JPH02187612A - Curve comparing and checking device - Google Patents

Abstract

PURPOSE:To accurately detect whether a specular curve of a body to be checked is good or not by online without contacting by irradiating this specular curve with plural light sources and condensing the reflected light to observe intervals of peaks of the reflected light. CONSTITUTION:Bodies 1, 2, and (n) to be checked having the same shape are laminated and an successively moved downward from the top. Parts (a) to (f) relatively close to one another of their curves are irradiated with at least two light sources 3 and 4 like tubular bulbs having linear filaments. Each reflected light is photoelectrically converted by an optical system like a lens 5 and a one-dimensional sensor 6 and is observed as the distribution waveform of an electric signal which indicates the light intensity distribution having two peaks La and Lb. Peak intervals d1 to dn are measured and are compared with standard values of normal bodies to be checked to detect the difference in curvature and molding defects of curves by online without contacting.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for comparing and determining the shape of a relatively specular curved portion of a bare surface or a painted surface of metal, plastic, ceramics, or wooden products by a simple means. The aim is to provide an inspection device that can

In particular, it is suitable for use in fields where non-contact, high-speed, and accurate detection is desired on a production line without providing a separate stage exclusively for inspection.

[Conventional technology] Until now, there was no reliable and simple inspection device that could accurately and quickly compare and determine differences in the shape of curved parts of molded products, pressed products, etc., and inspections generally relied on the naked eye. .

Therefore, as production speeds have become extremely fast these days, eye fatigue for inspectors has actually developed into a major social problem.

Therefore, various attempts have been made to utilize recent information technology related to pattern recognition, but such processing requires a huge amount of time and equipment costs, making it difficult to use as a practical solution. Many were far from it.

[Summary and operation of the invention] The curved part comparative inspection device of the present invention includes a plurality of light sources that irradiate relatively close positions of a curved part having specularity in a subject, and condenses the reflected light. A photoelectric observation device having an optical system and an electronic imaging system is provided, and by observing the interval between the peaks of the reflected light from each close position of the subject, the difference in shape of the curved portion of each subject is compared and determined. The invention is characterized in that it is configured to do so.

That is, when a plurality of light sources are used to irradiate several points close to a curved portion of a subject having specularity, such as an edge, the same number of reflected lights as the light sources are obtained from those points. By imaging this reflected light with a one-dimensional or two-dimensional sensor.

A waveform with convex peaks is obtained at time intervals that depend on imaging factors such as the shape of the curved part of the object, the magnification of the optical system, and the scanning time of the sensor.

However, when the imaging element is fixed, the interval between the peaks changes depending on the distortion or omission of the curved portion of the subject. Therefore, by measuring and comparing the intervals between the peaks, it is possible to determine the difference in shape of the object.

In this case, it is possible to extract an image signal in which optical distortion and defocus caused by differences in relative distance to the electronic imaging system are corrected using a two-dimensional area sensor in the electronic imaging system when observing each subject. It is also possible to configure it as follows.

The configuration is configured to compare and determine differences in the shape of the curved portion over a wide range by observing the interval between the peaks of the reflected light while relatively moving the subject and any of the plurality of light sources or the photoelectric device. Further, the plurality of light sources and the photoelectric device are configured to rotate relative to each other around the subject, so that a comparative inspection can be performed over the entire circumference of the subject. It is.

Furthermore, the time interval between the peaks due to the reflected light from the object near the extension of the optical axis of the electronic imaging system and the object further away, caused by distortion of the components of the photoelectric device and differences in the optical path, etc. To correct the shift, the area of the image sensor is divided into several parts in advance.

A coefficient based on the reflected light of the object near the extension of the optical axis of the electronic imaging system is assigned to each of them, and the peak interval of the reflected light input to that area and its coefficient are calculated. It is composed of

[Example 1] Example 1 of the apparatus according to the present invention will be described with reference to FIG. Several objects 1, 2, and n having the same shape are stacked in a stacked state, and these objects are sequentially moved from top to bottom. Then, relatively close points of the curved portion of each of these objects are irradiated with at least two light sources 3 and 4, such as a tube having a linear filament or a tube fluorescent lamp lit by a high frequency power source. .

