Defect detection device based on liquid crystal screen glass edge inclined plane and control method

Abstract

The invention relates to the technical field of liquid crystal screen glass defect detection, in particular to a liquid crystal screen glass edge inclined plane-based defect detection device, which comprises a mobile platform, a lifting mechanism, an optical system, a camera connecting cylinder, a detection camera illumination system and a controller, the lifting mechanism comprises a lifting end controlled to move. According to the defect detection device based on the liquid crystal screen glass edge inclined plane, through the technical means of adjusting the light source angle, the illumination intensity and the light source type of the illumination system by the controller, the illumination system can adjust the illumination included angle of the light source according to the angles of different liquid crystal screen glass edge inclined planes; therefore, the problems of image distortion and false detection or missing detection of a detection result caused by insufficient or excessive reflection of the fixed angle of the irradiation light on different glass inclined surfaces in the prior art are effectively solved.

Description

Technical Field

[0001] The present invention relates to a liquid crystal screen glass defect detection device, and in particular to a defect detection device and a control method based on a liquid crystal screen glass edge slope. Background Art

[0002] In the modern display manufacturing industry, the quality of the LCD screen glass edge directly affects the display effect and structural strength of the LCD screen. Especially in high-end electronic products, the edge bevel of the LCD screen glass may have defects due to flaws in the processing process. These defects will lead to a decline in the product appearance quality and may even affect the life of the LCD screen. Therefore, defect detection for the edge bevel of the LCD screen glass has become an important part of ensuring the quality of display products, and the market demand for high-precision, low-error detection equipment is gradually increasing.

[0003] At present, the device for detecting the edge bevel of the LCD screen glass usually includes an optical system, a camera, a mobile platform, a lifting mechanism and a lighting system. The device focuses and amplifies the image of the glass edge through the optical system, and the detection camera collects the image data and analyzes it. In the prior art, the lighting system usually irradiates light onto the edge bevel of the glass at a fixed angle so as to form an appropriate reflection effect on the bevel at different angles, thereby obtaining a clear image.

[0004] However, due to the different angles of the LCD screen glass edge bevel, the fixed angle irradiation light cannot adapt to all angles of the bevel. Due to the light incident angle, the light may be insufficiently or excessively reflected, causing image distortion, thereby leading to false detection or missed detection results. Therefore, it is urgent to propose a defect detection device and control method based on the LCD screen glass edge bevel to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a device for detecting defects on the edge bevel of a liquid crystal screen glass, which can adjust the light source irradiation angle, light intensity and light source type of the lighting system through a controller to adapt to different angles of the edge bevel of the liquid crystal screen glass.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: a defect detection device based on the edge slope of liquid crystal screen glass.

[0007] A defect detection device based on the edge bevel of a liquid crystal screen glass, comprising:

[0008] The mobile platform comprises a placement plane for placing liquid crystal screen glass.

[0009] A lifting mechanism comprises a lifting end that moves in a controlled manner, wherein the moving direction of the lifting end of the lifting mechanism is configured to be perpendicular to the placement plane.

[0010] The optical system is arranged directly above the mobile platform and is used to focus and magnify the image of the inclined surface of the edge of the liquid crystal screen glass. The optical system is connected to the mobile platform, and the optical axis of the optical system is perpendicular to the placement plane of the mobile platform.

[0011] A camera tube is connected to the optical system.

[0012] The detection camera is fixed on the camera tube and is used to collect the image data of the edge slope of the liquid crystal screen glass generated by the optical system.

[0013] The lighting system is arranged between the optical system and the moving platform and is used for illuminating the edge slope of the liquid crystal screen glass at a predetermined angle.

[0014] A controller is connected to the mobile platform, the lifting mechanism, the detection camera and the lighting system to control the movement of the mobile platform, the lifting of the lifting mechanism and the illumination angle and illumination intensity of the lighting system.

[0015] Wherein, when the defect detection device is in working state, the controller controls the mobile platform to move the edge bevel of the LCD glass placed on the placement plane to directly below the optical system, the angle between the irradiation light of the lighting system and the edge bevel of the LCD glass is adjusted to a predetermined angle for irradiation, and the detection camera collects image data of the edge bevel of the LCD glass focused by the optical system.

[0016] Preferably, the mobile platform includes a pedestal and an adjustment plate movably connected to the pedestal, the pedestal is connected to the lifting end of the lifting mechanism, the side of the adjustment plate facing away from the pedestal is the placement plane, the adjustment plate is configured to move on a plane parallel to the placement plane, and the adjustment plate moves in a controlled manner.

[0017] Preferably, the lighting system comprises:

[0018] The rotating bracket moves in a controlled manner and is movably connected to the pedestal.

[0019] A light source assembly is connected to the rotating bracket to change the irradiation angle between the irradiation light of the light source assembly and the edge slope of the liquid crystal screen glass.

[0020] Preferably, the light source assembly comprises a plurality of light source units, and the irradiated light of each of the light source units has a different wavelength.

[0021] Preferably, the light source assembly further includes:

[0022] A switching mechanism is electrically connected to each of the light source units to selectively activate light source units of different wavelengths.

[0023] Preferably, the rotating bracket comprises:

[0024] A positioning ring is connected to the adjustment plate and is arranged on the placement plane.

[0025] A mounting portion is connected to the light source assembly.

[0026] A rotating arm, one end of which is slidably connected to the positioning ring, and the rotating arm is controlled to move along the circumference of the positioning ring, and the other end of the rotating arm is connected to the mounting portion, so as to move the light source assembly to change the irradiation angle of the irradiation light of the light source assembly and the inclined surface of the edge of the liquid crystal screen glass.

[0027] Preferably, the rotating arm is an arc-shaped structure, and the rotating arm is arranged perpendicular to the placement plane.

[0028] The mounting portion is arranged on the rotating arm in a controlled movable manner, so that the mounting portion can be controlled to move along the rotating arm, thereby changing the irradiation angle between the irradiation light of the light source assembly and the edge slope of the liquid crystal screen glass.

[0029] In particular, a control method for a defect detection device based on an edge slope of a liquid crystal screen glass comprises the following steps:

[0030] The liquid crystal screen glass to be tested is placed on the placement plane of the mobile platform.

[0031] Determine the angle of the inclination of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength of the lighting assembly when it is working.

[0032] The setting parameters of the lighting system are obtained according to the inclination angle of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass and the wavelength when the lighting component is working.

[0033] The control parameters of the lighting system are adjusted according to the setting parameters.

[0034] Preferably, the step of obtaining the setting parameters of the lighting system according to the inclination angle of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength of the lighting component when working comprises the following steps:

[0035] Set the target value of the evaluation function to 1.

[0036] The wavelength at which the illumination assembly operates is selected.

[0037] The angle of the LCD screen glass edge bevel, the refractive index of the LCD screen glass, the basic light intensity, the absorption coefficient of the LCD screen glass, the reflection coefficient of the LCD screen glass and the wavelength of the lighting component when working are brought into the evaluation function to calculate and obtain the incident angle.

[0038] Preferably, the evaluation formula is as follows:

[0039] P(θ l ,I,λ,n,θ g ) = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0040] in:

[0041] P(θ l ,I,λ,n,θ g ) is the evaluation function value.

[0042] I effective is the effective light intensity.

[0043] A(λ,n) is the effective transmission intensity.

[0044] θ l is the angle of incidence.

[0045] θ g It is the inclination angle of the glass edge bevel.

[0046] n is the refractive index of the LCD glass.

[0047] λ is the wavelength of the lighting assembly when it is working.

[0048] I is the light intensity when the lighting assembly is working.

[0049] k 1 , k 2 and k 3 To adjust the coefficient, it can be obtained through experiments and data fitting. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The schematic structure of a defect detection device in one embodiment of the present invention is Figure 1 .

