Exterior inspection apparatus and method

Abstract

An exterior inspection apparatus according to the present invention comprises: a light source for emitting light at the surface of an object to be inspected; a screen onto which the light emitted from the light source is reflected from the surface of the object to be inspected and the reflected light is projected; a camera for capturing the light projected onto the screen; and a control unit, which analyzes a surface image of the object to be inspected, captured through the camera, so as to determine defects of the surface.

Description

Appearance inspection device and method

[0001] The present invention relates to an exterior inspection device and an exterior inspection method using a laser, and more particularly, to an exterior inspection device and an exterior inspection method using a three-dimensional reverse-polarization line laser, including a three-dimensional reverse-polarization line laser and a configuration for adjusting the position and angle of a light source and a camera when photographing reflected light formed on a screen. Therefore, the invention is applicable to the technical fields of a used mobile phone exterior inspection device, a used electronic device exterior inspection device, and an automobile exterior surface inspection device.

[0002] The information contained in this background section is intended to enhance understanding of the background of the invention and may include matters that are not prior art and are already known to those of ordinary skill in the art.

[0003] Due to the rapid development of semiconductor and information and communication technologies, manufacturers are releasing new and improved products every year, which is causing existing electronic products such as mobile phones, PCs, and tablets to become second-hand products, and the cycle of this second-hand product repurposing is gradually shortening.

[0004] Consumers purchase these used products at relatively low prices and reuse them. In particular, the appearance of used mobile phones is a key factor in determining their resale value. In the process of inspecting the appearance of a used mobile phone to determine its grade and, based on this, to determine its purchase / sale price, conventional exterior inspection devices illuminate the surface of the inspection target (such as a used mobile phone) with light and photograph the illuminated area with a camera to determine whether there are any defects on the surface, such as scratches, breaks, damage, crazing, or other defects. These devices have the necessary components to perform such inspections.

[0005] In particular, in the case of mobile phones, the upper surface is equipped with tempered glass to cover and protect the screen, but the tempered glass can be damaged by scratches, cracks, etc., and there was a need for more precise condition analysis of the tempered glass, which is a relatively expensive product.

[0006] However, conventional exterior inspection devices and inspection methods had to perform inspections with uneven brightness areas and low contrast, and it was difficult to precisely determine the area and degree of wear, such as scratches on the glass surface, due to diffuse light reflection. In addition, it was difficult to inspect the surface of an inspection object while it was being transported, so a method had to be used to temporarily stop the inspection object for exterior inspection, then irradiate light and photograph the surface, which resulted in a somewhat slow inspection speed.

[0007] Therefore, a specific method to solve the above problems is required.

[0008] The exterior inspection device and exterior inspection method using a three-dimensional reverse-polarization line laser corresponding to the present invention have a more precise surface defect detection performance and aim to shorten the inspection time in the fields of a used mobile phone exterior inspection device, a used electronic device exterior inspection device, and an automobile exterior surface inspection device.

[0009] In order to solve the above problem, the present invention discloses an appearance inspection device characterized by including a light source that irradiates light onto the surface of an inspection object, a screen on which the light irradiated from the light source is reflected from the surface of the inspection object and the reflected light is projected, a camera that photographs the light projected onto the screen, and a control unit that analyzes the surface image of the inspection object photographed through the camera and determines the bonding of the surface.

[0010] In the above, a first driving unit that is connected to a light source and adjusts an angle of light irradiation of the light source, and a second driving unit that is connected to the camera and adjusts an angle of the camera are further included, wherein the control unit can control the first driving unit and the second driving unit according to the size, height, and reflectivity of the inspection target.

[0011] In the above, the light source is configured as a line laser, the camera is configured as an area camera, the screen is positioned between the surface of the inspection object and the camera, and light reflected on the surface of the inspection object can be reverse-deflected.

[0012] In the above, at least one camera may be formed, and may include a first camera that photographs a reflection point where light irradiated from the light source is reflected, and a second camera that photographs a projection point where the reflected light is projected onto the screen.

[0013] In the above, the camera further includes an auto-focus control unit, and the auto-focus control unit is controlled by the control unit and can automatically adjust the focus of the camera according to the surface thickness of the inspection target.

[0014] In the above, a cleaning unit for removing foreign substances from the surface of the inspection object may be further included.

