JPH06288928A - Surface flaw inspection apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a surface flaw inspection apparatus capable of inspecting the presence or absence of a flaw on a surface without requiring an image processing apparatus for positioning a disc-shaped object such as a rotation angle. In a surface flaw inspection device for inspecting the surface of a disk-shaped object 10 for scratches, a rotating means 13 for rotating the object 10 conveyed to an inspection position around the center of the object 10. , 12a, 12b, 27a, 27b, 3
2, 33, a linear sensor 15 for imaging the surface state of the object 10 in the radial direction, and determining means 17, 18, 1 for detecting the presence or absence of a scratch from the image data from the linear sensor 15.
It is characterized by having 9 and.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus, and more particularly to a surface flaw inspection apparatus for inspecting a disc-shaped object for the presence of flaws on its surface.

[0002]

2. Description of the Related Art When manufacturing disc-shaped objects such as coins and medals, it is necessary to inspect the surface of the objects for scratches. is there. This is to inspect the presence or absence of scratches on the surface of an object by comparing the image data captured by capturing the surface of the object with an image capturing device and the image data that is a standard captured in advance.

FIG. 5 is a conceptual diagram of a conventional surface flaw inspection apparatus.

In the figure, reference numeral 1 is a 500-yen coin as an object which is conveyed to an inspection position by a conveying means (not shown). 2 is a condenser lens 3 for condensing the incident light from the 500-yen coin 1 and forming an image on the exit side, and a condenser lens 3
C including an area sensor 4 which is provided on the emission side of the and converts the formed image of a 500-yen coin into an electric signal (image data)
The CD camera 5. The CCD camera 5 has an imaging range (500
When the area is covered with the yen coin 1) S ₁ and is stationary, the entire image of the surface of the 500 yen coin 1 is picked up at one time to be converted into image data, and the acquired image data is stored in the CPU.
Output to 6. Reference numeral 7 is a memory in which image data of the surface condition of a 500-yen coin serving as a reference is stored in advance. CP
U6 controls the operation of the conveying means and compares the image data captured by the CCD camera 5 with the reference image data read from the memory 7 to obtain 500
The presence or absence of scratches on the surface of the yen coin 1 is detected.

FIG. 6 is another conceptual diagram of a conventional surface flaw inspection apparatus.

The difference from the surface flaw inspection apparatus shown in FIG. 5 is that a CCD sensor 5a is formed by using a linear sensor 8 instead of the area sensor 4 and a broken line of the linear sensor 8 by a conveying means (not shown). The image pickup range (slit-shaped region) S ₂ is conveyed so that the 500-yen coin 1 passes through, and the slit-shaped partial images of the 500-yen coin 1 are sequentially captured, and the captured image data and the memory 7a are stored in advance. The presence or absence of scratches on the surface of the 500-yen coin 1 is detected by comparing the stored and stored reference slit-shaped image data.

[0007]

However, the surface flaw inspection apparatus shown in FIG. 5 has the center of the 500-yen coin 1 and the CC
Align the optical axis of D camera 5 with CC at the time of inspection.
The position (rotation angle) of the 500-yen coin 1 must be determined so that the difference between the rotation angle of the 500-yen coin 1 captured by the D camera 5 and the rotation angle of the reference 500-yen coin is within 2 to 3 °. For example, even if a 500-yen coin for inspection is a non-defective item, data different from the reference data will be captured, so that it is determined as a defective item (with surface scratches).
For that purpose, an image processing device for positioning is additionally required, which complicates the device, requires a long processing time, and is high in cost.

Further, the surface flaw inspection apparatus shown in FIG. 6 is held so that the rotation angle of the 500 yen coin 1 imaged by the CCD camera 5a at the time of inspection and the rotation angle of the reference 500 yen coin match. Unless the 500-yen coin 1 is translated in the direction of the arrow, even if the 500-yen coin 1 for inspection is a non-defective product, data different from the reference data will be taken in and it will be determined as a defective product. I will end up.

Therefore, an object of the present invention is to solve the above problems and to inspect the presence or absence of scratches on the surface without the need for an image processing device for positioning the rotation angle of a disk-shaped object. An object is to provide a surface flaw inspection device.

[0010]

In order to achieve the above object, the present invention provides a surface flaw inspection apparatus for inspecting the surface of a disc-shaped object for the presence of flaws, and the object conveyed to the inspection position. The rotating means for rotating the object around the center of the object, the linear sensor for imaging the surface state of the object in the radial direction, and the determining means for detecting the presence or absence of scratches from the image data from the linear sensor are provided. It is a thing.

