Display assembly precision detection device

Abstract

The invention discloses a display assembly precision detection device, and relates to the technical field of display quality inspection, the display assembly precision detection device comprises a detection platform, an image capture platform and an industrial computer, the image capture platform is arranged above the detection platform in an opposite manner, and the lower surface of the image capture platform is provided with a CCD industrial camera and two groups of light source lamps; the two sets of light source lamps are arranged on the two sides of the CCD industrial camera respectively, the CCD industrial camera is used for optical alignment of the displayer, the light source lamps are used for emitting polarized light to a displayer panel, and the industrial computer is used for receiving data collected by the CCD industrial camera. Through cooperation of the expanding assembly and the adjusting assembly, the relative position of the light source lamp and the convex lens is automatically adjusted according to the scanning position of the CCD industrial camera, so that polarized light is irradiated at an angle dynamically adaptive to the radian of the curved screen, and reflected light in a high-reflection area is accurately prevented from entering the lens; the imaging noise of the surface of the curved screen can be obviously reduced without manual intervention, and the definition and reliability of the detected image are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of display quality inspection, and particularly to a device for detecting the assembly precision of a display. Background Art

[0002] The assembly of a display is a process of combining components such as a display screen (e.g., LCD, LED panel), a driving circuit board, a power module, a housing, and a bracket into a complete display product through processes such as precise installation, circuit connection (e.g., flexible cable soldering, interface assembly), and structural fixation (e.g., screw tightening, snap fitting). In order to ensure the normal use of the assembled display, such as displaying images and connecting external devices, it is necessary to perform precision testing on the assembled display.

[0003] In the precision inspection of a display screen, large imaging noise caused by a highly reflective surface is a typical and intractable problem, especially in inspection scenarios involving high-reflectivity materials such as glass substrates, metal frames, and mirror coatings. The technical solution of using linearly polarized light plus a multi-angle combined light source can suppress partial reflection.

[0004] In the panel precision inspection of a curved screen, since the panel of the curved screen is in the shape of a concave mirror, the concave mirror can converge and reflect the light source inward, and the reflection angles formed in different illumination areas are different. For example, in the attached Figure 1 and attached Figure 2 figure, when the light source illumination area is close to the middle of the curved screen, the formed reflection angle is smaller, and it is easier for the CCD industrial camera to collect the high-light area formed by the reflected light, which hinders image acquisition.

[0005] However, in the prior art for detecting a curved screen, the adjustment of the light source angle depends on manual presetting or manual calibration, and it is difficult to achieve dynamic adaptive adjustment according to the curvature changes of different areas of the curved screen. When the detection device scans the curved screen, the light source with a fixed angle easily causes the reflected light in a specific area to return along the original path to the industrial camera lens, forming a strong exposure high-light spot, which seriously interferes with the image acquisition quality. Summary of the Invention

[0006] The purpose of the present invention is to provide a device for detecting the assembly precision of a display, so as to solve the problem of manual adjustment of the light source and difficulty in adapting to the reflection of the curved screen interfering with the image as proposed in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: A display assembly precision detection device includes a detection platform and an image capture platform. The image capture platform is disposed directly above the detection platform. A CCD industrial camera and two groups of light source lamps are installed on the lower surface of the image capture platform. The two groups of light source lamps are respectively arranged on both sides of the CCD industrial camera. The CCD industrial camera is used for the optical alignment of the display, and the light source lamp is used to emit polarized light to the display panel. The CCD industrial camera transmits information to an industrial computer, and the industrial computer is used to receive the data collected by the CCD industrial camera and analyze the assembly precision of the display. A positioning jig is arranged outside the detection platform, and an anti-reflection mechanism is arranged between the light source lamp and the display. The anti-reflection mechanism includes a convex lens, and the convex lens is used to refract the light emitted by the light source lamp;

[0008] A hydraulic linear actuator is installed outside the CCD industrial camera. The hydraulic linear actuator is used to drive the CCD industrial camera, the light source lamp and the anti-reflection mechanism to move linearly. The CCD industrial camera moves linearly to scan the surface of the display panel. High-precision servo linear actuators are installed outside the two groups of light source lamps. The high-precision servo linear actuators are used to control the movement of the light source lamp and adjust the relative position between the light source lamp and the convex lens.

