JPH0862155A - Object 0bserving apparatus - Google Patents

Abstract

PURPOSE: To obtain a precise observation result by obtaining an image which accurately reflects the feature of the part to be observed of an object. CONSTITUTION: A television camera 5 is disposed above an object (cap) 4 to be inspected, and the image obtained by imaging it is processed to decide the presence or absence of the wrinkle of an inner wall. A ring strobe 13 and a diffusion plate 41 are disposed in the periphery of the camera 5. On the other hand, a shielding hood 15 is mounted at the end of the wide angle lens 12 of the camera 5, and a shielding plate 16 is disposed between the hood 15 and the object 4 to be inspected. The illumination light from the strobe 13 is projected only to the bottom inner surface of the object 4 to be inspected by the hood 15 and the plate 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object observing apparatus for executing a predetermined image processing such as measurement using an image obtained by picking up an image of an object.

[0002]

2. Description of the Related Art FIG. 8 shows the appearance of a cap fitted in a bottle mouth. Conventionally, this type of cap is formed by subjecting a metal plate to a drawing process. When this process is appropriately performed, the cap 1 having flat inner and outer wall surfaces as shown in FIG. 8A is formed. However, a vertical wrinkle 2 as shown in FIG. 8 (2) may be formed on the entire peripheral surface near the opening edge on the inner surface of the cap due to a pressing failure or the like. When the cap 1 having such vertical wrinkles 2 is fitted into the bottle mouth, it causes air leakage and the like, so it is necessary to inspect the inner surface of the cap and remove the cap 1 of this kind as a defective product.

Conventionally, this type of inspection relies on visual inspection by an operator, but since the inspection location is the inner surface of the cap, it is not easy to reliably determine the presence or absence of vertical wrinkles, and a defective product is detected. The inspection accuracy is lowered due to the oversight. Also, the inspection speed is slow because it is a manual inspection,
Not only is the inspection efficiency low, but the work load on the workers is heavy, and there is a problem of causing extreme fatigue.

Therefore, recently, it has been proposed to automate this type of inspection by image technology (Japanese Patent Laid-Open No. 62-8).
2344). This device irradiates diffused light on the inner surface of the cap by an annular illumination device having a diffuse reflection surface, and determines the defect on the inner surface of the cap by an image obtained by capturing the reflected light.

[0005]

However, in the above device, since the illumination light directly from the illumination device is applied to the entire inner surface of the cap, the unevenness of the inner wall surface of the cap is less likely to appear as a difference in brightness on the image. There is a problem that the inspection accuracy decreases.

The present invention has been made in order to solve the above-mentioned problems, and the illumination light is adjusted so as not to directly illuminate the observation target portion of the object, and the image pickup device is adjusted to be more than the observation target portion. Reflection of illumination light by a reflecting means located at a distant place and irradiating the reflected light to the observation target area provides an image that accurately reflects the characteristics of the observation target area, thus obtaining an accurate observation result. The purpose is to provide a device.

[0007]

An object observing device of the present invention is an image observing means for picking up an observation target portion of an object, a light source, and illumination light from the light source which is directly received and the reflected light thereof is observed. A reflecting means for irradiating the part and an image processing means for executing a predetermined process using an image of the observation target part imaged under the irradiation light from the reflecting means are provided. In the first invention, the light source is arranged so that the illumination light thereof is not directly irradiated to the observation target portion, and the reflecting means is positioned farther than the observation target portion with respect to the imaging means. There is.

Further, in the object observing device of the second invention, a shielding means is provided between the light source and the object so as to shield the illumination light from the light source so as not to directly irradiate the observation target portion. The reflection means is located farther than the observation target portion with respect to the imaging means.

[0009]

The illumination light from the light source is applied to the reflecting means without being directly applied to the observation target portion of the object. The reflection means is located farther than the observation target portion with respect to the image pickup means, and the reflected light is applied to the observation target portion as indirect illumination light. If the observation target portion is imaged under this indirect illumination light, an image that accurately reflects the characteristics can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a wrinkle inspection device for the inner surface of a cap according to an embodiment of the present invention. In this example of the apparatus, the inspection target is the metal cap fitted in the bottle mouth, but the present invention is not limited to this, and the inspection object can be a canned container or the like. The apparatus shown in the figure is for inspecting a large number of objects to be inspected 4 conveyed by the conveyer conveyor 3 at a predetermined inspection position at high speed one after another for the presence or absence of vertical wrinkles on the inner wall surface of the cap. 6, a video monitor 7, a light pen 8, an object detection sensor 9, a strobe lighting device 10, a strobe control device 11, and the like.

