KR20130127758A - Vision inspection apparatus of improved image visibility - Google Patents

Abstract

A vision inspecting device with improved image definition according to the present invention is a vision inspecting device for determining a quality of an object to be inspected by photographing the object to be inspected with a camera and includes a stage unit on which the object to be inspected is seated; a camera unit which is composed of a lens and an image sensing unit and photographs images of the object to be inspected; a lighting unit providing lights to the object to be inspected; a vision processing unit which determines a quality of the object to be inspected by reading the images photographed by the camera unit; and a control unit which controls the components. The camera unit includes a central camera unit which is arranged on the vertical upper side of the object to be inspected; and a lateral camera unit which is installed to be tilted at a predetermined angle toward the object to be inspected. The lighting unit includes an upper lighting unit which is installed on the underside of the central camera unit and a lower lighting unit which is installed on the underside of the lateral camera unit. A polarizing filter is formed each on the upper and lateral lighting units. In case of the regular reflection of the lights emitted by the lighting unit, the present invention enables clear images to be obtained by removing polarizing components from the regular reflection lights.

Description

VISION INSPECTION APPARATUS OF IMPROVED IMAGE VISIBILITY

The present invention relates to a vision inspection apparatus having improved image clarity, and more particularly, to a vision inspection apparatus which improves image clarity by removing polarization components of scattered light by installing polarization filters in an illumination unit and a camera unit. to be.

In general, Surface Mounting Technology (SMT) for assembling surface mount components on a printed circuit board (PCB) is a technology for miniaturizing / integrating Surface Mounting Device (SMD) Development of precise assembly equipment for precise assembly, and techniques for operating various assembly equipment.

Typically, the surface mount line consists of equipment such as surface mount and vision inspection devices.

The surface mount device is a device for mounting a surface mount component on a printed circuit board. Various surface mount components supplied in the form of a tape, a stick, and a tray are supplied from a component feeder, And then putting it on the mounting position on the circuit board.

The vision inspection apparatus inspects the mounting state of the surface mounted component before or after the soldering process of the surface mounted component is completed, and transfers the printed circuit board to the next process according to the inspection result.

At this time, when the soldering completed printed circuit board is transported horizontally by the conveyor, the position adjusting device adjusts the initial position, and after the adjustment is completed, when the lamp illuminates the printed circuit board, the camera photographs the soldered portion of each surface mounting component.

After that, the vision inspection device outputs the photographed state of the soldering part to the monitor and calculates the result of the inspection of the good / bad of the mounting or the mounting of the surface mount component.

Accordingly, the vision inspection apparatus is disposed on a vertical upper surface of the surface on which the inspection object is placed, and a vertical camera for photographing a planar image of the inspection object, and a side camera and an illumination unit disposed to be inclined at the side of the inspection object to photograph the inspection object. It is configured to include.

However, when the light from the lighting unit is reflected on the surface of the inspection object, for example, when a specular reflection occurs, too much light is incident through the camera, and thus a clear image cannot be obtained due to light blurring. Is generated.

If a clear image is not obtained as described above, it may be a limitation in accurately determining a fine pattern or three-dimensional shape of a small component.

The present invention has been made to solve the above problems, an object of the present invention is to remove the polarization component from the specular light when the light from the light reflecting, the image sharpness is configured to obtain a clear image It is to provide an improved vision inspection device.

Vision inspection apparatus with improved image clarity according to the present invention for achieving the above object is a vision inspection apparatus for determining the good or bad by photographing the inspection object with a camera, a stage unit for mounting the inspection object, the lens and the image A camera unit for capturing an image of the inspection object, a lighting unit for providing illumination to the inspection object, and an image photographed by the camera unit to read the image of the inspection object to determine whether the inspection object is good or bad. And a vision processing unit and a control unit for controlling the components, wherein the camera unit includes a central camera unit disposed on a vertical upper portion of the inspection object and a side camera unit installed at an angle with respect to the inspection object, and the illumination unit Is an upper lighting unit and the side camera disposed at the central camera load unit. Portion including a lower illumination portion is disposed at the bottom, and the upper illumination portion and the side camera unit is characterized in that the polarization filter is installed.

Here, the polarization filter installed in the upper lighting unit and the polarization filter installed in the side camera unit may have different polarization directions.