[0009] Preferably, the method for detecting the assembly precision of the display includes the following steps:

[0010] Step 1: Place the display on the detection platform and position the display using the positioning jig;

[0011] Step 2: Enable the hydraulic linear actuator, and the hydraulic linear actuator pushes the CCD industrial camera and the light source lamp from the left side of the display to the right side;

[0012] Step 3: When the CCD industrial camera moves from the left side of the display to the middle, enable the light source lamp on the left side. At the same time, use the high-precision servo linear actuator to push the light source lamp outward, gradually increasing the refraction angle of the incident light to illuminate the area to be detected on the lower display;

[0013] Step 4: When the CCD industrial camera moves from the middle of the display to the right side, enable the light source lamp on the right side. At the same time, use the high-precision servo linear actuator to pull the light source lamp towards the middle, gradually decreasing the refraction angle of the incident light to illuminate the area to be detected on the lower display;

[0014] Step 5: The CCD industrial camera scans the display completely from left to right, inputs the collected data into the industrial computer to generate an image, and uses software to detect the image and analyze the assembly precision.

[0015] Preferably, a circular opening is provided at the center position of the convex lens, and a plano-convex lens is embedded at the circular opening. The CCD industrial camera is positioned directly opposite the plano-convex lens, and the light source lamps are distributed at the outer peripheral position of the convex lens. A light-shielding cylinder is fixedly connected between the plano-convex lens and the lens of the CCD industrial camera.

[0016] Preferably, side plates are provided on both sides of the CCD industrial camera, and a spreading component is arranged between the two side plates. The light source lamps are fixedly installed on the side plates. The spreading component includes a spreading rod and a limiting ring. The limiting ring is rotatably connected to the outer side of the CCD industrial camera. One end of the spreading rod is fixedly connected to the outer side wall of the limiting ring, and the other end of the spreading rod is fixedly connected with a slider. The inner side wall of the side plate is fixedly connected with a guide rail, and the slider is slidably connected inside the guide rail.

[0017] Preferably, a gantry is fixedly connected to the outer side wall of the CCD industrial camera, and both ends of the gantry are fixedly connected to the convex lens.

[0018] Preferably, a conveyor belt is arranged below the detection platform, and the conveyor belt is used to transport the display.

[0019] Preferably, the high-precision servo linear actuator is fixedly installed on the side wall of the gantry. The high-precision servo linear actuator is built-in with an encoder to provide real-time feedback on the displacement.

[0020] Preferably, a laser displacement sensor is installed on the edge of the convex lens, and the laser displacement sensor is used to detect the horizontal displacement of the light source lamp.

[0021] Preferably, the hydraulic linear actuator is fixedly installed on the lower surface of the image capture platform. A magnetostrictive displacement sensor is installed at the actuator end of the hydraulic linear actuator. The magnetostrictive displacement sensor is used to detect the operating position of the actuator end of the hydraulic linear actuator. A solid-state relay is installed inside the high-precision servo linear actuator. The magnetostrictive displacement sensor outputs a current signal to control the solid-state relay to manipulate the operating state of the high-precision servo linear actuator.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. In the present invention, through the cooperation of the spreading component and the adjustment component, the relative positions of the light source lamp and the convex lens are automatically adjusted according to the scanning position of the CCD industrial camera, so that the polarized light irradiates at an angle that dynamically adapts to the curvature of the curved screen, accurately avoiding the reflected light from the highly reflective area from entering the lens. Without manual intervention, the imaging noise on the surface of the curved screen can be significantly reduced, and the clarity and reliability of the detected image are improved;

[0024] 2. In the present invention, the CCD industrial camera is driven by the hydraulic linear actuator to reciprocally scan the display, and multiple scans are completed within a single cycle. By collecting multiple groups of image data, the signal noise is effectively filtered, and the reliability of the detected data is improved;

[0025] 3. In the present invention, through the snap - fit cooperation between the guide rail and the slider, the slider slides inside the guide rail, preventing the expansion rod from falling off or shaking when pushing the side plate carrying the light source lamp, and ensuring the stable movement of the light source lamp along the preset trajectory. Description of the Drawings

[0026] Figure 1 It is a simplified diagram of the detection light for the accuracy of the curved screen in the prior art;

[0027] Figure 2 It is a simplified diagram of the reflected light ray paths when the light shines at different positions in the prior art;

[0028] Figure 3 It is a schematic diagram of the principle for adjusting the reflected light ray path by using the incident deflection angle in the prior art;

[0029] Figure 4 It is a simplified diagram of the reflected light ray path with a fixed incident deflection angle in the prior art;

