KR20230101744A - Vision alignment system using stage mark and smart vision alignment method using thereof - Google Patents

Abstract

The present invention relates to a vision alignment system using stage marks and a vision alignment method using the same. A vision alignment system using stage marks of the present invention includes a stage on which a first mark is displayed on one side and an object on which a second mark is displayed is loaded; a transfer unit that transfers the stage loaded with the object to an examination area; a vision camera unit capturing a first video image including the first mark and the second mark by photographing the stage transported to the inspection area; a correction controller installed on the stage and correcting the position of the stage; a location information acquiring unit acquiring first location information of the first mark and second location information of the second mark by using the first video image; a position difference calculator configured to calculate a first difference value between the first position information and the reference position information when the first position information is different from preset reference position information; A correction control unit controlling the position correction unit so that the position of the object is corrected using the first difference value may be included.

Description

Vision alignment system using stage mark and vision alignment method using the same

The present invention relates to a vision alignment system using a stage mark and a vision alignment method using the same, and more particularly, to a vision alignment system using a stage mark capable of improving productivity by forming a mark on a stage and a vision alignment using the same It's about how.

Recently, in various manufacturing devices and production facilities such as semiconductors and displays, for example, machine vision, etc. A vision system configured to increase productivity and accuracy and reduce a defect rate by automatically determining defects by analyzing images is widely used.

In addition, in order to use the vision system, calibration and correction work are essential to align the camera and the stage to the correct position and accurately reach the designated position even when moving. For this purpose, vision alignment (Vision Alignment) system is being applied.

More specifically, the conventional calibration work is generally performed using, for example, a calibration sheet or a panel on which a fiducial mark is displayed, thereby performing the calibration work There was the hassle of preparing a calibration sheet or panel beforehand.

In addition, in the prior art calibration methods, time is consumed for installation, movement, and removal of the calibration sheet and the recognition mark panel in addition to the time required for the calibration work, so there is a problem in that the overall work time becomes that much longer.

Moreover, as described above, there is also a problem in that the longer the time consumed for the calibration work, the longer the tact time, which means the time required to produce one product, increases.

Therefore, as described above, in order to solve the problems of the prior art vision alignment systems and calibration methods, which have limitations in that the complexity of preparation and the overall work time increase due to the use of a separate calibration sheet or recognition mark panel, It is desirable to present a calibration method of a new configuration and a vision alignment system using the same, which are configured so that calibration can be performed quickly and accurately at a simple configuration and low cost without the need for separate preparations. A device or method has not been presented yet.

Korean Patent Registration No. 10-2260620 (2021.06.07.) Korean Patent Publication No. 10-2019-0053457 (2019.05.20.)

The problem to be solved by the present invention is configured so that the alignment work is performed using a separate calibration sheet or a panel marked with a fiducial mark, so the sheet or panel is prepared in advance before the alignment work There is a hassle to do, and time is consumed for installation and removal of sheets and panels, which lengthens the overall work time, which delays the process and increases the tact time. In order to solve the problems of the alignment system, a vision alignment system and vision alignment method using a stage mark configured to perform alignment work quickly and accurately with simple configuration and low cost without the need for a separate fiducial mark panel is to provide

Another problem of the present invention is the inconvenience of preparing a separate alignment sheet or recognition mark panel in advance for the alignment work as described above, and the limitation of increasing the tact time due to the long working time. In order to solve the problems of the prior art vision alignment system, a fiducial mark is added to the stage and configured to check the operation of the stage using the stage mark, so that there is no separate recognition mark panel. The progress of the alignment work is possible through the marks displayed on the stage, thereby reducing the hassle and work time for preparations for the alignment work, and a vision alignment system using stage marks configured to contribute to productivity improvement, and this It is to provide a vision alignment method using the present invention.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

A vision alignment system using stage marks according to the present invention includes a stage on which a first mark is displayed on one side and an object marked with a second mark is loaded; a transfer unit that transfers the stage loaded with the object to an examination area; a vision camera unit capturing a first video image including the first mark and the second mark by photographing the stage transported to the inspection area; a position correction unit installed on the stage and correcting the position of the stage; a location information acquiring unit acquiring first location information of the first mark and second location information of the second mark by using the first video image; a position difference calculator configured to calculate a first difference value between the first position information and the reference position information when the first position information is different from preset reference position information; and a correction controller configured to control the position correction unit so that the position of the object is corrected using the first difference value.