According to the present invention, a clear image can be obtained by removing the polarization component from the specularly reflected light when the light from the illuminating part is specularly reflected.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a schematic side cross-sectional view of a vision inspection apparatus according to the present invention,
2 is a graph showing the intensity of the reflected light according to the incident angle of the illumination unit divided by the polarization component,
3 is also a graph showing the intensity of the reflected light according to the incident angle of the illumination unit divided by the polarization component,
4 is an example of an image before removing the S-polarized component from the reflected light of the lower lighting unit;
5 is an image example in which the S-polarized component is removed from the reflected light of the lower lighting unit;
6 is an example of an image before removing the S-polarized component and the P-polarized component from the reflected light of the upper lighting unit;
7 is an image example in which the S-polarized component and the P-polarized component are removed from the reflected light of the upper lighting unit.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

Prior to this, the terms used in the specification and claims should not be construed in a dictionary sense, and the inventor may, on the principle that the concept of a term can be properly defined in order to explain its invention in the best way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention.

Therefore, the embodiments shown in the present specification and the drawings are only exemplary embodiments of the present invention, and not all of the technical ideas of the present invention are presented. Therefore, various equivalents It should be understood that water and variations may exist.

1 is a schematic side cross-sectional view of a vision inspection apparatus according to the present invention.

Vision inspection apparatus with improved image clarity according to the present invention is a vision inspection device for determining the good or bad by photographing the inspection object with a camera, the stage unit 10 for seating the inspection object 15, the lens and the image A camera unit 20 and 30 for capturing an image of an inspection object, an illumination unit 40 and 50 for providing illumination to the inspection object 15, and the camera unit 20 and 30. And a vision processor 60 for determining whether the inspection object is good or bad by reading the captured image, and a controller 70 for controlling the components, wherein the camera units 20 and 30 are the inspection. The central camera unit 20 is disposed on the vertical top of the object and the side camera unit 30 is installed at an angle tilted with respect to the inspection object, the lighting unit 40, 50 is the central camera unit 20 Image placed in the lower part And a sub illumination unit 40 and a lower illumination unit 50 disposed below the side camera unit 30, and polarization filters 80 and 90 are installed in the upper illumination unit 40 and the side camera unit 30. It is characterized by.

The vision inspection apparatus according to the present invention is installed so that vision inspection can be performed before moving to a next process through a conveyor of a preceding equipment when inspecting a surface mounted component of a printed circuit board finished in a surface mounting line.

Such a vision inspection device may be installed in a manner such that it is disposed in a space formed between the conveyor of the line and the trailing equipment and the conveyor, or may be used in the form of a single table without being linked with the line or trailing equipment.

The stage unit 10 is a component for seating the inspection object 15, such as a PCB substrate to be subjected to vision inspection, for example, a robot arm, a transfer roller or a motor and a conveyor belt through the control of the control unit 70. The inspection object 15 conveyed by the conveying means, such as, is seated.

The camera units 20 and 30 are configured to photograph the two-dimensional shape and the grid shadow of the inspection object, and the side camera 30 is installed at an angle to the inspection object 15 at an angle.

The image sensing unit included in the camera units 20 and 30 includes an imaging device such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

The lighting units 40 and 50 are configured to illuminate the inspection object 15, and are disposed under the upper lighting unit 40 and the side camera unit 30 disposed below the central camera unit 20. It is composed of a lower lighting unit 50 is disposed.

Conventional vision inspection apparatus is to form a grid-shaped shadow on the surface of the inspection object 15, by photographing the grid-shaped shadow formed in this way through the camera unit (20, 30). The three-dimensional height of the object to be inspected is measured.

Here, in the portion where the three-dimensional height is the same on the surface of the inspection object 15, the grid-like shadows are photographed in a straight line shape.

However, in the case where the three-dimensional height is different on the surface of the object to be inspected 15, the lattice-like shadows are distorted in such a manner as to be mutually misaligned. By calculating the degree of such distortion by the trigonometric function, It is possible to calculate the three-dimensional height of the lens 15.

The images photographed by the camera units 20 and 30 are read by the vision processing unit 60 so that the three-dimensional height of the surface of the inspection object 15 is calculated, and the height of the inspection object 15 is previously determined. If it is significantly higher or lower than the stored reference data height, it is determined that the inspection object 15, for example a chip on the PCB substrate, is not correctly mounted.

The control unit 70 is a component for controlling the driving and operation of the camera unit 20, 30 and the lighting unit 40, 50, etc., may be provided to control the driving of the entire inspection apparatus according to the present invention.

The controller 70 is responsible for the physical control of the position control of the inspection apparatus, the processing of the photographed image and the control of the light source unit according to the system control program, as well as performing a data operation.

In addition, the control unit 70 is responsible for the overall control of the inspection apparatus, such as output device control for outputting the test results to the monitor and input device control that allows the operator to set and input various items.

On the other hand, the upper light unit 40 is provided with a polarization filter 80, for example, a P polarization filter that can remove the P polarization component of the light irradiated from the upper light unit 40 is provided.

In addition, the side camera unit 30 is provided with an S polarization filter capable of removing S polarization components, for example.

