Hybrid optical apparatus

Abstract

The present invention relates to a hybrid optical device and a surface condition detection method, comprising a light source unit that irradiates light onto a moving object, a first image acquisition unit that directly acquires a first image from light reflected from the object, an image forming unit in which light reflected from the object forms a second image, and a second image acquisition unit that acquires the second image.

Description

Technology Field

[0001] The present invention relates to a hybrid optical device and a surface condition detection method. Background Technology

[0002] One type of surface inspection system known as a bright field often illuminates a large area in a system known as flood illumination. A high-resolution image of the illuminated area of ​​the surface is obtained from radiation reflected by the surface by a two-dimensional imaging optics as the surface is scanned beneath the imaging optics. Due to the data transfer rate required for imaging, such systems require sufficient time to image the entire surface of a photomask or semiconductor wafer. In some bright field systems, radiation from the source passes through a beam splitter toward the surface being imaged, and radiation reflected from the surface passes through the beam splitter again before being directed toward the detector. Therefore, the radiation passes through the beam splitter twice between the source and the detector, causing the intensity of the radiation to be significantly reduced upon reaching the detector. This greatly reduces the amount of photons originating from the source reaching the detector and thus reduces the sensitivity of the bright field inspection. Therefore, it is desirable to provide an improved bright field system in which such defects do not exist.

[0003] Recently, methods for detecting the surface of moving objects using 3D optical systems have been introduced. Such 3D optical systems require separate lighting or projector beams, or are constructed using only optical systems of the same type. However, configuring optical devices in this way requires a large installation space, and there were problems with reduced surface detection capability because the same image is acquired repeatedly.

[0004] The background technology of the present invention is disclosed in Korean Patent Registration No. 10-0052604 (Registered on June 30, 1992; Title of Invention: Device and Method for Detecting Surface Defects of Wire Using Optics).

[0005] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The problem to be solved

[0006] The purpose of the present invention is to provide a hybrid optical device and a surface state detection method capable of improving surface detection performance.

[0007] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0008] A hybrid optical device according to one aspect of the present invention may comprise: a light source unit that irradiates light onto a moving object; a first image acquisition unit that acquires a first image from the light reflected from the object; an image forming unit in which the light reflected from the object forms a second image; and a second image acquisition unit that acquires the second image.

[0009] The light above includes a laser, and the first image acquisition unit and the second image acquisition unit may include a camera.

[0010] The light source unit irradiates the light onto the object at an angle based on the direction of movement of the object, and the first image acquisition unit may be positioned in a direction perpendicular to the direction of movement of the object.

[0011] The image forming unit may be positioned in an area different from the area where the light source unit is located, based on a virtual line connecting the object and the first image acquisition unit.

[0012] The second image above may be larger than the first image above.

[0013] The present invention further includes a control unit that receives the first image from the first image acquisition unit and acquires the second image from the second image acquisition unit, and the control unit can detect the surface state of the object by comparing the first image and the second image.

[0014] The light source unit may be positioned at an angle of 20° to 45° relative to the direction of movement of the object, the image forming unit may be positioned at an angle of 135° to 160° relative to the direction of movement of the object, and the first image acquisition unit may be positioned at a 90° relative to the direction of movement of the object.

[0015] The light source unit, the first image acquisition unit, and the second image acquisition unit may each be one.

[0016] The first image acquisition unit can directly acquire the first image from the light reflected from the object, and the second image acquisition unit can acquire the second image from the light reflected from the object in an amplification manner.

[0017] The above image forming part may be a screen.

[0018] A surface condition detection method according to another aspect of the present invention may include: (a) irradiating a moving object with a laser; (b) acquiring a first image from the laser reflected from the object; (c) forming a second image on an image forming part from the laser reflected from the object; (d) capturing the second image to acquire the second image; and (e) detecting the surface condition of the object from the first image and the second image.

[0019] The second image above may be larger than the first image above. Effects of the invention

[0020] The hybrid optical device and surface condition detection method according to the present invention can reduce installation space by applying two different types of optical systems to simplify the structure.

