JP2012083282A - Illumination system for inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the complication and an inefficient and unreliable adjustment work relying on experience or guess in an illumination device of an inspection device, to realize logical optimization and improvement in inspection productivity and hence decrease in fraction defective and increase in operating rate.SOLUTION: The inspection device having a camera and sensor 200 and 201 for sensing includes: an illuminator 100 with a light source of one color and, mainly, a plurality of colors of different wavelength and functions 102, 103, and 104 which are able to move the illuminator 100 in multiple axial directions; and/or an illuminating portion with a dedicated light receiving sensor 107, and a controller 101 and a PC software 105 for the illuminating portion. The device has the functions of actively changing the luminescent color of the illuminator 100, the emission wavelength, the quantity of light emission, the irradiation distance/range, the irradiation angle, etc., storing, calling, comparing, and determining them.

Description

       The present invention is used in general-purpose inspection devices that are used in all production factories, etc., to irradiate an inspection object with light emitted from an illuminating device and perform inspection using reflected light or transmitted light from the inspection object. Relates to the device.

In an inspection device that irradiates the inspection object with the light emitted from the illumination device and uses the reflected light or transmitted light from the inspection object, the reflected light or transmission from the inspection object is used for inspection judgment. In most cases, light sensing is performed with a CCD camera or sensor element. However, in any case, sensing is performed using reflected light or transmitted light from the specimen, so the light irradiating the specimen has a large effect on the sensing result. The effect is clear. Therefore, there are many kinds of illumination devices such as various light sources, wavelengths, irradiation distances, and irradiation angles. The inspection device designer and the person in charge of the inspection use the illumination device selected according to the inspection object and the inspection content, or use the same illumination device to adjust the inspection device and the inspection content each time and perform the inspection.
A method to realize the function of automatically adjusting to the appropriate light quantity with a large-scale surveillance camera system, such as monitoring in a tunnel, has been devised using image processing, but it can be easily done with a general-purpose inspection device such as this patent. Things that can be used have not been realized.
JP 2008-59846 A

        Adjustment items of the illumination device include the amount of emitted light, the emission color, the irradiation range, the irradiation distance, the irradiation angle, and the like, which influence the inspection result. Adjustment work is necessary while checking the display of the sensor, the monitor screen of the image processing device, etc. while adjusting the illumination device. For example, if you want to determine the difference in hue in the approximate color of the inspection object, or in the inspection of subtle differences in gloss, the presence or absence of scratches, etc., skill and experience are required to adjust the lighting to enable discrimination, It can take a lot of time.

In the case of a food factory or the like in which the type of inspection object is frequently changed, various setup changes are required every time the inspection object is changed, and in particular, a lot of time may be consumed for changing the lighting setting of the inspection apparatus.

In an inspection apparatus using a camera or a sensor, the adjustment of the illumination device and the adjustment of an image sensor or a single sensor using the camera affect the inspection result. In addition, there are many setting items for each camera, sensor, and lighting device, and countless combinations occur, so there are some cameras and sensors that can recall past settings. There is no specific measure to accurately reproduce the setting of the above or the setting (including irradiation distance and angle) adapted to each inspection object.

      Lighting equipment used in inspection equipment is not affected by the light emission quality itself due to changes in external factors such as ambient temperature, ambient humidity, and ambient brightness, and changes over time of light emitters and light emitting elements. Absent. The lighting may be adjusted again depending on the inspection time even for the same inspection object.

The problem to be solved is to improve the inefficiency and uncertain adjustment work depending on the complexity of the illumination device in the inspection apparatus and experience and intuition. The present invention aims to reduce the above-mentioned lighting device adjustment work, logically optimize it, improve the productivity in inspection, and consequently lower the defect rate and increase the operating rate.

To stably discriminate between non-defective and defective products in the inspection object, the lighting device actively changes and reproduces various combinations of illumination light, illumination position and angle for each inspection object to be identified. A function that collects information from the camera and sensor in each state, and stores, compares, and calculates the information to derive the most suitable illumination setting for the detected object.
Examples of parameters and ranges that can be changed

Appropriate setting values for each inspection object derived in the above section are stored in the inspection object's unique name, etc., and can be recalled and reproduced by the lighting device. Corresponds to inspections that are frequently changed and repeated.

With the setting values memorized and reproduced in the above item, the non-defective product (reference product) of the inspection object is set at the inspection position, and the difference from the stored R, G, B setting values is automatically illuminated. Function to correct the side. Mainly corresponds to correction of light source deterioration over time.

A function that corrects the set value without stopping the inspection line that operates continuously for a long time. For example, the non-defective product (reference product, standard test product used for initial setting) with an identifiable mark or bar code is periodically flowed to the line in operation, and the initial R, G, B incident light amount Compare and correct on the illumination side.

A function that allows you to select and set manually the setting items and parameters of the lighting device.
For example, with regard to the G (green) light source, it is possible to automatically and slowly repeat the light and darkness, and the setter can set the most optimal setting while observing the numerical values of the sensor and the state of the image processing screen in a continuous light and dark state. Stop and confirm. Corresponding to cases where there are no multiple persons in charge. The numerical value of the light quantity parameter ensures linearity that sensuously coincides with the actual light quantity (count value) even during manual setting.

A function that informs the outside of the situation that cannot be handled by changing the automatic setting of the lighting device.
The incident light level in the absence of an inspection object is monitored for a relatively long time, and when the incident light intensity tends to decrease continuously, or the light intensity is increased by automatic correction, it is likely to exceed the rated value of the light source. In addition, the function of detecting an abnormal temperature of the lighting device from a temperature sensor or the like and outputting an alarm as an electrical contact. A function that can be used to control the air blower and other devices when the cause is dust, etc.