When the light is irradiated by the upper lighting unit 40 and the lower lighting unit 50, the large amount of light is incident mainly due to the specular reflection by the surface of the inspection object 15. The part 20 is not much influenced by the specular reflection by the inspection object on the installation angle of the camera.

Accordingly, it is an object of the present invention to remove the polarization component from the specularly reflected light incident on the side camera unit 30 so as to obtain the light brightness appropriately required to secure the clarity of the image.

2 is a graph showing the intensity of the reflected light according to the incident angle of the illumination unit according to the polarization component, and FIG. 3 is also a diagram illustrating the intensity of the reflected light according to the incident angle of the illumination unit according to the polarization component.

2 and 3, the incident angle is an angle measured from the central camera unit 20 toward the stage unit 10. The stage unit corresponds to an incident angle of 90 degrees and the central camera unit 20 corresponds to 0 degrees.

As can be seen in the graph of FIG. 2, in the range of the incident angle of 40 to 60 degrees, that is, the light irradiation angle range R1 by the lower illumination unit 50, almost no P-polarized component of the reflected light appears, and most of the S-polarized component This week.

Therefore, when the S polarization component is removed from the specularly reflected light by the lower lighting unit 50, a clear image may be secured by removing the light blurring phenomenon.

As described above, the S polarization filter 90 is installed in the side camera unit 30 to remove the S polarization component from the light reflected by the lower illumination unit 50.

4 is an example of an image before removing the S-polarized component from the reflected light by the lower illumination unit 50, and FIG. 5 is an example of an image from which the S-polarized component is removed from the reflected light by the lower illumination unit.

As can be seen in the above image example, before removing the S polarization component from the lower illumination unit 50, an excessive amount of light is incident on the side camera unit 30 at the upper portion of the image to cause light blurring. .

Therefore, by removing the S-polarized component from the light reflected by the lower illumination unit 50, as shown in Figure 5 to obtain a clearer image in which the light blur is removed from the upper portion of the image.

In addition, as can be seen in the graph of FIG. 3, in the range of the incident angle of 15 degrees to 30 degrees, that is, the light irradiation angle range R2 by the upper lighting unit 40, the S-polarized component and the P-polarized component are reflected within the reflected light. All are strong.

Therefore, it is preferable to remove both S polarization component and P polarization component with respect to the specular reflection light by the upper illumination part 40. FIG.

As described above, in order to remove the P polarization component from the light of the upper lighting unit 40, a P polarizing filter is installed in the upper lighting unit 40.

Thus, the P polarization filter 90 is removed from the light of the upper lighting unit 40 by the P polarization filter 80 installed in the upper lighting unit 40, and the S polarization filter 90 installed in the side camera unit 30. It was configured to remove the S polarization component by.

FIG. 6 is an example of an image before removing the S-polarized component and the P-polarized component from the reflected light of the upper lighting unit 40. FIG. 7 is an example of the image removing the S-polarized component and the P-polarized component from the reflected light of the upper lighting unit 40. FIG. .

As can be seen in the above image example, before removing the S-polarized component and the P-polarized component from the upper lighting unit 40, an excessive amount of light is incident on the side camera unit 30 at the lower part of the image. Light blurring occurs in the lower portion of the.

Thus, by removing the S-polarized component and the P-polarized component from the light reflected by the upper lighting unit 40, as shown in FIG.

As mentioned above, although the present invention has been described by way of limited embodiments and drawings, the technical idea of the present invention is not limited thereto, and a person having ordinary skill in the art to which the present invention pertains, Various modifications and variations may be made without departing from the scope of the appended claims.

10: stage unit 15: inspection object
20: center camera portion 30: side camera portion
40: upper lighting unit 50: lower lighting unit

Claims (2)

As a vision inspection device to determine the good or bad by photographing the inspection object with a camera,
A stage unit for seating the inspection object;
A camera unit configured to include a lens and an image sensing unit, and to capture an image of an inspection object;
An illumination unit for providing illumination to the inspection object;
A vision processor for reading the image photographed by the camera unit and discriminating the good or bad of the object to be inspected;
A control unit for controlling the components,
The camera unit includes a central camera unit disposed on the vertical upper portion of the inspection object and a side camera unit installed at an angle with respect to the inspection object,
The lighting unit includes an upper lighting unit disposed at the lower portion of the central camera and a lower lighting unit disposed below the side camera unit.
Vision inspection apparatus with improved image clarity, characterized in that the upper illumination unit and the side camera unit is provided with a polarization filter. The method of claim 1,
And a polarization filter installed in the upper lighting unit and a polarization filter installed in the side camera unit, wherein the polarization direction is different from each other.

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