KR20230118476A - Photographing apparatus for vision inspection - Google Patents

Abstract

According to the present invention, it includes a photographing unit for photographing an object for vision inspection, wherein the photographing unit includes a plurality of image sensors that simultaneously and independently obtain image data for the object to be inspected, and each of the plurality of image sensors. A photographing device for vision inspection is provided which includes a plurality of lenses installed in a one-to-one correspondence, and each of the plurality of lenses provides a corresponding image sensor with a different focal length.

Description

Photography device for vision inspection {PHOTOGRAPHING APPARATUS FOR VISION INSPECTION}

The present invention relates to a vision inspection technique, and more particularly, to a photographing device for photographing an inspection object in a non-point inspection.

In general, vision inspection refers to inspecting the shape, size, foreign matter, damage, etc. by photographing an inspection object to determine whether or not defects are present in various parts of the inspection object. As the characteristics of inspection objects diversify according to industrialization structure changes, it is becoming more and more difficult to respond immediately to the depth of field in vision inspection. Depth of field refers to the range in the distance in which the photographed subject has an acceptable level of sharpness. To improve the depth of field in vision inspection, a method of adjusting the focal length of the lens of the photographing part is generally used. The focal length of a lens is usually adjusted by physically moving the position of the lens or changing the shape of the lens. However, since this conventional lens focal length control method takes time to move or deform the lens, it acts as a factor that increases inspection time. As a background technology of the present invention, Patent Registration No. 10-0609604 describes a configuration for moving a camera for focus adjustment in a vision inspection device.

Republic of Korea Registered Patent Registration No. 10-0609604 (2006.08.08)

SUMMARY OF THE INVENTION An object of the present invention is to provide a photographing device for vision inspection that enables to quickly obtain an accurate image of an object to be inspected in a vision inspection.

In order to achieve the object of the present invention described above, according to an aspect of the present invention, a plurality of photographing units for photographing an object to be inspected for vision inspection, wherein the photographing unit simultaneously and independently obtains image data for the object to be inspected. It includes two image sensors and a plurality of lenses installed in a one-to-one correspondence with each of the plurality of image sensors, and each of the plurality of lenses provides a different focal length to the corresponding image sensor for vision inspection. A photographing device is provided.

A relative position of each of the plurality of lenses with the corresponding image sensor may be fixed.

Each of the plurality of lenses may arrange the focal lengths along a distance direction.

The image data obtained by each of the plurality of image sensors is analog image data, and the vision inspection photographing device includes a conversion unit that converts the analog image data into digital image data, and arithmetic and processing of the digital image data. It may further include an arithmetic processing unit that produces a final image of an object to be inspected.

According to the present invention, all of the objects of the present invention described above can be achieved. Specifically, the photographing unit provided in the imaging device for vision inspection according to the present invention includes a plurality of image sensors and a plurality of lenses installed in a one-to-one correspondence with each of the plurality of image sensors, each of the plurality of lenses Since different focal lengths are provided for the object to be inspected, clear images of the entire range of the object to be inspected can be obtained at the same time. Accordingly, the time required for focus adjustment in the conventional method is reduced and productivity is improved by omitting individual photographing time.

1 is a block diagram showing a schematic configuration of a photographing device for vision inspection according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a photographing unit in the photographing device for vision inspection shown in FIG. 1 .
FIG. 3 is a diagram explaining the operating principle of the photographing unit shown in FIG. 2 .
FIG. 4 is a block diagram showing a schematic configuration of a conversion unit in the imaging device for vision inspection shown in FIG. 1 .

Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the drawings.

1 shows a schematic configuration of a photographing apparatus for vision inspection according to an embodiment of the present invention as a block diagram. Referring to FIG. 1 , a photographing apparatus 100 for a vision inspection according to an embodiment of the present invention includes a power supply unit 110, a photographing unit 120, a conversion unit 130, and an arithmetic processing unit 140. and an output unit 150.

The power supply unit 110 maintains a stable waveform of supply power, and supplies power necessary for operation to the photographing unit 120, the conversion unit 130, the arithmetic processing unit 140, and the output unit 150.

