JP2003139509A - Size measuring method and device for transparent object to be measured having curved surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method capable of accurately measuring a size of a transparent object 4 to be measured having a curved surface, and a device used for the method. SOLUTION: By interposing a transparent plate 2 formed with oblique lines 21 between a luminaire 1 and the transparent object 4 to be measured having a curved surface, irradiating on the object 4 with a light from the luminaire 1 via the transparent plate 2, and projecting distorted oblique lines 22 in a state broken near the outer circumferential rim part of the object 4 on the object 4, the edges A and B of the oblique lines 21 of the transparent plate 2 passing an outer side of the circumferential rim part of the object are shown, the edges A and B are taken in an image processing camera 3 and the size of the object 4 is measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring method and apparatus used for measuring the size of a transparent object having a curved surface such as a container for storing various chemicals, foods and other articles. Is.

[0002]

2. Description of the Related Art In general, a chemical container or the like is measured for dimensions such as a diameter of a neck or a body of the container in order to confirm whether or not the container has a prescribed size. Then, in measuring the dimensions of a container or the like, conventionally, an object to be measured is placed between a lighting fixture and an image processing camera, and an image of the object to be measured is captured by the camera while light from the lighting fixture is applied. The size of the object to be measured is detected by detecting the outer peripheral edge of this image. At this time, as a lighting fixture, a large number of light emitting LEs are used.
It is usual to use a so-called backlight in which a diffuser plate is arranged on the front surface of the substrate on which D is attached, and the light from the light emitting LEDs is diffused by the diffuser plate to irradiate the DUT as uniform light.

[0003]

However, when measuring an object to be measured which is transparent and has a curved surface, when the light from the backlight is applied to the object to be measured, the light hits the outer peripheral edge of the object to be measured and diffusely reflects. Cause For this reason, the outer peripheral portion of the image captured by the camera is entirely blurred, and accurate dimension measurement of the measured object cannot be performed (see FIG. 6 described later).

The inventors of the present invention have conducted diligent research to accurately measure the dimensions of a transparent object having a curved surface.
We found the following. When the light from the luminaire is applied to the object to be measured through the transparent plate on which the oblique line is formed, the oblique line is refracted and distorted by passing through the curved surface of the object to be measured. There is a break near the section. That is, the diagonal line passing through the object to be measured is distorted and becomes discontinuous in the vicinity of the outer peripheral edge portion, whereas the diagonal line of the transparent plate passing outside the outer peripheral edge portion is linear, The edge of this straight diagonal line (the boundary with the object to be measured) clearly appears. Then, they have found that if the edge of this clear diagonal line is taken into an image processing camera and processed, accurate dimension measurement of an object to be measured can be performed. Therefore,
An object of the present invention is to provide a measuring method capable of accurately measuring the dimensions of a transparent object to be measured having a curved surface, and an apparatus used therefor.

[0005]

In order to achieve the above object, the dimension measuring method of the present invention includes a transparent plate having a diagonal line formed between a lighting fixture and a transparent object to be measured having a curved surface, By irradiating the object to be measured with light from the lighting equipment through the transparent plate and projecting a distorted oblique line in a discontinuous state in the vicinity of the outer peripheral edge of the object to be measured, the outer peripheral edge of the object to be measured is projected. The shaded edge of the transparent plate that passes through the outside is exposed, and this edge is taken into the image processing camera to measure the dimension of the object to be measured.

As described above, the outer peripheral edge of the object to be measured, that is, the slanted edge of the transparent plate (the boundary between the object and the object to be measured) can be clearly revealed, so that the object to be measured having a curved surface is transparent. Can be accurately measured.

In the dimension measuring apparatus of the present invention, a transparent object to be measured having a curved surface is arranged between the lighting fixture and the image processing camera, and the object to be measured is image-processed while light is emitted from the lighting fixture. It is a measuring device which photographs with a use camera and measures the dimension of an object to be measured based on the image, and a transparent plate having a diagonal line is interposed between the lighting fixture and the object to be measured.

By using this apparatus, the method of the present invention can be easily carried out and the intended purpose can be achieved.

In the above apparatus, it is preferable that the width of the diagonal lines of the transparent plate is set to 1 to 4 mm and the distance between the diagonal lines is set to 3 to 10 mm. Further, the angle of the oblique line of the transparent plate with respect to the horizontal line is preferably set to 10 to 30 degrees. The conditions of the width, interval and angle of these slanted lines are particularly optimal when measuring a small object to be measured used as a medicine bottle or the like that requires dimensional accuracy. Furthermore, the width of the diagonal line of the transparent plate is preferably set to be equal to or less than the thickness of the object to be measured. Further, it is preferable to set so that the distorted oblique line projected on the object to be measured and the oblique line adjacent to the distorted oblique line outside the object to be measured do not overlap.
By doing so, the diagonally shaded edges of the transparent plate appear more clearly, so that the dimensions of the object to be measured can be measured more accurately. If the above conditions are deviated, the edge of the oblique line of the transparent plate may be blurred or may be covered with another oblique line, and the dimension of the measured object may not be accurately measured.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a dimension measuring device of the present invention. The dimension measuring apparatus of FIG. 1 includes a backlight 1 which is a lighting fixture, a transparent plate 2 attached to the front side of the backlight 1 and having a diagonal line, and a CCD camera 3 for image processing.

