JP2000171409A - Visual examination method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a quality decision processing time to a large extent by synthesizing a plurality of images obtained by photographing the surface of an object to be inspected on one screen. SOLUTION: At least either one of the object 1 to be inspected and line sensor cameras 2a, 2b, 2c, 2d-is relatively moved with respect to the other one of them to photograph the surfaces A, B, Cof the object 1 and a plurality of inspection images are fetched in by photographing to be synthesized into one screen on a main scanning time axis Y or a sub-scanning time axis X or both time axes X, Y and, succeedingly, the inspection images on the synthesized screen are compared with the reference images respectively corresponding to them to decide the quality of the appearance of the object 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method for a printed material, a packaging container, an electronic component, a telephone card, a printed circuit board and other various surfaces to be inspected, a method for reliably detecting difficult-to-detect defects, and the method. To achieve the above.

[0002]

2. Description of the Related Art Conventionally, printed materials, food containers, electronic components, packaging containers such as chemical containers, resin printed materials such as telephone cards, or printed surface printed materials such as manuals and leaflets, and printed circuit boards. Inspection of the appearance of electronic components such as ICs and plastic products such as suction tubes attached to laminate containers was mainly performed by visual inspection by inspectors. With the improvement of mechanical pattern recognition performance and the improvement of transport control technology, a wave of labor saving has spread to this field.

In such an automatic inspection apparatus, if a conventional inspection apparatus for a sheet-like object is used, a large number of sheet-like objects are generally stacked and stacked, and the sheet-like objects are intermittently arranged in a stacking direction. The stacking unit to be moved, the sheet-like material take-out device for taking out the stacked sheet-like materials one by one from the top, the transporting unit for accurately transporting the taken-out sheet-like material, and the printing state of the sheet-like material being transported. An inspection device for inspecting, a sorting unit for determining the quality of the inspected sheet-like material, and sorting the quality;
The storage unit includes a non-defective product storage unit for storing the selected non-defective product sheets and a defective product storage unit for storing defective products.

[0004] Such an automatic inspection apparatus has been applied to inspection objects of various shapes including three-dimensional ones as well as sheet-like ones in accordance with the improvement in performance of a transport mechanism, a line sensor camera, and the like. It goes without saying that a large number of items to be inspected are processed as quickly as possible. For example, one surface is inspected under a plurality of conditions, such as illuminating the surface to be inspected from multiple directions. It has also been required to detect special defects that cannot be detected by inspection.

[0005] For this reason, recently, the speed of image processing has become an essential factor in accordance with the increase in inspection images. However, when the processed image is dramatically increased and the capability of the line sensor camera is improved, the number of pixels is also dramatically increased, and the amount of memory covering these is also increased exponentially. The control equipment became complicated, and the problem that the equipment cost increased many times occurred.

[0006]

The problem to be solved by the present invention is as follows.
It is possible to reliably detect defects that cannot be detected by one detection method by imaging the inspected surface of the inspection object under different conditions, or to reduce the defect rate by making the inspection sensitivity appropriate. The second relates to an appearance inspection method that can greatly shorten the quality judgment processing time by synthesizing a plurality of images obtained by imaging the inspected surface of the inspection object on one screen. The third is to suppress the increase in the number of memories by performing real-time processing for the synthesis processing, and to reduce the apparatus cost irrespective of the increase in performance. The fourth is to develop an apparatus that achieves the above method.

[0007]

The visual inspection method described in claim 1 is a basic method for synthesizing a single screen according to the present invention. The visual inspection method includes a method of inspecting an object (1) and a line sensor camera (2a). (2b) (2
c) (2d) at least one of the surface to be inspected of the object to be inspected (1) (A) (B) by relatively moving at least one of the other
(C) ~, and a plurality of inspection images (31) (3
2) (33) and (34) are fetched and synthesized into one screen on the main scanning time axis (Y) or the sub-scanning time axis (X) or both time axes (X) and (Y). Inspection image on screen (31) (32) (33) (34)
And comparing with the reference images respectively corresponding thereto to judge the quality of the appearance of the inspected object (1). "

According to this, a plurality of inspection images (31), (32), (3
3) Since (34) to are combined on the main scanning time axis (Y) or the sub-scanning time axis (X) or both time axes (X) and (Y) to make one screen, comparison with the reference image is determined. Time can be greatly reduced,
Therefore, it is possible to increase the cycle of the inspection time.

