Apparatus for inspecting curved profile following

Abstract

The present invention proposes a curved profile-following inspection device that precisely scans the three-dimensional shape of an object to be inspected to generate profile data, and controls the movement of a robot arm based on this data so that an inspection unit measures physical properties while maintaining a constant distance along the surface curvature of the object. The device may include a support module having a mounting area on which an object to be inspected is placed; a shape recognition module that scans the shape of the object to be inspected located in the mounting area and generates 3D profile data for the surface curvature of the object to be inspected; an inspection module installed adjacent to the mounting area and measures physical properties of the object to be inspected while moving and maintaining a preset distance from the surface of the object to be inspected based on the 3D profile data generated from the shape recognition module; and a control module that generates an inspection path that follows the surface curvature of the object to be inspected based on the 3D profile data generated from the shape recognition module and controls the operation of the inspection module along the generated inspection path.

Description

Technology Field

[0001] The present invention relates to an automated inspection device. More specifically, it relates to a curved profile-following inspection device capable of precisely inspecting a non-flat surface by acquiring three-dimensional shape information of an object to be inspected having various curvatures and controlling the object to move while maintaining a constant distance along the surface curvature of the object to be inspected during the inspection process. Background Technology

[0002] A display device refers to an output device that receives an image signal and displays video information on a screen. With the advancement of information and communication technology, such display devices are used as core components in various electronic devices, including televisions, computer monitors, smartphones, and tablets. Representative display panels include Liquid Crystal Displays (LCDs) and Organic Light Emitting Diodes (OLEDs), and technological development continues in recent years to meet demands for lighter weight, thinner form factors, and lower power consumption.

[0003] Recently, flexible display technology, which allows the substrate itself to bend to maximize design flexibility and immersion beyond simply providing flat images, is being commercialized. Accordingly, various types of curved products are being released, including not only curved monitors with fixed curvature but also foldable and rollable displays that users can fold or unfold at will. In particular, in the automotive electronics sector, there is a growing trend of applying curved display panels that incorporate ergonomic design.

[0004] A display inspection device refers to equipment that detects defects such as scratches, foreign substances, lighting failures, and color non-uniformity on the panel surface that may occur during the manufacturing process, or determines whether a product is of good quality by measuring optical characteristics such as luminance and color coordinates. Generally, an inspection device is composed of an inspection unit equipped with a high-resolution camera, optical sensor, laser displacement sensor, etc., and a stage that supports the object to be inspected.

[0005] The general display inspection process proceeds as follows: when an object to be inspected is loaded onto a stage, the inspection unit moves to a preset position or the stage moves to align the inspection position, after which surface data of the object is acquired through a sensor. The acquired data is then transmitted to a control unit for comparative analysis with preset reference values, through which the location of defects or physical property values ​​are calculated.

[0006] However, most conventional inspection devices are designed based on flat objects, so as mentioned earlier, there were structural limitations in inspecting display panels that include curved surfaces.

[0007] Specifically, inspection methods using gantry-type robots that move along a fixed axis or Cartesian robots have a problem in that the distance between the sensor and the surface fluctuates frequently depending on the curvature of the object being inspected. This change in distance causes the sensor to deviate from its depth of field, thereby reducing measurement precision. Furthermore, in curved areas, the sensor's optical axis fails to be incident perpendicularly to the surface, leading to insufficient reflected light or noise caused by scattering, which consequently significantly reduces the reliability of the measurement data.

[0008] To address these issues, a method in which an operator manually holds measuring equipment and moves it along the curved surface for inspection is sometimes implemented; however, this method inevitably relies on the operator's skill level, which limits the ability to guarantee consistency in measurement results. Furthermore, manual inspection methods require excessive inspection time, hindering production efficiency, and present the problem that 100% inspection on mass production lines is virtually impossible. Prior art literature

[0009] Korean Registered Patent Publication No. 10-0676817, 'Gamma Adjustment Method and Gamma Adjustment System for Display Device', (Published Nov. 08, 2021) The problem to be solved

[0010] One objective of the present invention is to provide a curved profile-following inspection device that precisely scans the three-dimensional shape of an object to be inspected to generate profile data, and controls the movement of a robot arm based on this to enable an inspection unit to measure physical properties while maintaining a constant distance along the surface curvature of the object.

[0011] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0012] To achieve the technical objectives described above, the present invention proposes a curved profile-following inspection device that precisely scans the three-dimensional shape of an object to be inspected to generate profile data, and controls the movement of a robot arm based on this data so that an inspection unit measures physical properties while maintaining a constant distance along the surface curvature of the object. The device may include a support module having a mounting area on which an object to be inspected is placed; a shape recognition module that scans the shape of the object to be inspected located in the mounting area and generates 3D profile data for the surface curvature of the object to be inspected; an inspection module installed adjacent to the mounting area and measures physical properties of the object to be inspected while moving and maintaining a preset distance from the surface of the object to be inspected based on the 3D profile data generated from the shape recognition module; and a control module that generates an inspection path that follows the surface curvature of the object to be inspected based on the 3D profile data generated from the shape recognition module and controls the operation of the inspection module along the generated inspection path.