[0051] Figure 2 The schematic structure of a defect detection device in one embodiment of the present invention is Figure 2 .

[0052] Figure 3 The schematic structure of a defect detection device in one embodiment of the present invention is Figure 3 .

[0053] Figure 4 It is a flowchart of a control method of a defect detection device in one embodiment of the present invention.

[0054] Among them: 100, mobile platform; 110, pedestal; 120, adjustment plate; 121, placement plane; 200, lifting mechanism; 300, optical system; 400, detection camera; 500, lighting system; 510, light source assembly; 520, rotating bracket; 521, positioning ring; 522, rotating arm; 523, installation part. DETAILED DESCRIPTION

[0055] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0056] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description created by the present application, unless otherwise specified, "multiple" means two or more.

[0057] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0058] like Figures 1 to 3As shown. A defect detection device based on the edge bevel of a liquid crystal screen glass proposed in a preferred embodiment of the present application includes a mobile platform 100, a lifting mechanism 200, an optical system 300, a camera tube, a detection camera 400, a lighting system 500 and a controller, wherein the mobile platform 100 includes a placement plane 121 for placing the liquid crystal screen glass, the lifting mechanism 200 includes a lifting end that moves under control, and the moving direction of the lifting end of the lifting mechanism 200 is configured to be perpendicular to the placement plane 121, and the optical system 300 is arranged directly above the mobile platform 100, and is used to focus and magnify the image of the edge bevel of the liquid crystal screen glass, and the optical system 300 is connected to the mobile platform 100, and The optical axis of the optical system 300 is perpendicular to the placement plane of the mobile platform 100, the camera tube is connected to the optical system 300, the detection camera 400 is fixed on the camera tube, and is used to collect image data of the edge slope of the liquid crystal screen glass generated by the optical system 300, the lighting system 500 is arranged between the optical system 300 and the mobile platform 100, and is used to illuminate the edge slope of the liquid crystal screen glass at a predetermined angle, and the controller is connected to the mobile platform 100, the lifting mechanism 200, the detection camera 400 and the lighting system 500 to control the movement of the mobile platform 100, the lifting and lowering of the lifting mechanism 200, the shooting of the detection camera 400, the illumination angle and light intensity of the lighting system 500, etc. When the defect detection device is in working state, the controller controls the mobile platform 100 to move the edge slope of the LCD glass placed on the placement plane 121 to directly below the optical system 300, and the angle between the irradiation light of the lighting system 500 and the edge slope of the LCD glass is adjusted to a predetermined angle for irradiation, and the detection camera 400 collects image data of the edge slope of the LCD glass focused by the optical system 300.

[0059] The defect detection device in this embodiment uses a technical method of adjusting the light source angle, light intensity and light source type of the lighting system 500 through a controller, so that the lighting system 500 can adjust the irradiation angle of the light source according to the angle of the edge bevel of the different LCD screen glass, thereby ensuring that the light is irradiated onto the bevels at different angles at the best angle. Therefore, the problem in the prior art that the fixed angle of the irradiated light produces insufficient or excessive reflection on different glass bevels, resulting in image distortion, false detection or missed detection results, is effectively solved, thereby achieving high-precision defect detection that adapts to different bevel angles, and ensuring image clarity and accuracy of detection results.

[0060] The mobile platform 100 is used to place the LCD screen glass and accurately move the glass to just below the optical system 300 for inspection. By controlling the mobile platform 100, the defect detection device can quickly align the inspection position, thereby improving the inspection efficiency. The mobile platform 100 can be a high-precision electric translation stage, or it can be a manually controlled mobile platform 100 when the accuracy requirement is low. This platform is usually equipped with an XY plane moving mechanism to facilitate moving the object to be tested to a specific position. The mobile platform 100 can achieve rapid positioning and precise movement of the LCD screen glass, making the inspection process more efficient, while ensuring that the optical system 300 can accurately focus on the inspection area, reducing manual intervention and improving inspection accuracy.

[0061] In some embodiments, Figure 1 As shown, the mobile platform 100 includes a pedestal 110 and an adjustment plate 120 movably connected to the pedestal 110, the pedestal 110 is connected to the lifting end of the lifting mechanism 200, the side of the adjustment plate 120 away from the pedestal 110 is a placement plane 121, the adjustment plate 120 is configured to move on a plane parallel to the placement plane 121, and the adjustment plate 120 moves in a controlled manner.

[0062] The pedestal 110 is connected to the lifting end of the lifting mechanism 200 as a fixed base of the mobile platform 100, and plays a supporting and stabilizing role. The pedestal 110 is fixed on the lifting mechanism 200, and can be adjusted up and down in the vertical direction with the movement of the lifting end, providing a stable foundation for the adjustment plate 120. In the actual device, the pedestal 110 can be made of high-strength metal materials (such as aluminum alloy, stainless steel, etc.) to ensure that the structure is stable and has sufficient load capacity. It can be a fixed component of an electric or pneumatic lifting platform for supporting the adjustment plate 120. The pedestal 110 realizes the adjustment function in the vertical direction by connecting with the lifting mechanism 200, so that the entire mobile platform 100 can be adjusted to different height positions according to the detection requirements. The fixation and stability of the pedestal 110 provide a stable foundation for the horizontal movement of the adjustment plate 120, ensuring dual adjustment in the vertical and horizontal directions, which helps to accurately align the optical system 300.

[0063] The positioning plate 120 serves as a bearing platform for placing the LCD screen glass. Through the movable connection with the pedestal 110, it can move on a plane parallel to the placement plane 121 (i.e., a horizontal plane). The movement mode of the positioning plate 120 is controlled by the controller, and the position of the LCD screen glass can be accurately adjusted to achieve accurate alignment of different detection positions. The positioning plate 120 can be a high-precision XY axis displacement platform, which is usually driven by a linear slide rail driven by a servo motor or a guide shaft driven by a stepper motor to achieve precise in-plane movement. The surface of the positioning plate 120 generally has a fixed structure, such as an anti-slip surface or a clamp, to ensure that the LCD screen glass is stably placed. The positioning plate 120 can fine-tune the position of the LCD screen glass in the horizontal direction to ensure that the detection area is accurately aligned with the optical system 300. By controlling the horizontal movement of the positioning plate 120, the area to be tested can be quickly located, the detection efficiency can be improved, and the stability and positioning accuracy of the LCD screen glass during the detection process can be ensured.

[0064] Among them, the placement plane 121 is a side plane of the positioning plate 120 away from the pedestal 110, which is mainly used to place the LCD screen glass. The placement plane 121 directly supports the LCD screen glass and is the actual support surface of the glass during the detection process. The placement plane 121 can be made of smooth and wear-resistant metal or plastic materials to ensure the stability of the LCD screen glass during the detection process. As needed, positioning grooves or fixing clamps may be added to the placement plane 121 to ensure that the LCD screen glass to be tested does not slide during the detection process. The placement plane 121 ensures the positioning and stability of the LCD screen glass during the detection process, avoiding the impact of glass sliding or vibration on the detection accuracy. The combination of the placement plane 121 and the positioning plate 120 enables the entire device to have the functions of precise placement and flexible adjustment of the glass, thereby improving the stability and accuracy of the detection.

[0065] In this embodiment, through the coordinated action of the pedestal 110, the positioning plate 120 and the lifting mechanism 200, the defect detection device realizes a detection platform with vertical and horizontal bidirectional adjustment. The optical system 300 adjusts the height through the lifting mechanism 200, and the positioning plate 120 realizes the precise horizontal positioning of the LCD screen glass through controllable movement in the plane, so that the detection of the edge bevel of the LCD screen glass can be carried out at the optimal focal length position. Since the placement plane 121 can be stably and accurately adjusted through the positioning plate 120, the defect detection device effectively solves the problems of inaccurate positioning and inappropriate focal length in the prior art, and improves the accuracy, flexibility and stability of detection.