[0015] In the present invention, a method for external appearance inspection may be disclosed, including the steps of adjusting a light irradiation angle of a light source and a shooting angle of a camera, a step of irradiating the light and reflecting it from a surface of an inspection object, a step of projecting the reflected light onto a screen, a step of automatically adjusting the focus of the camera according to the surface thickness of the inspection object, a step of photographing a projection point projected onto the screen with the camera, and a step of analyzing the photographed surface image of the inspection object to determine a surface defect, wherein the light source is composed of a line laser, the screen is positioned between the surface of the inspection object and the camera, the step of adjusting the light irradiation angle of the light source is performed by a first driving unit that is connected to the light source and adjusts the light irradiation angle of the light source, the step of adjusting the shooting angle of the camera is performed by a second driving unit that is connected to the camera and adjusts the angle of the camera, the step of automatically adjusting the focus of the camera is performed by an automatic focus control unit included in the camera, and the light reflected on the surface of the inspection object may be reverse-deflected.

[0016] The appearance inspection device and appearance inspection method using a 3D reverse-polarization line laser corresponding to the present invention can precisely detect minute defects (scratches, breakage, nicks, scratches, etc.) on a non-metallic surface such as glass, compared to a conventional photographing method using visible light, through a configuration that adjusts the position and angle of a light source and a camera when photographing the reflected light formed on the 3D reverse-polarization line laser and the screen.

[0017] Additionally, it has the effect of easily detecting surface defects in the form of edges as well as planes.

[0018] In addition, it has the effect of shortening the time for external inspection as it allows for quick surface inspection while transporting the inspection object.

[0019] The effects according to the present invention are not limited to the contents presented above, and more diverse effects are included in this specification.

[0020] Embodiments of the present disclosure may be better understood by reference to the following description taken in conjunction with the accompanying drawings in which like reference numerals designate identical or functionally similar elements.

[0021] Figure 1 is a conceptual diagram of an exterior inspection device according to one embodiment of the present invention.

[0022] Figure 2 is a perspective view of an exterior inspection device according to an embodiment of the present invention.

[0023] Figure 3 is a front view of an exterior inspection device according to an embodiment of the present invention.

[0024] FIG. 4 is a conceptual diagram illustrating an appearance of a driving unit added to an exterior inspection device according to one embodiment of the present invention.

[0025] FIG. 5 is a conceptual diagram illustrating an appearance in which an additional device is added to an exterior inspection device according to one embodiment of the present invention.

[0026] FIG. 6 is a drawing illustrating a transport device added to an exterior inspection device according to one embodiment of the present invention.

[0027] Figure 7 is a flowchart illustrating an appearance inspection method according to one embodiment of the present invention.

[0028] FIG. 8 is a flowchart illustrating a method for identifying a defect status by applying defect data learned by machine learning of artificial intelligence in an appearance inspection method according to another embodiment of the present invention.

[0029] The drawings referenced above are not necessarily drawn to scale, but should be understood to present rather simplified representations of various preferred features that illustrate the fundamental principles of the present disclosure. For example, specific design features of the present disclosure, including specific dimensions, orientations, positions, and shapes, will be determined in part by the specific intended application and usage environment.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will also be understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any one or all combinations of the associated listed items.

[0031] Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element in between. Furthermore, when a part is said to "include" a component, this should be understood to mean that, unless specifically stated to the contrary, it may include other components rather than excluding other components, and does not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] In the present disclosure, a vertical direction may be defined. The vertical direction may be a direction substantially perpendicular to the ground. The forward / backward direction may be a direction perpendicular to the vertical direction, and the left / right direction may be a direction perpendicular to both the vertical direction and the forward / backward direction.

[0033] Hereinafter, the present invention will be described in more detail through the following embodiments of the invention.

[0034] FIG. 1 is a conceptual diagram of an exterior inspection device according to an embodiment of the present invention, FIG. 2 is a perspective view of an exterior inspection device according to an embodiment of the present invention, FIG. 3 is a front view of an exterior inspection device according to an embodiment of the present invention, FIG. 4 is a conceptual diagram illustrating an exterior inspection device with a drive unit added according to an embodiment of the present invention, FIG. 5 is a conceptual diagram illustrating an exterior inspection device with an additional device added according to an embodiment of the present invention, and FIG. 6 is a diagram illustrating an exterior inspection device with a transport device added according to an embodiment of the present invention.

