KR20090013611A - Lens inspection system using stereoscopic microscope and method thereof - Google Patents

Abstract

A lens test system and method using a stereoscopic microscope are provided to photograph an image of a stereoscopic microscope with a CCD(Charge Coupled Device) camera to obtain a stereoscopic image to thereby acquire a correct image having less image interference. A lens test system using a stereoscopic microscope includes a driver transferring at least one lens, a lens holder loading the lens transferred by the driver, a stereoscopic microscope(50) for acquiring an image in order to check whether the lens loaded on the lens holder is poor, a controller(60) for binarizing image data of the lens, acquired by the stereoscopic microscope and comparing the binarized image data with a previously stored reference lens image to determine whether the lens is poor, and an unloading unit for unloading the lens.

Description

Lens inspection system using stereo microscope and its method {LENS INSPECTION SYSTEM USING STEREOSCOPIC MICROSCOPE AND METHOD THEREOF}

The present invention relates to a lens inspection system and a method using a stereo microscope, and more particularly, to obtain an image of the lens to be inspected using a stereo microscope, and to store the basic data stored in advance by binarizing black and white image data of the obtained lens The present invention relates to a lens inspection system and method using a stereo microscope capable of checking the overall coating process state and other defects of the lens at high speed by determining whether there is a defect and outputting a defect and a good selection signal compared to the lens image. .

In general, spectacle lenses, contact lenses or camera lenses are usually injected and manufactured with high precision and accuracy, but some lenses may have an amorphous form, such as coating or other defects, so before they are sold or mounted on equipment after injection Essentially, the lens should be examined to determine suitability.

In one form of a conventional lens inspection system, when an illumination beam is transmitted through a lens to focus on a screen and a lens image is formed thereon, the operator looks at the image to determine whether the lens has an amorphous shape. If any irregularities or flaws are found and the lens is defective, the lens is removed from the lens inspection system or marked as defective.

However, in such a conventional inspection system, the lens is relatively small in size, and thus accurate focus adjustment is not performed because the focus inspection is performed immediately without measuring the current installation position angle of the lens for focus inspection. In addition, the process of injecting the adhesive for fixing the lens also injects the adhesive into the gap around the lens by hand, making it extremely difficult to achieve uniform focus adjustment and uniform adhesion of the lens. In addition to the problem that the productivity is greatly reduced, the resolution and accuracy of the acquired image is poor, there is a limit to accurate defect inspection through the screen of the lens.

The present invention has been made to solve the above-described problems, an object of the present invention is to obtain an image of the lens to be inspected using a stereo microscope, and to store the image data of the obtained lens by binarizing the image data of the obtained lens in advance and stored in advance The present invention provides a lens inspection system and method using a stereo microscope capable of checking the overall coating treatment state of the lens and other defects at high speed by determining whether the defect is inferior and outputting a selection signal of the defect and the good.

Lens inspection system using a stereo microscope of the present invention for achieving the above object of the present invention, the lens sample stage for loading the at least one lens and the driving unit for carrying at least one lens; And a stereo microscope for acquiring an image to search for defects of the lens loaded on the inspection unit of the lens sample table, and comparing the image data of the lens obtained by the stereo microscope with a pre-stored basic lens image. And a unloading unit for determining whether there is a defect and outputting a selection signal of defective or good quality, and an unloading unit for unloading the defective lens and the good quality lens according to the output defective and good quality selection signal.

Here, the stereo microscope includes two alternative lenses, and the angle between the two alternative lenses is preferably 13 degrees to 17 degrees, which is a recognition angle of a human.

In addition, the sample stage is preferably provided with a vertical driving device for adjusting the depth of the inspection lens.

In addition, the stereo microscope includes a housing disposed above the sample table to seal a space for photographing the surface of the lens with a dark room, a high frequency fluorescent lamp installed inside the housing to illuminate the surface of the lens, and inside the housing. It is preferable to further include a charge coupled device (CCD) camera installed to photograph the surface of the lens.

In addition, a diffuser is installed at an upper end of the housing of the stereo microscope to prevent the high frequency fluorescent lamp projected from the lens from being captured.

In addition, by performing a vector comparison of the image of the binarized black and white lens with a lens image of a pre-stored basic frame, the overall coating processing state and defect of the lens can be confirmed through a computer monitor electrically connected to the controller at high speed. This is preferred.