[0066] The lifting mechanism 200 is used to control the vertical position of the optical system 300, so that the lens of the optical system 300 can be adjusted within different height ranges to ensure that the glass surface is within the optimal focal length of the optical system 300. The lifting mechanism 200 can be a precision electric lifting platform, or a manual lifting platform driven by a screw, which can provide high-precision vertical movement. Through the height adjustment of the lifting mechanism 200, it can ensure that the vertical distance between the LCD screen glass and the optical system 300 is maintained within a suitable range, ensuring that the optical system 300 can clearly focus on the detection slope, effectively improving the clarity of the image and the detection accuracy.

[0067] The main function of the optical system 300 is to focus and magnify the image of the edge bevel of the LCD screen glass, and transmit a clear image of the inspection area to the inspection camera 400 for subsequent image acquisition and analysis. The optical system 300 is usually composed of a high-resolution microscope lens or an industrial magnifying lens, and may include an autofocus device and an aperture adjustment device to meet the needs of different inspection environments. The optical system 300 ensures the image magnification and clear imaging of the edge bevel of the LCD screen glass, so that the inspection camera 400 can collect sufficiently detailed image data, effectively identify tiny edge defects, and ensure the accuracy of the inspection.

[0068] The camera tube is a component used to connect the optical system 300 with the detection camera 400, ensuring that the image focused by the optical system 300 can be stably transmitted to the detection camera 400. The camera tube can be a standard optical interface (such as C interface, CS interface), which is suitable for connecting the industrial microscope lens to the camera. According to actual needs, the length and interface type of the camera tube can be different. The camera tube can stably transmit the image data collected by the optical system 300, ensure the integrity and clarity of the image data, and provide a high-quality image source for subsequent defect detection.

[0069] The detection camera 400 is used to collect the image data of the edge bevel of the LCD screen glass generated by the optical system 300, and transmit it to the image processing system for defect analysis. The detection camera 400 can use a high-resolution industrial camera or a CCD camera to ensure that high-resolution images can be collected. According to actual detection requirements, the resolution and sensitivity of the camera can be flexibly selected. The detection camera 400 can collect and transmit high-definition image data in real time, provide accurate and clear image information for the detection system, and effectively support subsequent image processing and defect identification.

[0070] The controller is the core control component of the detection device, which is used to control the operation of the mobile platform 100, the lifting mechanism 200, the detection camera 400 and the lighting system 500. The controller adjusts the parameters of each component based on the detection requirements of different LCD screen glasses to ensure the best detection effect. The controller can be a device based on a PLC (programmable logic controller) or an embedded control system, which can achieve high-precision automatic control. The controller can be connected to a computer for parameter setting and data collection. The controller realizes the automatic operation and precise control of the defect detection device by automatically controlling and adjusting the parameters of each component in real time, thereby improving the detection efficiency and ensuring adaptability to the edge bevels of different LCD screen glasses.

[0071] The lighting system 500 is used to illuminate the edge bevel of the LCD screen glass at a predetermined angle to provide optimal detection light. The lighting system 500 can adjust the angle, intensity and type of the light source according to the detection requirements to ensure that glass bevels at different angles can be properly illuminated. The lighting system 500 can select adjustable light sources such as LED light sources and halogen lamps. The adjustable light source angle and intensity of the lighting system 500 enable the defect detection device to adapt to different glass bevel angles, avoid image distortion caused by insufficient or excessive light reflection, and improve image clarity and detection accuracy.

[0072] In some embodiments, the lighting system 500 also includes a light source assembly 510 and a rotating bracket 520, wherein the rotating bracket 520 moves in a controlled manner and is movably connected to the base 110, and the rotating bracket 520 is used to install the light source assembly 510, and the light source assembly 510 is connected to the rotating bracket 520 to change the irradiation angle of the light of the light source assembly 510 and the inclined surface of the edge of the liquid crystal screen glass.

[0073] Among them, the light source assembly 510 is the core part of the lighting system 500, which is mainly used to emit irradiation light so as to illuminate the inclined surface of the edge of the LCD screen glass during the detection process. By adjusting the incident angle and light intensity of the light emitted by the light source assembly 510, the inclined surface of the glass edge can be ensured to be clearly visible, so that the detection camera 400 can collect clear image data. The light source assembly 510 includes an LED light source, a halogen lamp, a laser light source or a multi-wavelength light source to meet different detection needs. For example, an LED light source usually provides a uniform and adjustable light intensity, while a laser light source is suitable for emphasizing edge details during high-precision detection. The light source assembly 510 can provide suitable irradiation conditions on the inclined surface of the glass edge at different angles by emitting adjustable light irradiation angles and intensities.

[0074] The rotating bracket 520 is used to install the light source assembly 510 and provide a basic structure for the rotation of the light source assembly 510. Through the movement of the rotating bracket 520, the light source assembly 510 can illuminate the edge bevel of the LCD screen glass at different angles, thereby adapting to different bevel angles and ensuring that the light can illuminate the detection area at a suitable incident angle. The rotating bracket 520 can be a rotating arm 522, or an electrically controlled rotating table, usually driven by a servo motor, or driven by a precision stepping motor in conjunction with a transmission mechanism such as a screw rod to provide controllable angle adjustment. In addition, real-time feedback and precise control of the light source angle can be achieved by adding a position sensor or an angle encoder. In addition, the rotating bracket 520 can be made of high-strength alloy or lightweight metal to support the light source assembly 510 and achieve smooth rotation adjustment. The rotating bracket 520 provides flexible light source angle adjustment, so that the light can be optimized according to the specific angle of the glass bevel. The rotating bracket 520 enables the light source assembly 510 to always maintain the optimal illumination angle at different glass bevel angles, effectively reducing the light reflection problem caused by improper incident angles. Through automated angle adjustment, it can quickly adapt to different inspection tasks, improve inspection efficiency and image clarity, ensure that the inspection camera 400 can obtain high-contrast, high-definition image data, and ensure the optimal incident angle of the inspection light, thereby achieving clearer imaging effects and avoiding false detection or missed detection.

[0075] The lighting system 500 in this embodiment, through the synergistic effect of the light source assembly 510 and the rotating bracket 520, enables the lighting system 500 to achieve a high-precision light source adjustment function, so that the light can illuminate the detection area at the optimal incident angle suitable for different glass bevel angles. The rotating bracket 520 makes the adjustment of the light source angle more flexible, and the light source assembly 510 provides a variety of light source types to further optimize the effect of the detection light. This design effectively solves the adaptability problem of the fixed light source angle in the multi-angle glass bevel detection, ensures the detection accuracy, reduces missed detection or false detection, and improves the detection flexibility and application scope of the device.

[0076] In some embodiments, the rotating bracket 520 includes a positioning ring 521, a rotating arm 522 and a mounting portion 523. The positioning ring 521 is connected to the positioning plate 120, and the positioning ring 521 is installed on the placement plane 121. The two are connected by fasteners. The placement plane 121 is provided with a plurality of mounting grooves that cooperate with the positioning ring 521 to cooperate with the fasteners. In addition, the plurality of mounting grooves indicate that the positioning ring 521 can be installed at different positions of the placement plane 121, thereby playing a role in adjusting the relative position of the rotating arm 522. The mounting portion 523 is connected to the light source assembly 510. One end of the rotating arm 522 is slidably connected to the positioning ring 521, and the rotating arm 522 is controlled to move along the circumference of the positioning ring 521. The other end of the rotating arm 522 is connected to the mounting portion 523, so that the light source assembly 510 moves to change the irradiation angle between the irradiation light of the light source assembly 510 and the edge bevel of the liquid crystal screen glass.