[0030] Figure 5 It is a simplified diagram of the principle for adjusting the incident light ray path by the convex lens in a display assembly accuracy detection device of the present invention;

[0031] Figure 6 It is a simplified diagram of the principle for adjusting the light ray path at different positions of the curved screen in a display assembly accuracy detection device of the present invention;

[0032] Figure 7 It is a flow chart of the distance change between the light source lamp and the anti - reflection mechanism in a display assembly accuracy detection device of the present invention;

[0033] Figure 8 It is a schematic diagram of the overall planar structure of a display assembly accuracy detection device of the present invention;

[0034] Figure 9 It is a flow chart of the operation of a display assembly accuracy detection device of the present invention;

[0035] Figure 10 It is a top view of the overall display assembly accuracy detection device of the present invention;

[0036] Figure 11 It is a schematic diagram of the structure of the anti - reflection mechanism in a display assembly accuracy detection device of the present invention;

[0037] Figure 12 It is a partial structure disassembly schematic diagram of the anti - reflection mechanism in a display assembly accuracy detection device of the present invention.

[0038] In the figure: 1. Detection platform; 10. Positioning fixture; 2. Conveyor belt; 3. Image capture platform; 4. CCD industrial camera; 5. Light source lamp; 6. Anti-reflection mechanism; 61. Convex lens; 62. Flat lens; 63. Expansion component; 631. Expansion rod; 632. Limit ring; 633. Slide block; 634. Guide rail; 64. Gantry; 65. Side plate; 7. Hydraulic linear actuator; 8. High-precision servo linear actuator. Detailed implementation mode

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Example 1: Refer to Figures 1 - 12 As shown: A display assembly precision detection device includes a detection platform 1, an image capture platform 3 and an industrial computer. The image capture platform 3 is disposed directly above the detection platform 1. A CCD industrial camera 4 and two groups of light source lamps 5 are installed on the lower surface of the image capture platform 3. The two groups of light source lamps 5 are respectively disposed on both sides of the CCD industrial camera 4. The CCD industrial camera 4 is used for optical alignment of the display, and the light source lamp 5 is used to emit polarized light to the display panel. The industrial computer is used to receive the data collected by the CCD industrial camera 4 and analyze the assembly precision of the display. A positioning fixture 10 is disposed outside the detection platform 1. An anti-reflection mechanism 6 is disposed between the light source lamp 5 and the display. The anti-reflection mechanism 6 includes a convex lens 61, and the convex lens 61 is used to refract the light emitted by the light source lamp 5. The anti-reflection mechanism 6 is used to adjust the light direction of the light source lamp 5. A hydraulic linear actuator 7 is installed outside the CCD industrial camera 4. The hydraulic linear actuator 7 is used to drive the CCD industrial camera 4, the light source lamp 5 and the anti-reflection mechanism 6 to move linearly. The CCD industrial camera 4 moves linearly to scan the surface of the display panel. A high-precision servo linear actuator 8 is installed outside the two groups of light source lamps 5. The high-precision servo linear actuator 8 is used to control the movement of the light source lamp 5 and adjust the relative position between the light source lamp 5 and the convex lens 61; The outer wall of the CCD industrial camera 4 is fixedly connected to a gantry 64, and both ends of the gantry 64 are fixedly connected to the convex lens 61. A conveyor belt 2 is disposed below the detection platform 1, and the conveyor belt 2 is used to transport the display.

[0041] The detection method for the assembly precision of the display lies in:

[0042] 1) Place the display on the detection platform 1 and position the display using the positioning fixture 10;

[0043] 2) Activate the hydraulic linear actuator 7, and the hydraulic linear actuator 7 pushes the CCD industrial camera 4 and the light source lamp 5 from the left side to the right side of the display;

[0044] 3) When the CCD industrial camera 4 moves from the left side to the middle of the display, activate the light source lamp 5 on the left side. At the same time, use the high-precision servo linear actuator 8 to push the light source lamp 5 outward, gradually changing the refraction angle of the incident light to illuminate the area to be detected on the lower display;

[0045] 4) When the CCD industrial camera 4 moves from the middle to the right side of the display, activate the light source lamp 5 on the right side. At the same time, use the high-precision servo linear actuator 8 to pull the light source lamp 5 towards the middle, gradually changing the refraction angle of the incident light to illuminate the area to be detected on the lower display;

[0046] 5) The CCD industrial camera 4 scans the display completely from left to right, inputs the collected data into the industrial computer to generate an image, and uses software to detect the image and analyze the assembly accuracy.