[0013] The support module is characterized by comprising: a base plate having a flat upper surface that provides a working area for the inspection object to be seated and fixed; a guide unit extending lengthwise on both sides along the longitudinal direction of the base plate and to which the shape recognition module is slidably coupled; and a robot mounting unit positioned behind the guide unit on the base plate and to which the inspection module is firmly fixedly installed.

[0014] The shape recognition module is characterized by including a transfer unit that moves along the longitudinal direction of the object to be inspected along the guide unit, and a laser displacement sensor installed at the end of the transfer unit, which irradiates a measurement light downward and scans the entire area of ​​the object to be inspected placed on the base plate as the transfer unit moves.

[0015] The control module is characterized by generating the 3D profile data by synthesizing a plurality of 2D cross-sectional profile data obtained by scanning the shape recognition module along the length direction of the object to be inspected.

[0016] The inspection module is characterized by comprising a multi-joint robot arm having a plurality of joints and a measurement head unit mounted on the end of the multi-joint robot arm, the measurement head unit comprising a light source that irradiates light onto the object to be inspected and an optical sensor that receives reflected light and analyzes optical characteristics.

[0017] The control module is characterized by correcting the Z-axis position of the multi-joint robot arm in real time so that the distance between the end of the measurement head unit and the surface of the object to be inspected is maintained at a constant preset reference measurement distance by reflecting the height information of the 3D profile data that changes in real time while the measurement head unit moves along the inspection path.

[0018] The control module calculates a normal vector of the surface of the object to be inspected at each coordinate point of the 3D profile data, and continuously controls the posture of the multi-joint robot arm so that the optical axis of the measurement head unit is parallel to the calculated normal vector while the measurement head unit moves along the inspection path.

[0019] The control module analyzes the 3D profile data to calculate the curvature value for each section of the inspection path, controls the movement speed of the inspection module to a first speed in flat sections where the calculated curvature value is less than a preset reference value, and controls the movement speed of the inspection module to a second speed slower than the first speed in curved sections where the calculated curvature value is greater than or equal to the reference value.

[0020] The control module is characterized by generating a virtual safety boundary spaced upward from the actual surface of the object to be inspected, which is identified based on the 3D profile data, by a pre-set safety margin, and monitoring the real-time position while the inspection module moves, and if the position of the inspection module is detected to have encroached upon the virtual safety boundary, immediately stopping the operation of the inspection module or retracting it in a direction away from the object to be inspected.

[0021] The control module analyzes the rate of change in height between adjacent coordinates of the 3D profile data, and if a discontinuous point is detected where the rate of change in height exceeds a preset threshold, identifies it as a particle section; when generating the inspection path, it excludes the height data of the particle section and performs interpolation processing to connect adjacent normal surface data to prevent abrupt lifting movements of the inspection module, and assigns an identification tag to the physical property data measured in the particle section.

[0022] The above device is characterized by further including a display module that outputs the inspection result of the inspection object measured by the inspection module.

[0023] The control module stores metadata including the start and end coordinates of the foreign substance section, the maximum protrusion height value, and the area information in the identification tag, generates a result map visualizing the physical property distribution of the object to be inspected, and outputs it through the display module, wherein the area to which the identification tag is assigned is masked with identification information that is distinguished from the normal measurement area and displayed.

[0024] The control module determines the quality grade of the object to be inspected based on the inspection results measured by the inspection module, and is characterized by automatically excluding the physical property data to which the identification tag is assigned from the parameters for determining the quality grade.

[0025] The above inspection module is characterized by further including an air nozzle that sprays air and is provided on one side of the measurement head unit.

[0026] The control module is characterized by, when the foreign substance section is identified, temporarily suspending the driving of the inspection path and controlling the inspection module to blow air so that the air nozzle is directed toward the foreign substance section to perform a cleaning operation, and then rescanning the section to update the shape data, wherein if the discontinuity point is resolved as a result of the rescan, the identification tag is deleted, and if the discontinuity point still exists, it is confirmed as a stickiness defect.

[0027] The above inspection module is characterized by further including a projector provided on one side of the measurement head unit, which converts measured physical property data into a visual pattern and projects it.

[0028] The control module is characterized by controlling the projector to project a marker image indicating the location of the defect onto the actual surface of the object to be inspected when the physical property data measured in real time while the inspection module is moving deviates from a preset normal range.

[0029] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0030] According to embodiments of the present invention, by controlling a multi-joint robot based on profile data obtained by precisely scanning the three-dimensional shape of an object to be inspected, the inspection unit can perform inspection on non-flat products with various curvatures while maintaining a constant separation distance and a vertical angle of incidence along the surface curvature. Through this, the occurrence of noise caused by deviation from the sensor's depth of focus or diffuse reflection can be fundamentally blocked, thereby dramatically improving the accuracy and reliability of the measurement data.