[0021] In addition, the present invention can acquire images using a single illumination unit, not only the conventional direct method but also the amplification method, thereby increasing surface detection capability.

[0022] In addition, the present invention can improve surface detection capability and reliability of detection by using images obtained by a direct method and images obtained by an amplification method.

[0023] In addition, since the present invention can detect the surface condition of an object using a laser irradiated from a lighting unit, separate lighting is not required.

[0024] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below. Brief explanation of the drawing

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a conceptual diagram illustrating a hybrid optical device according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating the image acquisition process of a hybrid optical device according to one embodiment of the present invention. FIG. 3 is a diagram showing the process of forming a second image in an image forming part according to an embodiment of the present invention. FIG. 4 is a drawing showing a second image formed in an image forming part according to an embodiment of the present invention. FIG. 5 is a drawing showing a defect on the surface of an object according to one embodiment of the present invention and a first image and a second image obtained from the defect. FIG. 6 is a flowchart showing a surface condition detection method according to one embodiment of the present invention. Specific details for implementing the invention

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0027] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0028] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0029] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0030] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0031] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0032] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0033] Furthermore, where one component is described as being "on," "connected to," or "coupled to" another component, it should be understood that while the components may be directly connected or coupled to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "coupled" through another component.

[0034] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Additionally, the use of “may” when describing embodiments of the present disclosure relates to “one or more embodiments of the present disclosure.” Expressions such as “one or more” and “one or more” preceding a list of elements modify the entire list of elements and do not modify individual elements of the list.

[0035] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less, unless specifically stated otherwise.

[0036] When syntax such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one selected from the group of A, B, and C", or "at least one selected from A, B, and C" is used to specify a list of elements A, B, and C, the syntax can refer to any suitable combination.

[0037] The term "use" may be considered synonymous with the term "utilize." As used herein, "substantially," "about," and similar terms are used as terms of approximation rather than degree, and are intended to account for the inherent variation of measured or calculated values ​​that a person skilled in the art would recognize.

[0038] In this specification, terms such as first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Accordingly, the first element, component, region, layer, or section discussed below may be named the second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0039] Spatial relative terms such as "beneath," "below," "lower," "above," and "upper" may be used herein for ease of explanation to describe the relationship between one element or feature and another element(s) or feature(s) as illustrated in the drawings. Spatially relative positions are to be understood as encompassing different orientations of the device in use or operation, in addition to the orientations depicted in the figures. For example, if the device in the drawing is inverted, an element described as "below" or "below" is understood as "above" or "upper" of another element. Thus, the term "below" may encompass both the up and down directions.

[0040] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0041] FIG. 1 is a conceptual diagram illustrating a hybrid optical device according to one embodiment of the present invention, and FIG. 2 is a block diagram illustrating an image acquisition process of a hybrid optical device according to one embodiment of the present invention.

[0042] Referring to FIGS. 1 and 2, a hybrid optical device according to one aspect of the present invention (1) includes a light source unit (10) that irradiates light (L1) onto a moving object (15), a first image acquisition unit (20), an image forming unit (30), and a second image acquisition unit (40).

[0043] In this embodiment, the object (15) may move parallel from the left to the right direction of FIG. 1. Alternatively, it may move parallel from the right to the left direction of FIG. 1.

[0044] The light source unit (10) can irradiate light (L1) onto a moving object (15). In this embodiment, the case where the light (L1) irradiated from the light source unit (10) is a laser is described as an example, but the present invention is not limited thereto, and various forms of light capable of achieving the purpose of the present invention may be used. As one embodiment, the light source unit (10) can irradiate light (L1) onto the object (15) at an angle relative to the direction of movement of the object (15). It is preferable that the light source unit (10) be positioned at an angle of 20° to 45° relative to the direction of movement of the object (15). That is, the light (L1) irradiated from the light source unit (10) can be incident on the object (15) at an angle of 20° to 45°. As one embodiment, the light source unit (10) may be a line laser beam.