For example, two lines of reflected light La and Lb or Lc-Lf are reflected from points a and b, c, d, e, f, etc., which are relatively close to each other on the curved part of each subject.
etc. have a light intensity distribution B each having two peaks as shown in FIG. t on the horizontal axis represents time.

Therefore, each of these reflected lights is subjected to photoelectric conversion using a photoelectric observation device having an optical system such as a lens 5 and an electronic imaging system such as a one-dimensional sensor 6.

It can be observed as a distribution waveform of an electrical signal representing a light intensity distribution of La and Lb having two peaks. The interval d1 to do between the two peaks depends on the scanning speed of the one-dimensional sensor, the configuration and magnification of the optical system including the light source, or the distance between these components and the subject. can generally be set within practical accuracy.

Moreover, the peak intervals d1 to dn are based on the reflected lights Lc and Ld from the subject 2 directly facing the optical system.

Reflected light L from object 1 or n located away from the center
Normally, the results obtained by a and Lb or Le and Lf differ somewhat due to distortions in optical elements such as the lens 5, differences in optical paths, and the like.

However, since these are unique depending on the distance between the subjects 1 to n and each part of the optical system and the characteristics of each element of the optical system, they can be corrected by calculation.

For example, the area of the one-dimensional sensor is divided into several parts in advance, and a coefficient based on the reflected lights Lc and Ld is assigned to each part. Then, the peak intervals d1 to d may be corrected by calculating the peak interval of the signal due to the reflected light input to that area and its coefficient.

Therefore, by measuring the peak intervals d1 to dn and comparing them with standard values based on the curved part of a normal subject, or by relatively comparing each value of each subject, it is possible to determine the difference in the curvature of the curved part and the shape of the curved part. It is possible to compare and determine the presence or absence of defects or defects such as chipping or crushing that occurred during the process.

Furthermore, if the distance between the object and the light source is brought closer with the imaging element fixed, the distances d1 to dn between each pair of peaks will increase, making it difficult to compare the observation results with adjacent objects. Become. On the contrary, when the subject and the light source are separated, each of the peak intervals d1 to dn becomes narrower, so that the detection accuracy inevitably decreases.

Therefore, when configuring the apparatus of the present invention, it is important to optimize the imaging elements and to design the light source to be placed at an optimal position depending on the size, curvature, etc. of the subject.

With the means described above, it is possible to perform an examination of a subject from only one direction, but images can be taken from multiple directions using multiple electronic imaging systems.

Alternatively, information about the entire circumference of the object can be obtained by relatively rotating either the object or the photoelectric observation device.

In this case, using a ring-shaped light source such as the No. 1-Kuru line would be effective in allowing observation without rotating the light source.

[Example 2] FIG. 3 shows a process in which a large number of deposited specimens 7 are sequentially and continuously moved from top to bottom.

The light [
3, 3', 4 and 4', and photoelectric observation devices 7, 8 including electronic imaging systems are configured to rotate together.

Two sets of photoelectric observation devices 7 and 8 consisting of lenses, one-dimensional sensors, etc. are combined with an annular combination body 9, and the large pulley 10 is driven and rotated by a motor 13 directly connected to a small pulley 12 via a belt 11. .

On the other hand, the cylindrical guide 14 for storing a large number of stacked objects and moving them while controlling their posture in an orderly manner is made of a transparent material such as glass in the portion corresponding to the photoelectric observation path, so that imaging can be easily performed. Configure it so that

However, when a transparent material is used, errors may occur due to unexpected reflections. One such measure is to provide a slit in a metal cylinder, for example, and to rotate the slit so that it always faces the imaging path.

In addition, the lower part of the guide 14 and the rotating part are connected by a bearing mechanism O-15, and the transmission is carried out via a slip ring 16 attached to this part or a non-contact signal transmission device using an electromagnetic induction method or a photoelectric method. , transmits the signal of the one-dimensional sensor, which is itself rotating, to an external fixed side.

Therefore, by rotating the electronic imaging system with the motor 13, it is possible to obtain electrical signals over the entire circumference of the subject 7 at a specific timing.

In this embodiment, two light sources are used, but by increasing the number of light sources to two, the amount of light reflected from the object increases, making it possible to detect conditions in more detailed parts.

As can be seen from the above explanation, this system
It can be applied to both individual and continuous deposits. It can also be used in a random laminated state with gaps between each layer or multiple layers.