[0011]

According to the above construction, the rotating means for rotating the object conveyed to the inspection position around the center of the object, and the linear sensor for imaging the surface condition of the object in the radial direction,
Since the determination means for detecting the presence or absence of scratches from the image data from the linear sensor is provided, the angle of the object conveyed to the inspection position does not have to be adjusted to the angle of the object corresponding to the reference image data, By rotating the object at the inspection position, the entire surface condition of the object can be imaged. By comparing this image data with the reference image data, the presence or absence of scratches on the surface of the object can be inspected. You can

[0012]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of an embodiment of the surface flaw inspection apparatus of the present invention.

In the figure, reference numeral 10 is a 500-yen coin as an object which has been conveyed to an inspection position by rails 11a and 11b as a part of conveying means described later. Positioning rollers 12a and 12b as a part of rotating means (shown by a broken line) for rotating the 500-yen coin 10 around the center of the 500-yen coin 10 and a rotating roller 13 are provided at the inspection position. ing.

On one side (upper side in the figure) of the 500-yen coin 10, a condenser lens 14 for condensing and forming an image of incident light from the radial portion of the 500-yen coin 10, and a condenser lens. An imaged 500-yen coin 10 provided on the exit side of 14
CCD camera 1 formed with a linear sensor 15 for converting a surface state image of a radius portion of the image signal into an electric signal (image data)
6 is provided.

In the CCD camera 16, the center of the 500-yen coin 10 is within the imaging range (slit-shaped area) S ₃ , and the longitudinal length of the imaging range S ₃ is at least the radius of the 500-yen coin 10. Length (500
The distance between the circular coin 10, the condenser lens 14, and the linear sensor 15 and the position of the optical axis are preset.

Reference numeral 18 is a memory (for example, RAM (random accelerator memory)) for temporarily storing image data of the 500 yen coin 10 for inspection taken by the CCD camera 16, and 19 is a reference 500 yen. It is a memory (for example, ROM (Read Only Memory)) for storing and storing the image data of the coin 10 in advance.

Reference numerals 20a and 20b are drive circuits for driving a solenoid (described later) for moving the positioning roller according to an instruction from the CPU 17, and 21 is a motor for rotating a rotary roller (described below) according to an instruction from the CPU 17. Drive circuit. 22 (described later) is a CP
It is a drive circuit for driving a motor for rotating the intermittent feed gear according to an instruction from U17.

Now, when the CCD camera 16 takes an image of the 500-yen coin 10, the image data taken in when the rotation angle θ of the 500-yen coin 10 is θ ₁ becomes a signal in an analog format as shown in FIG. 2, It is output to the CPU 17. 2 is a waveform of the image pickup data of the CCD camera used in the surface flaw inspection device shown in FIG. In the figure, the vertical axis represents the brightness (imaging data), and the horizontal axis represents the radial distance.

The CPU 17 binarizes (converts into a digital signal) an analog signal continuously output from the CCD camera 16 with a predetermined threshold value L _TH at fixed time intervals (time division), and rotates the analog signal. The memory 18 is sequentially temporarily stored for each angle θ.

FIG. 3 is a diagram showing the relationship between the rotation angle θ of a 500-yen coin inspected by the surface flaw inspection apparatus shown in FIG. 1 and the binarized image data. In the figure, the horizontal axis represents the rotation angle θ (0 to 360 °), and the vertical axis represents the value of the image data (“1” logic level or “0” logic level) at the distance from the center of the 500 yen coin. There is. Where the analog signal is larger than the threshold value L _TH (for example, “1” logic level) is indicated by a broken line or a solid line.
The distance Δθ between the line groups corresponding to these rotation angles is the CPU 1
It is determined by the acquisition time of the image data of No. 7.

In the memory 19, a rotation angle θ when a reference 500-yen coin is rotated around the center of the 500-yen coin, and imaging data of the surface condition of the radius portion at the rotation angle θ. The binarized data is stored correspondingly.

The CPU 17 reads out the image data of the reference 500-yen coin from the memory 19 and at the same time the memory 1
The presence or absence of scratches on the surface of the 500-yen coin 10 is detected by comparing with the image data of the 500-yen coin 10 for inspection read out from FIG.

By the way, when the image data of the reference 500-yen coin is imaged, the first angle immediately before the imaging of the 500-yen coin and the first angle immediately before the inspection of the 500-yen coin 10 for inspection conveyed to the inspection position. It is considered that there is almost no coincidence with the angle, and even if the two image data are directly compared with each other, there is almost no coincidence. Therefore, when comparing both image data, 1 of the 500 yen coin 10 for inspection
After the image data for the rotation is once stored and stored in the memory 18, for example, one 1
The first image data is read out, the image data of the inspection 500-yen coin 10 loaded in the memory 18 is sequentially read from the first image data, and the image data is compared until they match. When the image data in the memory 18 when the two image data match each other are used as the first image data and the second and subsequent image data are compared, both 500 yen coins are compared in correspondence with the same rotation angle. You can

The CPU 17, the memory 18, and the memory 19 described above form a judging means. The 500-yen coin whose presence or absence of the surface flaw is detected by the determination unit is selected by the selection unit (not shown).

