JP3116249B2 - Alignment determination method and eccentricity measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining misalignment and a method for measuring misalignment, and more particularly, to easily determine whether or not misalignment of a centered object is within an allowable range. The present invention relates to a misalignment determining method and a misalignment measuring method capable of automatically measuring the misalignment when the misalignment is out of an allowable range.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 63-89254 discloses an observation device for positioning. This device performs alignment (centering) of a workpiece or the like facing a machining tool in drilling or electric discharge machining.
As shown in FIG. 5, a processing tool 42 and a workpiece 4 which have total reflection surfaces 40 and 44 and a half mirror surface 41 and face each other are provided.
3. Optical path combining optical system 4 for forming both images in the same visual field
5, a television camera 46 for reading the image, and a monitor television 47 for processing and displaying the read image.

An image of a workpiece 43 facing a processing tool 42 is formed in the same field of view by an optical path synthesizing optical system 45, and both images are read by a television camera 46, displayed on a monitor television 47, and displayed on a monitor television 47. (Position) The position is observed and the position is adjusted if necessary.

[0004]

However, in the method used in the above-described positioning observation apparatus, the operator observes the image displayed on the monitor television and judges the center (position) displacement. There was a problem that it took time to make a decision. The present invention has been devised in view of such a conventional problem, and it is possible to quickly and easily determine whether or not the center misalignment of a centered object is within an allowable range. It is an object of the present invention to provide a misalignment determination method and a misalignment amount measuring method that can automatically measure the misalignment amount and use the information to correct the misalignment when the misalignment amount is outside. .

[0005]

According to the present invention, in order to achieve the above object, the centering axes are positioned at positions on the respective centering axes of objects which are centered facing each other, A circular mark having a diameter of 1/2 of the misalignment OK / NG determination standard is provided, an image of the circular mark is formed in a visual field in the same direction by an optical system, and an image of the formed circular mark is read. The gist of the invention is to read the image with a device, extract the center of gravity of the read image by an image processing device, and determine whether the number of the extracted centers of gravity is one or not. In addition, a circular mark having a diameter of 1/2 of the center misalignment OK / NG determination standard, centered on the centering axis, is provided at a position on each centering axis of the object centered opposite to each other. Is provided, an image of the circular mark is formed in the visual field in the same direction by the optical system, the formed image of the circular mark is read by the image reading device, and the center of gravity of the read image is extracted by the image processing device. Then, it is determined whether the number of the extracted centroids is one or two. If it is determined that the number of the centroids is two, the distance between the centroids, the x-coordinate deviation amount, and the y-coordinate are calculated from the position coordinates of each centroid. The gist is to calculate the coordinate shift amount and measure the center shift amount.

[0006]

The present invention is constructed as described above, and the positions of the centering axes are centered on the respective centering axes of the objects centered opposite to each other, and the center misalignment OK · N
By providing a circular mark having a diameter of 1/2 of the G judgment standard,
The image of the circular mark is formed in the visual field in the same direction by the optical system, the image of the formed circular mark is read by the image reading device, and the center of gravity is extracted by the image processing device.
It is determined whether the number of the centers of gravity of the extraction mark is one, and when the number of the centers of gravity is one, it is determined that the misalignment is within an allowable range,
In other cases, it is determined that the misalignment is outside the allowable range, so that it is possible to quickly and easily determine whether the misalignment of the centered object is within the allowable range.

If it is determined that the misalignment is out of the allowable range, the distance between the centers of gravity, the amount of x-coordinate misalignment, and the amount of y-coordinate misalignment are calculated from the position coordinates of each center of gravity, and the amount of misalignment is measured. By automatically measuring the amount of misalignment, the state of misalignment of the mutual object can be easily known, and can be output and used as information for performing misalignment correction.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory view for explaining the configuration of an apparatus used for a method for determining misalignment and a method for measuring misalignment according to the present invention. Reference numeral 10 denotes an image of an object to be measured which faces a centered object in the same direction. The optical system is formed by combining in the field of view, a half mirror 11, a lens 12 for converting a light beam emitted from the light source 1 into a parallel light beam, a total reflection mirror 13,
4 is provided.