The backlight 1 and the CCD camera 3
A glass vial 4 is placed as a transparent object to be measured having a curved surface, and the oblique line 21 of the transparent plate 2 and an image of the vial 4 are shown in a state where the vial 4 is illuminated with light from the backlight 1. CC
The size of the medicine bottle 4 is measured based on the image captured by the D camera 3.

FIG. 2 is a front view in which the transparent plate 2 is partially cut away. The transparent plate 2 is made of a transparent plate material such as acrylic, and is drawn with black diagonal lines 21 at equal intervals. The diagonal line 21 preferably has a width T1 of 1 to 4 mm.
And the interval T2 of the diagonal lines is set to 3 to 10 mm, more preferably T1 is 2 to 3 mm and T2 is 4 to 6 mm.
Is set to. In addition, the angle θ of the oblique line 21 with respect to the horizontal line
Is preferably set to 10 to 30 degrees, and more preferably set to 13 to 25 degrees. The conditions of the width, interval and angle of these slanted lines are particularly optimal when measuring a small object to be measured used as a medicine bottle or the like that requires dimensional accuracy. Further, the width T1 of the oblique line 21 is preferably set to be equal to or less than the thickness of the medicine bottle 4.

FIG. 3 shows a preferable state when the oblique line 2 is projected on the medicine bottle 4, and FIG. 4 shows an unfavorable state. When the light from the backlight 1 is applied to the drug vial 4 through the transparent plate 2, the oblique line 21 of the transparent plate 2 is attached to the drug vial 4.
Is refracted and is projected as a distorted oblique line 22 in which the outer peripheral edge of the drug vial 4 is discontinuous. At this time, as shown in FIG. 3, it is preferable that the distorted oblique line 22 is set so as not to cover the oblique line 21 adjacent to the distorted oblique line 22 on the outer side of the medicine bottle 4, whereby the oblique line 21 of the transparent plate 2 is formed. Since the edge A (the boundary with the drug vial) clearly appears, the dimension of the drug vial 4 with respect to this edge A can be accurately measured. Here, if the width of the oblique line 21 is increased with respect to the interval, as shown in FIG. 4, the distorted oblique line 22 projected on the medicine bottle 4 and the distorted oblique line 22 outside the medicine bottle 4 are adjacent to each other. There is a case in which the diagonal line 21 and the shaded line 21 are covered with each other, the edge A is not clearly exposed, and accurate size measurement of the drug vial 4 cannot be performed.

FIG. 5 shows an actual image of the glass vial 4 (height 43 mm, diameter 23 mm) taken in by the CCD camera 3. This image shows C as backlight 1.
The LFL-100 manufactured by CS Co., Ltd. is used as the camera 3 using PULNIX CCD video camera TM-9700M-G manufactured by Takenaka System Equipment Co., Ltd., and the transparent plate 2 is a transparent acrylic plate with a width of 2 mm and an angle of 15 degrees. Black diagonal lines 21 drawn at equal intervals of 50 mm (see FIG. 2) are used, and the distance L1 from the backlight 1 to the center of the vial 4 is set to 20 mm. The distance L2 to the lens surface is 120 mm (see FIG.
(Refer to FIG. 3), the medicine bottle 4 is photographed. In the backlight 1, a diffuser plate is arranged on the front surface of a substrate on which a large number of light emitting LEDs are attached, and the light from the light emitting LEDs is diffused by the diffuser plate to irradiate the object to be measured as uniform light.

Here, since the light from the backlight 1 is applied to the medicine bottle 4 through the transparent plate 2 on which the oblique line 21 is formed, the oblique line 21 is refracted and distorted by passing through the curved surface of the medicine bottle 4. The distorted diagonal line 22 is discontinuous near the outer peripheral edge of the drug vial 4. That is, the diagonal line 22 passing through the medicine bottle 4 is distorted and becomes discontinuous near the outer peripheral edge portion, while the diagonal line 21 of the transparent plate 2 passing outside the outer peripheral edge portion of the medicine bottle 4 is linear. Therefore, the edges A and B (the boundary with the medicine bottle) of the straight oblique line 21 are clearly exposed. Then, the above image is captured by the CCD camera 3, and the diameter D of the body portion of the medicine bottle 4 is calculated by a PC (personal computer) based on the edges A and B of the image.