[0035] In particular, as can be seen with reference to FIG. 1, the appearance inspection device (1) according to the present invention may include a light source (10) that irradiates light onto the surface of an inspection object, a screen (30) on which light irradiated from the light source (10) is reflected from the surface of the inspection object and the reflected light is projected, a camera (20) that photographs the light projected onto the screen, and a control unit (40) that analyzes the surface image of the inspection object photographed through the camera (20) to determine the bonding of the surface.

[0036] The above light source is preferably a laser with linear properties. As long as it possesses linear properties, it can be converted into any other light source within the scope that can be borrowed by a skilled artisan. Furthermore, the above light source can be converted into a pattern laser that irradiates a specific pattern, in addition to a laser with linear properties.

[0037] The inspection target is typically the exterior of a used mobile phone, the exterior of a used electronic device, the exterior of a car, etc., and any object that can be checked for surface flaws, scratches, or defects is fine. It is also obvious that the specifications of the exterior inspection device can be expanded to any level that a typical technician can, depending on the size of the inspection target. The control unit (40) has a built-in function that can determine surface defects of the inspection target, and this can be any type of technology that can be borrowed at the level of a typical technician.

[0038] In particular, as can be seen with reference to FIGS. 2 and 3, the light source (10) may be configured as a line laser as described above, the camera (20) may be configured as an area camera capable of photographing and recording images of a wide area, and the screen (30) may be positioned between the surface of the inspection object and the camera. The screen (30) may be made of any material that can form a shape by projecting light reflected from the surface of the inspection object. In particular, one of the core technical concepts of the present invention is that the light reflected on the surface of the inspection object can be reversely deflected. Since the light irradiated by the light source is reflected on the surface of the inspection object and the shape projected on the screen (30) is photographed by the camera (20), the user can freely adjust the brightness of the light source, and a surface light source filter that can convert the light source into a surface light source in consideration of the properties of the surface of the inspection object can be additionally used. Alternatively, a narrow-angle filter that can make the angle of the light source narrow can be used to increase the efficiency of brightness with the same light source.

[0039] The above camera (20) may be equipped with at least one external inspection device, and as an example, may include a first camera (201) that photographs a reflection point where light irradiated from the light source (10) is reflected, and a second camera (202) that photographs a projection point where the reflected light is projected onto the screen (30). By installing a plurality of cameras, observation errors can be reduced, and only the second camera (202) may be equipped with the external inspection device.

[0040] The above camera (20) may be a relatively expensive component among the components of the present invention, and may be a component that may need to be replaced for the purpose of repair or quality improvement.

[0041] In addition, as can be seen with reference to FIG. 4, the exterior inspection device (1) according to the present invention may further include a first driving unit (11) that is connected to the light source (10) to adjust the light irradiation angle of the light source (10), and a second driving unit (21) that is connected to the camera (20) to adjust the shooting angle of the camera (20). Since the shooting direction of the camera (20) and the light irradiation angle of the light source (10) are bound to change depending on the type, surface area and thickness, reflectivity, etc. of the inspection target, a means for controlling these variables is required. Accordingly, the control unit (40) can control the first driving unit (11) and the second driving unit (21) depending on the size, height, and reflectivity of the inspection target. The first driving unit (11) and the second driving unit (21) may be controlled integrally, or may be controlled individually depending on the situation.

[0042] As an example, referring to the aforementioned FIG. 3, if the V vector component of light irradiated from the light source and the angle of incidence on the inspection surface are known, the reflection angle (2Ф) can also be estimated, and if the reflection angle and the W vector component of the reflected light are calculated, the values ​​of L1 and L2 can be obtained by the Pythagorean theorem (since the square of L1 and the square of L2 become the square of W, the lengths of L1 and L2 can be adjusted according to the absolute value of W, which ultimately becomes the coordinates of the arrangement position of the screen (30).), the screen (30) can be arranged according to the length values ​​of L2 and L1, and the angle of the camera (20), etc. can be adjusted according to the arranged screen (30).

[0043] In addition, as can be seen with reference to FIG. 5, the camera (20) may further include an auto-focus control unit (200). Since the auto-focus control unit (200) can independently set the focus of the camera (20) or be controlled by the control unit (40), the focus of the camera (20) can be automatically adjusted according to the surface thickness of the inspection target according to the instructions of the control unit (40).

[0044] In addition, the appearance inspection device (1) corresponding to the present invention may further include a cleaning unit (50) for removing foreign substances from the surface of the inspection object. By cleaning the surface of the inspection object with the cleaning unit (50), unexpected errors such as diffuse reflection or total reflection that may occur from an irregular surface containing foreign substances can be prevented in advance.