The television camera 5 is, for example, a two-dimensional CCD camera for taking an image of the object 4 to be inspected, and its video signal VD _i is given to the controller 6. The controller 6 binarizes the video signal VD _i from the television camera 5 and executes various calculations and processing relating to wrinkle inspection. The video monitor 7 displays an image of the inspection object 4 and the like, and also displays a menu and measurement / judgment results. The light pen 8 is used for menu selection and the like, and sets an inspection program in combination with the video monitor 7. The object detection sensor 9 is a photoelectric switch or the like,
Detects that the inspection position has arrived. The strobe illumination device 10 uses, for example, a ring strobe as a light source, and applies strobe illumination to the moving object 4 to be inspected to form a still image. The strobe control device 11 performs control regarding strobe light emission, for example, control such as light emission prohibition at the light reception prohibition timing of the television camera 5.

The TV camera 5 and the strobe lighting device 10 are individually mounted on columns (not shown) so that their heights can be adjusted, and after adjusting their respective heights with respect to the object 4 to be inspected, they are fixed to the positions with screws or the like. You can do it.

FIG. 2 shows an example of the assembly structure of the television camera 5 and the strobe lighting device 10, and the wide-angle lens 1
The stroboscopic lighting device 10 is arranged so as to surround the periphery of the TV camera 5 on which the TV camera 2 is mounted. The strobe lighting device 10 in the illustrated example is a ring strobe 1
Although 3 is used as the light source, for example, a configuration may be adopted in which glass fibers are arranged in a ring and the light of the filament is guided by each glass fiber. The ring strobe 13 is housed in a housing 14, and a diffusion plate 41 is arranged in the irradiation direction of strobe light source light.

Further, the strobe lighting device 10 regulates the irradiation range of the strobe light source light by the ring strobe 13, and regulates the direct irradiation of the strobe light source light on the inner wall surface of the inspection object 4. As a configuration, the light-shielding hood 15 attached to the wide-angle lens 12 of the TV camera 5
And a light shielding plate 16 disposed below the strobe lighting device 10.

The shading hood 15 is a ring strobe 1
3 for blocking the light incident on the wide-angle lens 12 and for restricting the direct irradiation of the strobe light source light to the inner wall surface of the object 4 to be inspected. Therefore, the front edge of the light shielding hood 15 can be moved back and forth between the ring strobe 13 and the inspection object 4 by adjusting the mounting position on the wide-angle lens 12 back and forth. The light-shielding hood 15 may be a dedicated hood or a lens hood. Further, by forming the light-shielding hood 15 in a structure that can be expanded and contracted in the radial direction, the tip edge of the light-shielding hood 15 can be advanced and retracted between the ring strobe 13 and the inspection object 4.

The light-shielding plate 16 is a black bakelite plate having a circular hole 17 in the center thereof, and is for preventing the strobe light source light from irradiating the outer wall surface of the inspection object 4. In the case of this embodiment, the irradiation range is adjusted by adjusting the vertical position of the light shielding plate 16, but the irradiation range may be adjusted by forming the circular hole 17 to be expandable and contractable.

The strobe light source light regulated by the light-shielding hood 15 and the light-shielding plate 16 is guided to the inner bottom of the inspection object 4. In the case of the illustrated example, a milk-white resin packing 20 is attached to the inner surface of the bottom of the inspection object 4, and the strobe light source light is diffusely reflected by the surface of the packing 20 and is generated as indirect illumination light. The indirect illumination light is applied to the inner wall surface of the inspection object 4, particularly near the opening edge where vertical wrinkles occur. When such indirect illumination is optimally performed, the binary image obtained by imaging the non-defective product has the image 18 of the object to be inspected appearing white, as shown in FIG. 4) appears in black, and in the binary image obtained by imaging the defective product, vertical wrinkle bright and dark images 19 appear in a circle in the image 18 of the white object to be inspected, as shown in FIG. 4B. become.

FIG. 3 shows a circuit configuration example of the controller 6 in the wrinkle inspection apparatus. In the figure, the television camera 5 images the inspection object 4 and outputs a video signal VD _i ,
The binarization unit 23 takes in the video signal VD _i and binarizes it to generate a binary image. Binarization threshold control unit 2
Reference numeral 4 sets a threshold value for binarizing the video signal VD _i , and controls the binarizing process of the binarizing unit 23. The reference pattern storage memory 25 is for registering a binary image obtained by imaging a non-defective sample as a reference pattern, and the measurement pattern storage memory 26 is an image obtained by imaging the inspection object 4. Is stored as a measurement pattern. The window storage memory 27 is a portion for storing an observation window and a measurement window, which will be described later, and the memory control unit 28 controls each of the memories 15-1.
The reading and writing of the image data for 7 are controlled.