A vision alignment method according to the present invention includes loading an object marked with a second mark on a stage marked with a first mark; transferring the stage on which the object is loaded to an examination area; obtaining a first video image by photographing the first mark of the stage and the second mark of the object transferred to the examination area; obtaining first location information of the first mark and second location information of the second mark using the first video image; calculating a first difference value between the first location information and the reference location information when the first location information is different from preset reference location information; and correcting the position of the object using the calculated first difference value.

Details of other embodiments are included in the detailed description and drawings.

According to embodiments of the present invention, a vision alignment system using a stage mark configured to add a fiducial mark to a stage and confirm an operation of the stage using the stage mark is provided, thereby providing a separate recognition mark. Alignment work can be performed through recognition marks displayed on the stage without the need for a panel, thereby contributing to productivity improvement by reducing the hassle and work time for preparations for alignment work.

In addition, according to the present invention, as described above, by providing a vision alignment system and method using a stage mark configured to quickly and accurately perform an alignment operation with a simple configuration and low cost without the need for a separate mark panel, Since the alignment work is performed using a sheet or marked panel, it is inconvenient to prepare the sheet or panel in advance before the alignment work, and the installation and removal of the sheet and panel are time consuming and the overall work time is long. Therefore, there is an effect that can solve the problem of the vision alignment system of the prior art, which has a limit in that the process is delayed and the tact time increases.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 and 2 are schematic diagrams showing a vision alignment system according to an embodiment of the present invention.
FIG. 3 is a plan view for explaining the vision alignment system of FIG. 1 .
FIG. 4 is a block diagram showing some configurations of the vision alignment system of FIG. 1 .
FIG. 5 is a diagram illustrating a second video image acquired by the vision camera unit of FIG. 1 .
6 is a diagram illustrating an example of a first video image acquired by the vision camera unit of FIG. 1 .
7 is a flowchart illustrating a vision alignment method according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Embodiments described in this specification will be described with reference to cross-sectional views and/or plan views, which are ideal exemplary views of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of technical content. Accordingly, the regions illustrated in the drawings have schematic properties, and the shapes of the regions illustrated in the drawings are intended to illustrate a specific shape of a region of a device and are not intended to limit the scope of the invention. Although terms such as first, second, and third are used to describe various elements in various embodiments of the present specification, these elements should not be limited by these terms. These terms are only used to distinguish one component from another. Embodiments described and illustrated herein also include complementary embodiments thereof.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, “comprises” and/or “comprising” means the presence of one or more other components, steps, operations, and/or elements in the stated component, step, operation, and/or element. or do not rule out additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

Hereinafter, with reference to the drawings, the concept of the present invention and the embodiments thereof will be described in detail.

1 and 2 are schematic diagrams showing a vision alignment system according to an embodiment of the present invention. FIG. 3 is a plan view for explaining the vision alignment system of FIG. 1 . FIG. 4 is a block diagram showing some configurations of the vision alignment system of FIG. 1 . FIG. 5 is a diagram illustrating a second video image acquired by the vision camera unit of FIG. 1 . 6 is a diagram illustrating an example of a first video image acquired by the vision camera unit of FIG. 1 .

1 to 6, the vision alignment system 10 according to an embodiment of the present invention has a simple configuration and low cost without requiring a separate recognition mark, a separate fiducial mark panel, quickly and accurately vision It may be configured to perform an alignment operation. The vision alignment system 10 may include a stage 100, a transfer unit 300, a vision camera unit 200, a position correction unit 400, and a control unit. The vision alignment system 10 may further include a database unit 600 .