According to the second aspect of the present invention, there is provided a visual inspection method according to the first aspect, wherein a plurality of inspection images (3
1) (32), (33), (34) to are imaged under different conditions at the same time ".

As an example of this case, (a) for example, a plurality of line sensor cameras (2a) (2b) to are inspected for each inspection image (31) (32) (33) (34) (B) or a plurality of mirrors (4a1) and (4a2) to each of the inspection images (31), (32) and (33) (3
When the same surface is imaged from different directions via mirrors (4a1) and (4a2) toward (4)-(c),
In the case where images are taken on different surfaces from the line sensor cameras (2a) and (2b) to (see FIG. 2), (d) a plurality of mirrors (4a1)
A case where (4a2) to (4a2) are directed to different surfaces and images are simultaneously taken through mirrors (4a1) and (4a2) to (see FIG. 9).
In the cases (a) and (b), a defect that cannot be detected from one direction can be completely detected.

Here, in the drawing of the even number, the inspection image
(31) (32) (33) (34) ~ (☆ a) (☆ b)
And the like mean images when the same inspection surface is imaged under different conditions, and dashes (* ') mean images of the inspection surface of the next inspection object. Also, in the odd-numbered drawings, the branch number (☆☆ 1) (☆☆ 2) of the line sensor camera (2a) (2b) ~, the light source (6a) (6b) ~ or the mirror (4a) (4b) ~ ~ Etc. are the test objects
(1) A line sensor camera that simultaneously captures the same or different surface, a light source that simultaneously illuminates the same or different surface, or a mirror that simultaneously captures the same or different surface, but the specification is used to avoid complexity. In the description, branch numbers and branch symbols may be omitted.

[0013] The present invention relates to a method for inspecting an appearance of a test object, wherein a plurality of inspection images (3
1) (32) (33) (34) ~ are different times (t0) (t1) (t2) ~
Are taken under different conditions. "

In this case, unlike the case of the second aspect, the surfaces to be inspected (A), (B), and (C) are different under different imaging conditions at different times (t0), (t1), (t2), and (t3). Since the image is taken (see FIG. 7),
Defects that match each imaging condition (illumination direction, brightness, color, or wavelength) can be selectively detected, and defects that could not be caught under one imaging condition can be captured, and a more complete visual inspection can be performed. Can be done. Alternatively, by adjusting the focus of the line sensor cameras (2a), (2b), (2c), and (2d), it is possible to set the allowable value of the surface defect.

The visual inspection method according to the fourth aspect is limited to the case where the composition is performed on the main scanning time axis (Y) in the first to third aspects, and a plurality of line sensor cameras (2a) (2b) (2c) (2d) When synthesizing a plurality of inspection images (31), (32), (33), and (34) captured by the main scanning time axis (Y), the plurality of line sensor cameras (2a) and (2b) (2c) A signal switching operation is performed at a certain timing on the main scanning time axis (Y) to synthesize a plurality of image output signals captured by (2d) to (2).

Here, "the signal switching operation is performed at a constant timing on the main scanning time axis (Y)" means that each line sensor camera (2a) (2b) (2c) (2d) to This means that the camera is switched on one main scanning time axis (Y) by a switch element as the camera switching switch means (20a) connected to each other. That is, on one main scanning line, every time a switching signal is input, the switch of the camera switching switch means (20a) is switched, and when the inspection images to be captured are (31) and (32), ( Three
The state is switched from 1) to (32), and returns to the original state in the next second main scanning line, and is switched from (31) to (32) as described above. In this way (t
(31) on the left side of the main scanning time axis (Y) between (0) and (t1)
Is captured, the entire image (32) is captured on the right side, and the inspection images (31) and (32) are combined as one combined screen with respect to the main scanning time axis (Y).