The lens sample stage may further include: a main rotating table including a loading rotary table for loading at least one lens carried by the driving unit, an inspection unit for inspecting the lens loaded on the loading rotary table, and And an unloading rotating table associated with the unloading unit for unloading the defective lens and the defective lens according to the selection signal of the defective product or the defective product output by the controller.

Lens inspection method using a stereo microscope of the present invention for achieving the above object of the present invention, the step of transporting at least one lens through the drive unit, and at least one of the lenses carried by the drive unit as a sample Loading the image, acquiring an image through a stereo microscope to search for a defect of the lens loaded on the sample stage, and pre-stored basic lens by binarizing black and white image data of the lens obtained from the stereo microscope Determining whether there is a defect compared to the image and outputting a selection signal of defective and good quality, and unloading the defective lens and the good quality lens through the unloading unit according to the output defective and good quality selection signal do.

As described above, according to the lens inspection system and method using a stereo microscope according to the present invention, by using a CCD camera to take images of the stereo microscope using two alternative lenses of approximately 15 degrees embossed to the human recognition angle By obtaining a three-dimensional screen, it is possible to obtain an accurate image with little image interference.

In addition, the inspection unit of the main rotating table, which is a sample table, is provided with a vertical driving device for adjusting the depth of the inspection lens, so that the lens depth can be moved up and down by a known driving means regardless of the magnification ratio, thereby obtaining sharp directivity. have.

In addition, the images of all the black and white processed lenses are judged to be inferior in comparison with the pre-stored base lens images. In this case, the overall coating treatment of the lenses is performed by performing a comparison between the lens image of the base frame and a normal vector. It is effective to check the status and other defects at high speed.

Moreover, since the size of the defective product can be determined according to the size of the number of pixels of the CCD camera, the accuracy of inspection can be adjusted at will.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 is an overall perspective view of a lens inspection system using a stereo microscope according to the present invention, Figure 2 is a perspective view of a stereo microscope of a lens inspection system using a stereo microscope according to the present invention, Figure 3 is a stereo microscope according to the present invention 4 is a perspective view of a delivery unit of a lens inspection system using a stereo microscope according to the present invention, and FIG. 5 is an inspection unit as a sample stage of a lens inspection system using a stereo microscope according to the present invention. FIG. 6 is a perspective view of the unloading part of the lens inspection system using the stereo microscope according to the present invention. Here, the lens inspection system 100 using a stereo microscope according to the present invention according to the present invention is a device for inspecting a lens produced in an injection molding machine as a stereoscopic microscope for defective elements (foreign materials, bubbles, bubbles, black spots, etc.) of the lens. Using various kinds of

It is a device that checks the lens with a camera system and distinguishes defects and good products.

First, as shown in FIG. 1, the lens inspection system 100 using the stereo microscope according to the present invention includes a lens input unit 10 and a lens transport unit 20 as a driving unit for carrying a plurality of lenses, and a lens. It consists of the sample stand 30, the lens unloading part 40, and the stereo microscope 50.

As shown in FIG. 3, the lens inlet 10 includes a lens tube 11 containing a plurality of lenses 1 and a flat plate shape for moving the lens tube 11 to a lens supply position. A conveying plate 12, a cylinder 13 for clamping the lens tube 11, and a rotating cylinder 14 for freely falling by rotating the lens at an inclination of approximately 40 degrees.

As shown in FIG. 4, the lens transporter 20 includes a free fall rail 21 through which the plurality of lenses 1 supplied through the lens inlet 10 free fall, and the free fall. A plurality of lenses 1 supplied to the rail 21 are composed of a lens loading portion 24 which is moved through a feeding rail 22 and a linear feeder 23 which causes fine vibration.

As shown in FIG. 5, the lens sample stage 30 for performing the inspection includes three rotary tables, that is, a main rotary table 31, a loading rotary table 32, and an unloading rotary table 33. All of them are made rotatable by a drive motor (not shown in the figure) such as a stepping motor (DD motor).