An object O may be loaded on the stage 100 . In an embodiment, the object O may be a display panel that is a part of a mobile phone, but is not limited thereto. The stage 100 may be formed in a rectangular plate shape in plan view, but is not limited thereto.

A first mark M1 may be displayed on one side of the stage 100 . In an embodiment, the first mark M1 may be filled with a mark groove recessed from one side of the stage 100 toward the other side and a paint filling the mark groove. The paint may have a complementary color relationship with the color of the stage 100 . Accordingly, the controller unit 500 to be described later can easily identify the first mark M1 included in the video image.

For example, a pair of first marks M1 may be displayed on one side of the stage 100 on which the object O is loaded. The pair of first marks M1 may be spaced apart from each other with the object O interposed therebetween.

In an embodiment, the first marks M1 may be positioned to be symmetrical to each other based on a center line parallel to the longitudinal direction of the stage 100 while passing through the center of the stage 100 . In an embodiment, the center line may be parallel to the Y-axis direction. In an embodiment, each of the first marks M1 may be formed in an “L” shape, but may be formed in various shapes such as a cross or a ribbon.

At least one second mark M2 may be displayed on one side of the object O. In an embodiment, the object O may include a pair of second marks M2. Each of the second marks M2 may be positioned adjacent to each of the first marks M1.

The second mark M2 may be formed in a shape different from that of the first mark. In an embodiment, the second mark M2 may be formed in a cross shape, but is not limited thereto.

The transfer unit 300 may transfer the stage 100 . The transfer unit 300 may include a guide rail and a linear motor. Accordingly, the transfer unit 300 may transfer the stage 100 to the inspection area IA along the guide rail. The inspection area IA may be one of areas in which the vision camera unit 200 photographs the stage 100 and the object O.

The position correction unit 400 may be installed on the stage 100 . The position correction unit 400 may correct the position of the stage 100 . For example, the position correction unit 400 may finely move the stage 100 in at least one of the X-axis direction and the Y-axis direction. Also, the position correction unit 400 may rotate the stage 100 based on the center of the stage 100 . Accordingly, the position of the stage 100 of the position correction unit 400 may be corrected. As the position correction unit 400 corrects the position of the stage 100, the position of the object O on the stage 100 may also be aligned.

In another embodiment of the present invention, the position correction unit 400 may include a plurality of spherical balls and a driving unit for rotating the balls. Spherical balls may be installed in the stage 100 . The stage 100 may include exposure holes for exposing spherical balls to the outside so that the loaded object O and the built-in spherical balls may come into contact with each other. Accordingly, the spherical balls installed in the stage 100 may contact the object O. In an embodiment, the spherical balls may be arranged in a line along the center line of the stage 100 . Alternatively, the spherical balls may be arranged in a grid pattern.

The driving unit may include a plurality of rollers contacting each of the spherical balls and motors rotating the rollers. Accordingly, as the motor rotates the rollers, it is possible to rotate the spherical balls. As the driving unit rotates the spherical balls, the position of the object O may be slightly moved on the X-Y plane. That is, the position correction unit 400 may correct the position of the object O.

The vision camera unit 200 may photograph the stage 100 . In an embodiment, the vision camera unit 200 may photograph the stage 100 transferred to the inspection area IA. Accordingly, the vision camera unit 200 may obtain a first video image including the first mark M1 and the second mark M2. Unlike this, the vision camera unit 200 may acquire a video image by photographing the stage 100 being transported.

The vision camera unit 200 may photograph the stage 100 before transferring the stage 100 loaded with the object O to the examination area IA. Accordingly, the vision camera unit 200 may obtain a second video image including the first mark M1 and the second mark M2.

The vision camera unit 200 may include a pair of CCD (Charge Coupled Device) cameras respectively positioned in left and right directions with respect to the stage 100 . It is preferable to mount an ND (Neutral Density) filter (not shown) on the CCD camera. If an ND filter is installed, reflected light can be reduced, so more accurate image information can be secured. Unlike this, in another embodiment, the vision camera unit 200 may include a camera other than a CCD camera. The vision camera unit 200 may transmit acquired video images to the controller unit 500 and/or the database unit 600 .