Setting time reduction function for automatic lighting adjustment.
In this function, it is important to search for a setting that can be carried out in a stable manner from among the enormous combinations of setting items and parameters, so that the optimal or necessary and sufficient solution can be reached quickly. Whether it can be done is important. Therefore, there is a fully automatic mode in which no prior information is given, for example, what color and what color discrimination. By entering information such as in advance, a mode for realizing the shortest search, setting the illumination origin and movable range, and setting parameter change priorities, etc., for practical customization at the inspection site I will provide a.

As described above, the illuminating device of the present invention controls the active light source unit and the movable unit in an integrated manner for adjustment and correction of the illuminating device that is often not logically controlled in the inspection device. Logical adjustment and correction are realized by the controller and software on the PC that allows the user to make settings according to the inspection. Actually, a significant man-hour reduction effect can be expected by adjusting the inspection illumination device, which is almost empirically performed.

Among the types of illumination devices for inspection devices, from the viewpoint of selecting a light source, there is currently a type in which various light sources are combined in one housing. For example, light sources such as red, blue, green, and white light sources are installed in the same housing. However, when such a multiple light source type is used for the illumination device of the present invention, illumination is performed. The effect of the present invention can be enjoyed with various inspection objects by changing the setting of the illumination device without changing the device itself.

Example of inspection for mixing different varieties of food (different color packages) (see Figure 1 below)
1. Place a non-defective product (reference product) 500 at the inspection position.
2. The illumination light source 100 increases the set values of the R, G, and B light sources individually to 0 to 2047 in response to a command from the controller 101. The camera / sensor 200, 201, the light receiving sensor 107 dedicated to the illumination system, etc. The minimum value of the setting in which the incident light amount 202 obtained from S is saturated (becomes the maximum value) in each of R, G, and B is stored.
3. Set the defective product 501 to the inspection position.
4. The dedicated software 105 installed in the controller 101 or the PC 106 stores in advance the R, G, and B incident light amounts of the good product 500 in step 2. This is compared with the R, G, and B incident light amounts of the defective product 501, and it is determined whether there is an absolute value difference of the incident light amount that is set in advance for each of the R, G, and B values. Confirm and confirm the setting value stored in step 2.
5. If a sufficient value difference cannot be obtained in step 4, check the distance 600 between the illumination light source 100 and the inspection object 500 at the inspection position, the relative angle between the illumination light source 100 and the inspection object 500 at the inspection position, etc. Give priority, change actively and repeat steps 1,2,3.

In any manufacturing site that requires an inspection process using a camera and an image sensor, it has the potential to contribute to shortening the number of inspection steps and improving the reliability of inspection.

It is an example of a general inspection system using the present invention.

100: Illumination light source (mainly having multiple or single light sources)
101: Lighting controller (power supply, control)
102: Illumination light source movable axis (in the direction of the object to be measured in the example)
103: Illumination light source movable motor 1 (in the direction of the object to be measured in the example)
104: Illumination light source moving motor 2 (in the irradiation angle direction in the figure)
105: PC software for this illumination system 106: Personal computer 107: Light reception sensor for this illumination system 200: Inspection camera / sensor controller 201: Inspection camera / sensor 202: Inspection camera / sensor determination data, this illumination system Dedicated light receiving sensor data 203: Inspection object arrival timing signal 204: FA touch panel 300: Inspection object conveyor 500: Inspection object (non-defective product standard)
501: Inspection item (defective product)
502: Inspection object 600: Distance between the illumination light source and the inspection object at the inspection fixed position 601: Distance settable range between the illumination light source and the inspection object at the inspection fixed position 602: On the lower surface of the illumination light source and the inspection fixed position Angle with an inspection object (irradiation angle)

Claims (4)

An illumination system that uses a reflected light or transmitted light from an inspection object or an image of the inspection object to provide a light source for the inspection object in an inspection apparatus equipped with a camera or a sensor, and adjusts the light emission amount of the light source. The function and the selection function of the light emission source have been equipped with the light receiving sensor for exclusive use of the present invention that has been incorporated in the same housing as the light emission source or can be freely selected in the mounting position depending on the case. It is equipped with means that can adjust the angle movably, and has an automatic adjustment function. For the determination, the light emission amount and color of the light source, the wavelength, the distance and angle between the light source and the inspection object are determined in advance. While referring to the input algorithm or arbitrary setting information, etc., it is changed actively and continuously, and each of these variables is obtained simultaneously from the camera, sensor, and dedicated sensor of the present invention. There are paired variables of captures multiple sets, and storing them, compared calculates, locate the optimum setting of the illumination, the illumination system having a function to call any organized store them. The lighting system according to claim 1 stores and judges the optimal setting while actively changing the light emission amount and color of the light source, the wavelength, the distance and the angle between the light source and the inspection object, etc. with respect to the inspection object, Dedicated software included in the lighting system, which is equipped with a basic algorithm for confirmation and has a function that allows an inspection user to customize the algorithm. In the lighting system according to claims 1 and 2, the setting items and parameters of the lighting device are arbitrarily selected, and automatically and actively, or manually and continuously or intermittently changed at an arbitrary speed. Dedicated software included in the lighting system with the function that allows manual adjustment and manual setting while checking the state of           In the illumination system according to claims 1, 2 and 3, the amount of light emitted from the light source, the color, the wavelength, the distance / angle between the light source and the inspection object are automatically and actively and at a speed not possible manually. While changing, store a plurality of pairs of combinations of setting items of the lighting device and values used for inspection judgment from the sensor, camera, and image processing device in each state, and compare and judge them. , Automatic adjustment setting method of saving and recalling.

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