[0045] The first image acquisition unit (20) can acquire a first image from light (L2) reflected from an object (15). In this embodiment, the first image acquisition unit (20) may include a camera. In one embodiment, the first image acquisition unit (20) may be a direct 3D optical system. The first image acquisition unit (20) can acquire a first image of the height shape generated after light (L1) irradiated from the light source unit (10) to the object (15) is reflected from the object (15). In one embodiment, the first image acquisition unit (20) may be positioned in a direction perpendicular to the direction of movement of the object (15). That is, the first image acquisition unit (20) may be positioned at a 90° angle relative to the direction of movement of the object (15) so that light can be reflected. Additionally, the first image acquisition unit (20) can directly acquire the first image from the light (L2) irradiated from the object (15). Since the method of acquiring the image is obvious to those skilled in the art, a detailed explanation thereof will be omitted.

[0046] In the image forming unit (30), light (L3) reflected from the object (15) forms a second image. In one embodiment, the image forming unit (30) may be positioned in an area different from the area where the light source unit (10) is located, based on a virtual line connecting the object (15) and the first image acquisition unit (20). For example, the object (15) and the first image acquisition unit (20) may be positioned between the image forming unit (30) and the light source unit (10). The second image is an image formed in the image forming unit (30) by light (L3) reflected from the object (15). At this time, the second image is amplified and formed in the image forming unit (30). The second image may be larger than the first image as an amplified image. For example, when light (L1) is irradiated from the light source unit (10) onto the object (15) using the principle of amplification, if there is a fine defect on the object (15), the light (L3) reflected due to the difference in inclination between the fine defect and the flat surface is amplified in the vertical direction, and a second image is generated in the image forming unit (30). In one embodiment, the image forming unit (30) may be positioned at a distance of at least 300 mm in the horizontal direction (movement direction of the object (15)) from the point where the light (L1) is incident on the object (15). Additionally, the image forming unit (30) may be positioned at an angle of 135° to 160° relative to the movement direction of the object (15). That is, the image forming unit (30) can be positioned opposite the light source unit (10) based on the position where light is incident on the object (15). In one embodiment, the image forming unit (30) may be a screen on which an image is formed.

[0047] The second image acquisition unit (40) can acquire the second image formed on the image forming unit (30). That is, the second image acquisition unit (40) can acquire the second image formed by amplification on the image forming unit (30) in an amplification manner. As an embodiment, the second image acquisition unit (40) may include a camera.

[0048] The control unit (50) receives a first image from the first image acquisition unit (20) and can acquire an amplified second image from the second image acquisition unit (40). The control unit (50) can detect the surface condition of the object (15) by comparing the first image and the second image.

[0049] In one embodiment, the light source unit (10), the first image acquisition unit (20), and the second image acquisition unit (40) may each be one. The first image acquisition unit (20) directly acquires a first image from light (L2) reflected from an object (15), and the second image acquisition unit (40) can acquire a second image from light (L3) reflected from an object (15) in an amplification manner as described above.

[0050] A hybrid optical device (1) according to one embodiment of the present invention is a device capable of acquiring images in two different ways (direct method, amplification method) from two cameras (one is a first image acquisition unit (20) and the other is a second image acquisition unit (40)) using one light source unit, for example, a line laser beam. The second image acquisition unit (40) is an optical system structure that acquires a second image of a height shape amplified from an image forming unit (30) by positioning an image forming unit (30) at an appropriate angle and distance so that light (L1) irradiated from the light source unit (10) is irradiated onto an object (15) and reflected, thereby amplifying and acquiring the second image of a height shape generated therefrom.

[0051] Hereinafter, a hybrid optical device and a surface state detection method according to an embodiment of the present invention will be described with reference to the attached drawings.

[0052] FIG. 3 is a diagram showing the process of forming a second image on an image forming part according to an embodiment of the present invention, and FIG. 4 is a diagram showing the second image formed on the image forming part according to an embodiment of the present invention. In addition, FIG. 5 is a diagram showing a defect on the surface of an object according to an embodiment of the present invention and a first image and a second image obtained from the defect, and FIG. 6 is a flowchart showing a surface condition detection method according to an embodiment of the present invention.