The main rotary table 31 is divided into 12 zones at a predetermined distance to form a divided portion. That is, it is divided into one loading section, five buffer sections, three inspection sections (refer to 70 of FIG. 2), two unloading selection sections (defective), and one unloading selection section (goods), and each lens 1 Equipped with a chuck structure 35 to hold the.

The loading part (not shown) supplies the lens 1 in association with the loading rotary table 32 and the unloading selection part (bad) (not shown) provides a solenoid cylinder 36. By using the free fall method of dropping the defective lens (1) by using the unloading selection part (goods) (not given the drawing number) in conjunction with the unloading rotary table 33 to convey the good lenses.

Here, the loading rotary table 32 and the unloading rotary table 33 are each divided into four zones, each of which has a solenoid cylinder 34 and a vacuum pad 37 for picking up the lens 1. It is equipped with a structure consisting of

As shown in FIG. 6, the unloading unit 40 is a defective lens that is distinguished from the main rotating table 31 through the stereo microscope 50 as described below. R) is supplied to the defective tube (not shown) of the unloading portion 40, and the unloading portion 40 is replaced by a flat plate 41 using the cylinder 42 and the ball bush 43 The lens 1 is placed in a defective tube. Of course, the good lens 1 is also loaded into the good quality tube (not shown) in the same way on the free-loading rail from the unloading rotary table 33.

On the other hand, as shown in Figure 2, the stereo microscope 50 for acquiring an image in order to search whether the lens (1) loaded on the inspection unit 70 of the main rotary table 31, which is the sample table is defective, The upper body is composed of a housing 52 formed integrally with the body 51 and the lower body.

Two alternative lenses 53 are formed which protrude upwards of the body portion 51 and the angle between them is approximately 13-17 degrees (most preferably about 15 degrees) which is approximately equal to the human perception angle. Although the example shown shows that the two alternative lenses 53 are approximately 15, which is the recognition angle of a person, the present invention does not limit the angle between them.

In addition, the stereo microscope 50 is provided in the upper part of the inspection unit 70 of the main rotary table 31 serving as a sample table, the housing 52 for sealing the space for photographing the surface of the lens 1 in a dark room, A high frequency fluorescent lamp 54 installed inside the housing 52 to illuminate the surface of the lens 1, and a charge coupled device (CCD) installed inside the housing 52 to photograph the surface of the lens 1; It further includes a camera 55.

In addition, the inspection unit 70 of the main rotating table 31 serving as the sample table is provided with a vertical driving device 55 for adjusting the depth of the inspection lens to move the lens depth up and down by a known driving means regardless of the enlargement ratio.指向 性 can be obtained.

In addition, a diffuser 56 is installed at an upper end of the housing 52 to prevent the high frequency fluorescent lamp 54 projected from the lens 1 from being captured.

Here, reference numeral 57 denotes an objective lens, and 58 denotes a grab board for data processing an image obtained through a CCD (charge coupled device) camera 55 and transmitting the data to the controller 60.

In addition, the control unit 60 binarizes the image data of the lens 1 acquired by the stereo microscope 50 to compare with the previously stored basic lens image to determine whether there is a defect, and outputs a selection signal of defective and good products. It performs a role and consists of a computer and a controller not shown as shown in the example shown.

In this case, the thresholding operation refers to applying the corresponding pixel value into 0 and 1 based on a certain boundary value, and is generally divided into black (0) and white (1 or 255) and storing. Since this binarization technology is a well-known technique, further description will be omitted. In addition, the images of all the black and white processed lenses are judged to be inferior in comparison with the pre-stored base lens images. In this case, the overall coating treatment of the lenses is performed by performing a comparison between the lens image of the base frame and a normal vector. Status and other defects can be checked at high speed. That is, the vector comparison of images can be processed by a known photo image matching method using a conventional visual basic programmed in a computer. Such failure types will be described in more detail with reference to FIGS. 8A to 8E.

Hereinafter, a lens inspection method using a stereo microscope according to the present invention will be described with reference to FIG. 7.

As shown in Figure 7, the lens inspection method using a stereo microscope according to the present invention, the step of transporting at least one lens (S100), the step of loading a sample (S110), and the image of the lens stereo microscope Acquisition through the step (S120), determining whether there is a defect and outputs a selection signal of defective and good quality (S130), and the step of unloading the defective lens and the good quality lens through the unloading unit (S140).