[0077] The positioning ring 521 is used to flexibly connect the rotating arm 522 to the pedestal 110, providing a stable fulcrum so that the rotating arm 522 can rotate around the positioning ring 521. The rotating arm 522 is driven by a gear mechanism driven by a servo motor or a screw adjustment mechanism driven by a precision stepping motor, thereby achieving controllable angle adjustment. This connection method ensures that the rotating arm 522 can rotate on a fixed axis when adjusting the incident angle of the light source assembly 510, thereby achieving precise angle adjustment. The positioning ring 521 can be made of high-strength metal materials, such as stainless steel or aluminum alloy, to ensure its sufficient stability and durability. In practice, the positioning ring 521 can be designed as a fixed bracket with a bearing to reduce rotational resistance and ensure that the rotating arm 522 can rotate smoothly and accurately. The positioning ring 521 provides a rotating axis of the rotating arm 522, making the angle adjustment of the light source assembly 510 more stable and controllable, and avoiding the angle error caused by the unstable fulcrum during the adjustment process. The stability of the positioning ring 521 improves the accuracy and reliability of the entire lighting system 500 during the adjustment process, and lays a foundation for achieving the optimal incident angle of the light source.

[0078] One end of the rotating arm 522 is connected to the positioning ring 521, rotates around the positioning ring 521, and the other end is connected to the rotating bracket 520, so as to adjust the incident angle of the light source assembly 510. The rotating arm 522 changes the angle between the light source assembly 510 and the edge bevel of the liquid crystal screen glass to ensure that the light can be irradiated onto the bevel at the best incident angle to reduce reflection interference and improve image clarity. The rotating arm 522 can be made of lightweight and strong materials, such as aluminum alloy or carbon fiber, to reduce inertia during rotation and ensure the accuracy of adjustment. The rotating arm 522 can be driven by installing a stepper motor or a servo motor, and cooperate with an angle encoder to achieve precise angle control. Some rotating arms 522 may be equipped with scales to facilitate observation during manual angle adjustment. The rotating arm 522 can rotate freely on the fulcrum of the positioning ring 521, so as to flexibly adjust the irradiation angle of the light source assembly 510 to meet the detection requirements of different glass edge bevels. This design enables the light source assembly 510 to achieve a suitable incident angle on glass slopes at different angles, reducing detection errors caused by insufficient or excessive light reflection, and significantly improving the accuracy and adaptability of the detection device.

[0079] Furthermore, the rotating arm 522 is an arc-shaped structure, and the rotating arm 522 is arranged perpendicular to the placement plane 121. The mounting portion 523 is arranged on the rotating arm 522 in a controlled manner so that the mounting portion 523 can move along the circumference of the rotating arm 522 in a controlled manner, thereby further changing the irradiation angle of the irradiation light of the light source assembly 510 and the inclined surface of the edge of the liquid crystal screen glass, so as to expand the adjustment range of the light source assembly 510.

[0080] The rotating bracket 520 in this embodiment realizes the function of accurately adjusting the incident angle of the light source assembly 510 through the combination of the positioning ring 521, the rotating arm 522 and the mounting portion 523. In the detection of the bevel edge of the LCD screen glass, the appropriate light source angle can significantly improve the clarity and contrast of the detected image. The positioning ring 521 provides a stable fulcrum to ensure that the rotating arm 522 can smoothly and accurately adjust the illumination angle of the light source, and the adjustability of the rotating arm 522 allows the light source assembly 510 to adapt to the needs of different detection angles. This design effectively solves the limitations of traditional fixed-angle light sources and ensures the optimal incident angle of light, thereby reducing missed detections and false detections and improving the accuracy and efficiency of the detection system.

[0081] In some embodiments, the light source assembly 510 includes a plurality of light source units and a switching mechanism, wherein the light emitted by each light source unit has a different wavelength. The switching mechanism is electrically connected to each light source unit to selectively activate light source units with different wavelengths.

[0082] The light source unit is a basic light-emitting unit in the light source assembly 510, and the light emitted by each light source unit has a specific wavelength. By setting a number of light source units with different wavelengths, the light source assembly 510 can provide a variety of different wavelengths of light to meet different materials and detection requirements. Light of different wavelengths has different reflection, refraction and transmission effects on the edge bevel of the LCD screen glass, which can be used to reduce reflections and improve image clarity. The light source unit can include light sources of different wavelengths such as red LED, green LED, blue LED, ultraviolet LED or infrared LED. According to the detection requirements, a group of LED light sources with a specific wavelength can be used, or a laser module with a wavelength tunable function can be used. The wavelength selection of each light source unit can be optimized according to the refractive index, reflectivity and transmittance of the glass material. By using light source units with different wavelengths, the system can flexibly adjust the wavelength of the irradiated light, thereby reducing interference caused by reflection from the glass surface and optimizing image contrast and clarity. In particular, for different types of LCD screen glass, by selecting a light source with a suitable wavelength, the visibility and detection accuracy of the image can be significantly improved, making the system more adaptable and the detection effect more stable.

[0083] The switching mechanism (not shown in the figure) is used to control the activation state of the light source unit to selectively activate the light source units of different wavelengths. The switching mechanism can control the light source unit emitting a specific wavelength according to the needs of the detection task, thereby realizing the function of quickly switching the light source type. This switching can ensure that the most suitable light source wavelength is used for illumination for each detection, avoiding image distortion or excessive reflection caused by wavelength mismatch. The switching mechanism can include an electronic switch module, a relay array or a solid-state relay, which can quickly switch the power-on state of different light source units. A controller (programmable logic controller (PLC) or microcontroller) can also be used to control the switching state of each light source unit. The switching mechanism can also include an electronic drive circuit for stabilizing the light source current to ensure that the light intensity of each light source unit is consistent when switching. The switching mechanism allows the system to flexibly select light source units of different wavelengths during the detection process and quickly respond to the needs of different detection scenarios. By switching light source units of different wavelengths, the system can reduce reflections, improve image contrast, and improve the accuracy of detection. At the same time, the fast switching function significantly improves the detection efficiency, avoids the trouble of manually changing the light source, and makes the detection process more efficient and automated.

[0084] In this embodiment, through the combination of the light source unit and the switching mechanism, the light source assembly 510 can selectively activate light sources of different wavelengths according to the detection requirements, thereby realizing a flexible wavelength adjustment function. Light of different wavelengths adapts to the material properties of different LCD screen glasses, effectively reduces image distortion caused by mismatched reflection and refraction, and improves image clarity and detection accuracy. The automated operation of the switching mechanism makes the detection process more efficient and flexible, avoids the cumbersome steps of replacing the light source in the traditional system, and provides higher adaptability and efficiency for the rapid detection of a variety of LCD screen glasses.

[0085] In order to further improve the accuracy of LCD screen glass edge bevel defect detection and avoid the problem of false detection and missed detection due to lighting factors, the present application proposes a control method for the above-mentioned LCD screen glass edge bevel defect detection device, such as Figure 4 As shown, the specific steps include:

[0086] Step 1: Place the LCD screen glass to be tested on the placement plane 121 of the mobile platform 100 .

[0087] Step 2, determining the angle of the edge bevel of the LCD glass to be tested, the refractive index of the LCD glass to be tested, the reflectivity of the LCD glass to be tested, and the transmittance of the LCD glass to be tested.

[0088] Step 3, determine the angle of the LCD glass edge bevel, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength when the lighting system 500 is working.

[0089] Step 4: derive setting parameter values ​​of the lighting system 500 according to the parameters.