[0045] In particular, as can be seen with reference to Fig. 6, the exterior inspection device (1) corresponding to the present invention can perform an exterior inspection in a manner in which the inspection target is transported by a transport device (60). As an example, the transport device (60) may correspond to a conveyor belt or a cylindrical rail. The inspection target is transported by the transport device (60) and reaches a pre-set light source irradiation point, and at this time, a light source is irradiated onto the surface of the inspection target moving from the light source, and the reflected light is projected onto a screen.

[0046] For example, when the inspection target reaches the light source irradiation point, the transport device (60) may be stopped for a moment, and light may be irradiated to the entire surface of the inspection target by adjusting the angle of the light source (10) and the camera (20), etc. The shape of the light reflected in this way and projected onto the screen may be transmitted to an electronic medium and recorded over time, and data may also be derived from photographs or videos taken in a panoramic format. Alternatively, by arranging a plurality of inspection targets in a row on the transport device (60), the surfaces of the plurality of inspection targets may be inspected sequentially and automatically within a short period of time as the inspection targets sequentially reach the light source irradiation point at regular intervals. In addition, it is natural that the inspection target may be stopped at the inspection position to perform an appearance inspection.

[0047] In addition, by installing a light source (10), a camera (20), and a screen (30), it is possible to inspect the upper surface while inspecting at least one of the lower surface, upper / lower / left / right sides.

[0048] Next, the appearance inspection method using the appearance inspection device below will be sequentially explained.

[0049] FIG. 7 is a flowchart illustrating an appearance inspection method according to one embodiment of the present invention, and FIG. 8 is a flowchart illustrating a method of identifying a defect status by applying defect data learned by machine learning of artificial intelligence in an appearance inspection method according to another embodiment of the present invention.

[0050] In particular, as can be seen with reference to FIG. 7, the light irradiation angle of the light source (10) and the shooting angle of the camera (20) can be adjusted in advance according to the specifications of the inspection object, and thereafter, the light is irradiated and reflected from the surface of the inspection object. The reflected light is projected onto the screen (30) to form a certain shape, and in the process, a step of automatically adjusting the focus of the camera (20) according to the surface thickness of the inspection object can be initiated. A step of capturing the projection point projected onto the screen (30) with the camera (20) to secure data in the form of a video or an image in a time-series order, and such data is transmitted to the control unit (40), and the control unit (40) analyzes the surface image of the inspection object captured above to determine surface defects.

[0051] In particular, in the above process, the light source (10) may be configured as a line laser, and the screen (30) may be positioned between the surface of the inspection object and the camera (20). The step of adjusting the light irradiation angle of the light source (10) may be performed by a first driving unit (11) that is connected to the light source (10) and adjusts the light irradiation angle of the light source (10), and the step of adjusting the shooting angle of the camera (20) may be performed by a second driving unit (21) that is connected to the camera (20) and adjusts the angle of the camera (20). The step of automatically adjusting the focus of the camera (20) may be performed according to an automatic focus control unit (200) included in the camera. Therefore, one of the technical features of the present invention is to adjust the corresponding appearance inspection device and appearance inspection method so that the light reflected on the surface of the inspection object is reversely deflected.

[0052] In the case of the present invention, the accuracy of the appearance inspection can be increased by utilizing artificial intelligence. In particular, as can be seen with reference to FIG. 8, the appearance inspection device of the present invention can further include an artificial intelligence system, and this artificial intelligence system can be electrically connected to the control unit (40) to receive the collected appearance inspection data as an electrical signal.

[0053] By collecting this kind of visual inspection data, algorithms for solutions can be developed for actual visual inspections. These algorithms are typically developed through AI's machine learning or deep learning. Specifically, they can classify the collected surface defect data by defect type and then categorize the classified data by defect severity. Generally, machine learning can be a branch of artificial intelligence. Machine learning can be defined as the ability to learn without explicit programming.

[0054] In other words, since a default value or average sample value is derived from the data, a comprehensive benchmark for defect data can be established. Users can compare actual measured surface defect data with this benchmark value to determine the current status.