[0047] In this embodiment, the device is mainly used for the accuracy detection of the curved screen, mainly to solve the problem of large imaging noise on the highly reflective surface caused by the panel of the curved screen. In view of the solution of the polarized light plus multi-angle illumination technology in the prior art, this device is directed to the reflective characteristics of the curved screen and involves a supplementary lighting system that can adjust the illumination light according to the illumination position. The device is externally provided with an aluminum profile shell to avoid interference from natural light.

[0048] Specifically, two groups of light source lamps 5 are arranged on both sides of the CCD industrial camera 4 to project polarized light onto the display, and a convex lens 61 and a plano-convex lens 62 are arranged between the CCD industrial camera 4 and the display. The CCD industrial camera 4 normally collects the image on the surface of the display through the area of the plano-convex lens 62. The convex lens 61 is located between the light source lamp 5 and the display. The convex lens 61 refracts the light emitted by the light source lamp 5 so that it shines on the curved screen at a certain angle. When the CCD industrial camera 4 moves to the middle position of the display, the reflection angle from the display becomes smaller and it is easier to return along the original path, thus forming a highly reflective area on the CCD industrial camera 4.

[0049] Therefore, when the CCD industrial camera 4 scans the display surface from left to right, the distance between the light source lamp 5 and the CCD industrial camera 4 is continuously adjusted, thereby changing the relative position of the light source lamp 5 and the convex lens 61. The closer the light source lamp 5 is to the center of the convex lens 61, the smaller the angle of refraction of the light through the convex lens 61; the closer the light source lamp 5 is to the edge of the convex lens 61, the larger the angle of refraction of the light through the convex lens 61. The CCD industrial camera 4 is in the middle position of the display, that is, the light source lamp 5 is pushed outward to both sides, thereby increasing the refraction angle, compensating for the reflection angle of the lighting, allowing the reflected light to avoid the lighting lens of the CCD industrial camera 4, and avoiding interference with the imaging process of the display detection image.

[0050] Embodiment 2: Figure 11 and Figure 12 As shown, a circular opening is provided at the center of the convex lens 61, and a flat lens 62 is embedded at the circular opening. The CCD industrial camera 4 is located opposite to the flat lens 62. The light source lamps 5 are distributed at the outer peripheral position of the convex lens 61. A light shielding tube is fixedly connected between the flat lens 62 and the lens of the CCD industrial camera 4. Side panels 65 are provided on both sides of the CCD industrial camera 4. An expansion component 63 is provided between the two side panels 65. The light source lamp 5 is fixedly installed on the side panels 65. The expansion component 63 includes an expansion rod 631 and a limit ring 632. The limit ring 632 is rotatably connected to the outer side of the CCD industrial camera 4. One end of the expansion rod 631 is fixedly connected to the outer side wall of the limit ring 632. The other end of the expansion rod 631 is fixedly connected to a slider 633. The inner side wall of the side panel 65 is fixedly connected to a guide rail 634. The slider 633 is slidably connected inside the guide rail 634.

[0051] In this embodiment, the refraction angle of the light of the light source lamp 5 is determined by the position, and the high-precision servo linear actuator 8 is used to control the relative position of the light source lamp 5 and the convex lens 61. The expansion component 63 drives the two groups of light source lamps 5 to adjust the position synchronously, wherein the positions of the CCD industrial camera 4 and the flat lens 62 are relatively fixed, and the two groups of light source lamps 5 are distributed on both sides through two side panels 65. The two expansion rods 631 are connected to the middle limit ring 632, and the two expansion rods 631 are located on the same straight line. The two groups of limit rings 632 are staggered on the outer periphery of the CCD industrial camera 4 and are rotatably connected relative to the CCD industrial camera 4.

[0052] The high-precision servo linear actuator 8 pushes one of the side plates 65 to move along the gantry 64. The gantry 64 drives the expansion support rod 631 to rotate. The expansion support rod 631 drives the slider 633 to move. The slider 633 slides inside the guide rail 634. The limit ring 632 rotates around the outer wall of the CCD industrial camera 4, driving the expansion support rod 631 at the other end to move synchronously. Due to the limiting effect of the expansion support assembly 63, the two side plates 65 move synchronously in position, enabling the two light source lamps 5 to be adjusted synchronously in position. A T-shaped groove is provided inside the guide rail 634, and the slider 633 is designed as a corresponding T-shaped block, so that the slider 633 is slidably clamped and matched with the guide rail 634, preventing the expansion support rod 631 from detaching from the side plate 65 and making the connection structure of the two side plates 65 stable.