[0090] Among them, step 4 is as follows:

[0091] Assume that the evaluation function value is 1, and substitute the evaluation function value into the evaluation function to obtain the specific setting parameter value.

[0092] The evaluation function is as follows:

[0093] P(θ l ,I,λ,n,θ g ) = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0094] in:

[0095] P(θ l ,I,λ,n,θg ) represents the evaluation function value of the comprehensive lighting conditions, which is used to estimate the control parameters of the lighting system 500.

[0096] k 1 , k 2 and k 3 To adjust the coefficient, it is determined according to different testing requirements and specific experimental values ​​of glass materials, as follows:

[0097] The coefficient k in the evaluation function 1 ,k 2 ,k 3 These coefficients are obtained through experiments and data fitting. These coefficients are used to calibrate the weights and effects of different optical and material parameters in the test results. The following are detailed steps to obtain these coefficients:

[0098] First, set the basic conditions for the experiment, including:

[0099] Sample preparation: Select different types of LCD glass materials and ensure that each material maintains the same experimental conditions in the detection system.

[0100] Variable selection: Angle of incidence θ l , light intensity I, wavelength λ, material refractive index n, and glass edge bevel angle θ g .

[0101] Target parameter: defines the “ideal state” of the inspection result, such as image clarity or defect detection accuracy, which can usually be given an ideal value, such as 1, through subjective evaluation or image processing algorithms.

[0102] Then, construct the experimental dataset.

[0103] Through experimental data collection, the actual detection effect under different combination conditions is obtained. This process includes the following steps:

[0104] Adjust the incident angle and light intensity: at multiple incident angles θ l The detection was carried out under the conditions of light intensity I.

[0105] Test different wavelengths: Test at multiple wavelengths λ to observe the effect of the wavelength of the light source on the imaging effect.

[0106] Changing material properties: Select glass materials with different refractive indices n to observe the impact of refractive index differences on the detection effect.

[0107] Then, a polynomial evaluation model is established.

[0108] Using the basic form of the evaluation function, substitute the experimental data into the following evaluation formula:

[0109] P(θ l,I,λ,n,θ g ) = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0110] Finally, the data is fitted to solve for k 1 ,k 2 ,k 3 .

[0111] Using experimental data to 1 ,k 2 ,k 3 Perform fitting. The steps are as follows:

[0112] Prepare the data matrix: Arrange the experimental data into a matrix form, where each row corresponds to an input parameter combination of an experiment, and the columns are the actual values ​​of the reflectance term, light intensity term, and wavelength absorption term.

[0113] Fitting method: Use the least squares method to perform regression analysis to minimize the error between the actual detection effect and the theoretical evaluation function. The goal is to find k 1 ,k 2 ,k 3 So that the calculated P(θ l ,I,λ,n,θ g ) is closest to the ideal value (such as 1).

[0114] Solution: Use linear algebra methods (such as matrix solving) or software tools (such as MATLAB, Python's NumPy library) to calculate the fitted k 1 ,k 2 ,k 3 value.

[0115] This formula utilizes multiple interacting terms, including incident angle, light intensity, and wavelength, and can quickly calculate the optimal lighting system 500 parameters based on the specific glass edge angle, thereby ensuring the accuracy of the inspection results.

[0116] Reflection relationship of light:

[0117]

[0118] Among them, R(θ l ,θ g,n) represents the reflectivity. This formula can be used to determine the impact of the incident angle and the material refractive index on the reflection intensity. This formula can accurately reflect the reflection behavior of the incident light at different incident angles and material refractive indices. Especially in high-precision detection, accurate reflectivity calculation is crucial for image clarity and accuracy of detection results.

[0119] θ l : The angle of incidence is the angle of the incident light relative to the normal line of the glass surface. Controlling the size of the angle of incidence helps to obtain the appropriate reflected light intensity.

[0120] θ g : The angle of the glass edge bevel. Different glass bevel angles will affect the reflection characteristics of the incident light. Choosing the incident angle to match the glass bevel angle will help optimize the reflection.

[0121] n: The refractive index of the LCD screen glass. The refractive index describes the ratio of the propagation speed of light in different media. The larger the value, the slower the light propagates in the medium. The refractive index has a direct impact on the reflectivity. The difference in the refractive index of the material will lead to different reflection and transmission conditions.

[0122] cos(θ l -θ g ): This is the cosine of the incident angle and the glass edge angle, which is used to measure the angle between the incident light and the normal of the glass surface. l -θ g ) indicates that the incident light is nearly parallel to the surface, resulting in a larger reflection.

[0123] This term describes the situation where light is totally internally reflected at the inclined surface of the glass. When the incident angle is large enough, part of the light will be completely reflected so that no light penetrates into the glass.

[0124] This formula is based on the Fresnel equations and can be used to calculate the reflection and transmission ratio of light at the interface of the medium, taking into account the influence of the refractive index difference and the incident angle on the reflectivity. In addition, because the edge bevel of the LCD glass has a certain angle, if the matching of the incident light angle and the material refractive index is not considered, the reflection will be too strong or too weak, causing image distortion. Furthermore, by accurately controlling the incident light angle, it can effectively avoid false detection or missed detection caused by mismatched light reflection, and improve the adaptability and flexibility of the detection system at complex angles.

[0125] Moreover, the formula is applicable to glass materials with different refractive indices and various incident angles. In particular, between high reflectivity and low reflectivity, the incident angle can be adjusted according to the detection requirements. In addition, the reasonable choice of incident angle can be adjusted through the cosine square term to prevent the reflected light from being too strong or too weak from affecting the detection image, thereby improving the image contrast and clarity. The formula also supports accurate detection of different edge bevels of glass by adjusting the incident angle in real time. It is suitable for use in detection systems that require continuous and rapid adjustment to ensure that the best reflectivity is always obtained under different angle conditions.

[0126] In summary, the use of this formula ensures the ability to adjust the reflected light intensity required for high-precision detection, allowing the system to provide accurate and clear image data in complex detection scenarios.

[0127] The interaction term between light intensity and incident angle:

[0128]

[0129] in:

[0130] I effective is the effective light intensity.

[0131] I 0 It is the reference light intensity, representing the initial light intensity of the light source in an ideal situation without angle interference and material loss. This is the basis for all subsequent light intensity calculations. Industrial light sources will indicate the reference light intensity when they leave the factory, which is based on the measured value of specific working conditions (such as distance, angle). These data can be used as a reference, especially when using standardized light sources.

[0132] cos 2 (θ l -θ g ): Angle cosine square term, which represents the angle between the incident light and the glass edge bevel. When the direction of the incident light is close to parallel to the glass bevel, the value of this term is close to 1, making the light intensity maximum; when the incident light angle is more oblique, the value will decrease significantly, reducing the effective light intensity. This term ensures that the light intensity is strongest when the incident angle of the light matches the angle of the glass edge.

[0133] k 4 : The influence factor of the material refractive index difference, which indicates the influence of the material refractive index on the light intensity. The difference in refractive index will introduce different transmission and reflection conditions, affecting the effective light intensity.

[0134] The refractive index correction term is used to express the difference in refraction and reflection of light between media with different refractive indices. The larger the refractive index, the greater the effective intensity of light when it enters the edge of the glass, so this term provides additional intensity compensation for the case of high refractive index materials.

[0135] Exponential correction term for material absorption and reflection. This term reflects the scattering and absorption characteristics of the material to light through the difference between the absorption coefficient α and the reflection coefficient β. It is used to adjust the loss of light intensity caused by absorption and scattering after entering the material. This exponential term ensures that the penetration of light in the material matches the material properties.

[0136] Determine the material correction factor k 4 and loss correction factor k 5 .