[0031] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art to which the present invention pertains from the description in the claims. Brief explanation of the drawing

[0032] FIG. 1 is a perspective view of a curved profile-following inspection device according to one embodiment of the present invention. FIG. 2 is a front view of a curved profile-following inspection device according to one embodiment of the present invention. FIG. 3 is a side view of a curved profile-following inspection device according to one embodiment of the present invention. FIG. 4 is a perspective view showing the internal structure of a curved profile-following inspection device according to one embodiment of the present invention. FIG. 5 is a logical configuration diagram of a control module according to one embodiment of the present invention. FIG. 6 is an illustrative diagram for explaining an inspection process according to one embodiment of the present invention. FIG. 7 is an illustrative diagram for explaining a curved profile-following inspection device according to another embodiment of the present invention. Specific details for implementing the invention

[0033] It should be noted that technical terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Furthermore, unless specifically defined otherwise in this specification, technical terms used in this specification should be interpreted in the sense generally understood by those skilled in the art to which the invention pertains, and should not be interpreted in an overly broad or overly narrow sense. Additionally, if a technical term used in this specification is an incorrect technical term that fails to accurately express the spirit of the invention, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. Moreover, general terms used in this invention should be interpreted according to their prior definitions or the context, and should not be interpreted in an overly narrow sense.

[0034] Additionally, singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as 'composed of' or 'have' should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as potentially including some of the components or steps, or including additional components or steps.

[0035] Additionally, terms including ordinal numbers, such as first, second, etc., used herein may be used to describe various components, but said components should not be limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0036] When it is stated that one component is 'connected' or 'connected' to another component, it may be directly connected or connected to that other component, or there may be other components in between. On the other hand, when it is stated that one component is 'directly connected' or 'directly connected' to another component, it should be understood that there are no other components in between.

[0037] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may obscure the essence of the present invention, such detailed description will be omitted. Additionally, it should be noted that the attached drawings are intended only to facilitate an easy understanding of the concept of the present invention and should not be interpreted as limiting the concept of the present invention. The concept of the present invention should be interpreted as extending to all modifications, equivalents, and substitutions other than those shown in the attached drawings.

[0039] FIG. 1 is a perspective view of a curved profile-following inspection device according to one embodiment of the present invention, FIG. 2 is a front view of a curved profile-following inspection device according to one embodiment of the present invention, FIG. 3 is a side view of a curved profile-following inspection device according to one embodiment of the present invention, and FIG. 4 is a perspective view showing the internal structure of a curved profile-following inspection device according to one embodiment of the present invention.

[0040] Referring to FIGS. 1 to 4, a curved profile-following inspection device (100) according to one embodiment of the present invention may be configured to include a support module (110), a shape recognition module (120), an inspection module (130), a display module (140), an input module (150), and a control module (160).

[0041] To describe each component, first, the support module (110) forms the overall exterior frame of the inspection device (100) and can perform the role of providing a workspace where an object to be inspected is placed and a structural base where each module is installed. This support module (110) may be configured to include a base plate (111), a guide unit (112), a robot mounting unit (113), a frame (114), and an output unit (115).

[0042] The base plate (111) is made of a high-rigidity material such as aluminum or steel to form the bottom surface of the upper workspace and can be machined to be flat so that the object to be inspected can be placed on it without shaking. A soft pad member may be attached to the upper surface of the base plate (111) to prevent damage that may occur upon contact with the object to be inspected and to increase friction to secure the object.

[0043] The guide unit (112) may include a rail structure that is arranged lengthwise (X-axis) along one edge of the base plate (111). The guide unit (112) may function as a linear motion guide (LM Guide) that guides linear motion while supporting the load of the shape recognition module (120) to be described later.

[0044] The robot mounting unit (113) may be positioned in a single-phase form having a predetermined height at the rear or center of the base plate (111). The robot mounting unit (113) may have a structure with an internal reinforcing frame to absorb the moment of inertia and vibration generated during high-speed operation of the inspection module (130).

[0045] The frame (114) can form a cuboid-shaped space by being composed of columns extending vertically from the corners of the base plate (111) and beams connecting them. Transparent protective windows that allow for internal observation while blocking external access are attached to the sides and front of the frame (114) to ensure the safety of the worker.

[0046] The output unit (115) may be configured in the form of a warning light that protrudes from the upper part of the frame (114). The output unit (115) can emit different colors of standby, operation, and error status of the device through an internal LED module, thereby allowing the status of the equipment to be identified even from a distance.

[0047] In the following configuration, the shape recognition module (120) can perform the role of scanning the overall shape of the object to be inspected and generating three-dimensional profile data including surface curvature information. Such a shape recognition module (120) may be configured to include a transfer unit (121) and a laser displacement sensor (122).

[0048] The transfer unit (121) may include a slider block coupled to the rail of the guide unit (112), a motor for driving the slider block, and a power transmission member. The transfer unit (121) is precisely position-controlled according to a control signal and can travel at a constant speed from the starting point to the ending point of the object to be inspected.