[0053] Embodiment 3: According to Figure 10 , Figure 11 and Figure 12 shown, the high-precision servo linear actuator 8 is fixedly installed on the side wall of the gantry 64. The high-precision servo linear actuator 8 is built-in with an encoder to provide real-time feedback on displacement. A laser displacement sensor is installed at the edge of the convex lens 61. The laser displacement sensor is used to detect the horizontal displacement of the light source lamp 5.

[0054] The hydraulic linear actuator 7 is fixedly installed on the lower surface of the image capture platform 3. A magnetostrictive displacement sensor is installed at the actuator end of the hydraulic linear actuator 7. The magnetostrictive displacement sensor is used to detect the operating position of the actuator end of the hydraulic linear actuator 7. A solid-state relay is installed inside the high-precision servo linear actuator 8. The magnetostrictive displacement sensor outputs a current signal to control the solid-state relay to manipulate the operating state of the high-precision servo linear actuator 8.

[0055] In this embodiment, the hydraulic linear actuator 7 controls the CCD industrial camera 4 to linearly move and scan the display. The display detection images can be effectively and comprehensively collected. The CCD industrial camera 4 can scan the display twice within one reciprocating cycle. By increasing the number of times of scanning images and collecting multiple groups of image data, the noise of the collected signals can be effectively filtered, thereby obtaining more complete collected data.

[0056] The cooperation mechanism of the laser displacement sensor, the magnetostrictive displacement sensor and the solid-state relay is the core to realize the dynamic adjustment of the position of the light source lamp. Its control logic can be disassembled into four links: position signal acquisition → threshold judgment → direction switching → closed-loop feedback.

[0057] Regarding the position signal acquisition and threshold judgment section, the magnetostrictive displacement sensor is installed at the actuator end of the hydraulic linear actuator 7 to monitor the horizontal displacement of the CCD industrial camera 4 in real time. For example, its stroke range is set to 0 - 500 mm, and the midpoint position is 250 mm. When the actuator end of the hydraulic linear actuator 7 moves to the middle position, the CCD industrial camera 4 is directly opposite the middle position of the curved screen. When the CCD industrial camera 4 moves from the left side (0 mm) to the right side, the magnetostrictive sensor signal increases linearly. When it reaches the midpoint (250 mm), the first direction switching signal is triggered; when the camera completes the right - hand scan (500 mm) and returns, the signal decreases linearly, and when it passes through the midpoint (250 mm) again, the second direction switching signal is triggered.

[0058] The laser displacement sensor is used for light source position feedback. It is horizontally installed along the edge of the convex lens 61. A transmissive laser displacement sensor is adopted to detect the horizontal distance between the light source lamp 5 and the center of the convex lens 61, and outputs a ±10V voltage signal. The voltage increases when the distance increases, and vice versa.

[0059] Regarding the direction switching control section of the solid - state relay (SSR), the high - precision servo linear actuator 8 is driven by a DC servo motor. The solid - state relay selects a dual - channel H - bridge type SSR, which can control the forward and reverse rotation of the motor of the high - precision servo linear actuator 8.

[0060] The signal of the laser displacement sensor is connected to the programmable logic controller of the industrial computer to calibrate the actual position of the light source lamp 5 in real time, forming a closed - loop control.

[0061] The magnetostrictive signal trigger switching logic is as follows: The industrial computer presets the midpoint threshold signal. For example, the current value corresponding to the 250 - mm position is 12 mA.

[0062] The first extrapolation (left → middle): When the output current of the magnetostrictive sensor < 12 mA and continues to rise (the camera moves from left to middle), the solid - state relay controls the motor to rotate forward to extrapolate the light source lamp 5.

[0063] The first retraction (middle → right): When the current reaches 12 mA and continues to rise (the camera moves from middle to right), the industrial computer sends a reverse signal to the solid - state relay to switch to reverse rotation to retract the light source lamp 5.

[0064] The second extrapolation (right → middle): When the camera completes the right - hand scan and starts to return, the output current of the magnetostrictive sensor > 12 mA and continues to decrease (the camera moves from right to middle), the solid - state relay controls the motor to rotate forward again to extrapolate the light source lamp 5.

[0065] Second pull (center → left): When the current drops to 12 mA and continues to decrease (the camera moves from the center to the left), the industrial computer sends a reverse signal to the solid-state relay to switch to reverse rotation, causing the light source lamp 5 to pull in.