In addition to the tubular light source, a point-shaped light source such as an LED can also be used, but it becomes somewhat difficult to set the alignment of the optical system.

Furthermore, it is also possible to install a light source on a fixed part and transmit the light to the nine rotating parts using a non-contact optical transmission device and an optical fiber.

Although a one-dimensional sensor was used in the imaging system in the above embodiment, the same effect can be obtained by using a two-dimensional sensor and using only data from one or more elements in the Y direction. It will be done. It goes without saying that information such as the inclination of the subject can be obtained by using elements in the rough X direction.

Additionally, there is no need to inspect the entire circumference of the subject.

For example, when only a specific range in the X direction is to be inspected, there is no need to rotate the imaging system.

In such cases, a two-dimensional sensor is used, and by optically or electronically correcting the difference in magnification, distortion, defocus, etc. that occur as the distance from the optical center of the imaging system increases in the X direction, the sensor's Y direction can be improved. The same effect as when using a one-dimensional sensor with the same number of bits can be obtained.

=11- [Effects of the Invention] Conventionally, there has been no inspection device of this type that attempts to compare and distinguish shapes by utilizing the light reflection effect from the curved portion of the object, and the reality is that the inspection system has mostly relied on the naked eye. be. Especially in recent years, production speeds have been so fast that inspectors' eyes have become extremely fatigued2.
It was becoming a problem.

It is very difficult to substitute the inspection apparatus according to the present invention using a normal image processing method, and even if it were possible, it would be necessary to create a stage dedicated to inspection separately from the production line. Therefore, it had to be extremely complicated and expensive.

As described in detail in the main text, the device according to the present invention has a small and simple configuration, so that a more accurate inspection device can be constructed and provided at low cost.

For test objects whose curved cross-sections at the edges can be assumed to be semicircular or other simple shapes, there is an effect that the quality can be accurately detected and determined in a non-contact and high-speed manner on the production line of the mass production process.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a first embodiment of the present invention, FIG. 2 is a diagram showing the intensity distribution of reflected light, and FIG. 3 is a schematic diagram of a second embodiment in which a light source and a photoelectric observation device are rotated. Code 1, 2. and n is the subject. 3.4 is the light source, 5 is the lens. 6 is a one-dimensional sensor; 7 and 8 are photoelectric observation devices; 69 is a ring-like combination; 10 is a human pulley. 11 is a belt, 12 is a small pulley. 13 is a motor, 14 is a guide. 15 is a bearing mechanism and 16 is a slip ring.

Claims (5)

[Claims] (1) Equipped with a photoelectric observation device having a plurality of light sources that illuminate relatively close positions of a curved portion having specularity in the subject, an optical system that collects the reflected light, and an electronic imaging system, A curved part comparison test, characterized in that the curved part comparison test is configured to compare and determine the difference in shape of the curved part for each subject by observing the interval between the peaks of the reflected light from each close position of the subject. Device (2) Optical distortion and defocus caused by differences in relative distance to the electronic imaging system during observation of each subject can be extracted as corrected image signals by using a two-dimensional sensor in the electronic imaging system. A curved portion comparative inspection device according to claim (1), characterized in that it is configured as follows. (3) By observing the interval between the peaks of the reflected light while moving the object and either of the plurality of light sources or the photoelectric observation device relatively, the differences in shape of the curved portion over a wide range are compared and determined. A curved portion comparative inspection device according to claim (1), characterized in that it is configured as follows. (4) Claim characterized in that the plurality of light sources and the photoelectric observation device are configured to rotate relative to each other around the subject, so that a comparative inspection can be performed over the entire circumference of the subject. (2) Curved portion comparative inspection device described in (5) The interval between peaks due to reflected light from a subject near the extension of the optical axis of the electronic imaging system and a subject further away, which is caused by distortion of the components of the photoelectric observation device or differences in the optical path. When correcting the deviation, divide the area of the image sensor into several areas in advance, assign each area a coefficient based on the reflected light from the object near the extension of the optical axis of the electronic imaging system, and adjust the area accordingly. The curved portion comparative inspection device according to claim 1, wherein the curved portion comparison inspection device is configured to be able to correct the interval between peaks of the reflected light inputted to the curve and its coefficient by calculation.