By performing the "signal switching operation at a constant timing on the main scanning time axis (Y)", image processing can be performed in real time, and at the same time, the memory of a storage device (not shown) is used. There is no need to increase the capacity unnecessarily, and the cost of the apparatus can be reduced. In addition,
In the present embodiment, the two images (31), (32), (33), (34) to are arranged side by side. However, the present invention is not limited to this, and three or more images (31), (32), (33) ) To can be juxtaposed.

Further, the visual inspection method according to claim 5 is limited to the case where the composition is performed on the sub-scanning time axis (Y) in claims 1 to 3 and is based on the description of “a plurality of line sensor cameras (2a) (2b) ( 2c) (2
d) a plurality of inspection images taken by (31) (32) (33) (3
4) When combining on the sub-scanning time axis (X), a plurality of image output signals captured by the plurality of line sensor cameras (2a) (2b) (2c) (2d) 1) is an imaging area (5a) (5b) (5) of each line sensor camera (2a) (2b) (2c) (2d) to
c) Signal switching work is performed at timings (t0), (t1), (t2), and t3) passing through (5d) and later, and image synthesis is performed.

Here, "the object to be inspected (1) is an image pickup area (5a) (5b) (5c) (5d)-of each line sensor camera (2a) (2b) (2c) (2d)-
The signal switching work is performed at the timing (t0) (t1) (t2) (t3) ~ '', which means that the test object (1) is each line sensor camera (2a) (2b) (2c) (2d) Imaging area (5a) (5b) (5c) (5d)
, One after another, the passage timing (t0) (t1)
(t2) (t3) ~ by some means (in this embodiment, sensors (3a) (3b) (3c) (3c) (3a) installed in accordance with each line sensor camera (2a) (2b) (2c) (2d) ~ 3d) is detected in-)
This means that the line sensor cameras (2a), (2b), (2c), and (2d) are operated in accordance with the passage timings (t0), (t1), (t2), and (t3) to capture images. Then, the captured inspection image (3
1), (32), (33), (34)-are subjected to image synthesis processing on the sub-scanning time axis (X).

In this case, the camera is switched at the passage timing (t0) (t1) (t2) (t3) of the test object (1), so that only the parts necessary for imaging can be imaged in real time. Since the processing can be performed, the memory capacity of the storage device (not shown) does not need to be increased unnecessarily, and the cost of the device can be reduced.

The camera changeover switch means (20a)
By switching the camera at both timings of the and the sensors (3a) (3b) (3c) (3d) ~, the inspection images (31) (32) (33)
(34) to (34) can be juxtaposed on the main and sub-scanning time axes (X) and (Y), and by doing so, it is possible to speed up the matching process with the standard image.

A sixth aspect of the present invention is a visual inspection apparatus for performing the above-described method, wherein the inspection object (1) or the inspection surfaces (A), (B), and (C) of the inspection object (1) are Line sensor camera for imaging (2a)
(2b) A moving device (10) for moving at least one of (2c) and (2d), and a line sensor camera (2a) (2b) (2c) (2d) for imaging an object to be inspected (1) And the line sensor camera
(2a) (2b) (2c) (2d)
A plurality of inspection images (31), (32), (33), (34)
(Y) or sub-scanning time axis (X) or both time axes (X) (Y)
A determining means (20) for combining the images into one screen and comparing the respective reference images with the corresponding reference images to determine the quality of the appearance of the inspected object (1); and determining whether the inspected object (1) is acceptable based on the determination result. And a sorting device (30) for sorting. "

According to this, a plurality of images (31) (32) (33) (3
4) Combining ~ on one screen, it is possible to delete unnecessary data to judge the appearance of the inspected object (1) and combine it with only the necessary data. Can be done quickly. In particular, when imaging one surface to be inspected (A) to a plurality of conditions, or when the number of processed images increases, such as when inspecting many surfaces of one inspection object (1) at a time, It is an effective means.