The rotating means and the conveying means will be described with reference to FIG.

FIG. 4 is a schematic side view of the rotating means and the conveying means shown in FIG.

In FIG. 1A, 11a is a rail for carrying the 500-yen coin 10 in the direction of the arrow P ₁ (a rail for carrying the 500-yen coin 10 in a vertical state is omitted). . Rails 11b are provided above the rails 11a in parallel with the rails 11a and at intervals slightly longer than the diameter of the 500-yen coin 10. An intermittent feed gear 23 for conveying the 500-yen coins 10 to the inspection position one by one on this rail 11b, and this intermittent feed gear 2
A conveyor motor 25 for rotating the sheet 3 through the belt 24 is provided. The transfer motor 25 is connected to the CPU 17 via the drive circuit 22, and the transfer motor 25 makes one rotation when a voltage is applied from the drive circuit 22 to transfer only one 500-yen coin 10 to the inspection position. It is like this. Rails 11a, 11b, intermittent feed gear 2
3, the belt 24 and the transport motor 25 form a transport unit.

There are five rails 11a on the downstream side of the conveying means.
A rotatable positioning roller 12a for positioning the 00-yen coin 10 at the inspection position, a swing arm 27a having one end connected to the positioning roller 12a and the other end swingably provided on a fulcrum 26a, and a plunger 28a. Is provided at the center of the swing arm 27a so as to be swingable via a pin 29a, and the coil portion is provided at a fulcrum 30a with a solenoid 31a swingably provided.

There are 5 rollers on the downstream side of the positioning roller 12a.
A rotatable positioning roller 12b for positioning the 00-yen coin 10 at the inspection position, and a positioning roller 12 at one end.
a swing arm 27b which is connected to b and whose other end is swingably provided on a fulcrum 26b, and a tip of a plunger 28b is swingably provided in the center of the swing arm 27b through a pin 29b. Is provided at a fulcrum 30b with a solenoid 31b swingably provided.

A rotating roller 13 for positioning the 500-yen coin 10 from the upper side and rotating the 500-yen coin 10 is provided on the rail 11b above the positioning rollers 12a, 12b. That is, the inspection position is determined by being supported at three points by the two positioning rollers 12a and 12b and the rotating roller 13. The CCD camera 16 described above is provided at this inspection position perpendicularly to the paper surface, but only the linear sensor 15 is shown for the sake of simplicity.

The rail 11b is provided with a rotation motor 33 for rotating the rotation roller 13 via a belt 32. The rotation roller 13, the belt 32, the rotation motor 33, the positioning rollers 12a and 12b, and the rocking roller 33 are provided. A rotating means is formed by the moving arms 27a and 27b and the solenoids 31a and 31b. The rotation motor 33 and both solenoids 31a and 31b are connected to the CPU 17 via the drive circuits 21, 20a and 20b, respectively.
Rotates when a drive voltage is applied from the drive circuit 21, and the solenoids 31a and 31b are connected to the drive circuits 20a and 20b.
When a voltage is applied to the plungers 28a and 28b, the plungers 28a and 28b are pushed out.

Next, the operation of the embodiment will be described.

50 for multiple inspections up to the intermittent feed gear 23
It is assumed that the 0-yen coin 10 is being carried by another carrying means (not shown). First, according to an instruction from the CPU 17, a voltage is applied from the drive circuit 20a to the coil portion of the solenoid 31a, and the positioning roller 12a lowers to the lower side of the rail 11a (FIG. 4A).

When the positioning roller 12a descends to the lower side of the rail 11a, a voltage is applied from the drive circuit 22 to the carrying motor 25 for a predetermined time according to an instruction from the CPU 17 (see FIG. 1), and the carrying motor 25 rotates. intermittent feed gear 23 is rotated one arrow P ₂ direction Te, 500 yen coin 10 is rotated in the arrow P ₃ direction by one, the process proceeds to arrow P ₄ directions (Figure 4 (b)).

The 500-yen coin 10 which has proceeded in the direction of arrow P ₄ hits the positioning roller 12b and stops, and at the same time C
According to an instruction from the PU 17, the voltage application from the drive circuit 20a to the solenoid 31a is stopped and the positioning roller 1
2a returns to the rail 11a (FIG. 4 (c)).

When the positioning roller 12a returns to the rail 11a, the drive circuit 21 is instructed by the CPU 17.
Voltage is applied to the rotation motor 33 from the rotation roller 1
3 rotates in the direction of arrow P ₅ , the 500-yen coin 10 rotates once in the direction of arrow P ₆ at the inspection position, and the CCD camera 1
6 operates to output the image data of the surface state of the 500-yen coin 10 in the radial direction to the CPU 17 (FIG. 4 (d)).