The controller unit 500 may control the transfer unit 300, the position correction unit 400, the vision camera unit 200, and the like. The controller unit 500 may control the transfer unit 300 and the location information unit using information transmitted from the vision camera unit 200 and/or the database unit 600 . Accordingly, the controller unit 500 may correct the position of the stage 100 and/or the object O. The controller unit 500 may be a CPU, microprocessor, PC, or the like. In an embodiment, the controller unit 500 may include a location information acquisition unit 510, a location difference calculation unit 520, and a correction control unit 530.

The location information acquisition unit 510 may acquire first location information of the first mark M1 using the first video image. The location information obtaining unit 510 may obtain second location information of the second mark M2 using the first video image.

The location information acquisition unit 510 may obtain third location information of the first mark M1 using the second video image. The location information acquisition unit 510 may obtain fourth location information of the second mark M2 using the second video image.

The location information acquisition unit 510 may map the first video image to an X-Y coordinate system. Accordingly, the location information acquisition unit 510 may express the first location information, the second location information, the third location information, and the fourth location information as X and Y coordinates.

As shown in FIG. 5 , the second video image may include a first mark M1 and a second mark M2. As described above, the second video image may be a video image captured by the vision camera unit 200 before the stage 100 loaded with the object O is transferred to the inspection area IA.

The location information obtaining unit 510 may obtain third location information about the reference point G1 of the first mark M1. In an embodiment, the reference point G1 of the first mark M1 may be a “L” shaped connection point, but is not limited thereto. The third location information may include X and Y coordinates of (X3, Y3). In an embodiment, the third location information may include X and Y coordinates of (0, 0).

The third location information may be set as reference location information to be described later. Accordingly, the reference location information may include third location information.

The location information acquisition unit 510 may obtain fourth location information about the reference point G2 of the second mark M2. In an embodiment, the reference point G2 of the second mark M2 may be a center point of a cross shape, but is not limited thereto. The fourth location information may include X and Y coordinates of (X4, Y4). In an embodiment, the fourth location information may include X and Y coordinates of (5, -2).

As shown in FIG. 6 , the first video image may include a first mark M1 and a second mark M2. As described above, the first video image may be a video image of the stage 100 transferred to the inspection area IA.

Positions of the first mark M1 and the second mark M2 of the first video image may be different from positions of the first mark M1 and the second mark M2 of the second video image. This means that when the stage 100 is transported by the transfer unit 300, the object O loaded on the stage 100 can be moved by vibrations generated. Accordingly, the position of the second mark M2 of the object O loaded on the stage 100 may be changed. That is, an error may occur because the position of the second mark M2 of the object O loaded on the stage 100 is captured in a changed state.

The location information obtaining unit 510 may obtain first location information about the reference point G1 of the first mark M1. The reference point G1 of the first mark M1 may be the same as the reference point G1 used when acquiring the third location information. The first location information may include X and Y coordinates of (X1, Y1). In an embodiment, the first location information may include X and Y coordinates of (0,10).

The location obtainer may obtain second location information about the reference point G2 of the second mark M2. In an embodiment, the reference point of the second mark M2 may be the same as the reference point G2 used when acquiring the fourth location information. The second location information may include X and Y coordinates of (X2, Y2). In an embodiment, the second location information may include X and Y coordinates of (5, 8).

When the first location information is different from the preset standard location information, the location difference calculation unit 520 may calculate a first difference value by calculating a difference value between the first location information and the standard location information.

In an embodiment, the reference location information may be third location information. The location difference calculator 520 may determine whether the first location information and the reference location information (third location information) are different. When the first location information and the third location information are different, the location difference calculation unit 520 may subtract the coordinate value of (X1, Y1) from the coordinate value of (X3, Y3). Accordingly, the position difference calculation unit 520 may calculate a first difference value. For example, the first difference value may include X and Y coordinate values of (0, -10).