A seventh aspect of the present invention relates to the visual inspection apparatus according to the sixth aspect, which relates to a means for performing image composition on the sub-scanning line time axis (X). t
0) (t1) (t2) (t3) ~ sensors to detect (3a) (3b) (3c) (3d) ~
Are installed for each of the plurality of line sensor cameras (2a) (2b) (2c) (2d), and the signal switching operation is performed by the output signals from the sensors (3a) (3b) (3c) (3d). The inspection images (31), (32), (33), and (34) captured by the line sensor cameras (2a) (2b) (2c) (2d) are performed on the sub-scanning time axis (X). Are synthesized by ".

According to this, each line sensor camera (2a)
(2b) The imaging timing by (2c) (2d) ~ is the sensor (3a) (3
b) Since (3c) and (3d) ~ are detected, by taking in each image at this timing, it is possible to perform image composition on the sub-scanning line time axis (X) without overlapping the images. In general, the imaging timing is set such that the test object (1)
(5a), (5b), (5c) and (5d) mean the timing of passing.

[0025] Claim 8 relates to means for performing image synthesis on the main scanning line time axis (Y) in the visual inspection apparatus according to claim 6, wherein the plurality of line sensor cameras (2a) (2
b) (2c) (2d) multiple inspection images (31) (3)
2) As means for synthesizing (33) and (34) on the main scanning time axis (Y), the image outputs of the plurality of line sensor cameras (2a) (2b) (2c) (2d) are output on the main scanning time axis (Y). Camera switching switch means (20a) that performs signal switching operation at a fixed timing on (Y)
Is provided. "

The camera changeover switch means (20a) sequentially switches the inspection images (31), (32), (33), and (34) to be taken in accordance with a changeover signal output by a timer or a counter, whereby , Inspection images (31) (32) (33)
A plurality of images (31), (32), (33), (34) of (34) to (34) are juxtaposed on the main scanning time axis (Y). In the case of the seventh or eighth aspect, since the memory capacity can be suppressed as described above, the apparatus cost can be reduced. Incidentally, the camera changeover switch means (20a) generally uses a semiconductor switching element.
A case where a semiconductor switching element is used as the camera changeover switch means (20a) will be described as a representative example.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. The inspection object (1) to which the present invention is applied includes:
Any shape, such as a polyhedron and a plate, is included. In this embodiment, a rectangular parallelepiped will be described as a representative example. Although not shown here, the plate-shaped body has a slightly thick plate-like shape, a paper-like or sheet-like shape having almost no meat, or a bent or folded shape thereof, Not only rectangles and squares, but also any shapes, such as complicated shapes such as boxes before assembly, windows, etc.

The surface to be inspected (1) has the necessary surfaces (front, back, both sides, plane and bottom, or all of them)
Characters and pictures are drawn by printing or engraving or other means. Here, letters A, B, C, D, E, and F are respectively provided on six surfaces, that is, up, down, left, right, and front, which constitute the surface of the inspection object (1).
Is drawn.

(2a), (2b), (2c) and (2d) to are line sensor cameras, which are attached to a support base (not shown),
Images are taken of the inspection surfaces (A), (B), and (C) of the inspection object (1). The imaging direction is appropriately determined as needed. The same line sensor cameras (2a) (2b) (2c) (2d) may all be used, but the type of camera may be changed according to the type of imaging, or a certain range of wavelengths may be selectively selected. A transmitting filter (not shown) may be attached to each of the line sensor cameras (2a) (2b) (2c) (2d).

The installation intervals of the line sensor cameras (2a) (2b) (2c) (2d) and the imaging timing detection sensors (3a) (3b) (3c) (3d) to Is set in accordance with the length (L) of the test object (1). Set these intervals to (L
1) (L2) and (L3). The set intervals (L1), (L2), (L3) to may be the same or may be changed individually.

The line sensor cameras (2a) (2b) (2c)
(2d) Illumination device that illuminates the imaging area (5a) (5b) (5c) (5d)
(6a) (6b) (6c) (6d) ~ are line sensor cameras (2a) (2b) (2c)
(2d) Installed according to. Lighting equipment (6a) (6b)
(6c) and (6d) ~ generally consist of, for example, a fluorescent lamp illumination or a linear illumination by an optical fiber guide, but of course, not limited to this, an optimal illumination device is selected according to the type of defect. You.