Reference numeral 20 denotes a condensing lens for enlarging an image of a point to be measured formed in the visual field in the same direction by the optical system 10, and 21 reads the image enlarged by the condensing lens 20. Reference numeral 22 denotes an image reading device such as a television camera (CCD camera, etc.). Image processing 22 extracts the center of gravity of the image read by the image reading device 21, counts the number of the centers of gravity, and measures the amount of displacement between the centers of gravity. Device.

Reference numerals 2 and 3 denote a reference mark plate and a measurement mark plate provided with a circular mark M (FIG. 2) having a diameter of 1/2 of the required misalignment accuracy (OK / NG determination standard), respectively. The circular mark M is provided on the plate bodies 2a and 3b formed of a light transmitting material. Also, 4, 5, 6
Is a connecting member that connects the image reading device 21 and the half mirror 11, the half mirror 11 and the light source 1, and the half mirror 11 and the total reflection mirror 13.

Next, a method for determining misalignment and a method for measuring misalignment of the present invention using the above-described apparatus will be described. First,
A circular mark M having a diameter of １ ／ the required accuracy of the misalignment is provided on the reference mark plate 2 and the measurement mark plate 3. For example, when the tolerance of the required misalignment is 0.5 mm,
Circles with a diameter of 0.25 mm are marked on the plate bodies 2a, 3a.

The reference mark plate 2 is mounted on the total reflection mirror 13 of the optical system 10, and the measurement mark plate 3 is mounted on the total reflection mirror 14. The total reflection mirror 13 to which the reference mark plate 2 is attached is attached to the connecting member 6. At this time, the circular mark M of the reference mark plate 2 is mounted so that the center of the circular mark M passes through the horizontal axis XX of the apparatus. The axis XX is a half mirror 1 installed at an angle of 45 ° with respect to the axis XX.
1, it intersects with the longitudinal axis YY of the device. Therefore, by aligning the axis YY with the centering axis A′-A ′ of one of the objects A facing and centered, the circular mark M becomes the centering axis A′-A of the object A. It is the same as that provided above.

Further, a total reflection mirror 14 on which the anti-measurement mark plate 3 is mounted is arranged on the other centered object B. At this time, the center of the circular mark M of the paired measurement mark plate 3 is set on the centering axis B′-B ′ of the object B.
Then, the axis Y-Y of the apparatus is made to coincide with the centering axis A'-A 'of the object A, and the light source 1, the image reading device 21, and the image processing device 22 are operated, and the reference mark plate 2 and the measuring mark The circular mark M on the mark plate 3 is read.

The light beam from the light source 1 passes through the lens 12 and becomes parallel light, and the half mirror 11 irradiates the circular mark M on the reference mark plate 2 and the measurement mark plate 3. Light rays are reflected by the total reflection mirrors 13 and 14 except for the circular mark M, enter the half mirror 11 again, and move in the direction of the image reading device 21 to the circular mark M of the reference mark plate 2 and the measurement mark plate. The image of the third circular mark M is synthesized.

Subsequently, an image enlarged by passing through the condenser lens 20 is read by the image reading device 21. The read image is input to the image processing device 22, subjected to preprocessing, and an image (image) synthesized by feature extraction is extracted.
The center of gravity is calculated. When an image S as shown in FIG. 3A is obtained, one center of gravity G1 is extracted, and it is determined that the misalignment of the centered objects A and B is within an allowable range. When an image T as shown in FIG. 3 (b) is obtained, two centers of gravity G1 and G2 are extracted, and the misalignment of the centered objects A and B is outside the allowable range. It is determined. When it is determined that the misalignment of the objects A and B is out of the allowable range, the position coordinates of the two centroids extracted by the image processing device 22 are obtained, and the distance between the centroids is calculated based on the position coordinates. If the x-coordinate displacement amount and the y-coordinate displacement amount are calculated, the misalignment amount is measured.

FIG. 4 shows an example in which a PCI (Post cure Inflator: expansion device after vulcanization) is used for determining misalignment and measuring misalignment. 31a and 31b are upper and lower ring mounting jigs for mounting the upper and lower measurement rings 32a and 32b on the upper and lower rims Pa and Pb of the PCI. The measurement ring 32a is mounted on the upper ring mounting jig 31a. Is
The upper end of the connecting member 5 of the device for determining the misalignment and measuring the misalignment is mounted.