The correction controller 530 may control the position correction unit 400 to correct the position of the object O using the first difference value. For example, the correction controller 530 may control the position corrector 400 to move the stage 100 by the first difference value. Accordingly, the stage 100 can move by the X and Y coordinates of (0, -10). That is, the position of the object O may be corrected by moving the position of the second mark M2 by the X and Y coordinates of (0, -10).

As such, even if the position of the second mark M2 of the object O loaded on the stage 100 is changed due to vibration or shaking during or after the stage 100 moves, the first mark M1 displayed on the stage Since the position is always at the same position, the position of the object O is corrected in real time by applying an offset as much as the changed position of the first mark M1 of the stage 100 using this position. ) can be measured accurately.

In another embodiment of the present invention, the correction controller 530 may determine whether the first difference value is within a preset error range. When the first difference value is out of the error range, the correction controller 530 may control the position correction unit 400 to correct the position of the object O using the first difference value. This is because if the change in the position of the stage 100 is minute, it may not have a large effect on the assembly of the object O.

The database unit 600 may store video images such as a first video image and a second video image captured by the vision camera unit 200 . Also, the database unit 600 may store the first to fourth location information acquired by the location information obtaining unit 510 . The database unit 600 may set and store the third location information as reference location information. The database unit 600 may store setting information used in the controller unit 500, such as error range information. Accordingly, the database unit 600 may provide various reference information, video images, and the like to the controller unit 500 .

A vision alignment method using the vision alignment system according to the present invention configured as above will be described as follows.

7 is a flowchart illustrating a vision alignment method according to an embodiment of the present invention.

Referring to FIG. 7 , the vision alignment method using the stage 100 mark according to an embodiment of the present invention includes the steps of loading an object O, transferring the stage 100 to the examination area IA, and It may include acquiring 1 video image, obtaining first location information and second location information, calculating a first difference value, and correcting the position of the object O.

The loading robot may pick up the object O marked with the second mark M2 and load it onto the stage 100 marked with the first mark M1 (S100). The loading robot may accurately load the object O onto the stage 100 at a preset position. Also, the loading robot may load the object O onto the stage 100 so as not to cover the first mark M1.

The vision camera unit 200 captures the first mark M1 of the stage 100 and the second mark M2 of the object O before the stage 100 is transferred to the examination area IA, thereby generating a second image. An image may be acquired (S150). A first mark M1 and a second mark M2 may be displayed on the second video image. The obtained second video image may be transmitted to the controller unit 500 and/or the database unit 600 .

The transfer unit 300 may transfer the stage 100 loaded with the object O to the examination area IA (S200). Accordingly, the object O may reach the examination area IA. Vibration or shaking may be transmitted to the stage 100 while the transfer unit 300 moves the stage 100 . Accordingly, the position of the object O loaded on the stage 100 may be changed due to vibration or the like.

When the object O is supplied to a product assembly process in a state where the position thereof is changed, defective products may be caused due to poor assembly. Accordingly, it is necessary to correct the position of the object O.

The vision camera unit 200 may acquire a first video image by photographing the first mark M1 of the stage 100 transferred to the examination area IA and the second mark M2 of the object O. (S300). The obtained first video image may be transmitted to the controller unit 500 and/or the database unit 600 . A first mark M1 and a second mark M2 may be displayed on the first video image.

The location information acquisition unit 510 may obtain first location information of the first mark M1 and second location information of the second mart by using the first video image (S400). The first location information and the second location information may be location information of the first mark M1 and the second mark M2 displayed in the first video image. As described above, the first location information may include X and Y coordinate values of (X1, Y1), and the second location information may include X and Y coordinate values of (X2, Y2).

The location information acquisition unit 510 may obtain third location information of the first mark M1 and fourth location information of the second mark M2 by using the second video image (S450). The location information acquisition unit 510 may set the third location information as reference location information. The location information acquisition unit 510 may store the set reference location information in the database unit 600 .