Sensors (3a), (3b), (3c) and (3d) are sensors disposed at predetermined intervals (L1), (L2) and (L3) on the transport line (10).
These are for detecting the imaging timing (t0) (t1) (t2) (t3) of the line sensor cameras (2a) (2b) (2c) (2d). The sensor installation interval (L1) (L2) (L3) ~
It can be changed appropriately according to the length (L) in the transport direction of (1). In general, the sensor installation interval is the set interval (L) of the line sensor cameras (2a) (2b) (2c) (2d) to
1) Installed according to (L2) (L3) ~.

The imaging time of the object to be inspected (1) is time
From (t0) (t1) (t2) (t3), the test object (1) is moved to each imaging region (5a) (5
b) The time required to pass through (5c) and (5d) ~ is set by a timer (not shown), and when the timer expires, the end of the passage is recognized so that the test object The imaging of (1) is performed. Alternatively, the time when a predetermined time has elapsed from the time when the object to be inspected (1) is no longer detected is set as the imaging end time. Of course, the present invention is not limited to the above method. When the imaging start time is (t0), the next imaging start time (t1) may be used also as the imaging end time when the imaging start time (t0).

(10) is a moving device for transporting the object to be inspected (1), at least a line sensor camera (2a) (2
b) (2c) (2d) ~ In the imaging area (5a) (5b) (5c) (5d) ~
(1) is transported with high reproducibility while the attitude is controlled. This moving device (10) is shown in FIG.
It is constituted by an appropriate means such as an endless conveyor belt or a robot hand (not shown) running at a substantially constant speed in the direction of the right arrow. The moving device (10) is a line sensor camera (2
a) (2b) (2c) (2d) to the object (1) to be inspected, or vice versa, the line sensor camera (2a) (2b) for the object (1)
(2c) Any type can be used as long as (2d)-can be relatively moved.

The camera changeover switch element (20a) is generally constituted by a semiconductor switch, and is provided between the line sensor cameras (2a) (2b) (2c) (2d)-and the image processing device (20). It is arranged in. Its function is that a switching timing signal output by a timer or a counter (in the tables shown in FIGS. 1 and 3, the output timing is shifted (a) and (b)).
Switch the camera according to the type of switching timing signal). For example, when switching with the line sensor cameras (2a1) and (2a2), the inspection images (31) and (32) taken by the line sensor cameras (2a1) and (2a2) are switched for each main scanning line. The image is sent to the image processing device (20).

Reference numeral (20) denotes an image processing device, which is imaged by the line sensor cameras (2a), (2b), (2c), and (2d) to form a surface image of a non-defective product constituting a reference image for the inspection.
(Not shown) and a surface image of the inspection object (1) to be inspected
(31), (32), (33), (34), and the function of capturing and storing them, on the sub-scanning line time axis (X), or on the main scanning line time axis (Y), or both. This is an apparatus having a function of synthesizing, and a function of detecting a defect by performing pattern matching of a grayscale image (or pattern matching of a color image) between a reference synthesized screen and a synthesized screen to be inspected to judge pass / fail.

The pass / fail judgment is made by passing a non-defective test object (1) in advance, and inspecting the test surface (A) (B) (C) using the line sensor cameras (2a) (2b) (2c) (2d) to Are captured, and the data are combined as described above. Then, the data is taken into a storage device (not shown) of the image processing device (20) and stored as reference data (non-defective gray image) under the same conditions as those described above. In the imaging area (5a) (5b) (5c)
The entire image of the inspection object (1) captured by passing through is captured as data, and after combining as described above, the reference combined image and the combined image of the inspection object (1) are compared by shading or color matching. An appearance inspection is performed based on the principle that if both match within an allowable range, it is determined to be good, and if they do not match, it is determined to be defective. The range of the matching is performed with a certain margin (the range of the margin).

2, 4, 6, 8, and 10 except for the composite screen at the right end are the line sensor cameras (2a), (2b), and (2c).
(2d) shows the captured images (31), (32), (33), and (34) when the inspected surfaces (A), (B), and (C) are captured. The image position is the detection timing (t0) (t1) (t) of the above-mentioned sensors (3a) (3b) (3c) (3d)
2) represents the positional relationship on the time axis (X) of the sub-scanning line recorded.