First, in the transporting step of the at least one lens (S100), by supplying a plurality of lens tubes 11 containing a plurality of lenses (1) to move to the lens supply position using a flat plate-shaped transfer plate (12) do. Then, the lens tube 11 is clamped using the cylinder 13 and rotated by an inclination of approximately 40 degrees with the rotating cylinder 14 to free fall.

Subsequently, the plurality of lenses 1 supplied through the lens input unit 10 are supplied to the feeding rails 22 from the free-falling rails 21, which are free-falling, and the feeding rails 22. Is moved to the lens loading section 24 through a linear feeder 23 causing fine vibration.

In step S110, the lens 1 supplied through the lens loading unit 24 is connected to the loading rotation table 32 (see FIG. 5) and the main rotation table 31 serving as the sample stage. Is transferred to the inspection unit 70 (see FIG. 2). Of course, the loading of such lenses is sequential and continuous.

In step S130 of determining whether the defect is defective and outputting a defective and good product selection signal, the inspection lens 1 located in the inspection unit 70 (see FIG. 2) of the main rotating table 31 serving as the sample stand is a chuck structure. It is fixed by 35 (refer FIG. 5). The distance between the inspection lens 1 and the objective lens 57 is changed according to the specifications of the stereo microscope.

Subsequently, light is irradiated to the inspection lens 1 by using the high frequency fluorescent lamp 54 and the refracted image is photographed by using a charge coupled device (CCD) camera 55 to acquire an image (S130). Here, the CCD image capturing device is composed of pixels. The pixel has a 1280 * 1024 pixel in a size range supported by a stereoscopic microscope, and the controller 60 edits about 2 megabytes of data. Is sent to. In addition, the image input to the CCD camera 55 is allocated in units of bits on each color supported per pixel, and the color is decomposed and received for each cell through filters GRGB and CMYK. In order to shorten the inspection time of the input image, the reference value is set as a threshold, which is a brightness measured in a dark room.

In this state, the control unit 60 binarizes the image data of the lens 1 acquired by the stereo microscope 50 (S131) and compares the image data with the pre-stored basic lens image (S132) to determine whether there is a defect. And calculate the area for the defects (refer to FIG. 8) that appear as dots or lines in the comparison image (S133), determine whether the size and number of the defects are consistent with the quality standard (S134), and then output the selection signal of the defective and good products. (S135). That is, all images are processed in binary black and white grade (grade) to perform a comparison of the basic frame image and a known vector, so that the overall coating state and other defects of the entire lens can be confirmed at high speed.

In the step of unloading the defective lens and the good lens through the unloading unit (S140), as described above, the corresponding lens 1 is selected as defective or good through the control unit 60, and then the defective signal is outputted. The lens is supplied to a defective tube (not shown) of the unloading part 40 by a free drop rail (not shown in the drawing), and the unloading part 40 is plated using a cylinder 42 and a ball bush 43. The lens 1 is placed in the defective tube while the tube is switched with the upper plate 41. In addition, a good lens 1 is also loaded into a good quality tube (not shown) in the same way on a free-falling rail from the unloading rotating table 33.

This lens inspection method using a stereo microscope according to the present invention is repeatedly performed.

8A to 8E illustrate examples of image results obtained by using a lens inspection system using a stereo microscope according to the present invention, which is displayed through a computer monitor of the controller 60.

That is, FIG. 8A shows a partial coating defect as a part scattered by external light, FIG. 8B shows a stain defect due to fingerprints or foreign objects, and FIG. 8C shows bubbles (white dots) appearing outside due to scattering of light generated in the lens. ) Shows a defect, FIG. 8D shows a stamping defect that appears along with a coating defect, and FIG. 8E shows a gate defect that appears as long as a line shape.

Although the present invention has been described in detail with reference to preferred embodiments, it is not intended to limit the present invention but merely to illustrate the present invention, and various changes and modifications can be made by those skilled in the art without departing from the gist and scope of the present invention. Of course, this is also within the scope of the present invention.

1 is an overall perspective view of a lens inspection system using a stereo microscope according to the present invention.

2 is a perspective view of a stereo microscope of a lens inspection system using a stereo microscope according to the present invention.