The location difference calculation unit 520 may determine whether the first location information is the same as preset reference location information (S500). In an embodiment, the reference location information may be third location information. For example, the position difference calculation unit 520 may determine whether the X, Y coordinate values of (X1, Y1) and the X, Y coordinate values of (X3, Y3) are the same.

When the first location information is different from the standard location information, the location difference calculation unit 520 may calculate a first difference value that is a difference value between the first location information and the standard location information (S600). As described above, the position difference calculating unit 520 may calculate the first difference value by subtracting the X, Y coordinate values of (X1, Y1) from the X, Y coordinate values of (X3, Y3). In an embodiment, the first location information may have X and Y coordinate values of (0, 10), and the third location information may have X and Y coordinate values of (0, 0). Accordingly, the first difference value may have X and Y coordinate values of (0, -10).

The correction controller 530 may correct the position of the object O using the first difference value (S700). In an embodiment, the correction controller 530 may control the position corrector 400 so that the position corrector 400 moves the stage 100 by the first difference value. Accordingly, the position of the object O loaded on the stage 100 may be corrected by the first difference value.

Unlike this, in another embodiment, the correction controller 530 may determine whether the first difference value is within an error range. When the first difference value is out of the error range, the correction controller 530 may correct the position of the object O using the first difference value.

When the position of the object O is corrected, the stage 100 is transferred to the assembly area by the transfer unit 300, and the object O can be precisely assembled with other parts (S800). As the position of the object O is corrected, assembly failure due to a change in the position of the object O due to vibration generated during movement of the stage 100 can be minimized.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications are possible by those skilled in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

10: vision alignment system 100: stage
200: vision camera unit 300: transfer unit
400: position correction unit 500: controller unit
510: location information acquisition unit 520: location difference calculation unit
530: correction control unit 600: database unit

Claims (8)

a stage on which a first mark is displayed on one side and an object marked with a second mark is loaded;
a transfer unit that transfers the stage loaded with the object to an examination area;
a vision camera unit capturing a first video image including the first mark and the second mark by photographing the stage transported to the inspection area;
a position correction unit installed on the stage and correcting the position of the stage;
a location information acquiring unit acquiring first location information of the first mark and second location information of the second mark by using the first video image;
a position difference calculator configured to calculate a first difference value between the first position information and the reference position information when the first position information is different from preset reference position information; and
A vision alignment system using a stage mark comprising a correction control unit controlling the position correction unit so that the position of the object is corrected using the first difference value. According to claim 1,
The correction control unit controls the transfer unit to correct the position of the object when the first difference value is out of a preset error range. According to claim 1,
The vision camera unit acquires a second video image including the first mark and the second mark by photographing the stage before transferring the stage to the inspection area,
The location information acquisition unit obtains third location information of the first mark and fourth location information of the second mark using the second video image,
The reference position information is the third position information,
The position difference calculator calculates a difference value between the first position information and the third position information. According to claim 3,
The first to fourth position information is a vision alignment system using a stage mark including X and Y coordinate values. According to claim 1,
The second mark is a vision alignment system using a stage mark formed in a different shape from the first mark. In the vision alignment method using the vision alignment system of claim 1,
loading an object marked with a second mark on a stage marked with a first mark;
transferring the stage on which the object is loaded to an examination area;
obtaining a first video image by photographing the first mark of the stage and the second mark of the object transferred to the examination area;
obtaining first location information of the first mark and second location information of the second mark using the first video image;
calculating a first difference value between the first location information and the reference location information when the first location information is different from preset reference location information; and
and correcting the position of the object using the calculated first difference value. According to claim 6,
Further comprising determining whether the calculated first difference value is within a preset error range,
In the correcting, when the first difference value is out of the error range, the vision alignment method corrects the position of the object using the first difference value. According to claim 6,
obtaining a second video image by photographing the first mark of the stage and the second mark of the object before transferring the stage to the examination area; and
Acquiring third location information of the first mark and fourth location information of the second mark using the second video image;
The reference position information is the third position information,
The calculating of the first difference value may include calculating a difference value between the first location information and the third location information.

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