[0066] Through such logic adjustment, the control process of "extrapolation → pull-in → extrapolation → pull-in" can be realized, ensuring that during the process of the CCD industrial camera 4 scanning the display back and forth, the position of the light source lamp 5 can be dynamically adjusted according to its position to compensate for the change in the reflection angle of the curved screen.

[0067] Embodiment 4: A control system and control logic for a display assembly precision detection device, the hardware architecture of which consists of the following parts:

[0068] 1. Industrial computer: Adopt the Advantech UNO-3082G industrial-grade embedded computer, equipped with the Windows 10 IoT operating system, integrated with NI LabVIEW data processing software, and has RS-485, USB 3.0 and Ethernet interfaces, supporting multi-sensor data synchronous acquisition and real-time control of actuators.

[0069] 2. Sensor group:

[0070] ① Magnetostrictive displacement sensor (MTS): Model MTS R series, installed at the end of the piston rod of the hydraulic linear actuator, with a detection accuracy of ±0.05 mm, outputting a 4-20 mA current signal to real-time feedback the horizontal position of the CCD industrial camera;

[0071] ② Laser displacement sensor (LDS): Adopt Keyence IL-600, installed at the edge of the convex lens, detecting the horizontal distance between the light source lamp and the center of the convex lens, with a measurement range of 0-300 mm, an accuracy of ±0.1 mm, and outputting an analog voltage signal (0-10 V);

[0072] ③ Positioning optoelectronic sensor: Model Omron E3Z-LS63, installed on both sides of the positioning jig, detecting the in-place signal of the display to ensure that the positioning deviation < 0.2 mm.

[0073] 3. Actuator group:

[0074] ① Hydraulic linear actuator: Select the Yuken A3H series, with a stroke of 500 mm, a speed adjustable from 0 to 200 mm / s, and built-in hydraulic locks to prevent sliding when power is off;

[0075] ② High-precision servo linear actuator: Adopt the THKK R33 linear module, equipped with a Panasonic MINASA6 servo motor, with a positioning accuracy of ±0.02 mm, supporting forward / backward rotation and speed control.

[0076] Regarding the implementation steps of the control logic of the present invention, specific examples are as follows:

[0077] I. Initialization and Calibration:

[0078] 1. After the equipment is started, the industrial computer sends a zeroing instruction. The hydraulic linear actuator drives the camera to move to the left limit position (0 mm), and at the same time, the high-precision servo linear actuator resets the light source lamp to the center-symmetric position of the convex lens (initial refraction angle 30°);

[0079] 2. Calibration of the laser displacement sensor: Collect the voltage value of the initial position of the light source lamp (such as 5 V corresponding to the center position) as the reference data for subsequent position adjustment.

[0080] II. Dynamic Adjustment Algorithm: The industrial computer pre-stores the curvature - refraction angle mapping model of the curved screen. Based on the least squares method to fit the curved surface equation z = f(x, y), calculate the required light source incident angle θ for the current detection area through the following formula:

[0081]

[0082] where θ is the required light source incident angle for the current detection area; x, y, z are the spatial coordinates of the curved screen; is the partial derivative of the curved surface equation with respect to z for x, which is used to reflect the change rate of x in the z direction when the curved surface changes, so as to determine the basic light source angle adjustment caused by the curved surface curvature; Δθ is the compensation coefficient (determined by the reflective simulation experiment, with a value range of ±15°), which is used to further fine-tune the light source incident angle to ensure that the reflected light deviates from the optical axis of the camera lens by > 45°.

[0083] III. Segmented Control Strategy:

[0084] 1. Scanning of the left half area: When the signal of the magnetostrictive sensor < 12 mA, the industrial computer calculates the extrapolation distance d = kx of the light source according to the real-time position x (proportional coefficient k = 0.8), drives the high-precision servo linear actuator to extrapolate at a speed of 5 mm / s, and synchronously enables the left light source lamp (power 80%);

[0085] 2. Scanning of the right half area: When the signal ≥ 12 mA, the light source lamp moves towards the center at a speed of 3 mm / s, and the distance calculation formula is d = 400 - kx. At the same time, switch to the right light source lamp (power 70%) to avoid interference between the two light sources;

[0086] 3. Return scanning: Repeat the above logic to achieve the fusion of scanning data for two round trips.