In the above embodiment, when the line sensor cameras (2a) (2b) (2c) (2d)-are installed up and down, left and right, and back and forth to inspect the entire surface of the test object (1) However, the present invention is not limited to this, and the recording may be limited to only the surface that requires the inspection.

Next, the operation of the present apparatus will be described. The pass / fail judgment is made by creating reference data (non-defective image) of the non-defective test object (1) in advance as described above, and then importing the data of the test object (1) under the same conditions as the reference data. The composite image and the composite image of the inspection object (1) are compared and inspected by shading or color matching to determine.

Accordingly, first, a non-defective product to be inspected (1) is shown in FIG.
Placed on the moving device (10) as shown in 3, 6, 7 and 9;
It passes in front of the line sensor cameras (2a) (2b) (2c) (2d)-. The line sensor cameras (2a) (2b) (2c) (2d)-each inspection surface of the inspection object (1) that sequentially or simultaneously passes through the imaging area (5a) (5b) (5c) (5d)- (A) (B) (C) ~, sensors (3a) (3b)
(3c) The detection timing (t0), (t1), and (t2) from (3d) onward are continuously taken.

On the other hand, as described above, camera switching is performed on the main scanning time axis (Y) by switching of the camera switching switch element (20a). Then, these data are taken into the judging means (20), and after the image processing is performed, the sub-scanning line time axis (X) direction or the main scanning line time axis (Y) direction, or the sub-scanning line time axis The image is stored in the storage device as a reference combined screen combined in both the (X) direction and the main scanning line time axis (Y).

Here, a method of synthesizing in the sub-scanning line time axis (X) direction will be described. Imaging area of line sensor camera (2a)
When the test object (1) approaches (5a), this is detected by the sensor (3a).
Is detected and imaging is started. This data is used by the judgment means (2
0) is stored. When the test object (1) passes through the first imaging area (5a) and approaches the second imaging area (5b), the second sensor (3b) detects this and
Activate the second line sensor camera (2b) and
(1) is imaged, and the data is stored in the determination means (20). By repeating such an operation, all the portions to be inspected are fetched, and these are joined in the sub-scanning line time axis (X) direction to be synthesized as one screen.

Next, a method of synthesizing the main scanning line in the time axis (Y) direction will be described. In this case, any one of the inspected surfaces of the inspected object (1) is detected by the plurality of line sensor cameras (2a1) (2a2) to
(A) and (C) or the same plane is imaged simultaneously under different conditions. The main scanning start signal is generated every fixed time (T), and one main scanning cycle is determined by this.

On the other hand, when a switch switching timing signal (a) (b) to a switch switching timing signal (b) are generated by a timer or a counter, etc., when the switch switching timing signal (a) or (b) is inputted, the camera switching switch element (20a) is switched to one type of scanning line. It switches every time. In this embodiment, one main scanning period (T) is divided into the first half (T1) and the second half (T1).
2) and is divided into (Here, two signals are input, but it is needless to say that the present invention is not limited to this. It is also possible to divide the signal into two or more by increasing the number of switch switching timing signals.) Considering the case where the same inspection surface (A) is simultaneously imaged under different conditions by the line sensor cameras (2a1) and (2a2), the first main scanning line has a line sensor camera (2a1) in the first half (T1). The inspection image (31a) of the inspected surface (A) captured by is captured, and the inspection image of the inspected surface (A) captured by the line sensor camera (2a2) in the latter half (T2) by switching the switch
(31b) is taken in. Thus, the first main scanning cycle (T) ends.

The same operation is performed on the second main scanning line, and the object to be inspected by the line sensor cameras (2a1) and (2a2) is used.
This is repeated until the end of the imaging in (1) or the next timing (t1). Therefore, the sub-scanning line time axis (X) is continuous within the range of the storage capacity or the set value, and when the storage capacity becomes full, it is cleared and the storage is started from 0.