[0137] Among them, the material correction factor k 4 Used to adjust the effect of refractive index differences on light intensity. The change in light intensity under different refractive index materials can be measured and compared with the reference light intensity (refractive index n = 1). Using these data to fit k 4 .

[0138] Loss correction factor k 5 Used to adjust the effect of absorption coefficient and reflection coefficient on light loss. Experiments can be conducted by changing the absorption and reflection coefficients α and β of different materials to measure the change in effective light intensity. Then use exponential fitting (such as taking the logarithm of the experimental results) to obtain k 5 .

[0139] Verify model accuracy: The k obtained by fitting 1 ,k 2 ,k 3 ,k 4 ,k 5 Substitute the evaluation function to calculate the P value under experimental conditions, and compare it with the actual detection effect to evaluate the accuracy of the model.

[0140] For further optimization, if the error is large, the coefficients can be adjusted through iterative fitting of more experimental data until the evaluation function predicts the test results accurately enough.

[0141] Through the above steps, k 1 ,k 2 ,k 3 ,k 4 ,k 5 It can be obtained by fitting experimental data. This method ensures the flexible adjustment of these coefficients to the optical characteristics under actual detection conditions, so that the evaluation function can accurately reflect the detection effect and provide the system with stable and reliable detection performance.

[0142] Among them, the absorption coefficient α and the reflection coefficient β are the optical parameters of the material, which can usually be obtained through experimental measurement and reference literature. The following is a detailed method of obtaining:

[0143] Experimental measurement method, using spectral analysis equipment can directly measure the absorption coefficient α and reflection coefficient β of the material:

[0144] The absorption coefficient α describes the intensity attenuation of light due to absorption when it propagates inside the material. The measurement process is as follows:

[0145] Using a transmission spectrometer: light of a specific wavelength (such as laser) is vertically incident on the sample material, and the intensity I of the transmitted light is measured on the other side of the sample.

[0146] Record the incident light intensity I 0 : Record the baseline intensity of the incident light in the absence of a sample.

[0147] Calculation of absorption coefficient α: According to Lambert-Beer Law, the absorption coefficient can be calculated by the following formula:

[0148]

[0149] Where T(λ) is the transmittance and d is the sample thickness. Taking the logarithm of the transmittance and dividing it by the sample thickness d gives the absorption coefficient:

[0150]

[0151] The reflection coefficient β describes the part of light lost due to reflection on the surface of the material. The measurement process is as follows:

[0152] Use a reflectance spectrometer: Measure the intensity R of reflected light from the surface of a material at a specific incident angle.

[0153] Record the incident light intensity I 0 : Record the baseline intensity of incident light.

[0154] Calculate the reflection coefficient β: The reflectivity R(θ) can be expressed as:

[0155]

[0156] Among them I r is the reflected light intensity. The reflection coefficient β can be calculated according to the formula, or it can be approximated as reflectivity when the surface reflection is large.

[0157] Reflected light intensity I r It can be obtained through optical theory calculation. The Fresnel equation describes the relationship between reflection and transmission of light at the interface of different media, as follows:

[0158] Fresnel equation calculation method

[0159] The refractive index n of the material and the incident angle θ l When known, the reflectivity R(θ) can be calculated by the Fresnel equation:

[0160]

[0161] The reflected light intensity can then be calculated:

[0162] I reflect =R(θ)×I 0 .

[0163] Effective light intensity I effective In practical application, it has the following effects:

[0164] cos 2 (θ l -θ g ) formula can accurately express the effect of the incident angle on the light intensity. This makes it possible to obtain the optimal light intensity in actual detection by simply adjusting the incident angle without changing other parameters, thus providing convenience in operation.

[0165] Refractive index related terms in the formula and k 4 The use of makes it suitable for edge detection of materials with different refractive indices. It is particularly suitable for scenes where multiple glass materials need to be detected, and can maintain high detection accuracy.

[0166] Index Correction The absorption or scattering of light by the material can be dynamically compensated to make the light intensity closer to the ideal value. This is especially important for detecting the edge bevel of materials with different transparency or absorption rates, which helps to improve the imaging quality.

[0167] In summary, the design of this formula can effectively control the incident light intensity in a refined manner to achieve high-precision detection of the edge bevel of the LCD glass. This structural light intensity control formula not only improves the applicability and flexibility of the detection equipment, but also provides better imaging effects when detecting complex edge structures, ensuring the accuracy of the detection data.

[0168] The incident light angle and the glass bevel angle, the cosine square term of this part ensures the effective intensity matching of the light angle, and the difference in material refractive index affects the reflection and transmission of light intensity. 1 The coefficient adjusts the effect of the refractive index. The α and β parameters in the exponential term adjust the loss of light in the material and can be determined by experimental data or material properties. In summary, this formula can better adapt to the detection environment of various materials and angles, and provide more accurate light intensity values.

[0169] For different wavelengths, the transmission and reflection characteristics of the material are different, so the choice of wavelength can be expressed by the following relationship:

[0170] A(λ,n)=e -α(λ,n) .

[0171] A(λ,n): This term represents the effective transmission intensity of light at a specific wavelength and material refractive index. It directly affects the effective intensity of the detected light to ensure that light of a specific wavelength is not excessively absorbed in the material and affects the imaging effect.

[0172] e: This is the base of the natural exponential, which is used to describe the exponential decay of light intensity with the absorption coefficient α(λ,n). The exponential decay model can accurately describe the loss of light in the material.

[0173] α(λ,n): Absorption coefficient term. This term represents the material's absorption rate for light of a specific wavelength λ. The magnitude of the absorption coefficient depends on the material's internal structure and characteristics. The larger the absorption coefficient α, the stronger the material's absorption of light of that wavelength, resulting in a rapid attenuation of the light intensity, and vice versa.

[0174] To obtain the absorption coefficient term α(λ,n), it can be obtained through experimental measurement or by referring to the optical property database of the material. The specific method is as follows:

[0175] Experimental measurement method: The commonly used method in the laboratory is to measure the transmittance and absorptivity of the material under different wavelengths of light through a spectrum analyzer or transmission spectrometer, and then calculate α(λ,n).

[0176] Experimental steps:

[0177] Prepare the sample: Ensure that the thickness and surface finish of the sample are consistent to reduce errors.

[0178] Incident light selection: Use light sources of different wavelengths (such as lasers or white light sources combined with filters) to illuminate the material and measure the transmitted light intensity on the back side of the material.

[0179] Calculation of absorption coefficient: According to the Lambert-Beer law, the absorption coefficient α can be calculated by the following formula:

[0180] T(λ)=e -α(λ,n)·d .

[0181] Where T(λ) is the transmittance and d is the sample thickness. Taking the logarithm of the transmittance and dividing it by the sample thickness, the absorption coefficient α(λ,n) can be found:

[0182]

[0183] Check the materials database

[0184] Optical databases provide the absorption coefficients of materials at different wavelengths. Common databases include:

[0185] RefractiveIndex.info: contains information about the refractive index and absorption coefficient of various materials as a function of wavelength.

[0186] MatWeb: A materials science database covering the optical and physical properties of a wide range of materials.

[0187] Optical constants handbooks: Some material handbooks (such as Handbook of Optical Constants of Solids) record the absorption coefficients of common materials at different wavelengths.

[0188] Fitting using formula

[0189] For some typical materials, data fitting can be performed using known absorption spectra to obtain a model of how the absorption coefficient α(λ,n) varies with wavelength. Commonly used models include:

[0190] Sellmeier equation: Applicable to calculating the refractive index and absorptivity of transparent media.

[0191] Cauchy formula or Lorentz formula: used to fit the light absorption characteristics of simple materials.

[0192] After obtaining α(λ,n) through the above method, it can be substituted into the formula to determine the light attenuation at a specific wavelength and material.