The observation window is for defining the observation range of the binary image, and is formed to have a size sufficient to include the cap image 18 as shown by W ₁ in FIG. 4 (1). . Moreover, the measurement window is for observing the bright and dark image 19 of the vertical wrinkles in this image 18, as shown in FIG.
(2) As shown by W ₂ in the center, a ring shape is formed concentrically with the image 18 and having a diameter slightly smaller than the contour of the image 18.

Next, the arithmetic processing unit 29 executes the arithmetic operation for obtaining the barycentric position of the contour of the binary image and the arithmetic operation for counting the number of black pixels in the measurement window W ₂ under the control of the arithmetic control unit 30. Further, the central processing unit 31 decodes and executes the program of the ROM 32, reads and writes data to and from the RAM 33, determines the shift amount of the position of the center of gravity of the binary image,
Various processes are executed, such as determining the presence or absence of wrinkles from the measurement result of the number of black pixels. The address control unit 34 is R
The addresses of the OM 32 and the RAM 33 are generated to control the reading and writing of instructions and data. Further, the central processing unit 31 controls the input / output operation, fetches a detection signal from the object detection sensor 9 via the measurement synchronization input interface unit 36, and a strobe trigger for strobe emission via the strobe control interface unit 37. A determination signal is output through the determination output interface unit 37.

The display synthesizing unit 38 takes in a grayscale image from the television camera 5 based on the designation from the display image designating unit 39 or reads out a binary image or a window stored in each of the memories 25 to 27, and at the same time, it is necessary. According to the above, the images are combined, and the images are sent to the video monitor 7 via the video monitor interface section 40.

Next, the operation of the above apparatus example will be described with reference to FIGS.
It will be described based on the flowchart shown in FIG. FIG. 5 shows a procedure for setting various inspection parameters in the above apparatus example. First, in step 1 (indicated by “ST1” in the figure) of the figure, the TV camera 5 images a non-defective sample under natural illumination, After the grayscale image of this non-defective sample is displayed on the video monitor 7, the focus adjustment is performed while observing this image so that the focus of the television camera 5 is near the opening edge of the cap.

In the next step 2, the display image designation unit 3
The waveform display is designated by 9 to display the video signal waveform at the appropriate position on the image on the video monitor 7, and then the aperture of the television camera 5 is adjusted while watching the waveform. At step 3, the defective sample is imaged under the illumination of the strobe lighting device 10, the positions of the ring strobe 13 and the light shielding hood 15 are adjusted while observing the waveform display, and the imaging target and the background are displayed on the signal waveform. Set so that the level difference of is sufficiently large. Next, in step 4, the non-defective sample is imaged and the same fine adjustment is performed, and then in step 5, the position of the light shielding plate 19 is adjusted while observing the waveform.

Next, in step 6, the non-defective sample and the defective sample are binarized alternately by the binarizing unit 23, and the binarization level is adjusted so that the two can be easily discriminated. In step 7, the binary image of the non-defective sample is registered in the reference pattern storage memory 25 as a reference pattern.

[0025] Then after setting the measurement window W ₂ in respect inspection area of the reference pattern (portions of appearance of light and dark image of the vertical wrinkles) Step 8, the number of black pixels in the measurement window W ₂ in step 9 the following Is measured by the arithmetic processing unit 29, and the measured value is set in the RAM 33 as an allowable value. Next, in step 10, for the binary image of the defective sample and the binary image of the other non-defective sample, the number of black pixels in the measurement window W ₂ is measured by the arithmetic processing unit 29, and the allowable value is finely adjusted. After that, in the subsequent step 11, the observation window W ₁ is set, and in step 12, the measurement synchronization condition, the stroboscopic light emission intensity, etc. are set, and the setting work of the inspection parameters is completed.

FIG. 6 shows a procedure for wrinkle inspection of the object 4 to be inspected by the above apparatus example, and step 21 in the figure determines whether or not the object 4 has reached a predetermined inspection position. .
The object to be inspected 4 on the transport conveyor 3 is now an object detection sensor 9
When it is detected by, the detection signal is given to the central processing unit 31 of the controller 6, and the determination in step 21 is “YE
In step S22, the central processing unit 31 determines whether or not the strobe light emission prohibition period is in progress. If the determination is “YES”, after the delay operation for the prohibition period is performed (step 2
3) The strobe trigger signal is given to the strobe control device 11 to cause the ring strobe 13 of the strobe lighting device 10 to emit strobe light at each timing (step 2).
4).