[0049] The laser displacement sensor (122) can be fixed to the upper bracket of the transfer unit (121) and installed so as to be oriented downward. The laser displacement sensor (122) can obtain cross-sectional height information of the object through a triangulation method in which a slit light is projected onto the object and the reflected light is received by an internal image sensor.

[0050] In the following configuration, the inspection module (130) can perform the role of moving to an actual inspection location and measuring the optical or physical properties of an object based on curved shape information identified by the shape recognition module (120). Such an inspection module (130) may be configured to include a multi-joint robot arm (131) and a measurement head unit (132).

[0051] A multi-joint robot arm (131) can achieve movement of 6 degrees of freedom (6-DOF) or more by including a base fixed to a robot mounting unit (113), a plurality of link members sequentially rotatably connected from the base, and joint drive motors that rotate each link member. The multi-joint robot arm (131) can move the end to any coordinate (X, Y, Z) in three-dimensional space by combining the rotation angles of each joint, and can also freely control the posture (Roll, Pitch, Yaw) of the end. In particular, the multi-joint robot arm (131) can move along a generated inspection path, rotate the wrist joint in real time so that the optical axis of the measurement head unit (132) aligns with the normal vector of the curved surface of the object to be inspected, and simultaneously perform a tracking operation to adjust the height of the robot arm so that the distance from the surface of the object maintains a set value.

[0052] The measurement head unit (132) can be mounted on the end flange of the multi-joint robot arm (131) to perform an inspection function. The measurement head unit (132) may include a light source module suitable for the measurement purpose and optical sensors such as a spectroscopic camera and a colorimeter.

[0053] In the following configuration, the display module (140) can perform the role of providing information to the user by outputting the device's operating software screen. The display module (140) may include a display panel installed on the front of the frame (114) at the user's eye level. The display module (140) can render and display the acquired three-dimensional shape image, or visualize and output measurement data by inspection location as a graph or numerical value.

[0054] With the following configuration, the input module (150) can serve as an interface for controlling the device through physical operation by the user. The input module (150) may be placed in the form of a separate panel on the bottom or side of the display module (140). The input module (150) may provide hardware safety by including a key switch for supplying power to the equipment, a push button for starting or stopping automatic operation, and an emergency stop button for immediately cutting off power to stop the drive unit in the event of an emergency.

[0055] Finally, the control module (160) can be installed in an electrical box provided in the lower space of the support module (110) to manage the overall operation of the device. The control module (160) may be configured to include a processor for computational processing, a motion controller for robot and motor control, a PLC for input / output signal processing, etc. The control module (160) can perform an algorithm to generate a 3D model by processing point cloud data received from the shape recognition module (120) into a mesh form.

[0056] Additionally, the control module (160) can analyze the curvature of the generated 3D model surface to calculate the trajectory of the robot to move, and generate and transmit position commands for each joint motor of the multi-joint robot arm (131) in real time through inverse kinematics analysis. Furthermore, the control module (160) can perform a pattern control function to evaluate optical characteristics by controlling the operation of the display panel, which is the object to be inspected. Unlike the conventional method of measuring by changing all pixels of the panel from minimum brightness to maximum brightness in a batch, the control module (160) can virtually divide the screen of the object to be inspected into multiple regions. The control module (160) can apply a light emission control signal restrictively to each divided region so that only one sub-pixel among red, green, and blue outputs a color. Accordingly, the inspection module (130) can minimize interference between adjacent subpixels and evaluate precise optical characteristics at the pixel level by independently measuring luminance and chromaticity for an area where only specific subpixels are activated by the control module (160).

[0057] Meanwhile, a detailed description of the control module (160) will be provided below with reference to the drawings.

[0059] Hereinafter, the logical configuration of the control module (160) according to one embodiment of the present invention will be described in more detail.

[0060] FIG. 5 is a logical configuration diagram of a control module according to one embodiment of the present invention, and FIG. 6 is an illustrative diagram for explaining an inspection process according to one embodiment of the present invention.

[0061] Referring to FIGS. 5 and 6, a control module (160) according to one embodiment of the present invention may be configured to include a communication unit (161), an input / output unit (163), a shape recognition unit (165), an inspection unit (167), and a storage unit (169).

[0062] To explain each component, the communication unit (161) can perform the role of an interface for transmitting and receiving data with an external upper management server and each lower driving module inside the device.

[0063] Specifically, the communication unit (161) supports various industrial communication protocols such as TCP / IP, Modbus, EtherCAT, or RS-232C, thereby ensuring data compatibility between heterogeneous devices. The communication unit (161) receives model information (Model ID) and work order of an object to be inspected from an upper management server and converts them into internal parameters. Conversely, after the inspection is completed, it transmits judgment results and measurement data to the upper management server to manage production history.

[0064] With the following configuration, the input / output unit (163) can provide a user interface (GUI) and process physical switch and lamp signals to mediate interaction between the device and the operator.

