JP3666826B2 - Appearance inspection method of transparent circular body - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of imaging a circular body as an inspection target and inspecting the appearance of the circular body by image processing.
[0002]
[Prior art]
Japanese Patent Laid-Open No. 3-125906 discloses an appearance inspection of a circular body. According to the outer diameter measurement, the outer diameter measurement is performed at the apexes of the four areas, top, bottom, left, and right. If the outline of the circular body is deformed in that area, the accurate outer diameter (diameter) cannot be measured. Further, the method of comparing the chipping and the meat pocket with the reference circle along the outer contour cannot know the degree of the size because the deformation amount (area) of the chipping or the meat pocket is not known.
[0003]
OBJECT OF THE INVENTION
An object of the present invention is to obtain the entire outline information of a circular object to be inspected, thereby accurately obtaining information necessary for appearance inspection, and to easily recognize the appearance and confirm the quality.
[0004]
[Means for Solving the Invention]
Under the above object, the appearance inspection method of a transparent circular body according to the present invention, a transparent glass background and upper by white Shiyatta circular body of the red light emitting LED ring illumination under LED ring to be examined Photographed by a camera with the center of illumination as the optical axis, memorized a circular body as image information, and traced the outer periphery of the circular body by image processing from this image information to obtain total contour information. more seek the center of gravity of the circular body, to calculate the radius of the entire circumference of the contour information and the center of gravity or et circle form, together with obtaining the outer diameter from the average value of all radii, radii and chipping level of each peripheral position, The lack of comparison with the meat level is checked, and the meat accumulation is inspected, and the eccentricity is inspected by comparing the difference between the maximum and minimum radii and the eccentricity level.
[0005]
【Example】
FIG. 1 shows an outline of the appearance inspection apparatus 1. The glass mount 2 to be inspected is guided to the inspection position by the conveyor 3. As shown in FIG. 2, the mount portion 2 is a transparent glass body that seals the end portion of the fluorescent lamp, has a filament 4, and has a circular shape at the bottom portion of the glass portion. This circular portion is called flare glass. The object of the appearance inspection is a portion of the flare glass 5 as a transparent circular body of the mount portion 2, and as shown in FIG. 3, the flare glass 5 is inspected for outer diameter measurement, chipping, meat accumulation, eccentricity, etc. To do.
[0006]
At the inspection position, the flare glass 5 is imaged from directly above by the camera 6. The camera 6 sends the image of the flare glass 5 to the image processing device 7 as image information. The image processing device 7 stores the image information, performs an appearance inspection of the flare glass 5 from the image information, makes it possible to visually confirm the data at that time by the monitor 8, and conforms to the non-defective product according to the inspection result. An (OK) or defective product (NG) signal is output.
[0007]
Due to the shape of the transparent flare glass 5, in ordinary ring fluorescent lamp illumination, the reflection on the inner surface of the glass is large and the illumination light is transmitted at the outer edge, making it difficult to detect the contour. As a countermeasure against this, the present invention employs LED ring illumination 9 that emits red light . The LED ring illumination 9 is arranged with the center of the ring on the optical axis of the camera 6, and the illumination power source 10 irradiates the flare glass 5 with red illumination light. According to the ring-shaped red illumination light, the transmittance of the red illumination light with respect to the flare glass 5 is lowered, so that the outer peripheral edge of the flare glass 5 and the front surface of the glass appear black , and the contrast with the white shutter 11 as the background comes out. Becomes easier to recognize. Further, if necessary, by using a bandpass + red filter 12 between the camera 6 and the LED ring illumination 9, the imaging is not affected by disturbance light such as sunlight.
[0008]
The shutter 11 is made of an aluminum plate having high reflectivity and is of an openable type. The flare glass is located behind the mount portion 2 as viewed from the camera 6 and has a hole smaller than the outer diameter of the flare glass 5. 5 is sufficient for the background surface. The aluminum plate should be white anodized and not mirror-reflected. During the movement of the mount portion 2, the pair of shutters 11 are opened and closed after positioning to constitute the background surface of the flare glass 5.
[0009]
Next, FIG. 4 shows the order of the outer diameter inspection method of the present invention. When the mount 2 to be inspected is guided to the inspection position, stopped, and positioned, the pair of open shutters 11 are closed and the LED ring illumination 9 is lit, and the camera 6 is connected to the flare glass 5. The contour portion is imaged. This imaging data is sent into the image processing apparatus 7 and stored in preparation for image processing. In the next step, a threshold value is automatically determined for subsequent image processing in accordance with the signal level of the imaging data.
[0010]
In the tracking of the contour of the next step, the slice level is automatically determined by the flare glass 5 and the background (shutter 11), and the contour edge is searched for. Since reflection on the surface of the shutter 11 is different, the slice level is automatically determined for each shutter 11, that is, for each semicircle of the contour corresponding to each shutter 11. In contour tracking, a contour is searched for in the vicinity of eight connections. As shown in FIG. 5, let the search start point be P ₀ . Neighboring point P ₁ of P ₀ point, P _2, in · · P _8, looking at either a clockwise direction there is no dark spots than the threshold value. If there is a dark point, that point becomes the contour point P _x . By setting P _x-1 as the next start point, contour tracking can be performed at high speed.
[0011]
In the next step of calculating the center of gravity and calculating the total radius, the center of gravity coordinates are calculated from the average value of the contour information of the entire circumference, and the total distance (total radius) is calculated from the center of gravity (center) and the contour information of the entire circumference. To store. Assuming that all contour coordinates are P ₁ (x ₁ , y ₁ ), P ₂ (x ₂ , y ₂ ),... P _n (x _n , y _n ), i = 1, 2,. The coordinates are obtained as P (Σx _i / n, Σy _i / n), and the centroid coordinates are P (x _p , y _p ), the radius of the contour coordinates P ₁ (x ₁ , y ₁ ) is given by the equation r ₁ = √ {(x ₁ −x _p ) ² + (y ₁ −y _p ) ² } From these, total radius r _1, r ₂ of the entire circumference to calculate the · · r _n.
[0012]
6, outline coordinates P _1, P ₂ corresponding to the direction of the contour tracing shows a · · P _n and the center of gravity P, FIG. 7 is a radius r _1, r _2, a · · r _n The entire circumference of the contour (circular angle of 0 to 360 °) is represented by a graph. Such a graph is displayed on the screen of the monitor 8 as necessary. Therefore, the operator can easily know the tendency of the data change amount of the contour information by checking this graph.
[0013]
In the next step, the entire radius r _1, r _2, calculation of the variation in · · r _n is performed. The variation K of the total radius is obtained by the equation K = r _max −r _min , and when variation K> the amount of eccentricity (parameter) E, it becomes a defect of any one of chipping, meat accumulation, and eccentricity.
[0014]
Therefore, in the next step, the magnitude comparison is performed by a comparison formula of variation K <eccentricity E, and when N (No), the outer diameter is calculated in the outer diameter measurement step. Mean value R of the total radius of the entire circumference, i = 1, 2, as · · n, are determined by the equation R = Σr _i / n, whereby the outer diameter is determined as 2R.
[0015]
When the size of the variation and the amount of eccentricity are compared, and Y (Yes), an inspection for chipping and meat accumulation is performed. The method for determining chipping and meat accumulation is as follows. First, the chipping level (parameter) L ₁ > r ₁ , r ₂ ,..., R _n , and its frequency> the chipping width parameter DL is set as a chipping defect, and the meat accumulation level (parameter) L ₂ > r ₁ , r _2, in · · r _n, and the meat reservoir disadvantage in that power> meat reservoir width parameter TL. Except these, it is set as eccentricity NG. As described above, the determination parameters of the chipping level L ₁ , the fillet level L ₂ , the chipping width parameter DL, the fillet width parameter TL, and the eccentricity E are used in the determination process.
[0016]
【The invention's effect】
In the present invention, obtained in the glass transparent circular body contour graph ready all radii data from information such as flare glass, since it accurately recognize the change in the outer periphery of the circular body, the appearance inspection Accuracy is increased. When the chipping or the accumulation of meat occurs, the center of gravity fluctuates at the defective portion, but the difference is at a level where the quality can be judged sufficiently.
[Brief description of the drawings]
FIG. 1 is a schematic side view of an appearance inspection apparatus.
FIG. 2 is a side view of a component (mounting portion) to be inspected.
FIG. 3 is an explanatory diagram of flare glass chipping, accumulation of meat, eccentricity, and outer diameter.
FIG. 4 is a flowchart of appearance inspection.
FIG. 5 is an explanatory diagram of contour tracking.
FIG. 6 is an explanatory diagram of a relationship between contour coordinates and coordinates of the center of gravity.
FIG. 7 is a graph of contour information of the entire circumference.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Appearance inspection apparatus 2 Mount part 3 Conveyor 4 Filament 5 Flare glass 6 Camera 7 Image processing apparatus 8 Monitor 9 LED ring illumination 10 Illumination power supply 11 Shutter 12 Filter