The CPU 17 uses a 500-yen coin 10 for inspection.
After the image data taken in from the memory 18 is once stored and stored in the memory 18, the first image data in the memory 18 is sequentially read out, and the image data taken in the memory 19 is read out and compared with this, and the image data at the time of coincidence is first read. After rearranging as the image data of, both image data are sequentially compared. After comparing the two image data, when the two image data are the same, it is determined that there is no scratch on one side of the 500 yen coin 10 at the inspection position, and when the image data are different, the 500 yen coin at the inspection position. It is determined that one side of 10 has a scratch.

When the surface scratch inspection of the 500-yen coin 10 is completed, the CPU 17 outputs a signal to the drive circuit 20b to operate the solenoid 31b to lower the positioning roller 12b to the lower part of the rail 11a and operate the rotation motor 33. Then, the rotating roller 13 is rotated and the tested 500
The yen coin 10 is moved in the direction of arrow P ₇ . After the 500-yen coin 10 moves, the CPU 17 stops the rotation of the rotation motor 33, stops the voltage application to the solenoid 31b, and returns the positioning roller 12b to the rail 11a. The 500-yen coin 10a before the inspection is moved in the direction of arrow P ₈ by another conveying means. At this time, the next 500-yen coin 10a before the inspection hits the intermittent feed gear 23 and is stopped. That is, the intermittent feed gear 23 functions as a stopper (FIG. 4 (e)).

Thereafter, the surface inspection of the 500-yen coin is repeated by repeating the operations shown in FIGS.

As described above, according to this embodiment, the rotating means for rotating the object conveyed to the inspection position around the center of the object, the linear sensor for imaging the surface condition of the object in the radial direction, Since the determination means for detecting the presence or absence of scratches from the image data from the linear sensor is provided, the angle of the object conveyed to the inspection position does not have to be adjusted to the angle of the object corresponding to the reference image data, By rotating the object at the inspection position, the entire surface condition of the object can be imaged. By comparing this image data with the reference image data, the presence or absence of scratches on the surface of the object can be inspected. You can

In the above description, the object of this embodiment is a 500-yen coin, but the present invention is not limited to this, and it goes without saying that other types of coins and medals may be used. Further, although the case where the object is inspected only for the surface condition of the radius portion has been described, the invention is not limited to this, and the surface condition of the diameter portion of the object is imaged by the line sensor and the object is rotated halfway. It may be configured as follows. Further, the sensor may be rotated with the work fixed. Further, in this embodiment, the surface condition on one side of the object is inspected, but CCD cameras are provided on both sides of the object at the inspection position so that the condition on both sides can be inspected at the same time. May be. Alternatively, the surface flaw inspection may be performed again after inverting an object whose one surface has been inspected by an inverting means (not shown).

Further, although the intermittent feeding gears are used as the conveying means of this embodiment, the invention is not limited to this, and if the objects can be conveyed one by one to the inspection position, they are star-shaped. A car or worm gear may be used.

Further, although the solenoid is used to move the positioning rollers 12a and 12b, the present invention is not limited to this, and other means such as an air cylinder may be used. Further, the roundness of the object may be measured using this apparatus.

[0045]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) The presence or absence of scratches on the surface can be inspected without the need for an image processing device for positioning the rotation angle of a disk-shaped object.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a surface flaw inspection device of the present invention.

FIG. 2 is a waveform of image pickup data of a CCD camera used in the surface flaw inspection device shown in FIG.

FIG. 3 is inspected by the surface flaw inspection apparatus shown in FIG.
It is a figure which shows the relationship between the rotation angle (theta) of a 0-yen coin, and binarized image data.

FIG. 4 is a schematic side view of the rotating means and the conveying means shown in FIG.

FIG. 5 is a conceptual diagram of a conventional surface flaw inspection device.

FIG. 6 is a conceptual diagram of another conventional surface flaw inspection device.

[Explanation of symbols]

 10 Object (500 Yen Coin) 12a, 12b Positioning Roller 13 Rotating Roller 15 Linear Sensor 17 CPU 18, 19 Memory 32 Belt 33 Rotation Motor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shuji Hoshino 3-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center (72) Inventor Toshio Hirose 3-chome, Toyosu, Koto-ku, Tokyo No. 1-15 Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center (72) Inventor Keizo Oishi 3-15-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center

Claims (1)

[Claims] 1. A surface flaw inspection apparatus for inspecting the surface of a disk-shaped object for the presence of flaws, the rotating means rotating the object conveyed to an inspection position around the center of the object. A surface flaw inspection apparatus comprising: a linear sensor for imaging the surface state of the object in the radial direction; and a determination unit for detecting the presence or absence of a flaw from the image data from the linear sensor.