[0065] Specifically, the input / output unit (163) can render a graphical user interface (GUI) in conjunction with the display module (140) and receive user commands by detecting touch events. The input / output unit (163) can convert setting values ​​such as the inspection tolerance range, scan speed, and robot movement path entered by the user on the screen into digital signals and record them in the storage unit (169) or immediately reflect them in the control logic.

[0066] Referring to FIG. 6, the shape recognition unit (165) can perform the role of restoring and analyzing the overall three-dimensional shape of an object to be inspected in digital space based on fragmentary two-dimensional data obtained from the shape recognition module (120).

[0067] First, as shown in the upper part of FIG. 6, the shape recognition unit (165) receives a real-time position pulse signal from the servo motor encoder of the transfer unit (121) and can generate a trigger signal whenever the transfer unit (121) moves by a preset pitch. The laser displacement sensor (122) performs a laser line scan in the width direction (Y-axis) of the object to be inspected (10) in response to this trigger signal, and the shape recognition unit (165) can map the acquired 2D cross-sectional profile (Line Profile) data to the corresponding transfer position coordinates and sequentially load them into a buffer memory.

[0068] Next, the shape recognition unit (165) can perform pre-processing and noise filtering on the collected raw data. Spike noise or missing values ​​may occur in the data depending on the surface material of the object to be inspected (10) or the surrounding lighting environment. Accordingly, the shape recognition unit (165) can determine reliable point cloud data by considering cases where the height difference between adjacent point data exceeds a threshold as outliers and removing them, or by applying a moving average filter or a Gaussian filter to smooth out sudden fluctuations in the data.

[0069] Afterwards, as illustrated in the lower part of FIG. 6, the shape recognition unit (165) can align and synthesize a plurality of preprocessed 2D cross-sectional profile data in the direction of transport to generate 3D profile data representing the surface curvature of the entire object to be inspected (10). At this time, the shape recognition unit (165) can apply a linear interpolation or spline interpolation algorithm to the empty space between data points to convert the point data into a 3D mesh model having continuous surface information. Through this, the complex curved shape of the object to be inspected (10), which is bent or twisted, can be precisely modeled.

[0070] Furthermore, the shape recognition unit (165) can calculate normal vector and curvature values ​​by analyzing the geometric characteristics of the generated 3D profile data. Specifically, the shape recognition unit (165) can calculate a normal vector representing a direction perpendicular to the surface by utilizing a principal component analysis (PCA) technique, such as analyzing the covariance matrix of adjacent points centered on an arbitrary point of interest on the 3D mesh. This can be used as key reference data to control the robot's orientation so that the measurement head unit (132) of the inspection module (130) always faces the surface of the object at a front (90 degrees) during a subsequent process. Additionally, the shape recognition unit (165) can derive the curvature value of the point by performing a differential operation on the rate of change of angle between adjacent normal vectors, and can separately identify edge regions or curved areas where the curvature changes rapidly and provide this as metadata to control the inspection speed.

[0071] With the following configuration, the inspection unit (167) can generate an optimal inspection path based on the three-dimensional profile data generated from the shape recognition unit (165) and precisely control the inspection module (130) to perform actual measurement and data processing.

[0072] Specifically, the inspection unit (167) can extract a normal vector at each coordinate point on the 3D profile data and perform precision tracking control logic based thereon. Specifically, the inspection unit (167) can control the multi-joint robot arm (131) by reflecting the height information of the 3D profile data that changes in real time while the measurement head unit (132) moves along the generated inspection path. At this time, the inspection unit (167) can correct the Z-axis position of the multi-joint robot arm in real time so that the distance between the end of the measurement head unit (132) and the surface of the object to be inspected is maintained at a constant preset reference measurement distance. In addition, the inspection unit (167) can calculate a normal vector of the surface of the object to be inspected at each coordinate point of the 3D profile data and continuously control the posture of the multi-joint robot arm so that the optical axis of the measurement head unit (132) is parallel to the calculated normal vector while the measurement head unit (132) is moving. This enables precise measurement without angle error, even on severely curved surfaces of the object being inspected.

[0073] Next, the inspection unit (167) can perform variable speed control logic to actively adjust the driving speed of the robot according to the shape characteristics of the curved surface. Specifically, the inspection unit (167) can calculate the curvature value for each section of the inspection path by analyzing three-dimensional profile data. In flat sections where the calculated curvature value is less than a preset reference value, the inspection unit (167) can control the movement speed of the inspection module (130) to a first speed to shorten the inspection time, and in curved sections where the calculated curvature value is greater than the reference value, it can control the movement speed of the inspection module (130) to a second speed slower than the first speed. Through this, the inspection unit (167) can suppress vibration of the robot in sections where a sudden change in posture is required and ensure the stability of the measurement data.

