JPH01201141A - Surface flaw inspection device - Google Patents

Abstract

PURPOSE:To speedily inspect the surface of a body to be inspected at a desired position by swiveling a laser generator and slanting laser slit beam, and operating a reflecting mirror as an optical path correcting member and making reflected light incident on a specific position in a camera part. CONSTITUTION:When the surface of the body W to be inspected moves down as a device main body 1 moves on the surface of the body W to be inspected by a robot, the optical path correcting member 6 is rotated accordingly to operate the reflecting mirror 7 on the internal surface of a front part 6a, thereby setting the focus of the reflected light at the position of the sensor in the camera part 5. Further, when the surface of the body W to be inspected slants from its set state, the laser generator is rotated by a gear 11 which is rotated by the motor of the projection part 3 and a gear 12 fitted to the laser generator to make the laser reflected light from the body W to be inspected incident on the specific position of the sensor in the camera part 5, thereby inspecting the surface at the desired position speedily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a surface defect inspection device for inspecting defects on the surface of an object to be inspected, such as a painted surface of an automobile or a machined object that is close to a mirror surface.

(Prior art) Whether the painted surface of an automobile body after top coating is completed or the surface of a machined object after cutting or grinding is in a predetermined finish state, that is, whether or not there are any scratches on the surface. ,
In order to detect whether protrusions, bumps, dirt, etc. have occurred, these days, this is automatically performed using a surface defect inspection device.

For example, a surface defect inspection apparatus such as that disclosed in Japanese Patent Laid-Open No. 60-228909 has been used to inspect the paint surface of an automobile body for defects. In this case, a surface defect inspection device is attached to the tip of the industrial robot's arm, and this device includes a laser generator that irradiates the surface of the object to be inspected with laser slit light, and a This device is configured to move along a predetermined trajectory along the painted surface of the object to be inspected, according to information taught to the control section of the robot. .

In such a surface defect inspection device, especially when inspecting a part with a curved surface such as the painted surface of an automobile body, when the device is moved along the surface of the object to be inspected by a robot, the device The distance between the object and the surface of the object to be inspected may change, or the inclination angle of the surface of the object to be inspected may gradually change. When such changes occur,
Since reflected light from the object to be inspected no longer enters the line sensor in the camera section, it becomes impossible to accurately detect the state of the surface. To this end, as shown in the above-mentioned publication, in the past, the laser generator was oscillated in two axes, or the robot arm itself was operated to correct the posture of the surface defect inspection device. There is.

(Problem to be Solved by the Invention) However, if the laser generator is oscillated in two axes as in the past, not only will the surface defect detection device become larger as a whole, but also the above-mentioned neck There was a problem in that the control for the swinging motion was complicated. Similarly, when operating the robot arm to correct the posture of the device, the entire device, which is relatively heavy, must be operated.
There is a problem in that a desired position cannot be inspected quickly.

The present invention has been made in view of the problems of the prior art described above, and it is an object of the present invention to enable rapid inspection of the surface of a predetermined position of an object to be inspected.

(Means for Solving the Problems) To achieve the above object, the present invention has an apparatus main body that is movable with respect to the surface of an object to be inspected, and has a laser generator that irradiates laser slit light. A reflection unit that includes a light section and a camera section that receives light emitted from the light projection section and reflected on the surface of the object to be inspected, and reflects the laser slit light from the light projection section onto the surface of the object to be inspected. a mirror is movably attached to the apparatus main body so that the irradiation position of the laser slit light applied to the test object changes according to the distance between the apparatus main body and the test object; This is a surface defect inspection device which is rotatably attached to the device main body.

(Function) Laser slit light from a laser generator is irradiated onto the object to be inspected via a reflecting mirror, and reflected light from there is made to enter a sensor in the camera section. As a result, the surface of the object to be inspected is inspected. As the device body moves along the surface of the object to be inspected, when inspecting a portion of the object whose surface is inclined, the laser generator attached to the device body is rotated. By tilting the laser slit light irradiated from here, the reflected light can be made to enter a predetermined position within the camera section. Similarly, even if the distance between the object to be inspected and the main body of the apparatus changes, the reflected light can be made to enter a predetermined position by operating the reflecting mirror forming the optical path correction member.

(Example) Hereinafter, the present invention will be described in detail based on an example of the present invention illustrated in the drawings.

FIG. 1 is a perspective view showing a surface defect inspection device according to an embodiment of the present invention. According to the information taught in advance,
The panel W after the prescribed painting is completed is the object to be inspected,
The device main body 1 will move along this surface.

The device body 1 is attached to the arm of the robot by attaching the connecting portion 2 attached to the device body 1 to the arm of the robot.