FIG. 6 shows the structure of FIG. 5 without using the transparent plate 2.
An actual image in which the drug vial 4 is taken into the CCD camera 3 is shown in the same manner as in the case of FIG. As shown in FIG. 6, when the transparent plate 2 is not used, the light from the backlight 1 is the medicine bottle 4
When the light is irradiated on the medicine bottle 4, the light impinges on the outer peripheral edge portion of the medicine bottle 4 to cause diffuse reflection, and the outer peripheral edge portion of the image is entirely blurred, so that the accurate size measurement of the medicine bottle 4 cannot be performed. In the figure, the blurry and thin line of the body of the drug vial 4 is the outline of the body, and the dark line is the line of the inner diameter.

FIG. 7 is a processing block diagram showing an example of measuring the diameter D of the body of the medicine bottle 4 based on the image of FIG. First, in step S1, the image is taken into the CP, the mouth of the medicine bottle 4 is searched (step S2), and the positions of the edges A and B are corrected based on the result of this search (step S3). . Then, in step S4, the positions of the edges A and B are detected as X and Y coordinates, and the diameter D of the body of the drug vial 4 is calculated based on these coordinates (step S5).

As described above, prior to detecting the positions of the edges A and B, the mouth portion having the smallest dimensional error in the medicine bottle 4 is searched and used as a reference, and the edge A is based on this reference. , B are corrected and then the positions of the edges A and B are detected, so that the vial 4 can be detected even on the inspection line.
Even if the position shift occurs, the positions of the edges A and B can be accurately detected.

In the above embodiment, the case where the diameter D of the body portion of the medicine bottle 4 is measured has been described. However, in the present invention, the diameter of the mouth and neck of the medicine bottle 4 and the inclined surface of the shoulder portion, etc. Can be measured in the same manner. Further, the present invention is not limited to glass vials, but can also be applied to the case of measuring a transparent object having a curved surface such as a food container formed of plastic or the like.

[0020]

As described above, according to the method and apparatus of the present invention, it is possible to accurately measure the size of a transparent object having a curved surface.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a dimension measuring apparatus according to the present invention.

FIG. 2 is a partially cutaway front view of a transparent plate used in the present invention.

FIG. 3 is an explanatory diagram showing a preferable state when the oblique line of the transparent plate is projected on the object to be measured (medicine bottle).

FIG. 4 is a reference diagram for explaining an unfavorable state when an oblique line of a transparent plate is projected on an object to be measured (medicine bottle).

FIG. 5 is an image showing an object to be measured (medicine bottle) taken into a camera for image processing (CCD camera) through a transparent plate.

FIG. 6 is a reference diagram showing an image of an object to be measured (medicine bottle) taken into an image processing camera without using a transparent plate.

FIG. 7 is a processing block diagram when measuring the dimensions of the object to be measured (medicine bottle) based on the image captured by the image processing camera.

[Explanation of symbols]

1 Lighting equipment (backlight) 2 transparent plate 21 diagonal lines 22 Distorted diagonal lines A, B edge 3 Image processing camera (CCD camera) 4 DUT (medicine bottle)

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Claims (6)

[Claims] 1. A transparent plate having oblique lines is interposed between a lighting fixture and a transparent object to be measured having a curved surface, and light from the lighting fixture is applied to the object to be measured through the transparent plate. By projecting a distorted diagonal line in a discontinuous state near the outer peripheral edge of the object to be measured, the edge of the diagonal line of the transparent plate that passes outside the outer peripheral edge of the object to be measured appears, and this edge is A dimension measuring method of a transparent object having a curved surface for measuring the dimension of the object to be measured by taking it into an image processing camera. 2. A transparent object to be measured having a curved surface is arranged between the lighting device and the image processing camera, and the object to be measured is photographed by the image processing camera in a state where light is emitted from the lighting device,
A measuring device for measuring the dimensions of an object to be measured based on the image, wherein the object to be measured is a transparent object having a curved surface in which a transparent plate with oblique lines is interposed between the lighting fixture and the object to be measured. Measuring device. 3. The size measuring device for a transparent object having a curved surface according to claim 2, wherein the width of the oblique line of the transparent plate is 1 to 4 mm, and the interval between the oblique lines is set to 3 to 10 mm. 4. The size measuring device for a transparent object according to claim 2, wherein the transparent plate has a curved surface in which the angle of the oblique line with respect to the horizontal line is set to 10 to 30 degrees. 5. The size measuring device for a transparent object to be measured according to claim 2, wherein the width of the oblique line of the transparent plate is set to be equal to or less than the thickness of the object to be measured. 6. The distorted oblique line projected on the object to be measured and the oblique line adjacent to the distorted oblique line outside the object to be measured are set so as not to cover each other. Dimensional measuring device for transparent objects with curved surfaces.