[0087] IV. Closed-loop Feedback Correction: The laser displacement sensor monitors the actual position of the light source in real time. If the deviation from the calculated value > 0.5 mm, the industrial computer triggers the error compensation mechanism:

[0088]

[0089] where, Δv is the adjustment amount of the servo motor speed; K p is the proportional coefficient (with a value of 0.6), which is used to quickly adjust the speed proportionally according to the current deviation e; e is the deviation between the actual position of the light source and the calculated value; K i is the integral coefficient (with a value of 0.1), and ∫edt represents the integral operation of the deviation e, which is used to eliminate the steady-state error of the system; K d is the differential coefficient (with a value of 0.3), is the rate of change of the deviation e, which is used to adjust the speed in advance according to the deviation change trend to improve the system response speed and stability, and ensure that the light source position accuracy is <0.2 mm.

[0090] The speed of the servo motor is adjusted by the PID algorithm (K p = 0.6, K i = 0.1, K d = 0.3), to ensure that the light source position accuracy is <0.2 mm.

[0091] V. Human-Machine Interface (HMI): Parameter setting and status monitoring are realized through the Weinview MT8102iE touch screen, and it supports:

[0092] ① Selection of the curved screen model (calling the corresponding curvature database);

[0093] ② Manual fine-tuning of parameters such as the light source power and scanning speed;

[0094] ③ Real-time display of status data such as the camera position, light source angle, and image acquisition quality;

[0095] ④ Fault alarm (such as abnormal sensor signal, overload protection) and historical data query.

[0096] In the present invention, through the built-in curvature database and the adaptive algorithm, the arc characteristics of different models of curved screens are automatically matched, without manual presetting of the light source angle, and based on the position correction of the PID algorithm and the real-time feedback of the sensor, the light source angle adjustment accuracy is ensured, significantly reducing the detection deviation caused by mechanical errors. At the same time, the full process automation from the monitor positioning, scanning to data generation supports pipeline-style batch production detection, adapting to the intelligent quality inspection requirements of Industry 4.0.

[0097] Usage Method and Working Principle of This Device: Place the display on the detection platform 1 and position it through the positioning fixture 10. After the conveyor belt 2 transports it in place, it stops. The hydraulic linear actuator 7 drives the CCD industrial camera 4, the light source lamp 5 and the anti-reflection mechanism 6 to move horizontally in a straight line reciprocally. It can be scanned twice in one cycle to filter noise. During scanning, in the left stage, the left light source lamp 5 is enabled, and the expansion component 63 pushes the light source lamp 5 away from the center of the convex lens 61 to increase the refraction angle to compensate for the reflection on the left side of the curved screen. The magnetostrictive sensor triggers the solid-state relay to switch the movement direction of the high-precision servo linear actuator 8, so that the light source lamp 5 transitions from "pushing out to increase the refraction angle" to "pulling in to decrease the refraction angle". With the closed-loop feedback of the laser displacement sensor, the change in the reflection angle of the curved screen can be accurately compensated.

[0098] In the right stage, the right light source lamp 5 is enabled and operates in the reverse direction to make the light source lamp 5 approach the center of the convex lens 61 to decrease the refraction angle to adapt to the reflection on the right side. The CCD industrial camera 4 collects the image of the area illuminated by the polarized light refracted by the convex lens 61 through the plano-convex lens 62, transmits the data to the industrial computer to generate an image and analyze the assembly accuracy. Among them, the expansion component 63 accurately adjusts the relative position of the light source and the convex lens 61 to control the refraction angle. The magnetostrictive sensor triggers the solid-state relay to automatically switch the light source position to adapt to the reflection characteristics of different areas. The hydraulic linear actuator 7 ensures stable and sufficient scanning.

[0099] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A display assembly precision detection device, comprising a detection platform (1) and an image capture platform (3). The image capture platform (3) is disposed directly above the detection platform (1). A CCD industrial camera (4) and two groups of light source lamps (5) are installed on the lower surface of the image capture platform (3). The two groups of light source lamps (5) are respectively arranged on both sides of the CCD industrial camera (4). The CCD industrial camera (4) is used for the optical alignment of the display. The light source lamp (5) is used to emit polarized light to the display panel. The CCD industrial camera (4) transmits information to an industrial computer, and the industrial computer is used to receive the data collected by the CCD industrial camera (4) and analyze the assembly precision of the display. It is characterized in that: A positioning fixture (10) is arranged outside the detection platform (1), and a de-reflection mechanism (6) is arranged between the light source lamp (5) and the display. The de-reflection mechanism (6) comprises a convex lens (61), and the convex lens (61) is used to refract light emitted by the light source lamp (5); A hydraulic linear actuator (7) is installed on the outer side of the CCD industrial camera (4). The hydraulic linear actuator (7) is used to drive the CCD industrial camera (4), the light source lamp (5) and the de-reflection mechanism (6) to move linearly. The CCD industrial camera (4) moves linearly to scan the surface of the display panel. A high-precision servo linear actuator (8) is installed on the outer side of the two groups of light source lamps (5). The high-precision servo linear actuator (8) is used to control the movement of the light source lamp (5) and adjust the relative position of the light source lamp (5) and the convex lens (61).