The photographing unit 120 acquires analog image information about an object to be inspected as a subject. 2 shows a schematic configuration of the photographing unit 120 as a block diagram. Referring to FIG. 2 , the photographing unit 120 includes a plurality of photographing units 121 , 122 , 123 , and 124 . Referring to FIGS. 2 and 3 , the plurality of photographing units 121 , 122 , 123 , and 124 acquire image information of the same object A. In this embodiment, the photographing unit 120 is described as including four photographing units 121, 122, 123, and 124, but the present invention is not limited thereto. The photographing unit 120 may include two, three, or five or more photographing units, which also fall within the scope of the present invention. In this embodiment, one of the four photographing units 121, 122, 123, and 124 is referred to as the first photographic unit 121, the other is referred to as the second photographic unit 122, and the other is referred to as the third photographic unit 121. The photographing unit 123 is called, and the other one is called the fourth photographing unit 124 .

The first photographing unit 121 includes a first image sensor 121a and a first lens 121b installed to correspond to the first image sensor 121a, and forms an independent first image acquisition channel. The first image sensor 121a converts light into an electrical signal and outputs it to a converter ( 130 in FIG. 1 ). The first image sensor 121a may be a charge coupled device (CCD). The first lens 121b is installed in a one-to-one correspondence with the first image sensor 121a. The distance between the first lens 121b and the first image sensor 121a is maintained constant. The first lens 121b provides a first focal length L1 to the first image sensor 121a. The first focal length L1 is the distance between the first focal point P1 of the first lens 121b and the first lens 121b. The first lens 121b provides a first depth of field D1.

The second photographing unit 122 includes a second image sensor 122a and a second lens 122b installed to correspond to the second image sensor 122a, and forms an independent second image acquisition channel. The second image sensor 122a converts light into an electrical signal and outputs it to a converter ( 130 in FIG. 1 ). The second image sensor 122a may be a charge coupled device (CCD). The second lens 122b is installed in a one-to-one correspondence with the second image sensor 122a. A distance between the second lens 122b and the second image sensor 122a is maintained constant. The second lens 122b provides a second focal length L2 to the second image sensor 122a. The second focal length L2 is the distance between the second focal point P2 by the second lens 122b and the second lens 122b. The second focal length L2 provided by the second lens 122b is greater than the first focal length L1 provided by the first lens 121b. To this end, the second lens 122b may have a shape different from that of the first lens 121b, or the distance between the second lens 122b and the second image sensor 122a may vary between the first lens 121b and the first image sensor 122a. It may be set differently from the distance between the image sensors 121a. The second lens 122b provides a second depth of field D2. The first depth of field D1 and the second depth of field D2 are overlapped over a partial section C1-2 on the optical axis in the distance direction.

The third photographing unit 123 includes a third image sensor 123a and a third lens 123b installed to correspond to the third image sensor 123a, and forms an independent third image acquisition channel. The third image sensor 123a converts light into an electrical signal and outputs it to the converter ( 130 in FIG. 1 ). The third image sensor 123a may be a charge coupled device (CCD). The third lens 123b is installed in a one-to-one correspondence with the third image sensor 123a. A distance between the third lens 123b and the third image sensor 123a is maintained constant. The third lens 123b provides a third focal length L3 to the third image sensor 123a. The third focal length L3 is the distance between the third focal point P3 by the third lens 123b and the third lens 123b. The third focal length L3 provided by the third lens 123b is greater than the second focal length L2 provided by the second lens 122b. To this end, the third lens 123b may have a shape different from that of the second lens 122b, or the distance between the third lens 123b and the third image sensor 123a may vary between the second lens 122b and the second lens 122b. It may be set differently from the distance between the image sensors 122a. The third lens 123b provides a third depth of field D3. The second depth of field D2 and the third depth of field D3 are overlapped over a partial section C2-3 on the optical axis in the distance direction.

The fourth photographing unit 124 includes a fourth image sensor 124a and a fourth lens 124b installed to correspond to the fourth image sensor 124a, and forms an independent fourth image acquisition channel. The fourth image sensor 124a converts light into an electrical signal and outputs it to the converter ( 130 in FIG. 1 ). The fourth image sensor 124a may be a charge coupled device (CCD). The fourth lens 124b is installed in a one-to-one correspondence with the fourth image sensor 124a. A distance between the fourth lens 124b and the fourth image sensor 124a is maintained constant. The fourth lens 124b provides a fourth focal length L4 to the fourth image sensor 124a. The fourth focal length L4 is the distance between the fourth focal point P4 by the fourth lens 124b and the fourth lens 124b. The fourth focal length L4 provided by the fourth lens 124b is greater than the third focal length L3 provided by the third lens 123b. To this end, the fourth lens 124b may have a shape different from that of the third lens 123b, or the distance between the fourth lens 124b and the fourth image sensor 124a may vary between the third lens 123b and the third lens 123b. It may be set differently from the distance between the image sensors 123a. The fourth lens 124b provides a fourth depth of field D4. The third depth of field D3 and the fourth depth of field D4 are overlapped over a partial section C3-4 on the optical axis in the distance direction.

