective film, so that the positioning reference structure is initially aligned with the first mating part, and the light guide plate and the reflective film are pre-positioned. 4) Based on the preset backlight component assembly parameters, the position of the pre-positioned light guide plate is calibrated by the positioning fixture so that the edge contour of the light guide plate is aligned with the preset assembly boundary of the light shielding adhesive. 5) Process the calibrated light guide plate to obtain a shaped light guide plate.

2. The rapid positioning and processing technology for a backlight light guide plate as described in claim 1, characterized in that, In step 1), the positioning reference structure is a positioning hole or a positioning boss. The number of positioning holes is 2-4, and they are distributed along the non-adjacent edges of the light guide plate blank. The diameter of the positioning hole is 3.0±0.05mm, and the hole spacing is 150±0.1mm.

3. The rapid positioning and processing technology for a backlight light guide plate as described in claim 2, characterized in that, In step 2), the first mating part is a through hole adapted to the positioning reference structure. The through hole of the reflective film and the positioning reference structure of the light guide plate blank are mated and positioned by positioning pins.

4. The rapid positioning and processing technology for a backlight light guide plate as described in claim 3, characterized in that, In step 4), the positioning fixture includes a CCD vision inspection component. This component is used to identify the positioning marks on the light guide plate and the boundary marks of the light-shielding adhesive. The position calibration accuracy is determined by the formula Δ=√(Δx). 2 +Δy 2 ) Calculate, where Δx is the horizontal deviation, Δy is the vertical deviation, and Δ≤0.015mm.

5. The rapid positioning processing technology for a backlight light guide plate as described in claim 4, characterized in that, The processing platform is equipped with a positioning groove that cooperates with the glue iron. In step 2), the fixing of the reflective film also includes embedding the edge of the reflective film into the positioning groove to achieve the pre-positioning of the reflective film and the glue iron.

6. The rapid positioning processing technology for a backlight light guide plate as described in claim 5, characterized in that, The backlight is a 12.3-inch automotive mini backlight. In step 5), the processing of the light guide plate includes contour cutting, wherein the length of the effective light-emitting area is 282.5±0.08mm, the width is 157.3±0.08mm, and the radius of curvature of the cutting path is R=5.0±0.03mm.

7. The rapid positioning processing technology for a backlight light guide plate as described in claim 6, characterized in that, In step 4), the position calibration also includes aligning the edge of the light-emitting surface of the light guide plate with the mounting reference line of the light strip / FPC, which is preset on the processing platform.

8. The rapid positioning processing technology for a backlight light guide plate as described in claim 7, characterized in that, In step 1), the positioning reference structure is formed by laser marking with a laser wavelength of 1064nm and a marking speed of 300-500mm / s. The edge roughness Ra of the formed positioning reference structure is ≤0.8μm.

9. The rapid positioning and processing technology for a backlight light guide plate as described in claim 8, characterized in that, When the backlight is a Mini-LED backlight, step 4) also includes aligning the positioning reference structure of the light guide plate with the positioning hole of the Mini-LED lamp plate.

10. The rapid positioning and processing technology for a backlight light guide plate as described in claim 9, characterized in that, Step 5) is followed by: detecting the assembly gap between the formed light guide plate and the diffusion film, where the gap δ = |D light guide plate - D diffusion film|, where D light guide plate is the actual edge size of the light guide plate, D diffusion film is the corresponding edge design size of the diffusion film, and δ ≤ 0.03 mm.

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