[0074] Additionally, the inspection unit (167) can perform collision prevention logic using a virtual safety boundary to prevent collision between the inspection module (130) and the object to be inspected. Specifically, the inspection unit (167) can create a virtual safety boundary that is spaced upward from the actual surface of the object to be inspected, based on 3D profile data, by a pre-set safety margin. The inspection unit (167) monitors the real-time position while the inspection module (130) is moving, and if it is detected that the position of the inspection module (130) is encroaching upon the virtual safety boundary, it can perform an evasive maneuver to immediately stop the operation of the inspection module (130) or to move it away from the object to be inspected.

[0075] Furthermore, the inspection unit (167) can perform particle identification and path interpolation logic to prevent measurement errors and equipment malfunctions caused by dust or foreign substances attached to the surface of the object to be inspected. Specifically, the inspection unit (167) can analyze the rate of change in height between adjacent coordinates of the 3D profile data and identify a discontinuous point where the rate of change in height exceeds a preset threshold as a foreign substance section. When generating an inspection path, the inspection unit (167) can prevent abrupt lifting movements of the inspection module (130) by excluding the height data of the foreign substance section and performing interpolation processing to connect adjacent normal surface data, and can manage the physical property data measured in the foreign substance section by assigning a separate identification tag.

[0076] Moving along a controlled path in this manner, the inspection unit (167) can perform display optical characteristic evaluation logic. Specifically, the inspection unit (167) can calculate luminance and chromaticity by analyzing spectral data obtained from a spectrometer or colorimeter mounted on a measurement head unit (132), and evaluate color reproducibility by calculating the color difference with a target value. In addition, the inspection unit (167) can analyze uniformity by calculating the ratio of minimum luminance to maximum luminance within the screen, perform gamma characteristic evaluation analyzing the correlation of output luminance according to input gradation, and perform mura inspection to detect local stains.

[0077] In addition, the inspection unit (167) can perform post-processing and visualization logic on data to which identification tags are assigned. Specifically, the inspection unit (167) can store metadata including the start and end coordinates of the foreign substance section, the maximum protrusion height value, and the area information in the identification tag. Subsequently, the inspection unit (167) can generate a result map visualizing the physical property distribution of the object to be inspected and output it through the display module (140), and the area to which the identification tag is assigned is masked with identification information that distinguishes it from the normal measurement area, thereby allowing the operator to intuitively identify the location of the foreign substance.

[0078] Finally, the inspection unit (167) can perform a quality grade determination logic to determine whether the product is good or defective by synthesizing the inspection results. Specifically, the inspection unit (167) determines the quality grade of the object to be inspected based on the inspection results measured from the inspection module (130), and can automatically exclude physical property data to which identification tags have been previously assigned from the parameters for determining the quality grade. That is, by excluding data contaminated by foreign substances from the overall uniformity calculation or the defect determination population, the inspection unit (167) can prevent foreign substance issues from being misjudged as optical performance defects of the panel itself and improve the reliability of the determination.

[0079] With the following configuration, the storage unit (169) can perform the role of storing program commands, setting parameters, input / output data, etc., required for the operation of the control module (160).

[0080] Specifically, the storage unit (169) may store operating software and algorithms for implementing operations performed by the shape recognition unit (165) and the inspection unit (167). That is, the storage unit (169) may include a modeling algorithm that synthesizes 2D cross-sectional data into a 3D mesh, a computation algorithm that calculates normal vectors and curvature from 3D profile data, and a motion control algorithm that generates 6-degrees-of-freedom motion commands by analyzing the inverse kinematics of the multi-joint robot arm (131).

[0081] Additionally, the storage unit (169) can store reference parameters that serve as standards for the inspection process in a database. Specifically, the storage unit (169) may include a curvature reference value for controlling the movement speed of the inspection module (130), a safety margin distance value set for preventing collisions, a height change rate threshold for identifying foreign substances, and target color coordinates and an allowable color difference range that serve as standards for evaluating optical properties.

[0082] Furthermore, the storage unit (169) can systematically classify and store real-time data and final result data generated during the inspection process. That is, the storage unit (169) can store raw scan data obtained from the shape recognition module (120) and 3D profile data processed from it by mapping them to the unique identification code (ID) of the object to be inspected. In particular, metadata generated according to the foreign substance identification logic performed in the inspection unit (167), the start and end coordinates of the foreign substance section, the maximum protrusion height value, and the area information can be managed in a separate table or combined with the corresponding coordinate data in the form of a tag and stored.

[0083] In addition, the storage unit (169) stores the finally generated result map data, and can store image data in which areas identified as foreign substances are masked, and quality grade judgment results calculated with foreign substance data excluded, as production history management data. This data can be transmitted to an upper management server via the communication unit (161) later, or used as big data to analyze the cause of process defects.

[0085] Hereinafter, a curved profile-following inspection device according to another embodiment of the present invention will be described in detail.

[0086] FIG. 7 is an illustrative diagram for explaining a curved profile-following inspection device according to another embodiment of the present invention.

[0087] Meanwhile, the curved profile-following inspection device according to another embodiment of the present invention has substantially the same configuration as the curved profile-following inspection device according to one embodiment of the present invention described above, except that some components have been added. Therefore, the same reference numerals are assigned to identical components, and redundant descriptions are omitted.