The reference image is prepared as described above, and then the untested object (1) is set on the moving device (10) and relatively moved by the same method as described above. Moving to the pass / fail judgment of the untested test object (1), the imaging method,
The synthesizing method is exactly the same as that of the non-defective product, and is recorded with the same image configuration as that of the non-defective product. Then, the image is compared with a non-defective image, and if the images do not match, the image is rejected as bad by the selection means (30). On the other hand, when they are almost the same, they are selected as non-defective products.

As described above, the captured images (31a) (31b) (32a) (32
b) By making (33a) and (33b) ~ a composite image that is continuous in real time, it is possible to intensively compare only the necessary parts and judge pass / fail, greatly reducing the judgment time and powering up the cycle In addition to this, it is possible to reduce the amount of memory for synthesizing images, which is effective in reducing the apparatus cost. In particular, this method uses the captured images (31), (32), (33)
It is effective when the number increases.

Next, each embodiment will be briefly described.
(Example 1 See FIGS. 1 and 2) In this case, the test object (1)
Of a plurality of line sensor cameras (2a1) (2a2), (2
This is a case where inspection is performed under a plurality of conditions using b1) and (2b2).
In the present embodiment, two line sensor cameras (2a1) (2a2),
(2b1) (2b2) ~ paired, use a filter to image the surface to be inspected (A) (B) (C) ~ from different angles, or to selectively pass only a specific wavelength and image Or a specific color
(Wavelength) is irradiated on the surfaces to be inspected (A), (B), and (C) to make the defect appear, thereby performing imaging.

(Example 2 See FIGS. 3 and 4) In this case,
This is a case where different surfaces (here, opposite surfaces) of the object to be inspected (1) are inspected simultaneously.

In the above, each line sensor camera (2a
1) Images captured in (2a2), (2b1) and (2b2) (31a) and (31b)
Are synthesized on the main and sub-scanning time axes (X) and (Y) as described above, are compared with the reference synthesized image, and the pass / fail of the object to be inspected (1) is determined, and sorted according to the determination. You. Figure 2 shows the composite screen.
This is shown in FIG. 4 (f).

(Embodiment 3 See FIGS. 5 and 6) In this case,
Number of line sensor cameras (2a) (2b) to match the inspection items
Are arranged in chronological order, and the inspection surfaces (A) and (B) of the inspection object (1) passing through the visual field regions (5a) and (5b) of each of the line sensor cameras (2a) and (2b) Are sequentially imaged, combined in the sub-scanning line time axis (X) direction to form a combined screen, and the pass / fail determination is performed in the same procedure as described above.

(Embodiment 4 See FIGS. 7 and 8) In this case,
Line sensor camera that is paired according to the inspection item
(2a) (2b), ~ are arranged in chronological order, and each line sensor camera
(2a) (2b) to (5a) (5b) to pass through the inspection surface (A) (B) ~ of the inspected object (1) through the imaging conditions in order to change the conditions, Combine in the scanning line time axis (X) direction to create a composite screen,
This is a case where the pass / fail judgment is performed in the same procedure as described above.

In this case, imaging of two inspected surfaces (A) and (C) using mirrors (4a1) (4a2), (4b1) and (4b2). To one line sensor camera (2
a) (2b) and above. A plurality of line sensor cameras (2a) (2b) to which are arranged in time series are respectively inspected surfaces (A)
(C) ~ imaged simultaneously and one line sensor camera (2a)
(2b) Sub-scanning line time axis (X)
The images are combined in the direction to form a combined screen, and the quality is determined by the same procedure as described above.

[0055]

As described above, in the present invention,
Since a plurality of inspection images are combined on the main scanning time axis and the sub-scanning time axis to form one screen, the time for comparing and judging with the reference image can be greatly reduced, and the cycle of inspection time can be increased. I was able to do it.

Further, by imaging the same surface of each inspection image of the object to be inspected from different directions, it is possible to completely detect a defect that could not be detected from one direction, and to perform imaging under different imaging conditions at different times. By imaging the surface to be inspected, 1
Defects that could not be captured under one imaging condition can be captured, and by adjusting the focus, it is possible to set an allowable value of surface defects.