This device main body 1 is composed of a plate-shaped member, and a light projecting section 3 is attached to the upper side of this device main body 1. A laser slit light beam is installed inside this projecting section 3 as shown in FIG. A laser generator 4 for irradiating is incorporated. As this laser generator 4, a semiconductor laser is used. A camera section 5 that receives light emitted from the laser generator 4 and reflected on the surface of the object W to be inspected is attached to the back side of the main body 1 of the apparatus. At the tip of the main body 1 of the apparatus, an optical path correction member 6, which has a gate-like shape as a whole and consists of a front part 6a and left and right side parts 6b, is attached to be rotatable at the side parts 6b. A reflecting mirror 7 is attached to the inner surface of the front part 6a of this optical path correction member 6, and the laser slit light emitted from the laser generator 4 in the light projecting part 3 is regularly reflected by the reflecting mirror 7 to The light is irradiated onto the surface of the panel W, where it is specularly reflected and received by the camera section 5. This camera section 5
A line sensor consisting of a CCD or the like is provided inside. Since this laser light is highly directional, if there are surface defects such as scratches or bumps on the surface of the object to be inspected, the irradiated laser slit light will be scattered, resulting in the photoelectric conversion output of the line sensor. Since the output changes, the presence or absence of surface defects can be detected based on the magnitude of this output.

Furthermore, a collimating lens 8 is provided on the front side of the device main body 1 to convert the laser slit light emitted from the light projecting section 3 into a parallel light beam in a tapered shape, and a parallelizing lens 8 is provided on the back side. A transmission type diffusion screen 9 made of ground glass or the like is provided which projects and diffuses the laser slit light reflected on the surface.

When the vertical distance between the surface of the spring W, which is the object to be inspected, and the main body 1 of the apparatus changes, the focus of the reflected light from the surface of the object to be inspected is focused on the line sensor in the camera section S. The optical path correction member 6 is rotatable to
This rotational movement is performed by a drive means (not shown). Therefore, for example, when a surface defect is being inspected at the position shown by the solid line in FIG. Assuming that the surface of the skin inspection object is lowered, the optical path correction member 6 is rotated as shown in FIG. 2 in accordance with this.

As a result, the focus of the reflected light will match the position of the sensor within the camera section 5.

Further, if the surface of the object W to be inspected is tilted more than the set state, the reflected light from the object W will no longer be focused on the sensor in the camera section S.

For this purpose, as shown in FIG. 1, the laser generator 4 is rotatably mounted on the receiver by a member 9, and in order to rotate the laser generator 4, a motor 1 is mounted on the front surface of the device body 1.
0 is housed therein and is rotated by this motor 10, and the gear 12 attached to the laser generator 4 meshes with it. Therefore, when the surface of the object to be inspected changes from a horizontal state to an inclined state as shown by the imaginary line, the surface of the object to be inspected can be rotated by driving the motor 10 and rotating the laser generator 4. The laser reflected light from the camera section 5 can be made to enter the sensor inside the camera section 5.

The above-mentioned adjustment movement of the rotation of the laser generator 4 and the rotational movement of the optical path correction member is performed by a signal from a control circuit for positioning as described in the above-mentioned publication, so that the laser reflected light from the object to be inspected is directed to the camera. It is controlled so that it enters a predetermined position of the sensor in the section S.

(Effects of the Invention) As described above, according to the present invention, by rotating the laser generator attached to the main body of the apparatus and tilting the laser slit light emitted from the laser generator, the object to be inspected can be placed in a tilted state. Even if this happens, the reflected light can be made to enter a predetermined position within the camera section. Similarly, even if the distance between the object to be inspected and the main body of the apparatus changes, reflected light can be made to enter a predetermined position by operating a reflecting mirror serving as an optical path correction member. This makes it possible to obtain a surface defect device that is smaller than the conventional one, and moreover, it becomes possible to accurately and quickly inspect the surface at a desired position.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a surface defect inspection apparatus according to an embodiment of the present invention, and FIG. 2 is a front view of FIG. 1. 18... Apparatus body, 3... Light projecting unit, 4... Laser generator, 5... Camera unit, 6... Optical path correction member, 7...
...Reflector, 10...Motor.

Claims (1)

[Claims] The main body of the device is movable relative to the surface of the object to be inspected.
A light projecting section having a laser generator for emitting laser slit light and a camera section receiving light emitted from the light projecting section and reflected on the surface of the object to be inspected are provided, and the laser slit from the light projecting section is provided. moving a reflecting mirror that reflects light onto the surface of the object to be inspected so that the irradiation position of the laser slit light applied to the object to be inspected changes according to the distance between the apparatus main body and the object to be inspected; 1. A surface defect inspection device, wherein the laser generator is rotatably attached to the device main body.