Figure 3 is a perspective view of the input portion of the lens inspection system using a stereo microscope according to the present invention.

4 is a perspective view of a transportation unit of a lens inspection system using a stereo microscope according to the present invention.

5 is a perspective view of an inspection unit as a sample stage of a lens inspection system using a stereo microscope according to the present invention.

6 is a perspective view of an unloading part of a lens inspection system using a stereo microscope according to the present invention.

7 is a flowchart illustrating a lens inspection method using a stereo microscope according to the present invention.

8A to 8E are diagrams showing examples of image results obtained using a lens inspection system using a stereo microscope according to the present invention.

Explanation of symbols on the main parts of the drawings

100: lens inspection system using a stereo microscope according to the present invention

1: lens

10: lens input 11: lens tube

12: Transfer plate of plate shape 13: Cylinder

14: rotating cylinder 20: lens transport

21: free fall rail 22: feeding rail

23: linear feeder 24: lens loading unit

30: lens sample table 31: main rotating table

32: loading rotary table 33: unloading rotary table

34, 36: solenoid cylinder 35: chuck structure

37: vacuum pad 40: unloading portion

41: plate on plate 42: cylinder

43: ballbush 50: stereo microscope

51: body 52: housing

53: two alternative lenses 54: high frequency fluorescent

55: CCD (charge coupled device) camera

55: Up and down drive device for adjusting the depth of inspection lens

56: diffuser 57: objective lens

58: GRAB board 60: control unit

70: inspection unit

Claims (10)

A driving unit for carrying at least one lens, A lens sample stage for loading at least one of the lenses carried by the driving unit; A stereo microscope for acquiring an image to search for defects of the lens loaded on the inspection unit of the lens sample table; A control unit which binarizes the image data of the lens acquired by the stereo microscope and compares it with a pre-stored basic lens image to determine whether there is a defect, and outputs a selection signal of the defective product and the good product; The lens inspection system using a stereo microscope, characterized in that the unloading unit for unloading the defective lens and the good lens in accordance with the output of the defective and good quality selection signal. The method of claim 1, The stereo microscope includes two alternative lenses, and the angle between the two alternative lenses is a human recognition angle of 13 degrees to 17 degrees. The method of claim 1, A lens inspection system using a stereo microscope, characterized in that the upper and lower driving device for adjusting the depth of the inspection lens is installed on the sample stage. The method of claim 1, The stereo microscope is provided in the housing to seal the space for photographing the surface of the lens in the dark room, a high frequency fluorescent lamp installed in the housing to illuminate the surface of the lens, and the inside of the housing And a charge coupled device (CCD) camera for photographing the surface of the lens. The method of claim 4, wherein A diffuser is installed at an upper end of the housing of the stereo microscope to prevent the high frequency fluorescent lamp projected from the lens from being captured. The method of claim 1, The image of the binarized black-and-white lens is compared with a lens image of a pre-stored basic frame to check the overall coating processing state and defect of the lens through a computer monitor electrically connected to the controller at high speed. A lens inspection system using a stereo microscope. The method of claim 1, The lens sample stage includes a loading rotary table for loading at least one lens carried by the driving unit, a main rotary table including an inspection unit for inspecting the lens loaded on the loading rotary table, and the control unit. And an unloading rotary table associated with the unloading unit for unloading the defective lens and the defective lens according to the defective and the defective article selected signal outputted by the stereo microscope. The method of claim 7, wherein And the main rotary table, the loading rotary table and the unloading rotary table are axially rotated by a drive motor. Carrying at least one lens through a drive; Loading at least one of the lenses carried by the driving unit into a sample; Acquiring an image through a stereo microscope to detect whether the lens loaded on the sample stage is defective; Binarizing the image data of the lens obtained from the stereo microscope and comparing the image data of the lens with a pre-stored basic lens image to determine whether there is a defect, and outputting a selection signal of the defective and good products; And unloading the defective lens and the non-defective lens through the unloading unit according to the output defective and the goodness-of-goods selection signal. The method of claim 9, In the step of outputting the selection signal of the defective or good, the image of the binarized black-and-white processed lens is compared with the lens image of the pre-stored basic frame to check the overall coating state and defect of the lens at high speed. Lens inspection method using a stereo microscope, characterized in that it further comprises the step of.

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