[0088] Referring to FIG. 7, an inspection module (130) according to another embodiment of the present invention may further comprise an air nozzle (133, Air Nozzle) and a projector (134, Projector) coupled to one or both sides of a measurement head unit (132).

[0089] Specifically, the air nozzle (133) and the projector (134) can be connected to each side of the housing of the measurement head unit (132) via brackets and installed so as to be tilted at a predetermined angle toward the surface of the object to be inspected, and configured to share a focal point.

[0090] First, the air nozzle (133) can be connected to an external air compressor and solenoid valve through a flexible pneumatic tube wired along the inside or outside of the joint of the robot arm (131).

[0091] At this time, the end of the air nozzle (133) has a tapered shape with a gradually narrowing diameter to increase the fluid flow rate, and can spray high-pressure pulse air at a short response speed of several milliseconds according to the opening and closing signal of the control module (160).

[0092] To increase the efficiency of removing foreign substances, the control module (160) can effectively remove foreign substances strongly attached to the surface by controlling the robot arm (131) to vibrate slightly or rotate spirally around the foreign substances, in addition to simple continuous spraying.

[0093] Next, the projector (134) may be composed of a lightweight, ultra-small LCOS (Liquid Crystal on Silicon) or MEMS-based laser scanning module so as not to affect the load capacity of the robot.

[0094] In particular, when installing the projector (134), a calibration process may be performed to align the optical center coordinates of the measurement head unit (132) with the projection center coordinates of the projector. Through this, the control module (160) can precisely convert the detected defective coordinates into pixel coordinates of the projector and project them without distortion.

[0095] In terms of operation, the control module (160) can change the pattern projected by the projector (134) depending on the type of defect. For example, if there is a foreign matter defect, a 'red circular dot' is projected, and if there is a color difference defect, a 'blue square' is projected, or the measured 'luminance value (e.g., 150 nit)' next to the defect location is directly projected in text form, thereby maximizing the information delivery capability so that the operator can intuitively and immediately identify the type and degree of the defect without separate equipment.

[0096] As previously described, the control module (160) can analyze the rate of change in height between adjacent coordinates of the 3D profile data. If, as a result of the analysis, a point of abrupt discontinuity is detected where the rate of change in height exceeds a preset threshold, the control module (160) can identify that point as a particle section. At this time, the control module (160) can prevent unstable operation in which the inspection module (130) rapidly ascends and descends by excluding the protruding height data of the particle section when generating the inspection path and performing interpolation processing to smoothly connect adjacent normal surface data. Additionally, the control module (160) can manage the data obtained in that section by assigning an identification tag indicating 'low reliability' or 'suspected foreign substance'.

[0097] Furthermore, the control module (160) can perform an active cleaning and re-verification sequence on the identified foreign matter section. Specifically, the control module (160) can temporarily stop the driving of the inspection path as soon as the foreign matter section is identified. After that, the control module (160) can control the multi-joint robot arm (131) to position the nozzle of the air nozzle (133) so that it is precisely directed toward the foreign matter section, and then perform a cleaning operation by blowing high-pressure air. This is to physically remove simple dust or non-stick foreign matter. When the cleaning operation is completed, the control module (160) can re-scan the section using the measurement head unit (132) and update the shape data. If, as a result of analyzing the rescan data, the discontinuity point is resolved and the rate of change in height returns to the normal range, the control module (160) determines that the simple foreign substance has been removed, deletes the previously assigned identification tag, and resumes normal inspection. On the other hand, if the discontinuity point still exists even after air injection, the control module (160) determines it as an unremovable scratch or adhesion defect and makes a final defect determination.

[0098] Additionally, the control module (160) can perform an augmented reality (AR)-based marking function by utilizing a projector (134) to directly visualize inspection results on the surface of the object to be inspected (10). The control module (160) can monitor physical property data, such as luminance and color difference, measured in real time while the inspection module (130) moves along the inspection path. If a defect is detected where the measurement data at a specific point deviates from a preset normal range, the control module (160) can immediately control the projector (134) to project a marker image indicating the location of the defect onto the actual surface of the object to be inspected (10). For example, by projecting an 'X' mark or a red circular pattern onto the coordinates where the defect occurred, the control module (160) can support the worker in visually identifying the location of the defect as soon as they look at the product surface without checking a separate monitor. This can provide the effect of significantly improving the efficiency of repair work in subsequent processes.