The photographing unit 120 captures the inspection object A once, and the first photographed image obtained by the first photographing unit 121 and the second photographed image obtained by the second photographing unit 122 are captured at the same time. , the third captured image acquired by the third photographing unit 123 and the fourth photographed image acquired by the fourth photographing unit 124 are provided. Since each photographed image provides a clear image at the subject depth set for the object A to be inspected, a clear image of the entire range of the object A can be obtained with one shot. Through separate image processing for each of the captured images, sharp parts of each of the captured images may be combined and merged into a single integrated image, which also falls within the scope of the present invention.

Referring to FIG. 1 , the conversion unit 130 converts analog image data of an object to be tested (A in FIG. 3 ) acquired by the photographing unit 120 into digital image data. Referring to FIG. 4 , the conversion unit 130 includes an ASIC or DSP 131 and an A/D converter 132 . Since the conversion of analog image data to digital image data performed by the conversion unit 130 uses a conventional technique, a detailed description thereof will be omitted.

Referring to FIG. 1 , the arithmetic processing device 140 calculates and processes the digital image data generated by the conversion unit 130 to produce a final image of the object to be inspected (A in FIG. 3 ). The processing unit 140 may be composed of a typical CPU (Central Processing Unit) and GPU (Graphic Processing Unit). Also, the arithmetic processing unit 140 may perform post-correction on the digital image data, and stores the produced final image. Although not shown, a memory device for storing data including a program and a final image necessary for the calculation processing device 140 to process digital image data is further provided. The final images produced by the arithmetic processing unit 140 are a plurality of images obtained from each of the plurality of photographing units 121, 122, 123, and 124 of the photographing unit 120, or the plurality of photographing units 121, 122, 123, and 124) may be a merged image of the clear parts of each of the plurality of images obtained.

The output unit 150 outputs the final image implemented in the arithmetic processing unit 140 . The output unit 150 may be a display device or a printing device.

Although the present invention has been described through the above examples, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will recognize that such modifications and changes also belong to the present invention.

100: imaging device for vision inspection 110: power unit
120: photographing unit 121: first photographing unit
122: second shooting unit 123: third shooting unit
124: fourth photographing unit 121a: first image sensor
122a: second image sensor 123a: third image sensor
124a: fourth image sensor 121b: first lens
122b: second lens 123b: third lens
124b: fourth lens 130: converter
140: arithmetic processing unit 150: output unit

Claims (8)

Including a photographing unit for photographing the inspection target for vision inspection,
The photographing unit includes a plurality of image sensors that simultaneously and independently acquire image data for the test object, and a plurality of lenses installed in a one-to-one correspondence with each of the plurality of image sensors,
Each of the plurality of lenses provides a different focal length to the corresponding image sensor,
Filming device for vision inspection. The method of claim 1,
Each of the plurality of lenses has a fixed relative position with the corresponding image sensor.
Filming device for vision inspection. The method of claim 2,
Each of the plurality of lenses is the same,
Each of the plurality of lenses is installed at a different distance from the corresponding image sensor to provide a different focal length to the corresponding image sensor.
Filming device for vision inspection. The method of claim 2,
Each of the plurality of lenses has a different shape to provide a different focal length to the corresponding image sensor.
Filming device for vision inspection. The method of claim 1,
Each of the plurality of lenses arranges the focal lengths along the distance direction,
Filming device for vision inspection. The method of claim 5,
The depth of subject of each of the two lenses providing two adjacent focal lengths among the plurality of lenses, respectively, overlaps in some section along the distance direction.
Filming device for vision inspection. The method of claim 1,
Image data obtained by each of the plurality of image sensors is analog image data,
a converter for converting the analog image data into digital image data;
Further comprising an arithmetic processing device for producing a final image of the inspection object by arithmetic processing of the digital image data,
Filming device for vision inspection. The method of claim 7,
The final image is a plurality of images corresponding to image data obtained from each of the plurality of image sensors,
Filming device for vision inspection.

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