[0193] Formula α(λ,n) describes the effect of wavelength selection on effective light intensity. Through this design, the system can select appropriate light source wavelengths for different material properties to ensure the contrast and clarity of the detected image. This wavelength selection method comprehensively considers the absorption characteristics of light under different materials and wavelengths, so that the detection process can obtain the best imaging effect.

[0194] Different wavelengths of light will produce different absorption and transmission phenomena in materials. For example, shorter wavelengths of light (such as blue light) are more easily absorbed by high refractive index materials, while longer wavelengths of light (such as green light) are more likely to be transmitted through certain materials without being absorbed too much. Therefore, by using e -α(λ,n) The absorption degree of light of different wavelengths can be flexibly described.

[0195] The absorption coefficient α(λ,n) is an important parameter for the absorptivity of a material to light of different wavelengths. Different materials have different responses to specific wavelengths of light. Therefore, by exponentially adjusting α(λ,n), detection can be optimized for specific wavelengths.

[0196] Furthermore, by selecting a wavelength with a lower absorption rate, reflection interference can be reduced during glass edge detection. This optimization of reflection suppression is critical to improving the clarity and accuracy of the detection image.

[0197] This formula has the following characteristics:

[0198] First, the formula allows the selection of the appropriate wavelength based on the absorption characteristics of different materials. By adjusting the absorption coefficient α(λ,n), the system can quickly switch between different types of glass materials (such as high-reflection glass or low-reflection glass) to ensure consistent detection results.

[0199] Secondly, selecting a suitable light source within a specific wavelength range can ensure that appropriate transmitted light intensity is obtained on the edge bevel of the material, thereby improving the image contrast and detection effectiveness.

[0200] Moreover, by adjusting the wavelength selection, the system can reduce the interference caused by the reflection of the material surface, improve the clarity of the detection image, and avoid frequent manual adjustments. Automated wavelength selection can significantly speed up the detection process and maintain high accuracy.

[0201] In short, this formula helps the detection system flexibly select the optimal wavelength to adapt to different materials and detection requirements, ensuring clear and good contrast images when detecting complex glass structures. This approach has obvious advantages in improving system efficiency and detection accuracy.

[0202] It should be noted that in the detection of LCD screen glass edge bevel defects, the commonly used light source wavelength is usually in the range of 450nm-570nnm, namely green light (495-570 nanometers) and blue light (450-495 nanometers). Because green light performs well in high-resolution detection, it can be used to detect tiny edge defects, and blue light has a shorter wavelength and is suitable for detecting finer surface details. Light sources of the two bands can provide clear reflection and good contrast on most materials.

[0203] Set the evaluation function value to P(θ l ,I,λ,n,θ g )=1, and after substituting into the evaluation function, the incident angle θ is solved l The steps are described below:

[0204] 1 = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0205] To solve for the incident angle θ l, we will decompose and substitute the parameters of each step to solve the final angle of incidence. Assume that we know the adjustment coefficient k 1 ,k 2 ,k 3 ,k 4 ,k 5 As well as the optical properties of the material, such as refractive index n, absorption coefficient α and reflection coefficient β. The following is a detailed process of the steps:

[0206] Set the evaluation function equal to 1.

[0207] 1 = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0208] The goal of this equation is to solve for the angle of incidence θ l Make the function value equal to 1.

[0209] Expand the reflectivity term R(θ l ,θ g ,n).

[0210] The formula for the reflectivity term is:

[0211]

[0212] Calculation steps:

[0213] First calculate the angle between the incident angle and the glass edge angle:

[0214] Δθ=θ l -θ g .

[0215] Substituting the values ​​of cos(Δθ) and sin(Δθ), calculate the reflectivity R(θ l ,θ g ,n).

[0216] n and θ g Knowing the specific values ​​of , we can substitute them in and simplify the expression.

[0217] Calculate the effective light intensity I effective .

[0218] Effective light intensity I effective It means that the intensity of light changes with the incident angle, and its formula is:

[0219]

[0220] Calculation steps:

[0221] Calculate cosine 2 (θ l -θ g ).

[0222] Determine the material's refractive index n, absorption coefficient α, reflection coefficient β, and constant term k 4 .

[0223] Calculated Items And multiply by the reference light intensity I 0 and the angle term cos 2 (θ l -θ g ).

[0224] Calculate the wavelength absorption term A(λ,n).

[0225] The absorption term A(λ,n) describes the absorption relationship of light in a material at different wavelengths. The formula is as follows:

[0226] A(λ,n)=e -α(λ,n) .

[0227] Calculation steps:

[0228] Find the absorption coefficient α(λ,n) of a material for a given wavelength λ.

[0229] Substitute the absorption coefficient into the exponential term.

[0230] Substitute into the simultaneous equations to solve for the incident angle θ l .

[0231] Substituting the above into the evaluation function equation:

[0232] 1 = k 1 ·R(θ l ,θ g ,n)+k 2 I effective +k 3 A(λ,n).

[0233] At this point, the only unknown variable in the equation is the angle of incidence θ l . You can use one of the following methods to solve it:

[0234] Since the formula is relatively complex, it may not be easy to directly substitute it into the analytical solution, so a numerical iteration method (such as Newton's method or bisection method) is used to gradually adjust θ l until the left and right sides of the equation are equal.

[0235] Substitute the formula into computing software (such as MATLAB, SciPy library in Python) and write a program to solve θ l , at different θ lThe evaluation function is calculated under the value and a solution that satisfies the conditions is found.

[0236] The incident angle θ is obtained l After that, the light intensity of the lighting system 500 is adjusted to the effective light intensity I effective , wavelength is selected in 450nm-570nnm (need to calculate the incident angle θ l The incident angle is adjusted to θ l , thereby achieving better detection results and reducing the detection error of the defect detection device.

[0237] It should be noted that setting the evaluation result to 1 means that the detection system has reached the "optimal detection state" under the currently set parameters, that is, the highest detection accuracy and the smallest error. This "optimal state" usually means that the following conditions are met, so that the accuracy of defect detection is maximized.

[0238] Reflectivity R(θ l ,θ g ,n): The reflectivity term is used in the evaluation formula to describe the reflection intensity of incident light at different angles and material refractive indices. The best reflectivity should ensure clear images and high contrast during the inspection process, so it is necessary to choose a suitable incident angle (θ l ) and the glass bevel angle (θ g ) so that the reflected light is neither too strong nor too weak. l Angle θ with glass edge g If the match is good, the reflectivity item will provide an ideal reflection intensity to avoid overexposure or underexposure of the image. At this time, the image captured by the inspection camera 400 has the contrast and clarity that are most suitable for identifying defects.

[0239] Effective light intensity I effective :The effective light intensity represents the intensity of the light actually entering the detection area, combining the angle of incidence and the angle of the glass slope (through cos 2 (θ l -θ g ) and material refractive index correction items (such as ). When the light intensity I effective When the ideal value is reached, it means that the light intensity and incident angle of the lighting system 500 are highly matched with the characteristics of the inspection material, so that the light can optimally penetrate or reflect to the edge of the glass to obtain a high-contrast image, thereby improving the accuracy of the inspection.

[0240] Wavelength absorption term A(λ,n): The wavelength absorption term is used to express the absorption of light in the material. Different glass materials have different absorption characteristics for light of a specific wavelength. This term balances the transmission and absorption of light in the material by selecting an appropriate light source wavelength (λ), thereby reducing interference from reflected light and ensuring the quality of the inspection image. If the wavelength term A(λ,n) reaches the ideal value, it means that the selected light wavelength matches the characteristics of the material, thereby improving the clarity of the image, so that the image captured by the inspection camera 400 has a clear contrast between defects and normal areas.