[0100] As described above, preferred embodiments of the present invention have been disclosed in this specification and drawings; however, it is obvious to those skilled in the art that other variations based on the technical spirit of the present invention are possible in addition to the embodiments disclosed herein. Furthermore, although specific terms have been used in this specification and drawings, they are used merely in a general sense to facilitate the explanation of the technical content of the present invention and to aid in understanding the invention, and are not intended to limit the scope of the present invention. Accordingly, the detailed description above should not be interpreted restrictively in any respect and should be considered illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included within the scope of the present invention. Explanation of the symbols

[0101] 100: Curved profile-following inspection device 110: Support module 111 : Base plate 112 : Guide unit 113: Robot-mounted unit 114: Frame 115: Output unit 120: Shape recognition module 121: Transfer unit 122: Laser displacement sensor 130: Inspection Module 131: Multi-joint Robot Arm 132: Measuring head unit 133: Air nozzle 134 : Projector 140 : Display module 150: Input Module 160: Control Module

Claims

Claim 1 A support module having a mounting area on which an object to be inspected is placed; a shape recognition module that scans the shape of the object to be inspected located in the mounting area and generates 3D profile data for the surface curvature of the object to be inspected; an inspection module installed adjacent to the mounting area and measuring the physical properties of the object to be inspected while moving and maintaining a preset distance from the surface of the object to be inspected based on the 3D profile data generated from the shape recognition module; and a control module that generates an inspection path following the surface curvature of the object to be inspected based on the 3D profile data generated from the shape recognition module and controls the operation of the inspection module along the generated inspection path; wherein the inspection module comprises: a multi-joint robot arm having a plurality of joints; a measurement head unit mounted at the end of the multi-joint robot arm and including a light source that irradiates light onto the object to be inspected and an optical sensor that receives reflected light and analyzes optical characteristics; and an air nozzle provided on one side of the measurement head unit and spraying air.A curved profile-following inspection device comprising: a control module that analyzes the rate of change in height between adjacent coordinates of the 3D profile data; identifies a discontinuous point where the rate of change in height exceeds a preset threshold as a particle section when such point is detected; performs interpolation processing to exclude the height data of the particle section and connect adjacent normal surface data when generating the inspection path to prevent abrupt lifting movements of the inspection module; assigns an identification tag to the physical property data measured in the particle section; and when the particle section is identified, temporarily suspends the driving of the inspection path and controls the inspection module to direct the air nozzle toward the particle section to perform a cleaning operation of air blowing, after which the section is rescanned to update shape data, wherein if the discontinuous point is resolved as a result of the rescan, the identification tag is deleted, and if the discontinuous point still exists, it is confirmed as a stickiness defect. Claim 2 The curved profile-following inspection device according to claim 1, wherein the support module comprises: a base plate having an upper surface formed flat to provide a working area on which an object to be inspected is seated and fixed; a guide unit extending lengthwise on both sides along the longitudinal direction of the base plate and to which the shape recognition module is slidably coupled; and a robot mounting unit disposed on the base plate at the rear of the guide unit and to which the inspection module is firmly fixedly installed. Claim 3 In claim 2, the shape recognition module comprises: a transfer unit that moves along the longitudinal direction of the object to be inspected along the guide unit; and a laser displacement sensor installed at the end of the transfer unit, which irradiates a measurement light downward and scans the entire area of ​​the object to be inspected seated on the base plate according to the movement of the transfer unit; and the control module is characterized by generating the 3D profile data by synthesizing a plurality of 2D cross-sectional profile data obtained by the shape recognition module scanning along the longitudinal direction of the object to be inspected. Claim 4 delete Claim 5 A curved profile-following inspection device according to claim 1, wherein the control module corrects the Z-axis position of the multi-joint robot arm in real time so that the distance between the end of the measurement head unit and the surface of the object to be inspected is maintained at a constant preset reference measurement distance by reflecting the height information of the 3D profile data that changes in real time while the measurement head unit moves along the inspection path. Claim 6 A curved profile-following inspection device according to claim 5, wherein the control module calculates a normal vector of the surface of the object to be inspected at each coordinate point of the 3D profile data, and continuously controls the posture of the multi-joint robot arm so that the optical axis of the measurement head unit is parallel to the calculated normal vector while the measurement head unit moves along the inspection path. Claim 7 A curved profile-following inspection device according to claim 1, wherein the control module analyzes the 3D profile data to calculate a curvature value for each section of the inspection path, controls the movement speed of the inspection module to a first speed in flat sections where the calculated curvature value is less than a preset reference value, and controls the movement speed of the inspection module to a second speed slower than the first speed in curved sections where the calculated curvature value is greater than or equal to the reference value. Claim 8 A curved profile-following inspection device according to claim 1, wherein the control module generates a virtual safety boundary spaced upward from the actual surface of the object to be inspected, determined based on the 3D profile data, by a preset safety margin, and monitors the real-time position while the inspection module moves, and if the position of the inspection module is detected to encroach upon the virtual safety boundary, the operation of the inspection module is immediately stopped or the module is retracted in a direction away from the object to be inspected. Claim 9 delete Claim 10 The curved profile-following inspection device according to claim 1 further comprises a display module that outputs the inspection result of the inspection target measured by the inspection module; wherein the control module stores the start and end coordinates of the foreign substance section, the maximum protrusion height value, and area information as metadata in the identification tag, generates a result map visualizing the physical property distribution of the inspection target and outputs it through the display module, and displays the area to which the identification tag is assigned by masking it with identification information that is distinguished from the normal measurement area.

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