JPH04110962U - Scratch inspection device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a means for performing flaw inspection with high precision by detecting and correcting variations even when the flatness of a surface to be inspected is not determined. [Structure] A CCD sensor 5 that receives reflected light from a surface to be inspected, a light receiving sensor 6 that is installed parallel to the scanning line adjacent to the CCD sensor 5 on both sides and receives scattered light, and a CCD sensor 5 that receives reflected light from the surface to be inspected; It has a drive device 7 that drives on a cylindrical surface. By detecting the amount of positional variation of the reflected light by the CCD sensor 5 and correcting the light receiving position by driving the drive device 7 according to the detected amount, flaw inspection can be performed without being affected by undulations of the surface to be inspected. .

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention is a flaw inspection device, especially a flaw inspection device that can be applied to precise inspection of flat objects to be inspected. Regarding.

0002

[Conventional technology]

As a conventional technique, for example, it is shown in Japanese Patent Application Laid-open No. 59-68653. There are methods for inspecting scratches on the surface of objects. Conventional flaw inspection equipment using this method The device includes a laser oscillator, a collimator, a light shielding body, and a light receiving body.

0003 Next, a conventional flaw inspection device will be described with reference to the drawings. Figure 4 shows conventional wound inspection FIG. 2 is a sectional view showing an example of a scanning device. The flaw inspection device shown in FIG. , modulator 32 , collimator 33 , light shield 34 , photoreceptor 35 , and photoreceptor 35 receive light. It also includes an indicator 36 that outputs a signal proportional to the amount of light when the amount of light reaches that level.

0004 A laser beam emitted from a laser oscillator 31 is modulated by a modulator 32 to create a collimator. 33, where the laser beam is converted into parallel light and irradiated onto the surface of the object. irradiated Light is reflected from the surface of an object. The reflection angle of reflected light varies depending on the surface condition of the object. Ru. Under normal conditions, with no scratches or dust on the surface, the reflection pattern of reflected light An abnormal condition in which the surface is covered within a certain area, but the surface is scratched or has dust attached to it. In this case, the reflected light scatters greatly and is scattered outside the normal reflection pattern area. Ru.

[0005] Therefore, on the reflected light pattern under normal conditions, an area at least larger than the area of that pattern is A light shielding body 34 is provided to block reflected light during normal operation, and a light receiving body 35 is provided outside the light shielding body 34. is provided to receive only the abnormal reflected light that is scattered to the outside of the light shielding body 34 when an object is abnormal. The light is received by a light body 35.

[0006]

[Problem that the idea aims to solve]

The conventional flaw inspection device described above detects the positional shift of reflected light due to the undulation of the surface to be inspected. Since a large light shield is installed in advance to block light, scattered light is also blocked as part of it. However, this method has the disadvantage of overlooking minute scratches with a small amount of scattered light.

[0007]

[Means to solve the problem]

The flaw inspection device of the present invention includes a light source and a light deflector that deflects the light emitted from the light source. a main scanning means for scanning the surface to be inspected; and a direction perpendicular to the scanning direction of this main scanning means. a sub-scanning means for driving the surface to be inspected in the direction; and a sub-scanning means for driving the surface to be inspected in the Receives the reflected light from the scanning surface and detects the deviation of this scanning light from the planned scanning line. a first light-receiving means that detects reflections from the surface to be inspected over the entire scanning area by the main scanning means; a second light receiving means for receiving scattered light adjacent to the light; and a second light receiving means for receiving scattered light adjacent to the light; The light detected by the first light receiving means on the cylindrical surface centered on the scanning line and a driving means that drives according to the amount of deviation.

[0008]

【Example】

Next, the present invention will be explained with reference to the drawings.

[0009] FIG. 1 is a perspective view of an embodiment of the present invention. The embodiment of FIG. 1 has a laser oscillator 1 and , a collimator 2 that collimates the laser beam 20 emitted from the laser oscillator 1; , the collimated light is focused onto the surface to be inspected with a beam diameter of approximately 1 mm by collimator 2. an optical lens 3 for scanning the surface to be inspected, and a laser beam 20 for scanning on one axis of the surface to be inspected. The galvanometer mirror 4 receives the reflected light from the surface to be inspected, and A CCD sensor 5 detects the positional shift of the reflected light in the direction, and a CCD sensor 5 runs adjacent to both sides of the reflected light. A light receiving sensor 6 that is provided parallel to the scanning line and receives scattered light, and the output of the light receiving sensor 6 The measuring display 8 that displays the size of the received light and the light receiving sensor 6 are centered on the scanning line. A driving device 7 drives the cylinder on a cylindrical surface to be A controller 9 that outputs a control signal proportional to the amount of positional deviation of the emitted light, and a control from the controller 9. A driver 10 receives a control signal and outputs a drive command to a drive device 7. be done.