[0053] In this embodiment, the case where the light is a laser is described as an example. Referring to FIGS. 1 to 6, a surface condition detection method according to one embodiment of the present invention may include: (a) a step of irradiating a moving object (10) with a laser (L1) (S10); (b) a step of acquiring (collecting) a first image from a laser (L2) reflected from the object (15) (S20); (c) a step of forming a second image on an image forming part (30) from a laser (L3) reflected from the object (15) (S30); (d) a step of capturing the second image to acquire (collect) the second image (S40); and (e) a step of detecting the surface condition of the object (15) from the first image and the second image (S50).

[0054] Referring to FIGS. 3 and FIGS. 4, the process of acquiring a second image using an amplification method is explained. In this embodiment, the case where the light source unit (10) irradiates a line-type laser (L1) is explained as an example.

[0055] Referring to FIGS. 3 and 4, a laser (L1) irradiated from a light source (10) is irradiated onto the surface of an object (15), reflected, and then reflected to an image forming unit (30) to create a second image. At this time, if there is a flaw (d1) on the surface of the object (15), the reflected light is amplified in the vertical direction due to the difference in inclination between the fine flaw (d1) and the flat area, and a second image is generated in the image forming unit (30). That is, the fine flaw (d1) formed on the surface of the object (15) is amplified in the image forming unit (30) by the same principle as above to create a flaw (d3).

[0056] A hybrid optical device (1) according to one embodiment of the present invention, for example, in a 3D optical system configuration using a line laser, can detect the surface condition of a moving object (15) without any special lighting by configuring two first and second image acquisition units (20, 40) of two different methods (direct method, amplification method) with one line laser light source unit (10). As shown in FIG. 5, when there is a defect (d1) on the surface of the object (15), the defect (d2) is acquired as a first image by the first image acquisition unit (20), and the defect (d3) is generated as a second image that is magnified compared to the first image by the image forming unit (30), and the second image acquisition unit (40) acquires the second image containing the defect (d3).

[0057] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0058] 1 : Hybrid optical device 10 : Light source unit 15 : Object 20 : First image acquisition unit 30 : Image forming unit 40 : Second image acquisition unit 50 : Control unit

Claims

Claim 1 A light source unit that irradiates light onto a moving object; a first image acquisition unit that directly acquires a first image from the light reflected from the object; and an image forming unit in which the light reflected from the object forms a second image; A hybrid optical device comprising: a second image acquisition unit for acquiring the second image; wherein the light includes a laser, the first image acquisition unit and the second image acquisition unit include a camera, the light source unit irradiates the light onto the object at an angle based on the direction of movement of the object, the first image acquisition unit is arranged in a direction perpendicular to the direction of movement of the object, the second image is larger than the first image, and further comprising a control unit that receives the first image from the first image acquisition unit and acquires the second image from the second image acquisition unit, wherein the control unit detects the surface state of the object by comparing the first image and the second image, the first image acquisition unit directly acquires the first image from the light reflected from the object, and the second image acquisition unit acquires the second image from the light reflected from the object in an amplification manner. Claim 2 delete Claim 3 delete Claim 4 A hybrid optical device according to claim 1, characterized in that the image forming part is positioned in a different area from the area where the light source part is located, based on a virtual line connecting the object and the first image acquisition part. Claim 5 delete Claim 6 delete Claim 7 A hybrid optical device according to claim 1 or 4, wherein the light source unit is positioned at an angle of 20° to 45° relative to the direction of movement of the object, the image forming unit is positioned at an angle of 135° to 160° relative to the direction of movement of the object, and the first image acquisition unit is positioned at a 90° relative to the direction of movement of the object. Claim 8 A hybrid optical device according to claim 1 or 4, characterized in that the light source unit, the first image acquisition unit, and the second image acquisition unit are each one. Claim 9 delete Claim 10 A hybrid optical device according to claim 1 or 4, wherein the image forming part is a screen. Claim 11 delete Claim 12 delete

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