Further, the light source 1 is mounted in a hole provided in the measurement ring 32a, and a lens 12 for converting a light beam emitted from the light source 1 from above into a parallel light beam in the connecting member 5;
And a reference mark plate 2 provided with a circular mark M, and a half mirror 11 and a total reflection mirror 13 are provided at a lower end of the connecting member 5. The center of the circular mark M of the reference mark plate 2 coincides with the centering axis OO of the rim Pa on the PCI.

A connecting member 4 is provided in the horizontal direction of the half mirror 11, and a condensing lens 20 is disposed inside the connecting member 4, and is connected to an image reading device 21 and an image processing device 22. Therefore, the connecting member 6 for connecting the half mirror 11 and the total reflection mirror 13 described above is not used. The measurement mark plate 3 provided with the circular mark M is mounted on the total reflection mirror 14, and the center of the circular mark M is
The centering axis O'-O 'of the rim Pb below I is made to coincide. The method of determining the misalignment and the method of measuring the misalignment amount are the same as described above.

As described above, according to the present invention, the centering axes A'-A ', B'-B' are positioned at positions corresponding to the respective centering axes A'-A ', B'-B'. As a center, a circular mark M having a diameter of の of the required misalignment is provided.
Optical system 10, image reading device 21, and image processing device 22
, The center of gravity is measured, and when the center of gravity is one, it is determined that the misalignment is within the allowable range. Therefore, it is quickly determined whether or not the misalignment of the centered object A is within the allowable range. And it can be easily determined. When the center of gravity is two NGs, the amount of misalignment can be quickly calculated automatically, and the amount of misalignment of the object can be easily measured and known. Can be used as information for performing

[0020]

The present invention is constructed as described above, and is arranged at a position on each centering axis of the objects centered opposite to each other, with the centering axis as the center and the center misalignment required. A circular mark having a diameter of の of accuracy is provided, an image of the circular mark is formed in a visual field in the same direction by an optical system, and the formed image of the circular mark is read by an image reading device, and image processing is performed. The center of gravity is extracted by the device, and it is determined whether or not the number of the centers of gravity is one. When the number of the centers of gravity is one, it is determined that the misalignment is within an allowable range. There is an effect that it is possible to quickly and easily determine whether or not the deviation is within an allowable range.

When the center of gravity is two (decision NG),
From the position coordinates of each center of gravity, the distance between the centers of gravity, the amount of x coordinate shift,
Since the amount of misalignment can be automatically calculated by calculating the amount of misalignment in the y coordinate, the amount of misalignment of the object can be easily measured and known, and further output to correct the misalignment. There is an effect that can be used as information for performing.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for determining centering according to the present invention.

FIG. 2 is an explanatory diagram of a circular mark.

FIG. 3 is an explanatory diagram of a center of gravity of an image.

FIG. 4 is an explanatory diagram of an apparatus for determining centering in PCI.

FIG. 5 is an explanatory diagram of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light source 2 Reference mark plate 3 Measurement mark plate 10 Optical system 11 Half mirror 12 Lens 13, 14 Total reflection mirror 20 Condensing lens 21 Image reading device 22 Image processing device A, B Object A'-A ', B ´
-B 'Centering axis M Circular mark S, T Image (image) G1, G2 Center of gravity

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 102

Claims (2)

(57) [Claims] At a position on each centering axis of an object centered opposite to each other, a diameter of 1/2 of the center misalignment OK / NG determination standard is set around the centering axis. A circular mark is provided, an image of the circular mark is formed in a visual field in the same direction by an optical system, the formed image of the circular mark is read by an image reading device, and the center of gravity of the read image is subjected to image processing. A method for determining misalignment, wherein the method is extracted by an apparatus, and it is determined whether the number of the extracted centers of gravity is one or not. 2. At a position on each centering axis of an object centered opposite to each other, a diameter of 1/2 of the center misalignment OK / NG determination standard is set around the centering axis. A circular mark is provided, an image of the circular mark is formed in a visual field in the same direction by an optical system, the formed image of the circular mark is read by an image reading device, and the center of gravity of the read image is subjected to image processing. It is determined whether the number of the extracted centroids is one or two by the device, and when it is determined that the number of the centroids is two, the distance between the centroids and the x-coordinate deviation are calculated from the position coordinates of each centroid. A method for measuring the amount of misalignment, comprising calculating the amount of misalignment and the amount of y coordinate and measuring the amount of misalignment.