0010 FIG. 2 is a diagram showing the positional relationship between the CCD sensor 5 and the light receiving sensor 6 in FIG. 1. The function and operation of the flaw inspection device shown in FIG. 1 will be explained with reference to FIG. 2. Leh The laser beam 20 emitted from the laser oscillator 1 passes through the collimator 2 and enters the optical lens 3. The beam is focused to a beam diameter of approximately 1 mm on the surface to be inspected. At this time, with galvano mirror 4 It is deflected and scans over the surface to be inspected. The reflected light from the surface to be inspected enters the CCD sensor 5. do. If there is a scratch on the scanning line of the surface to be inspected, scattered light will be generated and this will enter the light receiving sensor 6. shoot An output corresponding to the amount of scattered light is obtained from the measurement display 8. This output The presence or absence of scratches can be detected based on whether the value is larger or smaller than the set value. Na At this time, move the surface to be inspected in a direction perpendicular to the main scanning direction (in the sub-scanning direction) by the beam diameter. Inspection within a two-dimensional plane can be performed by moving the robot in the direction (direction).

[0011] However, due to pitching of the inspected surface in the sub-scanning direction and waviness of the inspected object, The optical axis of reflected light and the direction of scattered light vary. Figure 3 shows the actual undulations on the surface to be inspected. FIG. The distance L from the scanning point to the CCD sensor 5 is 2. 00mm, angle of incidence θ on the surface to be inspected₁is 45°, and the deviation ε of the surface to be inspected from the reference is 1 mm, slope θ₂is 1°, and the positional change of the laser beam 20 on the CCD sensor 5 is δ Then, δ=ε/sinθ₁+L・tanθ₂ Therefore, δ is approximately 5 mm. Similarly, the distribution of scattered light on the light receiving sensor 6 is Due to the physical shift, the amount of scattered light received by the light receiving sensor 6 fluctuates. Perform precise flaw inspection Therefore, it is necessary to suppress this fluctuation. Misalignment of reflected light due to CCD sensor 5 is detected, an output corresponding to the amount of deviation is output from the controller 9 to the driver 10, and the driver 10 drives the drive device 7 to position the light receiving sensor 6 on a cylindrical surface centered on the scanning line. Moving. Constant reflection by moving the light receiving sensor 6 according to the amount of deviation of the reflected light Scattered light adjacent to the light can be received correctly.

0012

[Effect of the idea] As explained above, the flaw inspection device of the present invention detects pitching on the surface to be inspected and Detects changes in the position of reflected light and scattered light due to the undulation of the object from the position of the reflected light, By moving the light receiving sensor for scattered light according to the amount of change in its position, precise scratches can be detected. This has the effect of allowing inspection to be carried out.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a diagram showing the positional relationship between the CCD sensor and the light receiving sensor in FIG. 1;

FIG. 3 is a diagram showing the deviation of reflected light due to the actual undulations of the surface to be inspected in FIG. 1;

FIG. 4 is a sectional view showing an example of a conventional flaw inspection device.

[Explanation of symbols]

1,31 Laser oscillator 2,33 Collimator 3 Optical lens 4 Galvano mirror 5 CCD sensor 6 Light receiving sensor 7 Drive device 8 Measurement display 9 Controller 10 Driver

Claims (1)

[Scope of utility model registration request] 1. A light source, a main scanning means for scanning the surface to be inspected by deflecting the light emitted from the light source by an optical deflector, and a main scanning means for scanning the surface to be inspected in a direction perpendicular to the scanning direction of the main scanning means. a sub-scanning means for driving the main scanning means; and a first light-receiving means for receiving the reflected light from the surface to be inspected of the scanning light by the main scanning means and detecting a deviation of the scanning light from a scheduled scanning line. ,
a second light receiving means for receiving scattered light adjacent to the reflected light from the surface to be inspected over the entire scanning area by the main scanning means; and a cylinder having the second light receiving means centered on the scheduled scanning line. A flaw inspection device comprising: a drive means that is driven according to the amount of deviation detected by the first light receiving means on the surface.