The strobe light source light at this time is diffused by the diffusion plate 41, and then the diffused light is shielded by the light shielding hood 15 and the light shielding plate 1.
6 is guided to the inside of the inspection object 4 by the regulation action of
The packing 20 on the bottom is irradiated without directly irradiating the inner wall surface of the inspection object 4. As a result, the irradiation light is diffusely reflected by the packing 20 and is generated as indirect illumination light, and the indirect illumination light is applied to the inner wall surface of the inspection object 4.

Under this indirect illumination light, the television camera 5 picks up an image of the object 4 to be inspected, and the video signal VD _i thereof is binarized.
The image is binarized by 3, and the binary image is stored in the measurement pattern storage memory 26 as a measurement pattern (step 25).

Next, in step 26, the arithmetic processing unit 29 extracts the contour of this measurement pattern, then calculates the center of gravity of the contour, and in the next step 27, the position of this center of gravity with respect to the center of gravity of the contour of the reference pattern. The shift amount is calculated.

FIG. 7 shows a state in which the center of gravity G of the measurement pattern and the center of gravity G _{0 of the} reference pattern are misaligned. In the figure, (X, Y) indicates the coordinates of the center of gravity G of the measurement pattern, and (X ₀ , Y ₀ ) indicates the coordinates of the center of gravity G ₀ of the reference pattern, which are relative to the center of gravity G ₀ of the center of gravity G. The positional deviation amounts ΔX and ΔY are as follows. ΔX = X−X ₀ ... ΔY = Y−Y ₀ ...

Next, the arithmetic processing unit 29 corrects the position of the measurement pattern based on the position shift amounts ΔX and ΔY of the center of gravity, and then the measurement window W for the corrected measurement pattern.
₂ is set and the number of black pixels in the window is measured (step 28). The measured value is given to the central processing unit 31, and the central processing unit 31 determines whether or not this count value is within a predetermined allowable value (step 29). As a result, when the count value is within the allowable value, the inspection object 4 is determined to be a good product, but when the count value exceeds the allowable value, the inspection object 4 is determined to be a defective product. And step 3
At 0, the inspection object 4 is removed from the transport line.

[0032]

As described above, the present invention prevents the illumination light from the light source from directly irradiating the observation target portion of the object, and the reflection means located farther than the observation target portion with respect to the image pickup means. Since the illumination light is reflected by and the reflected light is irradiated to the observation target portion, the observation target portion is imaged under the indirect illumination light by the reflection means to obtain an image that accurately reflects the characteristics. Therefore, it becomes possible to perform highly accurate observation using this image.

[Brief description of drawings]

FIG. 1 is an external view showing a schematic configuration of a wrinkle inspection device according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing an assembly structure of a television camera and a strobe lighting device.

FIG. 3 is a block diagram showing a circuit configuration example of a controller.

FIG. 4 is an explanatory diagram showing binary images of a good product and a defective product.

FIG. 5 is a flowchart showing a procedure for setting inspection parameters.

FIG. 6 is a flowchart showing a procedure for wrinkle inspection.

FIG. 7 is an explanatory diagram showing a position shift state of the center of gravity.

FIG. 8 is a perspective view showing the appearance of non-defective and defective caps.

[Explanation of symbols]

 1 Cap 4 Object to be inspected 6 Controller 13 Strobe light source 15 Light-shielding hood 16 Light-shielding plate 20 Packing

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // G06T 7/00

Claims (2)

[Claims] 1. An imaging means for imaging an observation target portion of an object, a light source, a reflection means for directly receiving illumination light from the light source and irradiating the reflected light to the observation target portion, and the reflection means. Image processing means for performing a predetermined process using the image of the observation target portion captured under illumination light of, the light source is arranged so that the illumination light is not directly irradiated to the observation target portion. In addition, the reflecting means is an object observing device that is located farther from the imaging means than the observation target portion. 2. An image pickup means for picking up an observation target portion of an object, a light source, a reflecting means for directly receiving illumination light from the light source and irradiating the reflected light to the observation target portion, and the reflecting means. Image processing means for performing a predetermined process using the image of the observation target portion imaged under the illumination light of, the illumination light from the light source is observed between the light source and the object. An object observing device in which shielding means for shielding the illuminating light so as not to be directly irradiated to the target portion is provided, and the reflecting means is located farther than the observation target portion with respect to the imaging means.