[0241] Adjustment factor k 1 ,k 2 ,k 3 :These coefficients are used to balance the effects of reflectivity, light intensity and wavelength absorption under different detection conditions. The values ​​of these coefficients are determined through experiments so that the weight of each variable in the formula reaches the best combination, thus ultimately achieving the optimal detection result in the evaluation formula.

[0242] Conditions for ideal detection results to be equal to 1: The ideal detection result with the evaluation value set to 1 is specifically reflected in the imaging effect, that is, the images of the defective area and the normal area show a clear contrast, without excessive or weak reflection, light spots or shadow interference. This means that the detection device successfully captures the edge defect under the current light intensity, incident angle, wavelength and other parameters, ensuring high-resolution imaging and accurate identification.

[0243] When specifically reflected on the image of the detection camera 400, its detection features are specifically manifested in the following aspects:

[0244] Clear edge contrast: The edges of the defect area are clear and distinct, forming a strong contrast with the normal area. In this way, the outline of the defect can be accurately identified without blurring or overexposure.

[0245] Uniform lighting: The image is evenly illuminated without light spots or shadows. The brightness of the entire inspection area is consistent, ensuring that the defect location does not flicker due to local light problems, making the defect easy to identify.

[0246] Optimal brightness gradation: The reflected light in the defect area and the transmitted light in the normal area form a clear brightness gradation. This means that the incident angle and light intensity of the inspection system are set correctly, and the defective part will neither be dim due to insufficient reflection nor distorted due to excessive reflection.

[0247] No unwanted reflections: In high-quality images, the influence of the material's own characteristics is minimized, and there is no interference caused by unwanted reflections or refractions. The wavelength of the light source is optimized to ensure that the absorption and transmission in the material are balanced.

[0248] Subtle defects appear: If the glass has tiny cracks, bubbles or flaws, these details will appear as subtle dark or light lines on the image, while normal areas remain smooth and uniform. This is the result of high-resolution defect details that appear when the light intensity and wavelength are perfectly matched to the material properties.

[0249] These features mean that the inspection images have the highest defect recognition capabilities, which directly reflects that the inspection device is in the optimal setting, thus achieving high-precision defect detection.

[0250] The above contents described in this specification are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, as long as they do not deviate from the contents of the present specification or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A defect detection device based on the edge slope of liquid crystal screen glass, characterized in that: include: A mobile platform, the mobile platform comprising a placement plane for placing a liquid crystal screen glass; A lifting mechanism, the lifting mechanism comprising a lifting end that moves in a controlled manner, wherein the moving direction of the lifting end of the lifting mechanism is configured to be perpendicular to the placement plane; An optical system is arranged directly above the mobile platform and is used to focus and magnify the image of the inclined surface of the edge of the liquid crystal screen glass. The optical system is connected to the mobile platform, and the optical axis of the optical system is perpendicular to the placement plane of the mobile platform. A camera tube connected to the optical system; A detection camera, fixed on the camera tube, used to collect image data of the edge slope of the liquid crystal screen glass generated by the optical system; An illumination system, disposed between the optical system and the mobile platform, for illuminating the edge slope of the liquid crystal screen glass at a predetermined angle; A controller connected to the mobile platform, the lifting mechanism, the detection camera and the lighting system to control the movement of the mobile platform, the lifting of the lifting mechanism and the illumination angle and illumination intensity of the lighting system; Wherein, when the defect detection device is in working state, the controller controls the mobile platform to move the edge bevel of the LCD glass placed on the placement plane to directly below the optical system, the angle between the irradiation light of the lighting system and the edge bevel of the LCD glass is adjusted to a predetermined angle for irradiation, and the detection camera collects image data of the edge bevel of the LCD glass focused by the optical system.

2. The defect detection device based on the edge slope of liquid crystal screen glass according to claim 1, characterized in that: The mobile platform includes a base and an adjustment plate movably connected to the base, the base is connected to the lifting end of the lifting mechanism, the side of the adjustment plate facing away from the base is the placement plane, the adjustment plate is configured to move on a plane parallel to the placement plane, and the adjustment plate moves in a controlled manner.

3. The defect detection device based on the edge slope of liquid crystal screen glass according to claim 2, characterized in that: The lighting system comprises: A rotating bracket, the rotating bracket moves in a controlled manner and the rotating bracket is movably connected to the pedestal; A light source assembly is connected to the rotating bracket to change the irradiation angle between the irradiation light of the light source assembly and the inclined surface of the edge of the liquid crystal screen glass.

4. The defect detection device based on the edge slope of liquid crystal screen glass according to claim 3, characterized in that: The light source assembly includes a plurality of light source units, and the irradiated light of each light source unit has a different wavelength.

5. The defect detection device based on the edge slope of liquid crystal screen glass according to claim 4, characterized in that: The light source assembly further comprises: A switching mechanism is electrically connected to each of the light source units to selectively activate light source units of different wavelengths.

6. A defect detection device based on the edge slope of liquid crystal screen glass according to any one of claim 3, characterized in that: The rotating bracket comprises: A positioning ring, the positioning ring is connected to the adjustment plate, and the positioning ring is arranged on the placement plane; A mounting portion, the mounting portion being connected to the light source assembly; A rotating arm, one end of which is slidably connected to the positioning ring, and the rotating arm is controlled to move along the circumference of the positioning ring, and the other end of the rotating arm is connected to the mounting portion, so as to move the light source assembly to change the irradiation angle of the irradiation light of the light source assembly and the inclined surface of the edge of the liquid crystal screen glass.

7. A defect detection device based on the edge slope of liquid crystal screen glass according to any one of claim 6, characterized in that: The rotating arm is an arc-shaped structure, and the rotating arm is arranged perpendicular to the placement plane; The mounting portion is arranged on the rotating arm in a controlled movable manner, so that the mounting portion can be controlled to move along the rotating arm, thereby changing the irradiation angle between the irradiation light of the light source assembly and the edge slope of the liquid crystal screen glass.

8. A control method for a defect detection device based on an edge slope of a liquid crystal screen glass according to any one of claims 1 to 7, characterized in that: The steps include: Placing the liquid crystal screen glass to be tested on the placement plane of the mobile platform; Determine the angle of the inclination of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength of the lighting assembly when it is working; Determining the setting parameters of the lighting system according to the inclination angle of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength when the lighting component is working; The control parameters of the lighting system are adjusted according to the setting parameters.

9. The control method according to claim 8, characterized in that: The step of obtaining the setting parameters of the lighting system according to the inclination angle of the edge of the LCD glass, the refractive index of the LCD glass, the basic light intensity, the absorption coefficient of the LCD glass, the reflection coefficient of the LCD glass, and the wavelength of the lighting component when working includes the following steps: Set the target value of the evaluation function to 1; Selecting a wavelength at which the lighting assembly operates; The angle of the LCD screen glass edge bevel, the refractive index of the LCD screen glass, the basic light intensity, the absorption coefficient of the LCD screen glass, the reflection coefficient of the LCD screen glass and the wavelength of the lighting component when working are brought into the evaluation function to calculate and obtain the incident angle.

10. The control method according to claim 9, characterized in that: The evaluation formula is as follows: P(θ l ,I,λ,n,θ g )=k1·R(θ l ,i g ,n)+k2·I effective +k3·A(λ,n). in: P(θ l ,I,λ,n,θ g ) is the evaluation function value; I effective is the effective light intensity; A(λ,n) is the effective transmission intensity; θ l is the angle of incidence; θ g is the angle of the glass edge bevel inclination; n is the refractive index of the LCD glass; λ is the wavelength of the lighting assembly when it is working; I is the light intensity of the lighting assembly when it is working; k1, k2 and k3 are adjustment coefficients, which can be obtained through experiments and data fitting.

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