2. The display assembly precision detection device according to claim 1, characterized in that, The method for detecting the assembly accuracy of the display includes the following steps: S1, placing a display on a detection platform (1), and positioning the display using a positioning fixture (10); S2, activating the hydraulic linear actuator (7), the hydraulic linear actuator (7) pushes the CCD industrial camera (4) and the light source lamp (5) from the left side of the display to the right side; S3, when the CCD industrial camera (4) moves from the left side to the middle of the display, the light source lamp (5) on the left side is activated, and at the same time, the light source lamp (5) is pushed outward by the high-precision servo linear actuator (8), gradually increasing the refraction angle of the incident light, and illuminating the area to be inspected on the lower display; S4, when the CCD industrial camera (4) moves from the middle of the display to the right, the light source lamp (5) on the right is activated, and at the same time, the high-precision servo linear actuator (8) is used to pull the light source lamp (5) toward the middle, gradually reducing the refraction angle of the incident light, and illuminating the area to be inspected on the lower display; S5, CCD industrial camera (4) completely scans the display from left to right, inputs the collected data into the industrial computer to generate an image, uses software to detect the image, and analyzes the assembly accuracy.

3. The accuracy detection device for assembling a display according to claim 1, wherein: A circular opening is provided at the center of the convex lens (61), and a flat lens (62) is embedded in the circular opening. The CCD industrial camera (4) is located opposite to the flat lens (62). The light source lamps (5) are distributed at the outer peripheral position of the convex lens (61). A light shielding tube is fixedly connected between the flat lens (62) and the lens of the CCD industrial camera (4).

4. A display assembly precision detection device according to claim 1, characterized in that: Side panels (65) are provided on both sides of the CCD industrial camera (4), an expansion assembly (63) is provided between the two side panels (65), the light source lamp (5) is fixedly mounted on the side panels (65), the expansion assembly (63) comprises an expansion rod (631) and a limit ring (632), the limit ring (632) is rotatably connected to the outer side of the CCD industrial camera (4), one end of the expansion rod (631) is fixedly connected to the outer side wall of the limit ring (632), the other end of the expansion rod (631) is fixedly connected to a slider (633), the inner side wall of the side panel (65) is fixedly connected to a guide rail (634), and the slider (633) is slidably connected inside the guide rail (634).

5. The precision detection device for assembling a display according to claim 1, wherein: The outer side wall of the CCD industrial camera (4) is fixedly connected to a gantry (64), and both ends of the gantry (64) are fixedly connected to the convex lens (61).

6. The accuracy detection device for assembling a display according to claim 1, wherein: A conveyor belt (2) is arranged below the detection platform (1), and the conveyor belt (2) is used to transport the display.

7. An accuracy detection device for assembling a display according to claim 5, characterized in that: The high-precision servo linear actuator (8) is fixedly mounted on the side wall of the gantry (64), and the high-precision servo linear actuator (8) has a built-in encoder to provide real-time displacement feedback.

8. An assembly precision detection device for a display according to claim 1, characterized in that: A laser displacement sensor is installed on the edge of the convex lens (61), and the laser displacement sensor is used to detect the horizontal displacement of the light source lamp (5).

9. The accuracy detection device for assembling a display according to claim 1, wherein: The hydraulic linear actuator (7) is fixedly mounted on the lower surface of the image capture platform (3); a magnetostrictive displacement sensor is mounted on the execution end of the hydraulic linear actuator (7); the magnetostrictive displacement sensor is used to detect the operating position of the execution end of the hydraulic linear actuator (7); a solid-state relay is mounted inside the high-precision servo linear actuator (8); the magnetostrictive displacement sensor outputs a current signal, and controls the solid-state relay to control the operating state of the high-precision servo linear actuator (8).

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