Further, since real-time processing is performed by a switching operation in synthesizing the screen, it is not necessary to increase the memory amount, which is effective in reducing the cost of the apparatus.

[0058]

[Brief description of the drawings]

FIG. 1 is a schematic configuration perspective view of a first embodiment of the present invention.

FIG. 2 is a view showing each imaging drawing obtained by the apparatus of FIG. 1 and a composite screen thereof;

FIG. 3 is a schematic structural perspective view of a second embodiment of the present invention.

FIG. 4 is a view showing respective imaging drawings obtained by the apparatus shown in FIG. 2 and a composite screen thereof;

FIG. 5 is a schematic perspective view showing the configuration of a third embodiment of the present invention.

FIG. 6 is a view showing each imaging drawing obtained by the apparatus shown in FIG. 5 and a composite screen thereof;

FIG. 7 is a schematic structural perspective view of a modification of the fourth embodiment of the present invention.

FIG. 8 is an image drawing obtained by the apparatus of FIG. 7 and a composite screen thereof;

FIG. 9 is a schematic structural perspective view of a modification of the fifth embodiment of the present invention.

FIG. 10 is a view showing each imaging drawing obtained by the apparatus shown in FIG. 9 and a composite screen thereof;

[Explanation of symbols]

 (1) Object to be inspected (2a) (2b)-Line sensor camera (3a) (3b)-Camera (4a1) (4a2) (4b1) (4b2)-Mirror (6) Lighting device (10) Moving device (20 ) Image processing equipment (30) Sorting means

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Kubota F-term (reference) 2G051 AA65 AA73 AB02 AB11 AB14 AB20 CA03 CA07 EA16 EB01 ED11

Claims (8)

[Claims] At least one of an object to be inspected and a line sensor camera are relatively moved with respect to the other one to image an inspected surface of the object to be inspected, and a plurality of inspection images are captured by the imaging. To compose a single screen on the main scanning time axis or the sub-scanning time axis or both time axes, and then compare the inspection image on the composite screen with the reference image corresponding to each of them to check the appearance of the object to be inspected. An appearance inspection method characterized by determining pass / fail. 2. The appearance inspection method according to claim 1, wherein a plurality of inspection images of the object to be inspected are captured under different conditions at the same time. 3. The appearance inspection method according to claim 1, wherein a plurality of inspection images of the object to be inspected are imaged at different times and under different conditions. 4. The visual inspection method according to claim 1, wherein a plurality of inspection images taken by a plurality of line sensor cameras are combined on a main scanning time axis. A visual inspection method characterized by performing signal switching work on a plurality of image output signals picked up by a camera at a certain timing on a main scanning time axis to synthesize images. 5. The visual inspection method according to claim 1, wherein a plurality of inspection images taken by a plurality of line sensor cameras are combined on a sub-scanning time axis. A visual inspection method characterized by performing signal switching work on a plurality of image output signals picked up by a camera at a timing when an object to be inspected passes through an image pickup area of each line sensor camera to synthesize images. 6. A moving device for moving at least one of a line sensor camera for imaging an object to be inspected or a surface to be inspected of the object to be inspected, relative to one of the other.
A line sensor camera for imaging an object to be inspected, and a plurality of inspection images of the surface to be inspected imaged by the line sensor camera are combined into one screen on the main scanning time axis, the sub-scanning time axis, or both time axes. And a judgment device for judging the appearance of the object to be inspected by comparing it with a corresponding reference image, and a sorting device for selecting the object to be inspected based on the judgment result. Inspection equipment. 7. A sensor for detecting an imaging timing of an object to be inspected is provided for each of the plurality of line sensor cameras,
7. The visual inspection apparatus according to claim 6, wherein a signal switching operation is performed based on an output signal from each sensor, and a plurality of inspection images captured by each line sensor camera are combined on a sub-scanning time axis. . 8. As means for synthesizing a plurality of inspection images taken by a plurality of line sensor cameras on the main scanning time axis, signal switching of image outputs of the plurality of line sensor cameras at a constant timing on the main scanning time axis. 7. The visual inspection apparatus according to claim 6, further comprising a camera changeover switch for performing an operation.