[0055] For example, data can be divided into two groups, one with a defect-free appearance and one with a defect, and data with different degrees of defects can be sampled to distinguish the degree of defects from 1 to 5, etc. If additional data is required in the process of determining the degree of defect data in artificial intelligence, the additional data can be acquired through electrical connection with the control unit (40), and if it is unclear which grade to determine based on the range of error in the process of determining the degree, the retransmission of the relevant data can be requested to the control unit (40) to attempt a re-evaluation.

[0056] Once surface defect data is acquired, the type and severity of the defect can be determined by comparing it to the reference values ​​generated by the AI. Based on the type and severity of the defect, the AI ​​can then provide a solution. For example, solutions could include component replacement or disposal. This process is repeated indefinitely, continuously accumulating data and further segmenting the defect type and severity.

[0057] In the present invention, the user terminal may be implemented with a recording medium containing software and an application stored on the recording medium to control the external inspection device. In other words, the method for controlling the external inspection device may be implemented as software or the like and stored on a medium, or may be implemented as a device equipped with the software.

[0058] Software may include computer programs, codes, instructions, or a combination of one or more of these, which may configure a processing device to perform a desired operation or may, independently or collectively, command the processing device. The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal waves, for interpretation by the processing device or for providing instructions or data to the processing device. The software may also be distributed over networked computer systems and stored or executed in a distributed manner. The software and data may be stored on one or more computer-readable recording media.

[0059] The method according to an embodiment of the present invention may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination. The program commands recorded on the medium may be those specially designed and configured for the embodiment or may be those known and available to those skilled in the art. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands, such as ROMs, RAMs, and flash memories. Examples of the program commands include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiment, and vice versa.

[0060] In general, the most desirable 3D reverse-polarization line laser and the ability to adjust the position and angle of the light source and camera when photographing the reflected light formed on the screen allow for precise detection of minute defects on the surface, and also have the effect of shortening the inspection time.

[0061] The foregoing description of the present invention is provided for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, components described as being single may be implemented in a distributed manner, and similarly, components described as being distributed may be implemented in a combined manner.

[0062] The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A light source that irradiates light onto the surface of the inspection object. The light irradiated from the above light source is reflected from the surface of the inspection object, and the screen on which the reflected light is projected, A camera that captures the light projected onto the above screen, A control unit that analyzes a surface image of an inspection object captured through the camera and determines the bonding of the surface; An appearance inspection device characterized by including:

2. In paragraph 1, A first driving unit connected to the light source and controlling the light irradiation angle of the light source; and Further comprising a second driving unit that is connected to the camera and adjusts the shooting angle of the camera, An appearance inspection device characterized in that the control unit controls the first driving unit and the second driving unit according to the size, height, and reflectivity of the inspection target.

3. In paragraph 1, The above light source is composed of a line laser, The above camera is configured as an area camera, The above screen is located between the surface of the inspection object and the camera, An appearance inspection device characterized in that light reflected on the surface of the inspection object is reversely deflected.

4. In paragraph 1, At least one of the above cameras is formed, A first camera that photographs a reflection point where light emitted from the light source is reflected; An appearance inspection device characterized by including a second camera that photographs a projection point where the reflected light is projected onto the screen.

5. In any one of paragraphs 1 to 4, The above camera further comprises an autofocus control unit, An appearance inspection device characterized in that the auto focus adjustment unit is controlled by the control unit and automatically adjusts the focus of the camera according to the surface thickness of the inspection target.

6. In paragraph 5, An appearance inspection device characterized in that it further includes a cleaning unit for removing foreign substances from the surface of the inspection target.

7. In the method of external inspection, A step of adjusting the light irradiation angle of a light source and the shooting angle of a camera; A step of irradiating the above light and reflecting it from the surface of the inspection object; A step in which the reflected light is projected onto a screen; A step of automatically adjusting the focus of the camera according to the surface thickness of the inspection target; A step of photographing a projection point projected on the above screen using the camera; and A step of analyzing the surface image of the photographed inspection object to determine surface defects; Including, but not limited to, The above light source is composed of a line laser, The above screen is positioned between the surface of the inspection object and the camera, The step of adjusting the light irradiation angle of the light source is performed by a first driving unit that is connected to the light source and adjusts the light irradiation angle of the light source. The step of adjusting the shooting angle of the above camera is performed by a second driving unit that is connected to the camera and adjusts the angle of the camera. The step of automatically adjusting the focus of the above camera is performed according to the auto focus control unit included in the camera, An appearance inspection method characterized in that light reflected on the surface of the inspection object is reversely deflected.

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