Claims (2)

A transparent glass circular object as an inspection object is photographed by a camera with the center of the LED ring illumination as the optical axis under the background of the white shutter and the LED ring illumination of red light emission above, and the circular object is used as image information. store, by the contour tracing by image processing the outer periphery of the circular member from the image information, obtains a full contour information, obtains the center of gravity of the circular member from the full contour information, the contour information and the centroid or al circular form It is characterized by calculating the radius of the entire circumference, obtaining the outer diameter from the average value of all the radii, and inspecting the missing and puddles by comparing the radius of each outer peripheral position with the missing level and the puddle level. the appearance inspection method of the transparent circular body. A transparent glass circular object as an inspection object is photographed by a camera with the center of the LED ring illumination as the optical axis under the background of the white shutter and the LED ring illumination of red light emission above, and the circular object is used as image information. store, by the contour tracing by image processing the outer periphery of the circular member from the image information, obtains a full contour information, obtains the center of gravity of the circular member from the full contour information, the contour information and the centroid or al circular form Calculate the radius of the entire circumference, obtain the outer diameter from the average value of all the radii, and check the missing and puddles by comparing the radius of each outer peripheral position with the missing level and the puddle level. appearance inspection method of a transparent circular body, characterized in that examining the eccentricity from the comparison between the difference and eccentricity level between the maximum and minimum values.

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